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HARVARD    UNIVERSITY 

Library  of  the 

Museum  of 

Comparative  Zoology 


^^s7 


BREVIORA 


MUSEUM  OF  COMPARATIVE  ZOOLOGY 
Harvard  University 


NUMBERS  351-379 
1970-1971 


CAMBRIDGE,    MASSACHUSETTS,    U.S.A. 

1971 


Edited 

by 

Penelope  Lasnik 


CONTENTS 

BREVIORA 
Museum  of  Comparative  Zoology 

Numbers  351-379 

1970 

No.  351.  A  new  species  in  the  nomeid  fish  genus  Psenes  from 
the  equatorial  eastern  Pacific.  By  Richard  L.  Haed- 
rich.    7  pp.   June  12. 

No.  352.  The  Chaiiares  (Argentina)  Triassic  reptile  fauna  VII, 
The  postcranial  skeleton  of  the  traversodontid 
Massetognathus  pascuali  (Therapsida,  Cynodontia). 
By  Parish  A.  Jenkins,  Jr.     28  pp.     July  10. 

No.  353.  Anolis  jacare  Boulenger,  a  solitary  anole  from  the 
Andes  of  Venezuela.  By  Ernest  E.  Williams,  Osvaldo 
A.  Reig,  Pablo  Kiblisky,  and  Carlos  Rivero-Blanco. 
15  pp.     August  10. 

No.  354.  Taxonomic  and  ecological  notes  on  some  Middle  and 
South  American  lizards  of  the  genus  Ameiva 
(Teiidae).  By  Arthur  C.  Echternacht.  9  pp. 
September  18. 

No.  355.  Generic  relations  and  speciation  patterns  in  the  Cara- 
caras  (Aves:  Falconidae).  By  Francois  Vuilleumier. 
29  pp.   November  30. 

No.  356.  On  a  new  species  in  a  new  earthworm  genus  from  Puerto 
Rico.    By  G.  E.  Gates.     11  pp.    November  30. 

No.  357.  A  review  of  the  fossil  Pelomedusidae  (Testudines, 
Pleurodira)  of  Asia.  By  Roger  Conant  Wood.  24 
pp.    November  30. 

No.  358.  South  American  anoles:    Anolis  apollinmis  Boulenger 
1919,  a  relative  of  A.  biporcatus  Wiegmann  (Sauria, 
Iguanidae).      By    Ernest    E.    Williams.       11    pp. 
November  30. 


No.  359.  The  swimbladder  as  a  juvenile  organ  in  stromateoid 
fishes.    By  Michael  H.  Horn.    9  pp.    November  30. 

No.  360.  Mammals  from  the  early  Cenozoic  of  Chubut,  Argen- 
tina. By  George  Gaylord  Simpson.  1 3  pp.  Novem- 
ber 30. 

No.  361.  Additions  to  knowledge  of  the  Argyrolagidae  (Mam- 
malia, Marsupialia)  from  the  late  Cenozoic  of 
Argentina.  By  George  Gaylord  Simpson.  9  pp. 
November  30, 

No.  362.  Addition  to  knowledge  of  Groeberia  (Mammalia, 
Marsupialia)  from  the  mid-Cenozoic  of  Argentina. 
By  George  Gaylord  Simpson.    17  pp.    November  30. 


1971 

No.  363.  Non-specificity  of  host-selection  in  the  ectoparasitic 
snail  Odostomia  (Menestho)  bisuturalis  (Say)  (Gas- 
tropoda: Pyramidellidae).  By  Robert  C.  Bullock 
and  Kenneth  J.  Boss.    7  pp.    January  8. 

No.  364.  A  new  scincid  lizard  from  Bougainville,  Solomon 
Islands.  By  Allen  E.  Greer  and  Fred  Parker.  1 1  pp. 
January  8. 

No.  365.  Characters  and  synonymies  among  the  genera  of  ants. 
Part  IV.  Some  genera  of  subfamily  Myrmicinae 
(Hymenoptera:  Formicidae).  By  William  L.  Brown, 
Jr.     5  pp.    January  15, 

No.  366.  Pulsed  sound  of  the  porpoise  Lagenorhynchus  australis. 
By  William  E.  Schevill  and  William  A.  Watkins.  10 
pp.     January  15. 

No.  367.  Micromischodus  sugillatus,  a  new  hemiodontid  characin 
fish  from  Brazil,  and  its  relationship  to  the  Chilo- 
dontidae.  By  Tyson  R.  Roberts.  25  pp.  January 
15. 

No.  368.  Structural  habitats  of  West  Indian  Anolis  lizards  I. 
Lowland  Jamaica.  By  Thomas  W.  and  Amy 
Schoener.     53  pp.     January  29. 

No.  369.  Lithophaga  aristata  in  the  shell-plates  of  chitons  (Mol- 
lusca).  By  Robert  C.  Bullock  and  Kenneth  J.  Boss. 
10  pp.     January  29. 


No.  370.  Ecological  observations  on  a  little  known  South 
American  anole:  Tropidodactyliis  onca.  By  James 
P.  Collins.     6  pp.    March  31. 

No.  371.  A  new  species  of  bromeliad-inhabiting  galliwasp 
(Sauria:  Anguidae)  from  Jamaica.  By  Albert 
Schwartz.     10  pp.     March  31. 

No.  372.  The  paleontology  and  evolution  of  Cerion  II:  age  and 
fauna  of  Indian  shell  middens  on  Curacao  and  Aruba. 
By  Stephen  Jay  Gould.     26  pp.     March  31. 

No.  373.  The  Chanares  (Argentina)  Triassic  reptile  fauna.  VIII. 
A  fragmentary  skull  of  a  large  thecodont,  Liipero- 
suchus  fractus.  By  Alfred  Sherwood  Romer.  8  pp. 
March  31. 

No.  374.  The  fishes  of  the  Malaysian  family  Phallostethidae 
(Atheriniformes).  By  Tyson  R.  Roberts.  27  pp. 
June  15. 

No.  375.  Structural  habitats  of  West  Indian  Anolis  lizards  II. 
Puerto  Rican  uplands.  By  Thomas  W.  and  Amy 
Schoener.     39  pp.     June  15. 

No.  376.  Podocnemis  venezuelensis,  a  new  fossil  pelomedusid 
(Testudines,  Pleurodira)  from  the  Pliocene  of 
Venezuela  and  a  review  of  the  history  of  Podocnemis 
in  South  America.  By  Roger  Conant  Wood  and 
Maria  Lourdes  Diaz  de  Gamero.     23  pp.     June  15. 

No.  377.  The  Chanares  (Argentina)  Triassic  reptile  fauna  IX. 
The  Chaiiares  Formation.  By  Alfred  Sherwood 
Romer.     8  pp.     June  15. 

No.  378.  The  Chanares  (Argentina)  Triassic  reptile  fauna  X. 
Two  new  but  incompletely  known  long-limbed 
pseudosuchians.  By  Alfred  Sherwood  Romer.  10 
pp.     June  15. 

No.  379.  The  Chanares  (Argentina)  Triassic  reptile  fauna  XL 
Two  new  long-snouted  thecodonts,  Chanaresuchus 
and  GuaiosLichus.  By  Alfred  Sherwood  Romer.  22 
pp.     June  15. 


INDEX  OF  AUTHORS 

BREVIORA 

Museum  of  Comparative  Zoology 

Numbers  351-379 

1970-1971 

No. 

Boss,  Kenneth  J 363,  369 

Brown,  William,  Jr 365 

Bullock,  Robert  C 363,  369 

Collins,  James  P 370 

Diaz  de  Gamero,  Maria  Lourdes 376 

Echternacht,  Arthur  C 354 

Gates,  G.  E 356 

Gould,  Stephen  Jay 372 

Greer,  Allen  E 364 

Haedrich,  Richard  L 351 

Horn,  Michael  H 359 

Jenkins,  Parish  A.,  Jr 352 

KiBLisKY,  Pablo 353 

Parker,  Fred 364 

Reig,  Osvaldo  a 353 

Rivero-Blanco,  Carlos   353 


No. 
Roberts,  Tyson  R 367^  374 

RoMER,  Alfred  Sherwood 373.  377,  378,  379 

ScHEviLL,  William  E 366 

Schoener,  Thomas  W.  and  Amy   368.  375 

Schwartz,  Albert    37I 

Simpson,  George  Gaylord 360,  361,  362 

Vuilleumier,  Francois 355 

Watkins,  William  A 366 


{j'li^^^''''  . 


BREVIORA 

Mmseuim    of    Compsirative    Zoology 

Cambridge,  Mass.  12  June,   1970  Number  351 


A   NEW   SPECIES   IN  THE   NOMEID  FISH   GENUS  PSENES 
FROM  THE  EQUATORIAL  EASTERN  PACIFIC^ 

Richard   L.   Haedrich- 


Abstract.  Psenes  sio  n.  sp.  is  based  on  five  specimens  23-66  mm  SL 
from  the  equatorial  eastern  Pacific  Ocean.  The  new  species  belongs  to  the 
species-group  (others  are  P.  pelliicidiis,  P.  maculatus,  and  P.  arafurensis) 
with  large,  laterally  compressed,  knifelike  teeth  in  the  lower  jaw.  P.  cya- 
nophrys  and  P.  whiteleggii  have  small  conical  teeth  in  both  jaws.  The  new 
species  is  characterised  by  its  light  color,  long  pelvic  fins,  two  weak  anal 
spines  and  23-24  rays,  18-19  pectoral  finrays,  and  36-38  vertebrae. 

In  a  recent  unpublished  yet  widely  distributed  manuscript 
(Haedrich  and  Horn,  1969),  a  new  species  of  Psenes  was  included 
in  a  key  (p.  36).  It  was  stated  explicitly  that  use  of  the  name  in 
the  key  did  not  constitute  publication,  and  it  was  indicated  that  a 
formal  description  would  soon  appear  in  a  review  of  the  entire 
genus.  Other  responsibilities,  however,  have  virtually  brought  this 
work  to  a  halt,  and  early  completion  of  the  review  does  not  seem 
likely.  Therefore,  in  order  to  avoid  the  nomenclatural  debacle  that 
I  see  developing,  this  note  has  been  prepared  describing  the  new 
species. 

The  specimens  upon  which  the  new  species  is  based  were  made 
available  by  J0rgen  Nielsen,  and  are  housed  in  Universitetets  Zoo- 
logiske  Museum,  Copenhagen  (ZMC).  They  were  collected  by 
Dr.  Nielsen  on  Step-I,  a  cruise  conducted  by  the  Scripps  Institution 
of  Oceanography.  The  manuscript  has  been  read  by  Richard  H. 
Backus  and  Giles  W.  Mead.   Figure  1  was  drawn  by  E.  Leenders. 


1  Contribution  No.  2486  from  the  Woods  Hole  Oceanographic  Institution. 

2  Woods    Hole    Oceanographic    Institution,    Woods    Hole,    Mass.,    and 
Museum  of  Comparative  Zoology,  Harvard. 


2  BREVIORA  No.    351 

Portions  of  this  work  were  supported  by  a  United  States  Govern- 
ment Grant  under  the  Fulbright-Hays  Act,  the  Johs.  Schmidt 
Fund,  and  National  Science  Foundation  grant  GB- 15764. 

Among  stromateoid  fishes,  the  genus  Psenes  is  distinguished  in 
having  two  dorsal  fins  with  the  first  dorsal  originating  over  or 
before  the  pectoral  insertion,  persistent  thoracic  pelvic  fins,  a  deep 
to  moderately  elongate  body,  and  teeth  present  in  some  species  on 
the  palatines  and/or  basibranchials  but  never  on  the  glossohyal. 
The  genus,  its  relationships,  and  the  nominal  species  were  treated 
in  a  general  way  by  Haedrich  (1967),  though  recent  findings  will 
modify  this  account  somewhat.  Within  Psenes,  there  seem  to  be 
two  species  groups.  One  group  (including  P.  cyanophrys  and 
P.  whiteleggii)  is  characterized  by  small,  conical,  slightly  recurved 
teeth  in  both  the  upper  and  lower  jaw.  The  other  group  (in- 
cluding P.  pellucidus,  P.  arajurensis,  P.  maciilatus  and  the  new 
species)  has  small,  conical,  slightly  recurved  teeth  in  the  upper 
jaw  and  large,  laterally  flattened,  bladelike  teeth  in  the  lower  jaw. 

In  recognition  of  the  considerable  contributions  to  marine  ich- 
thyology made  by  the  Scripps  Institution  of  Oceanography,  the  new 
species  will  be  known  as 

Psenes  sio  n.  sp. 
Figure   1 

Material.  Five  specimens,  23-66  mm  SL,  all  in  ZMC;  those 
marked  with  an  asterisk*  have  been  X-rayed:  *1  spec,  60  mm  SL, 
HOLOTYPE,  Step-I  sta.  23,  11°10'S  80°01'W,  17  Oct.  1960, 
2250-2345  hrs.,  0-90  m,  5'  net,  surf.  temp.  17.8°C.  PARA- 
TYPES:  *1  spec,  66  mm  SL,  Step-I  sta.  80-1,  1°24'S  94°55'W, 
2/3  Dec.  1960,  2335-0230  hrs.,  high-speed  net,  battered.  2  spec, 
26  &  44  mm  SL,  Step-I  sta.  73-1,  4°22'S  95°04'W,  2  Dec.  1960, 
0200-0500  hrs.,  high-speed  net,  very  battered,  smaller  spec, 
cleaned-and-stained.  *1  spec,  23  mm  SL,  Step-I  sta.  80,  1°59'S 
94°55'W,  2  Dec.  1960,  2200  hrs.,  dipnet-nightlight,  surf.  temp. 
22°C.   All  specimens  are  immature. 

Diagnosis.  An  elongate,  compressed,  light-colored  Psenes  with 
large,  compressed  close-set  teeth  in  the  lower  jaw,  long  pelvic  fins, 
two  weak  anal  spines  and  23-24  rays,  and  36  to  38  vertebrae. 

Description.  Individual  proportions  and  counts  are  presented  in 
Table  1. 

The  body  is  elongate,  the  maximum  depth  of  larger  specimens 


1970  NEW    NOMEID    FISH  3 

being  around  30  per  cent  of  the  standard  length,  and  is  very  com- 
pressed. The  caudal  peduncle  is  tapered,  compressed,  and  some- 
what elongate.  The  musculature,  though  firm,  is  translucent,  par- 
ticularly along  the  anal  fin  base  and  over  the  viscera.  The  two 
dorsal  fins  are  scarcely  divided.  The  first  dorsal  fin  originates  over 
the  edge  of  the  opercle  and  comprises  10  to  12  thin  brittle  spines, 
the  second  originates  just  behind  mid-body  and  comprises  23  to  25 
long  rays.  The  entire  fin  folds  partially  into  a  very  shallow  groove 
and  terminates  behind  the  end  of  the  anal  fin.  The  anus  is  at  mid- 
body,  in  a  slit.  The  anal  fin  commences  shortly  behind  the  anus 
under  the  third  or  fourth  ray  of  the  second  dorsal,  and  is  composed 
of  two  weak  spines  and  23  or  24  long  rays.  The  muscles  for  ele- 
vating the  anal  rays  can  be  clearly  seen,  as  can  the  basal  elements 
of  both  median  fins.  The  pectoral  fin  is  long  and  fairly  broad,  with 
18  or  19  rays;  its  base  is  incUned  about  45°  to  the  vertical.  The 
pelvic  fins  are  very  long;  they  insert  under  the  middle  or  end  of 
the  pectoral  fin  base  and  extend  beyond  the  anal  origin,  and  are 
composed  of  one  short  spine  and  five  long  branched  rays.  The 
caudal  fin,  broken  in  most  specimens,  is  apparently  long  and 
forked;  the  small  elements  preceding  the  principal  rays  extend 
well  forward  on  the  peduncle.  The  cycloid  scales  are  very  small, 
and  do  not  appear  to  extend  significantly  onto  the  bases  of  the 
median  fins.  The  scales  are  extremely  deciduous,  and  most  are 
gone;  the  count  of  scale  pockets  along  the  lateral  line  of  the  holo- 
type  is  ca.  85.  The  skin  is  thin;  the  subdermal  mucus  canal  system 
is  but  httle  developed,  and  the  body  pores  are  very  small  or 
wanting. 

The  head  is  around  35  per  cent  of  the  standard  length,  its  profile 
sloping.  The  skin  of  the  top  of  the  head  is  naked,  and  pores  are 
clearly  visible,  particularly  those  over  the  head  of  the  hyomandibu- 
lar.  The  eye  is  of  moderate  size,  located  a  little  more  than  its 
diameter  from  the  tip  of  the  truncate  snout,  and  does  not  enter 
into  the  profile  of  the  head.  There  is  apparently  no  adipose  tissue 
around  the  eye,  but  somes  does  extend  forward  from  the  front  of 
the  eye  to  surround  the  nostrils.  The  two  small  nostrils  are  located 
much  nearer  to  the  tip  of  the  snout  than  to  the  eye.  The  end  of 
the  maxillary  is  below  the  anterior  border  of  the  eye,  but  the  angle 
of  the  gape  is  well  before  the  eye.  The  premaxillary  is  not  pro- 
tractile. The  lacrimal  bone  is  large  and  transparent,  and  covers 
the  top  of  the  maxillary.  The  teeth  are  uniserial  in  the  jaws.  The 
teeth  in  the  upper  jaw  are  small,  conical,  slightly  recurved,  and 
spaced;  the  teeth  in  the  lower  jaw  are  large,  at  least  twice  as  long 


4  BREVioRA  No.  351 

as  those  in  the  upper  jaw,  compressed  and  knifeUke  with  very  small 
cusps,  and  very  close-set.  The  vomer,  palatines,  and  basibranchials 
appear  to  be  toothless.  The  oral  valves  are  prominent.  The  oper- 
cles  are  very  thin;  their  margins  are  either  entire  or  set  with  ex- 
tremely fine  spinules.  The  striated  opercle  has  two  very  weak  flat 
spines;  the  angle  of  the  preopercle  is  rounded  but  does  not  bulge 
backward.  The  gill-rakers  are  moderate,  blunt,  about  half  the 
length  of  the  filaments,  and  bear  fine  teeth  on  their  inner  edges;  the 
rakers  are  spaced,  about  15  on  the  lower  limb  of  the  first  arch. 
The  pseudobranch  is  well  developed,  but  there  are  no  rudimentary 
rakers  below  it.  The  light  yellow  thymus  is  clearly  visible.  There 
are  six  branchiostegal  rays. 

The  color  in  alcohol  is  tan,  darker  on  the  back  than  on  the  sides. 
There  is  a  suggestion  of  three  brownish  vertical  bands  on  the  after 
part  of  the  body  in  some  specimens.  The  first  dorsal  fin  is  dark, 
but  all  the  other  fins  are  whitish.  The  dark  lining  of  the  gill  cavity 
shows  clearly  through  the  transparent  opercles.  The  dark  peri- 
toneum shows  clearly  through  the  thin  abdominal  wall.  The  in- 
side of  the  mouth  is  fight  yellow,  and  the  eye  is  grey. 

The  skeleton  in  general  is  very  light.  This  is  particularly  ap- 
parent in  the  thin  transparent  dermal  skeleton.  There  is  no  supra- 
maxillary  bone.  The  supraoccipital  is  but  little  developed.  There 
is  a  wide  opening  between  the  cleithrum  and  the  coracoid.  The 
pelvic  bones  reach  to  the  cleithrum.  There  is  a  large  foramen  in 
the  scapula.  The  postcleithrum  can  be  plainly  seen  through  the 
body  wall,  and  it  extends  to  the  lower  margin  of  the  body.  There 
are  36  to  38  vertebrae,  including  the  hypural;  about  12  to  15  verte- 
brae appear  to  be  precaudal.  In  the  tail,  there  are  two  autogenous 
haemal  spines,  four  hypurals,  two  paired  uroneurals,  and  three 
epurals.  The  second  and  third  hypurals  are  broad  triangular  plates 
much  larger  than  any  other  caudal  element.  The  first  hypural  bears 
an  hypuropophysis.  Three  free  interneurals  precede  the  dorsal  fin. 
The  first  dorsal  interneural  supports  two  spines.  The  two  anal 
spines  are  weak. 

Remarks.  Most  species  of  P series  are  widely  distributed  in  the 
tropical  and  sub-tropical  parts  of  the  world  ocean.  P.  sio,  how- 
ever, is  quite  restricted,  and  has  been  found  only  in  the  eastern 
Pacific  from  about  11°  S  (holotype)  to  perhaps  10°  N  (R.  Rosen- 
blatt, additional  Scripps  specimens,  in  lift.).  P.  sio  most  closely 
resembles  P.  rnaculatus,  an  apparently  antitropical  species  known 
only  from  sub-tropical  waters  in  the  North  and  South  Atlantic. 

Within  the  range  of  Psenes  sio,  only  P.  cyanophrys  is  known  to 
occur  for  sure.    This  species  may  be  distinguished  from  P.  sio 


1970  NEW    NOMEID    FISH  5 

by  its  small  conical  teeth  that  are  similar  in  both  jaws  (as  men- 
tioned above),  its  color  pattern  of  fine  horizontal  stripes  (P.  sio 
has  about  three  indistinct  vertical  bands),  its  greater  maximum 
depth  (43-52%  SL  vs.  29-41%  SL  in  P.  sio),  its  generally  greater 
number  of  median  fin  rays  (D  24-29  vs.  23-25,  A  24-28  vs. 
23-24),  and  its  fewer  vertebrae  (31  v^.  36-38). 

As  yet  unrecorded  from  the  eastern  tropical  Pacific  but  known 
from  the  western  parts  of  that  ocean  are  Psenes  pellucidus  and 
P.  arafurensis.  The  former  has  more  median  finrays  and  verte- 
brae (D  27-32,  A  26-31,  vert.  41-42)  than  P.  sio,  the  latter  fewer 
(D  18-22,  A  20-22,  vert.  31). 

Psenes  whiteleggii,  from  the  Indian  Ocean  and  Australia,  has 
conical  teeth  in  both  jaws  and  low  median  finray  and  vertebral 
counts  (D  17-20,  A  17-18,  vert.  31-32).  The  Atlantic  P.  macu- 
latus,  the  species  most  similar  to  P.  sio,  has  slightly  fewer  median 
finrays  and  vertebrae  (D  22-24,  A  22-24,  vert.  35)  and  more 
pectoral  finrays  (21-22  vs.  19  in  P.  sio)  and  anal  spines  (III  vs. 
II).  The  preanal  distance  is  58-63%  SL  in  P.  maculatus,  and 
51-54%  SL  in  P.  sio. 

LITERATURE   CITED 

Haedrich,  Richard  L.  1967.  The  stromateoid  fishes:  systematics  and  a 
classification.     Bull.  Mus.  Comp.  Zool.,  Harvard,  135(2):  31-139. 

Haedrich,  Richard  L.,  and  Michael  H.  Horn.  1969.  A  key  to  the 
stromateoid  fishes.  Woods  Hole  Oceanographic  Institution  Ref.  No. 
69-70,  September   1969,  46  pp.     Unpublished  Manuscript. 

(Received  2  April   1970.) 


6  BREVIORA  No.    351 


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BREVIORA 

Miiseimi    of    Cointipairsitive    Zoology 

Cambridge.  Mass.  10  July,  1970  Number  352 


THE  CHANARES  (ARGENTINA)  TRIAS5IC  REPTILE  FAUNA 
VII.  THE  P05TCRANIAL  SKELETON  OF  THE  TRAVERSO- 
DONTID     MASSETOGNATHUS     PASCUALI     (THERAPSIDA, 

CYNODONTIA) 

Parish   A.  Jenkins,   Jr.^ 

Abstract.  The  postcranial  skeleton  of  Massetognathus  pascuali  is 
described  from  a  single  nearly  complete  individual  and  four  disarticulated 
specimens;  manus,  pes  and  pubis  could  not  be  described  from  the  available 
material.  M.  pascuali  has  a  postcranial  skeleton  morphologically  similar  to 
that  in  Pascualgnathns  polanskii  (an  earlier  traversodontid)  and  in  African 
Triassic  cynodonts.  The  basic  skeletal  pattern  of  all  these  forms  differs 
from  that  in  Exaeretodon  sp.,  an  advanced  traversodontid.  The  specialized, 
imbricating  ribs  of  M.  pascuali  are  intermediate  in  form  between  those 
of  P.  polanskii  (which  are  diademodontid  in  form)  and  those  of  Exaere- 
todon sp.  (which  essentially  have  lost  the  cynodont  specialization). 

Although  Richard  Owen  made  the  first  study  of  a  cynodont  more 
than  a  century  ago,  a  detailed  knowledge  of  cynodonts  has  accumu- 
lated only  recently.  First  known  only  from  Africa,  representatives 
of  this  advanced  group  of  mammallike  reptiles  have  now  been 
recovered  from  Asia  and  North  and  South  America.  The  most 
specialized  and,  during  the  early  and  middle  Triassic,  the  most 
abundant  cynodonts  were  the  herbivorous  gomphodonts.  Trans- 
versely broad,  multicuspid  postcanine  molars  with  heavy  occlusal 
wear  (often  to  the  point  of  effacing  the  original  crown  pattern) 
are  characteristic  of  the  group.  Romer  (1967)  recognized  three 
gomphodont  families:  Diademodontidae,  Traversodontidae,  and 
Trirhachodontidae.  Massetognathus  pascuali  is  a  traversodontid 
and  is  one  of  two  species  described  by  Romer  (1967)  from  the 


'  Department    of    Anatomy,    Columbia    University,    New    York,    New 
York  10032 


2  BREVIORA  No.    352 

Chanares  Formation  of  Argentina.  Other  undoubted  traversodon- 
tid  genera  include  Traversodon  from  the  Santa  Maria  Formation  of 
Brasil,  Exaeretodon,  Proexaeretodon  and  Ischignathus  from  the 
Ischigualasto  Formation  of  Argentina,  and  Scalenodon  and  Scal- 
enodontoides  from  the  Manda  and  Molteno  beds,  respectively,  of 
Africa.  Pasciialgnathus  polanskii  from  the  Puesto  Viejo  Forma- 
tion of  Argentina,  originally  classified  as  a  diademodontid  (Bona- 
parte, 1966a;  1966b),  is  now  interpreted  as  a  primitive  traverso- 
dontid  on  the  basis  of  tooth  morphology  (Bonaparte,  1967,  and 
personal  communication). 

The  present  account  of  the  Massetognathus  pasciiali  postcranial 
skeleton  is  based  upon  the  disarticulated  remains  of  at  least  four 
individuals  and  an  almost  completely  articulated  skeleton  of  a  fifth 
individual,  all  about  the  same  size  and  preserved  in  a  nodule  several 
inches  thick  and  two  and  one-half  feet  in  diameter.  The  1964-65 
expedition  of  the  Museo  de  la  Plata  and  Museum  of  Comparative 
Zoology  collected  the  nodule  from  the  Chanares  Formation  in  the 
Chanares-Gualo  region  of  western  Argentina.  All  the  skeletal 
material  is  catalogued  as  No.  3691  in  the  Museum  of  Compara- 
tive Zoology. 

Although  the  available  postcranial  material  of  Massetognathus 
pasciiali  is  incomplete,  there  are  two  reasons  why  even  a  partial 
account  is  important.  First,  some  workers  regard  cynodonts  as 
ancestral  to  mammals  (Crompton  and  Jenkins,  1968;  Hopson  and 
Crompton,  1969).  Gomphodont  cynodonts  are  certainly  not  di- 
rectly related  to  mammals,  but  they  undoubtedly  possessed  a  de- 
gree of  biological  organization  that  at  least  approximated  that  of 
their  carnivorous-insectivorous  relatives  (from  some  form  of  which 
mammals  were  derived).  Thus  all  cynodonts  are  relevant  to  evalu- 
ating the  reptile-mammal  transition.  Second,  most  published  in- 
vestigations of  cynodonts  have  been  restricted  to  cranial  anatomy. 
Well-preserved,  generically  determinate  postcranial  skeletons  are 
rare.  Of  South  American  genera,  only  Belesodon  (von  Huene, 
1935-1942),  Exaeretodon  (Bonaparte,  1963a)  and  Pasciialgna- 
thus are  known  from  relatively  complete  skeletons;  the  preservation 
of  known  Belesodon  material  is  poor,  however,  and  Exaeretodon 
appears  to  be  morphologically  aberrant  in  comparison  to  the  gen- 
eral pattern  known  from  other  cynodonts.  Postcranial  material 
associated  with  Traversodon  and  Chiniquodon  (von  Huene,  1935 
1942)  is  only  fragmentary,  although  Romer  (1969)  has  recently 
described  more  complete  limb  bones  of  Chiniquodon.  I  have  re- 
viewed the  postcranial  skeletons  of  African  cynodonts  (Jenkins,  in 


1970 


MASSETOGNATHUS    POSTCRANIAL    SKELETON 


press).    Of  the  Russian  forms  very  little  is  known;  some  data  is 
available  for  Permocyiiodon  (Konjukova,  1946). 

Vertebral  column  and  ribs 

The  number  of  presacral  vertebrae  in  Massetognathus  pascuali 
is  at  least  23  and  is  here  interpreted  to  be  about  26.  A  hiatus  in 
the  lumbar  series  of  the  one  nearly  complete,  articulated  vertebral 
column  is  responsible  for  this  uncertainty.  Present  are  7  cervicals, 
164-?  dorsals,  and  6  sacrals.  Judging  from  the  length  of  several 
articulated  but  incomplete  caudal  series,  tail  vertebrae  numbered 
at  least  17  and  probably  as  many  as  25.  A  count  of  26  presacral 
vertebrae  in  M.  pascuali  compares  with  26  in  Leavachia  duven- 
hagei  (Broom,  1948),  27  in  Thrinaxodon  liorhinus  (Jenkins,  in 
press),  28  in  Exaeretodon  sp.  (Bonaparte,  1963a),  29  in  Cynog- 
nathus  crateronotus  (Seeley,  1895 )  and  at  least  30  in  a  large  cyno- 
dont  identified  tentatively  as  Diademodon  sp.  (Brink,  1955;  Jen- 
kins, in  press). 

Two  separately  articulating  atlas  arches  appear  to  conform  to 
the  general  pattern  known  from  African  Triassic  cynodonts  (Jen- 
kins, in  press),  but  their  preservation  is  too  poor  to  allow  specific 
description  or  comparison.  The  atlas  intercentrum.  transversely 
elongate  and  ventrally  convex,  bears  a  posteriorly  directed  process 
or  lip  (1,  Fig.  IB).  A  concave  articular  facet  on  the  dorsal  sur- 
face of  this  lip  contacts  a  median  convex  facet  on  the  anterior 
aspect  of  the  atlas  centrum  (f  a  i,  Fig.  6B ) .  The  lateral  extremities 
of  the  intercentrum  each  bear,  on  their  dorsal  surfaces,  a  concave 
facet  that  articulates  with  the  ventral  aspect  of  one  of  the  two 
occipital  condyles.   The  atlas  centrum  (6  mm  long)  is  synostosed 


Figure  1.  Vertebral  elements  in  Massetognathus  pascuali.  A.  Cervical 
vertebrae,  probably  the  third  and  fourth,  in  lateral  view.  B.  First  or  atlantal 
intercentrum  in  ventral  view  with  anterior  margin  toward  the  top  of  the 
page.  C,  Anterior  dorsal  ("thoracic")  vertebrae;  vertebra  on  the  right  is 
in  lateral  view,  on  the  left  posterolateral  view.  All  X  1.  Abbreviations: 
fo,  costal  fovea  for  rib  head;  1.  posterior  lip  of  the  intercentrum;  p.  para- 
pophysis;  t,  transverse  process. 


4  BREVIORA  No.    352 

to  the  axis  centrum  (8.5  mm  long),  forming  a  conspicuously  large 
vertebra.  On  the  dorso-lateral  aspects  of  the  atlas  centrum  are  two 
facets,  one  for  each  atlas  arch  half  (f  a  a.  Fig.  6B).  Protruding 
from  the  median  aspect  of  the  centrum  between  these  facets  is  a 
small  process  (d,  Fig.  6B)  homologous  with  the  dens  or  odontoid 
process  of  mammals.  Elsewhere  (Jenkins,  1969;  in  press)  I  have 
proposed  that  the  mammalian  dens  originated  as  a  neomorphic 
process  from  the  atlas  centrum  of  cynodonts.  The  occurrence  of  a 
dens  in  Massetognathus  pascuali  is  unequivocal  and  supports  the 
theory  that  both  a  dens  and  an  atlas  centrum  (of  which  the  dens 
was  formerly  thought  to  be  a  vestige)  occur  together  among 
cynodonts. 

The  axis  centrum  of  the  one  articulated  cervical  series  is  about 
9  mm  long,  1  mm  longer  than  the  centra  of  the  following  cervicals. 
The  axial  prezygapophyses  have  been  broken  off  on  all  specimens, 
but  from  the  appearance  of  their  narrow  bases^ — no  thicker  than 
the  laminae  from  which  they  protrude — they  are  vestigial.  Axial 
postzygapophyses  of  normal  size  bear  articular  facets  at  an  angle 
estimated  to  be  25°  to  the  horizontal.  The  axial  spine,  a  flat  blade 
with  a  distinctly  mammalian  shape,  exhibits  a  straight  dorsal  mar- 
gin that  was  probably  slightly  convex  during  hfe.  The  robust 
transverse  processes  are  directed  posterolaterally. 

Cervical  centra  are  amphicoelous,  as  are  all  other  centra  in 
Massetognathus  pascuali,  with  the  exception  of  the  atlas  (only  the 
posterior  aspect  bears  a  notochordal  concavity)  and  possibly  some 
of  the  smaller  caudal  vertebrae.  In  cervical  vertebrae,  the  rim  sur- 
rounding the  notochordal  concavity  on  each  end  is  swollen,  and 
this  increases  the  concave  curvature  of  the  sides  and  ventral  aspect 
of  each  centrum.  A  bulbous  parapophysis  is  to  be  found  on  the 
ventrolateral  aspect  of  each  anterior  rim  (p.  Fig.  lA).  If  the  rib 
head  articulated  on  the  apex  of  the  parapophysis,  as  seems  most 
likely  on  the  basis  of  the  large  size  of  the  process,  then  this  condi- 
tion differs  from  that  in  species  of  Thrinaxodon  and  Cynognathus, 
in  which  cervical  rib  heads  are  situated  intervertebrally.  A  median 
ventral  keel,  similar  to  that  in  other  cynodont  cervicals,  traverses 
the  length  of  each  cervical  centrum. 

Cervical  pedicles  are  narrow  anteroposteriorly  and  bear  short, 
stout  transverse  processes  (t,  Fig.  lA).  Cervical  spines,  broken 
off  on  all  but  two  disarticulated  cervicals  (Fig.  lA),  are  trans- 
versely slender  and  recurved,  and  taper  abruptly  toward  the  apex. 
Of  particular  interest  are  the  zygapophyses,  which  provide  a  basis 
for  distinction  between  cervical  and  dorsal  (anterior  thoracic) 
vertebrae.   As  noted  above,  the  axial  postzygapophyseal  facets  are 


1970  MASSETOGNATHUS    POSTCRANIAL    SKELETON  5 

oriented  at  an  angle  of  about  25°  to  the  horizontal;  the  orientation 
of  posterior  facets  on  the  third  through  sixth  cervical  are  more  than 
25° — probably  about  35°.  The  distance  between  their  lateral  mar- 
gins is  approximately  7  mm.  The  anterior  articular  facets  of  the 
seventh  cervical  of  course  conform  in  orientation  and  spacing  to 
those  of  the  foregoing  series.  The  posterior  articular  facets,  how- 
ever, appear  to  be  oriented  at  about  45°.  Those  on  the  succeeding 
(eighth)  vertebra  are  nearly  parasagittal — i.e.,  within  a  few  de- 
grees of  vertical — and  are  only  3.5  mm  apart.  The  articular  facet 
characteristics  of  the  eighth  vertebra,  continued  (with  gradual 
modification)  through  the  dorsal  series,  definitely  estabhsh  a  dif- 
ferent pattern.  Although  transitional,  the  seventh  vertebra  most 
closely  resembles  other  neck  vertebrae  and  thus  may  be  regarded 
as  the  last  cervical.  Similar  changes  in  facet  orientation  and 
spacing,  together  with  other  morphological  changes,  occur  between 
the  seventh  and  eighth  vertebrae  of  Tlvinaxodon  liorhimis  and 
Cynognathiis  craterouotiis  (Jenkins,  in  press).  The  condition  in 
Massetognathus  pascuali  reaffirms  the  fact  that  the  "mammalian" 
number  of  seven  cervical  vertebrae  was  already  established  in 
cynodonts. 

With  the  exception  of  the  atlas  intercentrum,  no  other  cervical 
intercentra  have  been  identified.  The  broad  grooves  formed  by  the 
rims  of  adjacent  centra  are  evidence  that  intercentra  were  present — 
as  in  Thrinaxodon  liorhimis,  for  example — and  the  state  of  dis- 
articulation accounts  for  their  postmortem  loss. 

The  dorsal  vertebral  column  in  cynodonts  is  either  a  relatively 
undifferentiated  dorsal  series  (as  in  most  reptiles)  or  two  series — 
"thoracic"  and  "lumbar"  (as  in  mammals).  In  certain  African 
Triassic  cynodonts,  separation  of  thoracic  and  lumbar  regions  may 
be  made  on  the  basis  of  distinct  morphological  specializations  of 
the  posterior  dorsal  (=  lumbar)  ribs  (Jenkins,  in  press).  In  other 
cynodonts  (e.g.,  Exaeretodon  sp.;  Bonaparte,  1963a)  the  trunk 
cannot  be  divided  into  thoracic  and  lumbar  regions  because  the 
posterior  ribs  are  not  specialized.  Massetognathus  pascuali  has 
specialized  "lumbar"  ribs  and  clearly  belongs  to  the  first  category. 
The  exact  number  of  thoracic  and  lumbar  vertebrae  is  unknown 
because  a  complete  vertebral  column  with  ribs  is  not  yet  available. 
Therefore,  thoracic  and  lumbar  vertebrae  will  be  given  only  a 
general  description  as  anterior  and  posterior  dorsals,  respectively, 
although  the  ribs  (to  be  discussed  below)  clearly  give  evidence  of 
a  differentiated  series. 

The  centra  of  anterior  dorsal  vertebrae  are  approximately  8.5 
mm  long;  those  of  posterior  dorsals  are  about  1 1  mm  long  (10  mm 


6  BREVIORA  No.    352 

in  the  one  articulated  specimen).  The  costal  foveae  (fo.  Fig.  IC) 
of  anterior  dorsal  vertebrae  form  a  cleft  for  reception  of  the  rib 
head,  which  is  therefore  intervertebral  in  position.  On  posterior 
dorsals  the  rib  head  articulates  with  a  parapophysis  (p,  Fig.  2B) 
and  is  not  intervertebral.  Transverse  processes  are  laminar  and 
bowed  dorsally  on  anterior  dorsal  vertebrae  (t,  Fig.  IC)  but  are 
rodlike  and  round  in  cross-section  on  posterior  dorsals  (t,  Fig.  2B). 
The  posterior  intervertebral  notch  is  deep  throughout  the  dorsal 
series,  the  anterior  notch  negligible  or  absent.  In  contrast  to  many 
cynodonts,  anapophyses  are  lacking.  Dorsal  prezygapophyses  are 
robust,  extending  to  or  slightly  beyond  the  level  of  the  anterior 
aspect  of  the  centrum.  Articular  facets  on  the  first  dorsal  vertebra 
are  about  3.5  mm  apart  and  on  the  ninth  are  4.0  mm;  an  abrupt 
widening  takes  place  at  some  point  in  the  middle  or  posterior  dorsal 
series,  for  the  articular  facets  of  the  penultimate  dorsal  vertebra 
are  about  7  mm  apart.  The  narrowly-spaced  facets  of  anterior 
dorsals  are  nearly  vertical,  whereas  those  wider  apart  on  the  pos- 
terior dorsals  are  oriented  at  angles  of  as  much  as  45°.  Neural 
spines  on  anterior  dorsals  are  narrow,  but  unlike  cervical  spines, 
do  not  taper  significantly  at  the  apex;  they  incline  caudad  at  angles 
of  about  30°.  Spines  on  posterior  dorsal  vertebrae  are  broad  an- 
teroposteriorly,  leaving  only  a  narrow  gap  between  vertebrae;  their 
inclination  is  only  a  few  degrees  caudad. 

Sacral  vertebrae  successively  decrease  in  size  posteriorly.  The 
centrum  of  the  first  sacral  is  approximately  as  long  as  those  of  the 
posterior  dorsals  (about  10  mm),  while  the  sixth  and  last  sacral 
centrum  is  some  2  mm  shorter.  Massive  synapophyses — repre- 
senting fused  parapophyses  and  transverse  processes — arise  from 
the  pedicles  and  from  the  anterior  half  of  the  side  of  the  centrum. 
The  zygapophyses,  proportionately  less  robust  than  in  the  dorsal 
series,  diminish  in  size  on  successively  more  posterior  sacrals.  In 
contrast  to  the  orientation  and  spacing  in  the  posterior  dorsals, 
sacral  articular  facets  incline  nearly  parasagittally  and  are  nar- 
rowly spaced.  At  the  last  dorsal-first  sacral  articulation,  the  facets 
are  5.5  mm  apart,  but  between  the  third  and  fourth  and  fourth  and 
fifth  sacrals  they  are  only  about  2  mm  apart.  At  the  fifth-sixth 
sacral  articulation  the  trend  is  reversed;  the  facets  are  spaced 
3.5  mm  apart  and  appear  to  be  inclined  at  10°  from  the  vertical. 
The  trend  toward  less  verticality  of  facets  is  continued  into  the 
caudal  series.  Sacral  spines  successively  diminish  in  height  and 
anteroposterior  breadth.  The  spine  on  the  first  sacral  is  approxi- 
mately 8  mm  in  height  and  7  mm  in  breadth  (versus  8.5  mm  height 
and  8  mm  breadth  for  the  last  dorsal  spine).    On  the  fifth  sacral 


i 


1970  MASSETOGNATHUS    POSTCRANIAL    SKELETON  7 

the  same  measurements  are  5.5  mm  and  4.2  mm  respectively.  This 
trend  is  continued  into  the  caudal  series.  The  apices  of  sacral 
spines  tend  to  be  oval  in  contrast  to  those  of  the  posterior  dorsals 
which  are  elongate  and  attentuated  at  each  end. 

Caudal  centra  decrease  in  length  from  6.5  mm  at  the  first  caudal 
to  about  5  mm  at  the  fifth.  More  posterior  caudals  preserved  with 
MCZ  3691  are  disarticulated,  and  their  position  cannot  be  posi- 
tively assigned.  However,  one  isolated  series  of  eleven  caudals 
shows  a  decrease  in  centrum  length  from  5  mm  (which  is  evidence 
that  it  is  approximately  the  fifth  caudal)  at  the  first  to  4  mm  at 
the  last  (?  fifteenth  caudal).  Other  specimens  show  that  at  least  the 
first  five  caudals  bear  synapophyses.  Articular  facets  are  inclined 
at  approximately  45°,  at  least  through  the  first  five  caudals.  The 
width  between  the  lateral  edges  of  these  facets  decreases  from 
6  mm  (between  the  last  sacral  and  first  caudal)  to  4.5  mm 
(between  the  fourth  and  fifth  caudals).  The  terminal  caudal  is 
unknown. 

Massetognathus  pascuali  probably  possessed  ribs  on  all  presacral 
vertebrae,  as  in  other  cynodonts  for  which  adequate  material  is 
known.  Ribs  were  not  found  in  association  with  the  first  six  cervi- 
cal vertebrae,  although  the  morphology  of  the  transverse  processes 
and  parapophyses  on  the  axis  through  sixth  cervical  is  clear  evi- 
dence of  their  existence.  These  features  cannot  be  verified  at  pres- 
ent on  the  atlas.  The  ribs  of  the  seventh  cervical  appear  to  have 
been  shorter  than,  but  otherwise  similar  to,  those  of  the  anterior 
dorsal  series. 

Dorsal  ribs  in  Massetognathus  pascuali  are  of  basically  two 
types:  in  the  anterior  and  middle  dorsal  series,  a  freely  articulating 
rib  of  normal  costal  form  and  proportions,  and  in  the  posterior 
dorsal  series,  a  fused  rib  with  a  Y-shaped  distal  end.  Unfortu- 
nately, the  transitional  ribs  between  the  two  types  are  as  yet 
unknown. 

The  proximal  ends  of  anterior  and  middle  dorsal  ribs  are  basi- 
cally triangular.  The  tuberculum  and  capitulum  form  two  corners 
of  the  triangle;  the  shaft  arises  from  the  third  (Fig.  3A).  On  the 
anterior  aspect  of  this  triangular  surface  is  a  slight  crest  (c.  Fig. 
3A)  comparable  to  a  similar  feature  on  the  anterior  dorsal  ribs  of 
Cynognathus  sp.  (c.  Fig.  3B.  C).  There  is  no  other  apparent  fea- 
ture that  makes  this  type  of  rib  distinctive.  The  maximum  widths  of 
the  shafts  near  their  proximal  ends  are  between  2.5  and  3  mm.  The 
distal  ends,  as  preserved,  are  approximately  1.5  mm  thick.  Ribs  of 
this  basic  morphology   (as  opposed  to  the   specialized  posterior 


8 


BREVIORA 


No.   352 


Figure  2.  The  posterior  dorsal  and  sacral  region  in  Massetoguathus 
pasciiali  in  A,  dorsal  and  B,  lateral  views.  X  1.  Abbreviations:  a  il, 
acetabular  facet  of  the  ilium;  a  p,  anterior  process  of  rib  shaft;  b,  ridge 
on  dorsal  aspect  of  rib  shaft;  f  a  p,  articular  facet  on  anterior  process  of 
rib  shaft;  gr,  groove  on  dorsal  margin  of  ischium;  il,  ilium;  is,  ischium; 
is  t,  ischial  tuberosity;  m  p,  medial  process  on  base  of  ilium  for  articulation 
with  ischium  and  pubis;  p,  parapophysis;  p  p,  posterior  process  of  rib  shaft; 
t,  transverse  process. 


dorsal  ribs  to  be  described  next)  are  associated  with  at  least  the 
first  thirteen  dorsal  vertebrae. 

The  following  description  of  the  specialized  posterior  dorsal 
ribs  is  based  on  the  penultimate  and  last  dorsal  ribs  preserved  in 
articulation  (Fig.  2)  and  in  addition,  a  few  disarticulated  pieces  of 
similar  morphology.  These  ribs  have  a  short  shaft  that  bifurcates 
into  a  Y-shaped  terminus  with  two  processes  (ap,  pp,  Figs.  2,  4B). 
The  anterior  process  is  broader  than  the  posterior  and  bears,  on 
the  dorsal  surface  of  its  tip,  a  rather  flat,  round  facet  (f  a  p,  Figs. 
2A,  4B).  Articulating  with  this  facet  is  the  end  of  the  posterior 
process  of  the  preceding  rib.    Presumably,  the  underside  of  the 


970 


MASSETOGNATHUS    POSTCRANIAL    SKELETON 


Figure  3.  Proximal  ends  of  dorsal  ribs  of  A,  Masseto^natliiis  pascuali 
(X  2),  and  of  B  and  C,  Cynognatlms  sp.  (X  V2)  in  anterior  view.  Ab- 
breviations:  c,  crest  on  anterior  aspect  of  shaft  (see  text  for  details). 


posterior  process  also  bears  a  facet.  The  rib  as  a  whole  projects 
laterad  from  the  vertebral  column  and  appears  not  to  have  had  any 
ventral  curvature.  In  lateral  view  (Fig.  2B)  the  shaft  and  point  of 
bifurcation  are  at  approximately  the  same  level,  but  the  anterior 
and  posterior  processes  incline  somewhat  ventrally.  A  low,  bony 
ridge  (b.  Figs.  2 A,  4B)  runs  obliquely  onto  the  posterior  process 
from  the  point  of  bifurcation  where  it  is  most  prominent.  This 
feature  is  comparable  to  a  similar  ridge  on  the  ribs  of  Cynognatlms 
sp.  (b.  Fig.  4A)  and  other  cynodonts;  in  the  fourteenth  thoracic 


Figure  4.  Specialized  posterior  dorsal  ("lumbar")  ribs  of  various 
cynodonts.  A.  Cynognathus  crateronotiis  (British  Museum  of  Natural 
History  no.  R.  2571),  X  V4.  B,  Massetogucithiis  pascuali.  XL  C, 
Leavacliia  duvenhagei  (Rubidge  Collection,  Graaf  Reinet,  South  Africa, 
no.  92),  X  V2.  All  dorsal  views.  Abbreviations:  a  p,  anterior  process 
of  rib;  b,  ridge  on  dorsal  aspect  of  rib  shaft  (of  unknown  function  but 
probably  homologous  in  the  forms  shown  here);  f  a  p,  articular  facet  on 
anterior  process  of  rib  shaft;  LI,  L2,  first  and  second  lumbar  vertebrae; 
p  p,  posterior  process  of  rib  shaft;  T14,  T15,  fourteenth  and  fifteenth 
thoracic  vertebrae. 


10  BREVIORA  No.    352 

rib  of  C  (T14,  Fig.  4A),  the  ridge  is  merely  a  linear  elevation  on 
the  flat  costal  plate.  On  successive  ribs,  however,  the  ridge  becomes 
more  prominent  until,  in  the  lumbar  ribs  (LI,  L2,  Fig.  4A),  it 
reflects  forward  to  contact  the  preceding  rib  plate  (see  Jenkins,  in 
press).  No  such  reflection  is  evident  in  Massetognathus  pascuali, 
but  the  ridge  morphology  and  general  pattern  of  the  process  are 
nevertheless  similar  to  that  of  the  fourteenth  and  fifteenth  thoracic 
rib  plates  of  C 

Specialized,  imbricating  ribs  are  common  but  not  universal 
among  cynodonts.  Known  members  of  the  earliest  cynodont  fam- 
ily, the  procynosuchids,  apparently  did  not  possess  this  specializa- 
tion (see  discussion  below,  however,  for  a  possible  exception). 
Galesaurids,  typified  by  the  well  known  Thrinaxodon  liorhinus 
(Jenkins,  in  press),  developed  costal  expansions  on  all  presacral 
ribs.  Members  of  three  other  families,  e.g.,  Cynogmitlms  craterono- 
tus  (Cynognathidae;  Seeley,  1895),  Diadeinodon  sp.  (Diademo- 
dontidae;  Jenkins,  in  press)  and  Cricodon  metabolus  (Triracho- 
dontidae;  Crompton,  1955),  possessed  imbricating  ribs  only  in  the 
posterior  dorsal  region.  The  ribs  in  chiniquodontids  (von  Huene, 
1935-1942)  are  as  yet  unknown.  There  remains  only  the  Traver- 
sodontidae,  which  Bonaparte  (1963b)  characterized,  on  the  basis 
of  species  of  Exaeretodon  and  supposedly  Traversodon,  as  lacking 
synostosed  ribs  with  overlapping  processes.  For  this  and  other 
reasons,  Bonaparte  interpreted  traversodontids  as  probably  having 
arisen  from  procynosuchids  along  a  lineage  separate  from  that  an- 
cestral to  all  other  cynodont  families  (whose  members  possess  rib 
specializations).  However,  Massetognathus  pascuali  unquestion- 
ably possesses  synostosed  lumbar  ribs  with  details  comparable  to 
the  Cynognathus-Diademodon  pattern.  Pascualgnathus  polanskii, 
now  classified  as  a  traversodontid  (Bonaparte,  1967),  has  lumbar 
ribs  that  are  unquestionably  diademodontid  in  pattern.  Further- 
more, von  Huene  (1935-1942;  137-140)  described  expanded  ribs 
("Facherrippen")  synostosed  to  the  lumbar  vertebrae  in  Traverso- 
don stahleckeri.  Crompton  (1955)  presented  circumstantial  evi- 
dence that  the  traversodont  Scalenodon  from  the  African  Manda 
beds  also  possessed  the  expanded  rib  specialization.  Yet  Bona- 
parte (1963a)  amply  demonstrated  that  at  least  one  traversodont, 
Exaeretodon  sp.,  did  not  possess  such  specialization.  Presacral  ribs 
in  Exaeretodon  sp.  are  morphologically  uniform  and  are  more  or 
less  freely  articulating  (although  the  more  "solid"  attachment  of 
the  last  three  dorsal  ribs,  as  described  by  Bonaparte,  possibly  rep- 
resents a  vestige  of  a  less  mobile  articulation  typical  of  expanded 
ribs ) .   In  view  of  this  unexpected  association  at  the  family  level  of 


1970  MASSETOGNATHUS    POSTCRANIAL    SKELETON  11 

forms  possessing  and  forms  lacking  rib  specializations,  the  taxo- 
nomic  significance  of  this  character  should  be  reassessed.  Further 
comment  is  reserved  for  the  discussion  below. 

Sacral  ribs  in  Massetognathiis  pascuali  have  an  essentially  con- 
fluent capitulum  and  tuberculum,  a  short  shaft  and  an  expanded 
distal  end  for  articulation  with  the  iliac  blade.  Proximally  each  rib 
is  synostosed  to  its  corresponding  vertebra.  If  I  may  judge  from 
the  disarticulated  condition  of  every  known  sacroiliac  joint,  liga- 
ments and  cartilage  must  have  been  chiefly  responsible  for  binding 
the  ilium  and  sacral  ribs.  The  concave  distal  ends  of  the  sacral  ribs 
conform  to  the  gently  convex  internal  surface  of  the  ilium,  but 
they  do  not  appear  to  form  any  osseous  interdigitation  by  which 
sacroiliac  joints  are  commonly  reinforced.  Viewed  from  above,  the 
distal  end  of  the  first  sacral  rib  (Si,  left  side.  Fig.  2A)  is  Y-shaped 
with  processes  directed  anterolaterad  and  posterolaterad.  Articu- 
lating with  the  dorsal  surface  of  the  anterolateral  process  is  the 
posterior  process  of  the  last  dorsal  (lumbar)  rib.  The  second  sacral 
rib  has  the  largest  distal  expansion;  irregularly  shaped  and  widest 
anteriorly,  the  expansion  is  7  mm  long  in  one  well  preserved  speci- 
men. The  third,  fourth  and  fifth  ribs  bear  more  or  less  symmetrical 
distal  expansions  that  are  successively  smaller  caudally.  The  first 
four  sacral  rib  shafts  are  oriented  more  or  less  laterally,  the  fifth 
slightly  anterolaterally.  The  sixth  and  last  sacral  rib  bears  a  shaft 
that  is  directed  posterolaterally  and  a  bifurcated,  Y-shaped  termi- 
nus resembling  that  of  posterior  dorsal  ribs.  Its  iliac  articular  sur- 
face is  narrow  and  strap  shaped;  the  rib  and  vertebra  could  well  be 
interpreted  as  the  first  caudal  were  it  not  for  its  position  opposite 
the  posterior  tip  of  the  ihac  blade  (S6,  Fig.  2A).  While  it  is  appar- 
ent that  the  width  between  the  distal  ends  of  this  pair  of  ribs 
(20  mm)  is  much  less  than  that  of  the  fourth  and  fifth  sacrals 
(27  mm),  the  intervening  gap  could  well  have  been  completed  by 
ligaments.  This  interpretation  of  the  sixth  sacral  vertebra  and  ribs 
may  be  open  to  future  modification,  but  on  present  evidence  ap- 
pears to  be  the  most  probable. 

Only  the  first  three  caudal  ribs  are  preserved.  All  are  synostosed, 
their  shafts  directly  posterolaterally.  The  first  is  only  8  mm  long 
(Cdl,  Fig.  2A),  with  two  blunt  processes  on  its  terminus  resembling 
a  stunted  version  of  the  last  sacral  rib.  As  far  as  can  be  deter- 
mined, terminal  processes  were  not  developed  on  the  second  and 
third  caudal  ribs,  which  are  5  mm  or  less  in  length.  Ribs  on  suc- 
ceeding vertebrae  must  have  been  very  small  and  probably  did  not 
occur  in  the  posterior  caudal  series. 


12 


BREVIORA 


No.  352 


Shoulder  Girdle 

Available  interclavicles  of  Massetognatlius  pascuali  are  incom- 
plete, although  there  is  sufficient  material  to  conclude  that  the 
morphology  is  very  similar  to  that  in  Thrinaxodon  liorhinus  and 
different  from  that  in  Exaeretodon  sp.  In  outline  the  interclavicle 
is  cruciate  with  an  elongate  posterior  ramus  (pr,  Fig.  5A).  The 
entire  bone,  although  basically  a  flat  plate,  is  bowed  ventrally  from 
front  to  back.  Two  ridges,  one  longitudinal,  the  other  transverse, 
divide  the  ventral  surface  of  the  interclavicle  into  quadrants.  The 
two  anterior  quadrants  (c  c.  Fig.  5A)  are  shallow  concavities  for 
reception  of  the  proximal  ends  of  the  clavicles.    The  ridges  are 


#^f 


prox 

Figure  5.  A,  The  interclavicle  and  B,  the  right  clavicle  of  Massetog- 
nathus  pascuali,  both  in  ventral  view.  X  1.  Abbreviations:  ca,  concavity 
for  acromion;  c  c,  concavity  for  proximal  end  of  the  clavicle;  dist,  distal 
end  of  clavicle;  f,  ventral  flange  on  distal  end  of  clavicle;  pr.  posterior 
ramus  of  interclavicle;  prox,  proximal  end  of  clavicle. 


most  prominent  at  their  intersection.  With  the  exception  of  the 
posterior  part  of  the  longitudinal  ridge,  which  gradually  fades  out, 
the  ridges  become  more  salient  toward  the  margins.  There  is  no 
evidence  that  the  longitudinal  ridge  was  a  deep  keel  as  in  Exaereto- 
don sp.  (Bonaparte,  1963a).  The  posterior  ramus  in  M.  pascuali 
is  similar  in  length  and  form  to  that  in  galesaurids,  and  is  unlike  the 
very  short  ramus  of  Exaeretodon  sp. 

The  Massetognathus  pascuali  clavicle  is  robust.  The  proximal 
two-thirds  are  more  or  less  straight  (Fig.  5B),  the  distal  third 
curving  sharply  posterodorsally.  The  broad,  flat  plate  on  the  proxi- 
mal end  articulates  with  the  previously  described  concavity  (c  c. 
Fig.  5A)  in  the  interclavicle.  Along  the  ventral  aspect  of  the  distal 


1970  MASSETOGNATHUS    POSTCRANIAL    SKELETON  13 

third  runs  a  flange  (f,  Fig.  5B)  similar  to  that  noted  in  African 
Triassic  cynodonts  (Jenkins,  in  press)  and  Exaeretodon  sp.  (Bona- 
parte, 1963a).  This  flange  continues  to  the  distal  end  where  it 
contributes  to  the  formation  of  a  concavity  (ca,  Fig.  5B)  for  re- 
ception of  the  acromion.  The  clavicle  is  essentially  identical  to 
that  in  galesaurids. 

The  scapula,  coracoid,  and  procoracoid  in  Massetognathiis  pas- 
ciicili  are  firmly  synostosed,  although  the  joints  can  readily  be  dis- 
tinguished (Fig.  6A).  The  scapular  blade,  elongate  and  narrow, 
bears  a  distinct  concavity  on  its  lateral  surface — a  fossa  presumably 
for  the  supracoracoideus  muscle,  the  infraspinatus  homologue  of 
mammals.  The  anterior  margin  of  the  blade  is  reflected  sharply 
laterally,  the  posterior  margin  somewhat  less  so.  An  acromion 
process  as  such  is  not  preserved  on  any  of  the  scapulae;  this  ab- 
sence may  be  due  to  postmortem  damage  to  a  delicate  process  or 
to  the  fact  that  the  clavicular  concavity  simply  fitted  to  the  convex 
edge  of  the  anterior  scapular  base  (ac,  Fig.  6A).  The  scapular 
half  of  the  glenoid  is  a  hemicircular  and  shghtly  convex  facet  that 
faces  posteroventrally  and  somewhat  laterally. 

The  coracoid  is  basically  triangular  in  lateral  view  (co.  Fig.  6A). 
The  posterior  end  forms  an  elongate,  attenuated  process  terminated 
by  a  tubercle  for  the  origin  of  the  coracoid  head  of  the  triceps  (co 
tr,  Fig.  6A ) .  The  process  is  morphologically  similar  to  the  same 
feature  in  Pascualgnathus  pokmskii  and  in  African  Triassic  cyno- 
donts, but  differs  in  form  from  that  in  Exaeretodon  sp.  as  inter- 
preted by  Bonaparte  ( 1963a).  Between  the  glenoid  and  the  triceps 
tubercle,  the  superior  margin  of  the  coracoid  is  about  2  mm  wide 
and  is  slightly  concave  from  front  to  back.  The  slightly  convex 
inferior  margin  is,  in  contrast,  extremely  thin  bone,  and,  as  a  con- 
sequence, is  invariably  damaged  postmortem.  A  saddle-shaped 
facet,  concave  dorsoventrally  and  convex  transversely,  constitutes 
the  coracoid  half  of  the  glenoid. 

The  procoracoid  (pr,  Fig.  6A)  appears  to  be  an  irregularly 
shaped,  flat  plate,  but  in  no  available  specimen  are  the  free  mar- 
gins complete.  There  are  so  many  basic  similarities  in  the  scapu- 
locoracoid  of  Massetognathiis  pascuali  and  African  cynodonts  that 
a  complete  procoracoid  of  the  former  would  probably  have  the 
same  oval  shape  characteristic  of  the  latter.  A  crescentic  depres- 
sion on  the  lateral  aspect  along  the  inferior  margin  may  represent 
the  biceps  origin.  Above  lies  the  round  procoracoid  foramen 
(f  pr.  Fig.  6A)  sculptured  in  a  ventrolateral  direction  to  facilitate 
passage  of  its  nerve  and  blood  vessels.  The  evidence  as  to 
whether  the  procoracoid  participated  in  the  glenoid  is  equivocal.   I 


14 


BREVIORA 


No.   352 


believe  that  the  procoracoid  probably  supported  articular  cartilage 
at  the  very  anterior  extremity  of  the  glenoid  (see  left  glenoid, 
Fig.  6A),  but  there  is  no  certainty  of  the  procoracoid  contribu- 
ting to  the  shoulder  joint  as  there  is  for  some  African  Triassic 
cvnodonts. 


970  MASSETOGNATHUS    POSTCRANIAL    SKELETON  15 


Figure  6.  Elements  of  the  postcranial  skeleton  of  Massetogiuithiis 
pasciiali,  drawn  as  preserved  in  situ.  A,  Incomplete  left  shoulder  girdle  and 
forelimbs  seen  from  the  left  side.  B.  Lateral  view  of  axis.  C,  Dorsal  view 
of  left  humerus.  D,  Medial  view  of  left  radius  and  ulna.  All  X  1.  Ab- 
breviations: ac,  area  of  clavicular  articulation  (distinct  acromion  process 
not  developed);  cl.  clavicle;  co,  coracoid;  co  tr,  tubercle  for  coracoid  head 
of  triceps;  cp.  capitellum;  d,  dens;  d  f.  distal  flange  on  radius;  dp,  delto- 
pectoral  flange;  f  a  a,  atlas  centrum  facet  for  atlas  arch;  f  a  i,  atlas 
centrum  facet  for  atlas  intercentrum;  f  ec,  ectepicondylar  foramen;  f  en, 
entepicondylar  foramen;  f  pr,  procoracoid  foramen;  g,  groove  possibly 
representing  teres  major  insertion  or  the  origin  of  one  of  the  humeral 
triceps  heads;  h,  humeral  head;  hu,  humerus;  1,  ridge  possibly  representing 
insertion  of  the  teres  minor;  1  t,  lesser  tuberosity;  p  f,  proximal  flange  on 
radius;  pr.  procoracoid;  ra,  radius;  s,  scapula;  ul,  ulna;  ul  f,  ulnar  flange. 


16  BREVIORA  No.    352 

Forelimb 

Principal  characteristics  of  the  humerus  of  Massetognathus  pas- 
ciuili  are  the  relatively  broad  expansion  of  the  proximal  and  distal 
ends,  and  the  large  deltopectoral  flange.  The  proximal  end  of  the 
shaft  is  bowed  dorsally  and  the  head  is  oriented  to  a  more  dorsal 
position.  The  well-rounded  head  (h,  Fig.  6C)  possesses  greatest 
curvature  along  its  dorsoventral  axis.  As  preserved,  the  articular 
surface  is  confluent  medially  whh  the  lesser  tuberosity  (1  t,  Fig. 
6C)  and  laterally  with  the  proximal  margin  of  the  deltopectoral 
flange.  The  greater  tuberosity  presumably  arose  in  the  mammalian 
lineage  between  the  head  and  the  proximal  margin  of  the  delto- 
pectoral crest,  but  in  M.  pasciiali  there  is  no  evidence  of  a  distinct 
tubercle.  The  greatest  width  of  the  proximal  end,  from  the  lesser 
tuberosity  to  the  region  of  the  presumptive  greater  tuberosity, 
measures  approximately  one-third  the  total  length  of  the  humerus. 
The  broad  deltopectoral  flange  is  slightly  more  than  half  the  total 
length  of  the  humerus.  The  free  edge  of  the  flange  thickens  and 
everts  (laterally)  at  its  proximal  and  distal  extremities,  but  along 
the  middle  part  is  rather  thin  and  flat.  From  the  region  of  the  pre- 
sumptive greater  tuberosity  a  low,  bony  ridge  runs  obliquely  across 
the  flange  toward  the  shaft  (1,  Fig.  6C).  An  identical  ridge  on  the 
humeri  of  certain  African  Triassic  cynodonts  has  been  interpreted 
as  possibly  representing  the  insertion  of  a  teres  minor  (Jenkins,  in 
press).  On  the  posterodorsal  aspect  of  the  shaft  is  a  groove  pos- 
sibly representing  the  insertion  of  the  teres  major  or  the  origin  of 
one  of  the  humeral  triceps  heads  (g.  Fig.  6C);  Bonaparte  ( 1966b) 
interpreted  a  rugosity  at  this  site  in  Pascualgnathus  polcmskii  as  the 
origin  of  the  medial  triceps  head. 

The  distal  end  of  the  humerus  is  triangular  in  dorsal  view,  its 
maximum  breadth  being  approximately  40  per  cent  of  the  humeral 
length.  Arising  from  the  robust  ectepicondylar  region,  a  thin  supra- 
condylar flange  runs  proximally  as  well  as  somewhat  dorsally.  The 
flange,  pierced  in  its  proximal  half  by  a  small  ectepicondylar  fora- 
men (f  ec,  Fig.  6A,  C),  becomes  a  low  crest  at  the  middle  of  the 
shaft  and  is  continuous  with  the  ridge  (1,  Fig.  6C)  described  above. 
A  stout  bar  of  bone  arising  from  the  entepicondylar  region  encloses 
an  elongate,  oval  entepicondylar  foramen  (f  en.  Fig.  6A,  C).  The 
capitellum  (cp,  Fig.  6A)  is  bulbous  and  contributes  to  the  thick- 
ness of  the  ectepicondylar  region.  The  trochlea  immediately 
adjacent  is  a  broad,  shallow  groove;  the  principal  axis  of  this 
groove  is  dorsoventral,  as  expected,  but  it  is  also  slightly 
oblique — the  dorsal  part  being  more  laterally  situated  than  the 


1970      MASSETOGNATHUS  POSTCRANIAL  SKELETON         17 

ventral  part.  Morphologically,  the  humerus  of  M.  pasciudi  is  essen- 
tially identical  to  that  in  Pasciuil^naihus  polcmskii  and  galesaurids; 
apparent  differences  with  galesaurids,  e.g.,  the  greater  roundness 
of  the  head  and  capitellum,  are  due  to  the  better  ossification  in 
M.  pascuali  and  P.  polcmskii.  As  Bonaparte  (1963a)  noted,  the 
humerus  of  Exaeretodon  sp.  is  more  similar  to  the  dicynodont 
or  gorgonopsid  pattern  than  to  that  typical  of  galesaurids,  and 
thus  stands  in  contrast  to  the  conventional  cynodont  humerus  of 
M.  pascuali. 

The  radius  has  a  slight  sigmoidal  curvature  (which  facilitates  its 
crossing  over  the  anterior  aspect  of  the  ulna)  and  expanded  proxi- 
mal and  distal  ends.  The  nearly  circular  proximal  articular  facet 
forms  a  shallow  concavity,  in  which  the  greatest  curvature  is  an- 
teroposterior (as  is  its  reciprocal  surface  on  the  capitellum).  On 
the  posteromedial  aspect  of  the  proximal  end  is  an  excrescence  that 
bears  a  facet  (f  u.  Fig.  6D)  apparently  for  articulation  with  the 
ulna.  From  this  excrescence,  a  distinct  flange  (p  f.  Fig.  6D)  runs 
distally  to  about  the  midpoint  of  the  shaft.  On  better  preserved 
material  of  African  Triassic  cynodonts,  I  interpreted  a  similar 
flange  as  possibly  being  associated  with  the  biceps  insertion  and 
the  radio-ulnar  interosseous  ligament  (Jenkins,  in  press).  Bona- 
parte (1963a)  interpreted  a  similar  feature  in  Exaeretodon  sp.  as 
marking  the  position  of  the  interosseous  ligament.  The  distal  end 
of  the  radius  expands  gradually  to  the  distal  articular  facet  which 
is  oval  (long  axis  transverse)  and  shallowly  concave.  A  distal 
flange  ( d  f.  Fig.  6D )  arises  near  the  midpoint  of  the  shaft  essen- 
tially as  a  continuation  of  the  attenuating  proximal  flange  described 
above.  Beginning  on  the  posterior  aspect  of  the  shaft,  the  distal 
flange  takes  a  spiral  course  toward  the  lateral  aspect  as  it  enlarges 
distally.  Its  position  is  suggestive  of  the  attachment  of  an  inter- 
muscular septum  separating  flexor  and  extensor  muscle  groups. 

The  ulna,  like  the  radius,  is  sigmoidally  shaped  but  is  expanded 
only  at  its  proximal  end  (Fig.  6D).  The  relatively  shallow  semi- 
lunar notch  represents  the  typical  cynodont  condition — basically 
oval  in  outline,  but  with  a  rather  straight  medial  margin  and  a 
nearly  hemicircular  lateral  margin.  An  olecranon  process  is  not 
present  or  at  least  was  not  ossified;  the  proximal  end  of  the  ulna, 
where  such  a  process  would  be  developed,  is  broad  and  rugose. 
The  transversely  narrow  shaft  of  the  ulna  bears  on  its  anteromedial 
aspect  a  flange  (ul  f.  Fig.  6D)  that  extends  from  the  semilunar 
notch  to  the  distal  articular  facet.  In  all  probability  this  flange  rep- 
resents the  ulnar  attachment  of  the  interosseous  ligament.  The 
lateral  surface  of  the  shaft  reveals  one  large,  spoon-shaped  fossa 
proximally,  and  on  the  medial  surface  two  fossae,  one  proximal, 
the  other  distal.    All  three  fossae  are  wefl  represented  in  African 


18  BREVIORA  No.    352 

Triassic  cynodonts,  and  I  have  proposed  (Jenkins,  in  press)  that 
they  represent  origins  of  various  manual  flexor  and  extensor  mus- 
cles. The  distal  articular  facet,  convex  from  front  to  back,  is  broad 
anteriorly  and  narrow  posteriorly  and  thus  is  triangular  in  outline. 
Both  the  radius  and  ulna  of  M.  pascuali,  as  far  as  available  mate- 
rial permits  comparison,  are  extremely  similar  to  their  counterparts 
among  galesaurids  and  in  Pascualgnathus  polanskii.  Although 
definite  similarities  exist  with  the  antebrachial  elements  of  Exaere- 
todon  sp.,  the  essential  identity  of  the  M.  /7<;/.vcwa//-galesaurid  pat- 
tern is  incontrovertible. 

Only  an  incomplete  and  disarticulated  series  of  seven  or  eight 
carpals  of  Massetognathus  pascuali  is  known,  but  these  are  so 
poorly  preserved,  and  good  comparative  material  is  so  scanty,  that 
no  constructive  observations  on  the  manus  can  be  made  at  this 
time. 

Pelvis 

A  complete  pelvis  of  Massetognathus  pascuali  is  not  yet  avail- 
able, although  enough  is  known  of  the  ilium  and  ischium  for  pre- 
liminary description  and  comparison  with  other  forms.  The  ilium 
bears  an  elongate,  vertical  blade,  spatulate  in  front  and  lanceolate 
behind  (il.  Fig.  2).  The  lateral  aspect  of  the  blade  is  concave, 
especially  anteriorly.  The  shape  of  blade,  as  well  as  the  relative 
proportions  of  the  pre-  and  postacetabular  regions,  is  most  similar 
to  that  in  Pascualgnathus  polanskii  and  is  comparable  to  that  of 
galesaurids,  cynognathids,  and  diademodontids;  Exaeretodon  sp., 
on  the  other  hand,  has  an  iliac  blade  quite  unlike  the  foregoing 
(Bonaparte,  1963a).  The  base  of  the  iliac  blade  in  M.  pascuali  is 
constricted  into  a  short  neck,  below  which  are  medial  and  lateral 
processes.  The  medial  process  (m  p.  Fig.  2B)  bears  two  articular 
surfaces — one  each  for  the  pubis  and  ischium — which  intersect  at 
an  angle  of  about  150°.  The  lateral  process  bears  a  nearly  circular, 
concave  facet  that  represents  the  iliac  contribution  to  the  acetabu- 
lum (a  il.  Fig.  2B).  The  facet  is  oriented  principally  in  a  postero- 
ventral  direction  but  with  a  slight  lateral  eversion. 

Only  the  dorsal  half  of  the  ischium  is  available  for  examination 
(is.  Fig.  2).  The  concave  acetabular  surface  faces  anterolaterally 
and  is  oriented  essentially  vertically.  The  postacetabular  part  of  the 
ischium  constitutes  a  broad  plate  that  ventrally  meets  its  counter- 
part of  the  opposite  side.  A  longitudinal  groove  (gr.  Fig.  2)  on 
the  dorsal  margin  of  this  plate  terminates  posteriorly  at  an  ischial 
tuberosity  (is  t.  Fig.  2). 

Available  pubes  have  been  extensively  damaged  postmortem. 


970 


MASSETOGNATHUS  POSTCRANIAL  SKELETON 


19 


The  pubic  contribution  to  the  acetabulum  is  considerably  smaller 
than  that  of  the  ischium.  Neither  the  obturator  fenestra  nor  the 
ventral  aspect  of  the  pelvic  basin  is  preserved. 

The  bony  acetabulum  is  relatively  shallow — a  little  more  than 
5  mm  deep.  The  continuous,  sharp  rim  around  the  acetabulum  de- 
fines a  more  circular  socket  than  that  known  in  African  Triassic 
genera.  In  all  other  details,  the  pelvis  of  Massetognathus  pasciiali 
appears  to  be  morphologically  similar  to  that  in  Pascualgnathus 
polanskii,  galesaurids,  and  even  larger  African  Triassic  forms. 

Hindlimb 

The  femur  (Figs.  7,  8A)  is  a  moderately  slender  bone,  except 
for  the  expanded  proximal  end,  which  bears  robust  trochanters. 
The  femoral  head,  bulbous  and  almost  hemispherical  as  in  mam- 
mals, is  reflected  medially  but  also  somewhat  dorsally  by  virtue  of 
the  dorsal  bowing  of  the  proximal  end  of  the  shaft  (Fig.  8 A ) .  The 
protuberant  trochanter  major  (tr  mj,  Figs.  7,  8A)  measures  about 
5  mm  in  thickness.  A  pear-shaped  area  of  smooth  bone  on  its  apex 
may  represent  the  principal  site  of  muscle  attachment  or  of  a  sub- 
tendinous bursa.  The  bone  surface  immediately  adjacent  to  the 
apex  is  rugose.  The  trochanter  minor  (tr  mn.  Figs.  7,  8A)  forms 
an  elongate  flange  that  arises  abruptly  near  the  intertrochanteric 


tr  mj 


tr  mn   tr  mn 


tr  mj 


Figure  7.  Reconstruction  of  a  left  femur  in  Massetognathus  pasciiali 
in  A,  ventral,  and  B,  dorsal  views.  X  1.  Abbreviations:  i  f.  intertrochanteric 
fossa;  tr  mj.  trochanter  major:  tr  mn.  trochanter  minor. 


20 


BREVIORA 


No.   352 


fossa  (i  f.  Fig.  7)  and  gradually  disappears  slightly  distal  to  the 
shaft's  midpoint.  In  cross-section,  the  middle  of  the  shaft  is  essen- 
tially rectangular;  its  thickness  from  extensor  (dorsal)  to  flexor 
(ventral)  surfaces  is  about  6  mm,  from  the  medial  to  lateral  sur- 
faces 4.5  mm.  The  distal  end  of  the  femur  expands  gradually  but 
asymmetrically,  the  lateral  condyle  being  broader  and  farther  offset 
from  the  femoral  axis  than  the  medial.  The  medial  condyle  pro- 
jects more  ventrally  than  does  the  lateral  condyle.  The  fibula  ap- 
pears to  have  articulated  on  the  lateral  epicondylar  region  where  a 
shallow  groove  (f  f,  Fig.  8A)  occurs.  The  femur  of  Massetog- 
nathus  pascuoli  is  morphologically  comparable  to  the  femora  of 
Pascualgnathus  pokmskii  and  even  the  larger  African  genera  in 
which  ossification  of  the  extremities  was  well  developed  (Jenkins, 
in  press).  In  smaller  forms,  such  as  galesaurids,  the  femur  appears 
to  be  diiTerent  because  of  the  lack  of  ossification  of  the  extremities 
and  trochanters. 

The  tibia  is  a  transversely  slender  bone,  bowed  somewhat  an- 
teriorly. The  two  proximal  articular  facets,  oval  in  outline  and 
shallowly  concave,  are  separated  by  a  low,  median  ridge.    The 


B 


Figure  8.  Elements  of  the  hindlimb  of  Massetognathiis  pascuoli.  drawn 
as  preserved  in  situ.  A.  Right  femur,  tibia  and  fibula  in  lateral  view.  B. 
Left  tibia  in  medial  view.  All  X  1.  Abbreviations:  f  f.  facet  for  articula- 
tion with  fibula;  fl,  fibular  flange  for  femoral  articulation;  f  t,  lateral  tibial 
fossa  of  uncertain  significance;  g  t,  groove  on  medial  aspect  of  tibia;  1  t. 
lineation  on  lateral  aspect  of  tibia;  tr  mj,  trochanter  major;  tr  mn. 
trochanter  minor. 


1970  MASSETOGNATHUS    POSTCRANIAL    SKELETON  21 

lateral  margin  of  the  lateral  facet  is  thickened  and  protuberant,  and 
it  appears  likely  that  part  of  the  proximal  fibula  articulated  here. 
On  the  proximal  end  of  the  lateral  aspect  of  the  shaft  is  a  deep 
fossa  (f  t,  Fig.  8A)  of  uncertain  significance;  from  the  posterior 
margin  of  this  fossa  a  faint  lineation  (1  t.  Fig.  8A)  runs  obliquely 
across  the  shaft  to  merge  with  the  narrow  anterior  margin  of  the 
shaft.  Also  of  uncertain  significance  is  a  slightly  curved  groove 
(g  t.  Fig.  8B)  along  the  middle  of  the  shaft's  medial  aspect.  The 
distal  extremity  of  the  tibia  has  a  marked  lateral  expansion  that 
sufficiently  widens  at  the  terminus  to  accommodate  a  broad, 
slightly  convex  facet  for  the  astragalus. 

The  fibula,  a  very  slender-shafted  bone  with  enlarged  extremi- 
ties, is  bowed  laterally.  The  shaft  appears  to  have  been  wider 
transversely  than  anteroposteriorly.  On  the  one  complete  speci- 
men, a  shallow  groove  running  the  length  of  the  shaft  along  its 
medial  aspect  can  be  detected.  A  flange  on  the  proximal  end 
(fl.  Fig.  8A)  probably  contacted  a  groove  on  the  lateral  epicon- 
dylar  region  of  the  femur;  the  remainder  of  the  proximal  fibula 
articulated  with  the  tibia.  The  distal  end,  like  the  proximal,  broad- 
ens anteroposteriorly  and  is  inflected  somewhat  medially.  All 
features  of  both  tibia  and  fibula  found  in  MassetognatJius  pascuali 
are  duplicated  in  galesaurids  and  even  in  the  larger  African  Triassic 
genera.  The  tibia  and  fibula  of  Exaeretodon  sp.,  by  contrast,  de- 
part from  the  uniform  pattern  of  other  cynodonts  by  being  pro- 
portionally more  massive. 

Nothing  can  be  described  of  the  pes  of  Massetognathus  pascuali 
from  the  available  material. 

Discussion 

Massetognathus  pascuali,  about  50  cm  in  length  from  head  to 
tail,  was  a  cynodont  of  relatively  slender  build  (Fig.  9).  The  short- 
ness of  the  limbs  relative  to  the  approximated  trunk  length  gives 
the  body  a  "low-slung"  appearance.  The  head  seems  dispropor- 
tionately large  for  the  body,  but  a  relatively  massive  head  is  a 
common  cynodont  characteristic. 

The  postcranial  skeleton  of  Massetognathus  pascuali  is  basically 
like  that  in  galesaurids,  diademodontids,  cynognathids  and  Pas- 
cualgnathus  polanskii.  Limited  morphological  diversity  appears  to 
be  the  rule  for  the  postcranial  skeletons  of  Triassic  cynodonts. 
Exaeretodon,  however,  is  an  exception;  the  postcranial  skeleton  in 
this  genus  differs  in  major  details  from  the  pattern  characteristic 
of  other  Triassic  cynodonts.  Bonaparte  (1963a)  recognized  post- 
cranial specializations  in  his  original  description  and  implied  that 


22 


BREVIORA 


No.  352 


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1970      MASSETOGNATHUS  POSTCRANIAL  SKELETON         23 

similar  features  might  also  be  characteristic  of  other  traversodon- 
tids.  From  similarities  between  the  genera  Exaeretodon  and  Lea- 
vachia,  Bonaparte  further  inferred  that  traversodontids  possibly 
evolved  from  procynosuchids  in  a  lineage  separate  from  that  giving 
rise  to  other  cynodont  families.  These  conclusions,  credible  on 
evidence  available  in  1963,  now  require  modification,  because 
P.  polanskii  and  M.  pasciiali  demonstrate  that  Exaeretodon  is  a 
specialized  traversodontid.  Such  specialization  is  not  surprising  in 
view  of  the  fact  that  this  genus  lived  later  in  the  Triassic  than  any 
form  with  which  it  has  been  compared.  Limb  bones  in  Exaereto- 
don sp.  are  more  robust  than  in  other  cynodonts  (Fig.  10),  no 
doubt  in  relation  to  its  unusually  large  size.  Some  Exaeretodon 
features  are  unknown  in  other  cynodonts.  For  example,  a  deep, 
sagittal  keel  occurs  on  an  unusually  short  interclavicle;  an  extra 
trochanteric  process  runs  distally  from  the  trochanter  major  along 
the  ventral  aspect  of  the  femur  (Bonaparte,  1963a;  a  similar 
process,  identified  as  a  trochanter  minor  by  Parrington  (1961),  is 
known  in  a  whaitsid  therocephalian  and  in  a  scaloposaurid  bauri- 
amorph).  Furthermore,  the  lack  of  rib  specialization  is  a  unique 
feature  for  a  Triassic  cynodont.  Thus,  as  a  specialized  traverso- 
dontid, Exaeretodon  is  no  longer  as  relevant  to  the  problem  of 
traversodontid  origins  as  it  was  when  other  traversodontid  genera 
were  poorly  known. 

Two  facts  bear  on  the  problem  of  traversodontid  origins.  First, 
morphological  similarities  between  the  postcranial  skeletons  of 
Massetognathus  pasciiali,  Pasciialgnathiis  polanskii,  and  African 
Triassic  cynodonts  are  evidence  of  close  phylogenetic  relationship. 
Similarities  between  the  skull  and  specialized  ribs  of  P.  polanskii 
and  Diadeinodon  (see  Bonaparte  1966b)  raise  the  likelihood  that 
traversodontids  and  diademodontids  were  derived  from  a  common 
stock.  Second,  the  paucity  of  information  available  on  the  pro- 
cynosuchid  postcranial  skeleton  does  not  appear  to  be  useful  in 
evaluating  relationships  with  other  cynodont  families.  Bonaparte 
( 1963a)  compared  the  postcranial  morphology  of  Exaeretodon  sp. 
and  Leavachia  duvenhagei  and  on  this  basis  suggested  the  possibility 
that  traversodontids  and  procynosuchids  were  directly  related.  The 
difficulty  of  this  approach  may  be  illustrated  with  respect  to  the 
forelimb  in  which,  for  example,  Bonaparte  noted  similarity  between 
the  radius  and  ulna  of  Exaeretodon  sp.  and  L.  duvenhagei.  The 
radius  and  ulna  of  E.  duvenhagei  are,  in  fact,  poorly  known  and  in 
relative  proportions  do  not  resemble  those  in  Exaeretodon  sp.  more 
than  those  of  African  Triassic  cynodonts  (Fig.  10).  Similarities 
cited  by  Bonaparte  between  the  manus  of  Exaeretodon  sp.  and 


24 


BREVIORA 


No.  352 


1970  MASSETOGNATHUS    POSTCRANIAL    SKELETON  25 


Figure  10.  Diagrammatic  comparison  of  postcranial  bones  in  various 
major  groups  of  cynodonts.  Leavachia,  in  part  modified  from  Broom 
(1948)  and  in  part  drawn  from  stereoscopic  photographs,  represents 
Procynosuchidae.  The  galesaurid  and  cynognathid-diademodontid  pat- 
terns are  taken  from  Jenkins  (in  press);  cynognathids  and  diademodontids 
are  sufficiently  alike  in  their  postcranial  morphology  to  be  represented 
here  by  a  single  pattern.  The  Exaeretodon  material  is  drawn  from  Bona- 
parte (1963b).  All  bones  have  been  reduced  to  a  standard  dimension  to 
illustrate  proportional  differences. 


26  BREVIORA  No.    352 

L.  diivenhagei  are  of  equivocal  significance  in  view  of  the  almost 
total  lack  of  information  on  the  manus  of  other  cynodonts.  Bona- 
parte's contention  that  the  humeri  of  Exaeretodon  sp.  and  L.  dii- 
venhagei are  proportioned  alike  is  valid,  but  the  dissimilarity  to 
those  in  other  cynodonts  is  not  so  great  as  to  make  this  comparison 
especially  significant  (Fig.  10).  Bonaparte  admitted  that  the 
scapulocoracoid  of  Exaeretodon  sp.  is  more  like  that  in  Cynog- 
nathus  sp.  than  that  in  L.  diivenhagei.  This  resemblance,  in  Fig- 
ure 10  at  least,  is  not  particularly  marked,  ahhough  the  speciahzed 
character  of  the  scapulocoracoid  in  Exaeretodon  sp.  is  evident. 
Thus,  comparisons  between  forelimb  features  of  several  cynodont 
families  provide  no  evidence  of  special  affinity  between  traverso- 
dontids  and  procynosuchids. 

The  iliac  blade  of  Massetognathus  pascuali  has  a  long  posterior 
process  like  that  in  African  Triassic  cynodonts  (Fig.  10)  and 
Pascualgnathiis  polanskii.  In  contrast,  the  same  process  in  Exaere- 
todon sp.  is  relatively  short  (Fig.  10),  and  as  a  consequence  the 
blade  as  a  whole  has  a  more  mammahan  shape  (Bonaparte, 
1963a).  The  iliac  blade  in  the  type  of  Leavachia  diivenhagei  ap- 
pears to  have  a  short  posterior  process  (Fig.  10;  Broom,  1948)  but 
also  appears  to  be  somewhat  damaged.  Thus  a  long  posterior 
process  may  have  existed  in  procynosuchids,  and  on  present  evi- 
dence, at  least,  the  ilia  of  Exaeretodon  sp.  and  L.  duvenhagei  do 
not  indicate  special  affinity  between  the  two. 

Bonaparte  (1963a)  cited  the  absence  of  specialized  ribs  in 
Exaeretodon  sp.  and  Leavachia  duvenhagei  as  possible  evidence  of 
a  close  relationship  between  traversodontids  and  procynosuchids. 
The  subsequent  discovery  of  specialized  ribs  in  Massetognathus 
pascuali  and  the  reclassification  of  Pascualgnathiis  polanskii  (which 
has  specialized  ribs  of  the  Diademodon  pattern)  make  this  observa- 
tion no  longer  significant.  It  is  interesting,  however,  that  in  the 
type  of  Leavachia  duvenhagei  (Rubidge  Collection  No.  92,  Graaf 
Reinet,  South  Africa)  the  last  dorsal  rib  appears  to  be  laterally 
oriented  (Fig.  4C),  much  as  in  M.  pascuali  and  in  other  cynodonts 
with  specialized  ribs.  On  the  dorsal  aspect  of  the  shaft  is  a  ridge 
(b,  Fig.  4C)  comparable  in  position  and  orientation  to  a  similar 
ridge  in  M.  pascuali,  cynognathids.  and  diademodontids  (b.  Fig. 
4A,  B).  Furthermore.  Konjukova  (1946)  figured  a  specimen  of 
the  procynosuchid  Permocynodon,  incompletely  prepared  from  the 
ventral  aspect.  The  posterior  dorsal  ribs  are  directed  anterolaterad 
(as  in  Thrinaxodon,  for  example)  and  the  shafts  appear  to  be 
wider  than  those  of  more  anterior  dorsal  ribs.  The  capitular  articu- 
lations of  posterior  dorsal  ribs  in  Permocynodon  are  relatively 
broad,  a  feature  typical  of  cynodonts  in  which  the  posterior  dorsal 


1970  MASSETOGNATHUS    POSTCRANIAL    SKELETON  27 

ribs  are  synostosed.  On  this  incomplete  evidence,  it  appears  pos- 
sible that  rib  specialization  was  already  underway  in  procyno- 
suchids  and  was  further  modified  in  the  various  cynodont  families 
descended  from  them. 

Hopson  and  Crompton  (1969),  in  a  discussion  of  the  origin  of 
mammals,  observe  that  galesaurids  such  as  Thrinaxodon  liorhinus 
would  be  ideal  candidates  for  mammalian  ancestors  were  it  not  for 
the  presence  of  specialized  ribs.  These  authors  suggest  that  Exaere- 
todon  is  relevant  to  this  problem  because  its  nonspecialized  ribs 
may  represent  a  reversion  from  a  specialized  pattern,  and  similar 
trends  may  have  occurred  in  galesaurids.  There  is  now  substantial 
evidence  favoring  the  view  that  rib  specialization  was  gradually  lost 
in  traversodontids.  P.  polanskii,  the  earliest  traversodontid  for 
which  ribs  are  known,  has  a  costal  morphology  of  a  Diadeinodon 
pattern.  M.  pascuali,  temporally  intermediate  between  P.  polanskii 
and  Exaeretodon  sp.,  has  ribs  with  less  extensive  specialization. 
Thus  the  ribs  of  Exaeretodon  sp.  apparently  represent  a  reversion 
to  a  nonspecialized  condition,  and  are  not  primitively  nonspecial- 
ized as  originally  suggested  by  Bonaparte  (1963a).  That  such  a 
loss  occurred  in  one  family  of  cynodonts  increases  the  possibility 
that  a  similar  reversion  occurred  in  advanced  galesaurids — or  their 
descendants — during  the  reptile-mammal  transition. 

ACKNOWLEDGMENTS 

I  am  grateful  to  Professor  Alfred  S.  Romer  of  Harvard  Univer- 
sity for  enabling  me  to  participate  in  the  Chanares  faunal  studies. 
Professor  Romer,  together  with  Professor  Rosendo  Pascual,  Uni- 
versidad  de  la  Plata  (Argentina),  generously  consented  to  my  re- 
quest to  describe  Massetognathus  pascuali  as  a  sequel  to  my  work 
on  African  cynodonts.  Professor  Romer  furthermore  provided 
preparational  facilities  and  staff,  skillfully  supervised  by  Mr.  Arnold 
D.  Lewis,  with  the  result  that  the  material  was  presented  to  me  in 
excellent  condition.  Dr.  Jose  F.  Bonaparte  of  the  Institute  Miguel 
Lillo  de  Tucuman  (Argentina)  kindly  read  the  manuscript  and 
clarified  several  important  points  of  cynodont  anatomy  and  rela- 
tionships. Figures  6  and  8  were  prepared  by  Mr.  Robert  J. 
Demarest.  I  thank  Dr.  James  A.  Hopson  of  the  University  of 
Chicago  for  making  available  his  collection  of  stereoscopic  photo- 
graphs of  Traversodon,  and  Dr.  James  Kitching  of  the  Bernard 
Price  Institute  for  Palaeontological  Research  (Johannesburg)  for 
verifying  some  features  on  a  specimen  of  Leavachia. 

The  collection  of  the  Chanares  material  was  aided  by  National 
Science  Foundation  Grant  GB-2454;  preparation  and  publication 
of  the  results  has  been  supported  by  grants  GB-46 1 5  and  GB-8 171. 


28  BREVIORA  No.    352 

LITERATURE    CITED 

Bonaparte,    J.    F.      1963a.     Descripcion    del    esqueleto    postcraneano    de 

Exaeretodon.    Acta   Geol.    Lilloana,  4:    5-52. 
1963b.     La  familia  Traversodontidae.   Acta  Geol.    Lilloana, 

4:   163-194. 
1966a.     Sobre   nuevos   terapsidos   Triasicos   hallados  en  el 


centro  de  la  Provincia  de  Mendoza,  Argentina.    Acta  Geol.    Lilloana. 
8:   91-100. 
1966b.     Una   niieva   "fauna"   Triasica   de   Argentina    (The- 


rapsida:    Cynodontia,    Dicyncdontia)    consideraciones    filogeneticas    y 
paleobiogeograficas.    Ameghiniana,  4:    243-296. 
1967.     Los  tetrapodos  Triasicos  de  Argentina.    First  Inter- 


national   Symposium    on    Gondwana    Stratigraphy    and    Paleontology, 

Mar  del  Plata. 
Brink,  A.  S.      1955.     A  study  on  the  skeleton  of  Diculenwdon.    Palaeont. 

Afr..  3:    3-39. 
Broom,    R.      1948.     A   contribution   to  our  knowledge   of  the  vertebrates 

of  the  Karroo  Beds  of  South  Africa.    Trans.    Roy.    Soc.    Edinburgh, 

61:   577-629. 
Crompton,  a.  W.      1955.     On  some  Triassic  cynodonts  from  Tanganyika. 

Proc.  Zool.  Soc.  London.  125:  617-669. 
Crompton.  A.  W.,   and  F.  A.  Jenkins,  Jr.     1968.     Molar  occlusion   in 

Late  Triassic  mammals.    Biol.  Rev.,  43:  427-458. 
HoPSON,  J.  A.,  AND  A.  W.  Crompton.      1969.     Origin  of  mammals.   In 

T.    Dobzhansky,   et   ai.    (eds. ),    Evolutionary   Biology,    Vol.    111.   New 

York:    Appleton-Century-Crofts,  pp.    15-72. 
HuENE,  F.  VON.      1935-1942.     Die  fossilien  Reptilien  der  siidamerikanischen 

Gondwanalandes.     Munich,    C.    H.    Beck'sche    Verlagsbuchhandlung, 

332  pp. 
Jenkins,  F.  A.  Jr.     1969.     The  evolution  and  development  of  the  dens  of 

the  mammalian  axis.    Anat.  Rec,  164:    173-184. 
In  press.     The   postcranial  anatomy  of  African   cynodonts 

and   problems   in   the  early  evolution   of  the   mammalian  postcranial 

skeleton.    Bull.  Peabody  Mus.  Nat.  Hist.,  Yale. 
KoNJUKOVA,  E.  D.      1946.     New  data  on  Perniocynodon  siishkiiii  Woodw., 

a  cynodont  member  of  the  Northern  Dvina  fauna.    Dokl.  Akad.  Nauk, 

54:   527-530. 
Parrington,  F.  R.      1961.     The  evolution  of  the  mammalian  femur.    Proc. 

Zool.  Soc.  London.  137:  285-298. 
RoMER,  A.  S.      1967.     The  Chanares   (Argentina)   Triassic  reptile   fauna. 

III.    Two  new  gomphodonts,  Massctogiuttluis  pasciiali  and  M.  teniggii. 

Breviora,  No.  264:    1-25. 
1969.     The   Brazilian  Triassic  cynodont  reptiles  Belesodon 

and  Chiniqiiodoii.    Breviora,  No.  332:   1-16. 
Seeley,    H.    G.     1895.     Researches    on    the    structure,    organization    and 

classification  of  fossil  Reptilia.    Part  IX,  Section  5.    On  the  skeleton  in 

new  Cynodontia  from  the  Karroo  rocks.    Phil.  Trans.  R.  Soc,  Ser.  B, 

186:  59-148. 

(Received  8  January  1970.) 


BREVIORA 


leseiiiini   of   Comtipsirative   Zoology 

Cambridge,  Mass.  10  August,  1970  Number  353 

Anolis  iacare  Boulenger,  a  "solitcry"  anole  from  the  Andes 

of  Venezuela 


Ernest  E.  Williams,^ 
Osvaldo  A.  Reig,!^- 
Pablo  Kiblisky,-  and 
Carlos  Rivero-Blanco'^ 

Abstract.  Anolis  jacare  Boulenger  is  the  sole  member  of  its  genus  in 
the  Andes  of  Merida  in  Venezuela.  In  external  morphology,  size,  and  to 
some  extent  in  behavior,  it  resembles  its  congeners  on  the  one  anole  islands 
of  the  Lesser  Antilles.  The  karyotype  of  A.  jacare.  however,  demonstrates 
that  it  is  not  closely  related  to  either  of  the  two  Lesser  Antillean  stocks 
which  it  resembles  and  these  we  know  not  to  be  closely  related  to  each 
other.  The  similarity  of  A.  jacare  to  the  two  Lesser  Antillean  stocks  and 
of  these  to  each  other  seems  to  be  due  to  selection  for  a  similar  ecological 
type. 


In  1903  Boulenger  described  Anolis  jacare  from  several  speci- 
mens in  a  collection  made  by  S.  Briceno  at  Merida,  Venezuela, 
at  an  elevation  of  1 600  meters.  As  all  too  frequently  happens  in 
Boulenger's  work,  the  description  was  altogether  without  com- 
parison or  note  on  relationship. 

Since  its  description  additional  specimens  have  been  taken,  all 
in  the  Venezuelan  Andes,  but  there  has  been  little  discussion  of  the 
species.      There    has    never   been    any    question    of    its    validity. 


1  Museum  of  Comparative  Zoology.  Harvard  University,  Cambridge,  Mass. 
02138 

2  Institute  de  Zoologia  Tropical,  Universidad  Central  de  Venezuela,  Aptdo. 
59058.  Caracas.    Venezuela 

■=  Jardin  Zoologico  "El  Pinar."  Cota  905,  Caracas,  Venezuela 


BREVIORA 


No.  353 


Schmidt  (1939:  9)  mentioned  a  peculiar  feature  of  the  spscies, 
the  double  row  of  keeled  scales  forming  the  dorsal  caudal  margin. 
This  is  a  feature  which  A.  jacare  shares  with  some  South  American 
species  and  with  the  very  distantly  related  A.  harkeri  of  Mexico. 
In  1960  Etheridge  placed  jacare  in  the  latijrons  series  of  his  alpha 
section  of  the  genus  Anolis.  This  section,  distinguished  by  the 
absence  of  transverse  processes  on  the  caudal  vertebrae,  represents 
an  old  endemic  South  American  stock,  which  today  shares  South 
America  with  more  recent  (beta  section)  invaders  from  Central 
America. 


Figure   1.   Anolis  jacare.    Dorsal  view  of  head.    AMNH    13444. 


No  previous  mention  of  A.  jacare  has  cited  its  most  interesting 
feature:  alone  of  native  South  American  species,  it  shows  a 
close  resemblance  to  West  Indian  species,  specifically  those  of  the 
Lesser  Antilles.  In  fact,  its  resemblance  to  Anolis  leachii,  except 
in  size,  is  such  that  even  an  experienced  student  of  Anolis,  pre- 
sented with  a  specimen  of  jacare  without  locality,  is  very  likely  to 
confuse  it  with  A.  leachii. 

Table  1  compares  A.  jacare  to  A.  leachii  and  to  the  Leeward 
Island  species  more  similar  in  adult  size.  A.  marmoratiis. 

When  A .  jacare  is  closely  examined,  of  course,  there  should  be 
no  real  possibility  of  confusing  it  with  A.  leachii.  The  dorsal 
squamation  of  the  tail,  larger  dewlap,  relatively  larger  ventrals. 
smaller  scales  on  the  snout,  etc.,  permit  easy  recognition  of  v4. 


1970  ANOLIS   JACARE  3 

jacare.  On  general  appearance,  however,  relationship  will  still 
seem  plausible. 

However,  in  terms  of  geography,  close  relationship  of  jacare  of 
the  Andes  of  Venezuela  and  leachii  of  the  northern  Lesser  Antilles 
is  prima  facie  unlikely.  In  addition,  there  is  good  evidence  that 
the  biniaculatus  group  (Gorman  and  Atkins.  1969)  is  derived 
from  the  still  more  distant  Puerto  Rican  stock  and  that  it  is  to  this 
Puerto  Rican  stock  or  a  still  more  primitive  group  that  any  phy- 
letically  meaningful  resemblance  would  be  expected. 

Geographically,  the  roquet  group  in  the  southern  Lesser  Antilles 
would  be  a  little  more  plausible  as  close  relatives  of  jacare  than  the 
biniaculatus  group.  Gorman  and  Atkins  (1969)  have  commented 
on  the  close  external  resemblance  of  the  roquet  and  biniaculatus 
groups.  Earlier,  Underwood  (1959)  was  able  to  find  only  the 
most  trivial  scale  differences  between  the  two  groups.  However, 
on  all  the  characters  by  which  Underwood  was  able  to  separate 
the  roquet  and  bimaculatus  groups,  jacare  fits  the  bimaculatus 
group. 

With  the  eight  Venezuelan  species  geographically  closest,  jacare 
shows  little  similarity.  (None  of  the  eight  appear  to  overlap  the 
distribution  of  jacare  at  all.)  Five  of  the  eight  {chrysolepis, 
auratus,  juscoauratus,  tropidogaster,  biporcatus)  belong  to  the 
beta  division  of  Anolis  (Etheridge,  1960)  and  are  neither  osteo- 
logically  nor  in  squamation  close  to  jacare.  The  three  remaining 
species  {squamulatus,  punctatus,  tigrinus)  are  referred  by 
Etheridge  (1960)  to  the  same  group  as  jacare  (the  latifrons  series 
of  the  alpha  section  of  Anolis).  However,  these  again  show  no 
evidence  of  close  relationship.  Squamulatus  and  tigrinus  are  very 
different  from  jacare  in  size  {squamulatus  a  giant,  tigrinus  a 
dwarf),  and  punctatus  is  conspicuously  specialized  in  the  swollen 
snout  of  the  male.  All  differ  significantly  from  jacare  in  scale 
characters. 

There  are  indeed  no  South  American  or  other  continental 
snecies  to  which  A.  jacare  shows  important  resemblances.  We  are 
left,  therefore,  with  the  external  similarities  to  the  bimacidatus 
species  group  and,  less  marked,  to  the  roquet  species  group.  If 
these  resemblances  go  deeper,  we  appear  to  be  faced  with  a  zoo- 
geographic  puzzle  which  may  need  a  difficult  and  complex  solution. 

It  has  seemed  worthwhile,  therefore,  to  broaden  the  study  of 
A.  jacare  to  include  such  more  recently  utilized  characters  as 
karyotype  and  ecology.  The  remainder  of  this  paper  deals  with 
the  results  of  these  analyses. 


4  BREVIORA  No.    353 

Chromososome  analysis  (O.  A.  Reig  and  P.  Kiblisky): 

Four  male  and  three  female  individuals  have  been  worked  for 
chromosome  analysis.  Our  report  is  based  on  the  four  male 
individuals.  We  failed  to  get  results  with  one  of  the  females,  and 
the  other  two  were  sent  to  Dr.  George  Gorman,  who,  by  the  use 
of  a  blood  culture  microtechnique,  obtained  a  chromosome  count 
agreeing  with  our  results  ( personal  communication ) .  The  male 
specimens  have  been  deposited  in  the  Collection  of  Herpetology 
of  the  Museum  of  Natural  History  of  Caracas  (MCNC  5601- 
5604).  Those  studied  by  Dr.  George  Gorman  are  in  the  Museum 
of  Vertebrate  Zoology,  University  of  California. 

Our  animals  were  injected  with  0.5  cc  Colchicine  Merck  (solu- 
tion 5  mg  per  cc )  2-3  hours  before  killing.  Testes  were  re- 
moved, minced  with  scalpel,  and  pretreated  for  20  minutes  in  a 
hypotonic  solution  of  sodium  citrate  0.7%.  The  material  was 
centrifuged  at  800  rpm  and  the  pellet  resuspended  in  3/1  alcohol- 
acetic  fixative.  After  a  new  centrifugation,  the  pellet  was  changed 
to  2/1  fixative.  Spreads  were  obtained  by  air-drying  on  chilled 
slides  or  by  squashing,  then  stained  with  acetolactic  orcein. 
Giemsa  and  Feulgen,  and  mounted  in  Canadian  balsam.  Chromo- 
somes were  observed  with  a  Wild  M-20  microscope,  and  each 
appropriate  metaphase  or  meiotic  prophase  was  recorded  and 
sketched.  Numerous  additional  cells  were  also  counted  and  ob- 
served. Selected  cells  from  those  recorded  were  photographed 
with  high  contrast  Copy  Kodak  film,  and  karyotypes  were  con- 
structed from  enlarged  prints.  A  total  of  50  cells  was  recorded, 
as  listed  below: 


Specimen  Nr.  MCNC  5601 

Specimen  Nr.  MCNC  5602 

Specimen  Nr.  MCNC  5603 

Specimen  Nr.  MCNC  5604 

All   specimens  41  8  1 

Results 

The  diploid  chromosome  complement  of  Anolis  jacare  is  com- 
posed of  32  chromosomes  (Figs.  3  and  4).  Of  them,  12  are 
macrochromosomes  and  20  are  microchromosomes.  The  diaki- 
neses  (Fig.  5  )  show  six  large  bivalents  and  ten  very  small  bivalents. 
Chromosome  number  and  structure  are  identical  in  all  the  studied 
specimens.    The  six  pairs  of  macrochromosomes  do  not  gradually 


ipermalos^onicd 

i)U'l<iplia\cs 

D 

akineses 

Metaphases  II 

9 

3 

4 

1 

1 

15 

1 

13 

3 

1970  ANOLIS    JACARE  5 

decrease  in  size  but  can  be  divided  into  tliree  groups  (Fig.  I). 
Group  A  is  formed  by  three  pairs  of  large  metacentric  and  sub- 
metacentric chromosomes.  (In  the  following,  we  use  the  nomen- 
clature proposed  by  Levan,  Fregda,  and  Sandberg,  1964.)  Pair 
A-1  comprises  sin  chromosomes,  whereas  pairs  A-2  and  A-3  are 
//^-chromosomes.  Chromosomes  of  pair  B-1  are  around  4/5  the 
length  of  those  of  pair  A-3.  Pairs  B-1  and  B-2  are  easily 
distinguishable  in  size.  Group  C  comprises  one  pair  of  small  si 
chromosomes  (r  =  3.66),  clearly  smaller  than  those  of  pair  B-2 
and  three  times  larger  than  the  largest  chromosome  of  the  set 
of  the  microchromosomes.  A  small  difference  in  size  and  arm 
ratio  was  found  in  the  chromosomes  of  this  pair  in  all  the  cells 
where  the  shape  of  these  chromosomes  was  clear  enough,  so  that 
the  pair  might  tentatively  be  considered  as  heteromorphic. 
Whether  or  not  the  presumptive  heteromorphic  pair  is  to  be 
interpreted  as  an  X-Y  sexual  system  cannot  be  solved  in  the 
absence  of  good  female  metaphases.  In  two  of  the  chromosome 
spreads  obtained  by  Gorman,  the  female  karyotype  also  shows 
heteromorphism  in  this  pair.  Moreover,  the  ring-shaped  form  of 
the  corresponding  bivalent  in  male  diakinesis  does  not  seem  to  fit 
with  the  X-Y  hypothesis.  The  20  pairs  of  microchromosomes 
steadily  decrease  in  size  and  seem  to  have  terminal  (/)  or  sub- 
terminal  (st)  centromeres. 

Gorman  (1965),  Gorman  and  Atkins  (1967,  1968a)  and 
Gorman,  Atkins  and  Holzinger  (1967)  have  demonstrated  that 
a  karyotype  of  six  pairs  of  macrochromosomes  and  twelve  pairs 
of  microchromosomes  is  shared  by  most  of  the  studied  species  of 
iguanid  lizards,  including  the  anoles  of  the  alpha  group  of 
Etheridge  ( 1960)  other  than  those  of  the  bimaculatus  series.  The 
anoles  of  the  beta  group  of  Etheridge  depart  from  this  "standard" 
iguanid  karyotype  in  showing  seven  pairs  of  macrochromosomes 
and  a  variable  number  of  microchromosomes.  Within  the  alpha 
group,  the  species  of  the  bimaculatus  series  known  in  chromosome 
constitution  {bimaculatus,  leachii,  gingivinus,  and  marmoratus) 
(see  Gorman,  1965;  Gorman  and  Atkins,  1966)  are  peculiar  in 
having  quite  another  kind  of  karyotype.  In  these  species  there  is 
no  sharp  distinction  between  macro-  and  microchromosomes. 
There  are  from  18  to  20  chromosomes  gradually  decreasing  in 
size  that  continue  in  five  or  six  pairs  of  dotlike  microchromosomes. 

Anolis  jacare  departs  from  both  the  beta  anoles  and  alpha 
anoles  of  the  bimaculatus  series  in  retaining  the  "standard"  set  of 
six  pairs  of  macrochromosomes,  easily  distinguishable  from   the 


6  BREVIORA  No.    353 

microchromosome  set.  The  morphological  similarities  referred 
to  above  with  members  of  the  bimaculatus  series  are  thus  not 
supported  by  chromosome  evidence,  but  this  evidence  agrees  with 
the  osteological  evidence  in  indicating  that  this  species  belongs  to 
the  alpha  group.  Within  the  non-biinaculatus  series  alpha  anoles 
so  far  known  in  chromosome  structure,  however,  a  considerable 
variation  occurs  in  details  of  structure  of  the  macrochromosome 
set  and  in  the  number  of  microchromosomes.  Anolis  roquet, 
equestris,  carolinensis,  and  cybotes  are  different  from  Anolis  jacare 
in  showing  22  or  24  microchromosomes  and  a  steady  decrease  in 
size  of  the  macrochromosomes,  the  only  distinguishable  break  in 
size  in  these  being  between  the  fifth  and  the  sixth  pairs.  Anolis 
cooki,  pulchellus,  cristatellus  and  scriptus  of  the  cristatellus  series 
(Gorman,  Thomas,  and  Atkins,  1968)  show  the  two  sharp  breaks 
in  the  macrochromosomes  that  are  also  observed  in  A.  jacare,  but 
in  them  the  second  break  falls  between  the  fourth  and  the  fifth 
pairs  instead  of  between  the  fifth  and  the  sixth  pairs  as  in  A.  jacare. 
In  addition,  those  species  of  the  cristatellus  series  mentioned  above 
have  heteromorphic  sex  chromosomes  and  only  from  15  to  18 
microchromosomes.  A.  trinitatis  and  A.  aeneus  of  the  primitive 
latijrons  series  agree  with  A.  jacare  in  the  two  size  discontinuities 
among  the  macrochromosomes.  They  have,  however,  24  and  22 
microchromosomes  respectively,  and  the  first  break  in  the  macro- 
chromosomes falls  between  the  second  and  the  third  pair.  More- 
over, the  first  pair  of  macrochromosomes  is  metacentric  in  all  the 
illustrated  karyotypes  of  alpha  anoles,  whereas  it  is  submetacentric 
in  A.  jacare. 

Anolis  jacare  thus  seems  to  be  an  isolated  species  within  the 
alpha  group  on  the  basis  of  the  pattern  of  the  size  discontinuities 
among  the  macrochromosomes  and  the  unique  number  of  20 
microchromosomes.  It  is  suggestive  that  a  distinction  of  three 
groups  within  the  macrochromosomes  falling  in  the  same  order  as 
in  A.  jacare  can  also  be  observed  in  the  species  of  the  beta  anoles 
of  the  grahami  and  chrysolepis  series  so  far  reported  (Gorman, 
1965;  Gorman  and  Atkins,  1967).  There  is,  however,  a  sharp 
difference  between  the  macrochromosome  set  of  these  species  and 
that  of  A.  jacare:  in  the  former  the  group  C  comprises  two  pairs 
instead  of  one  pair  as  in  the  latter,  the  number  of  pairs  of  macro- 
chromosomes thus  amounting  to  a  total  of  seven,  as  in  all  of  the 
beta  anoles. 


1970  ANOLIS    JACARE  7 

Given  the  widespread  occurrence  of  six  pairs  of  macrochromo- 
somes  in  alpha  anoles  and  most  iguanids,  we  are  inclined  to  evalu- 
ate differences  in  number  of  the  macrochromosome  set  as  more 
important  than  structural  rearrangements  within  this  portion  of  the 
karyotype.  For  this  reason,  and  because  A.  jcicare  is  clearly  an 
aipha  Anolis  on  ostcological  grounds,  the  similarities  it  shows  with 
some  of  the  beta  anoles  in  chromosome  structure  are  better  in- 
terpreted as  a  departure  from  the  "standard"  iguanid  karyotype 
that  converged  with  some  of  the  modifications  shown  in  the  anoles 
of  the  grahami  and  chrysolepis  series.  Admittedly,  the  amount 
of  this  convergence  may  be  considerable.  It  would  be  possible  to 
derive  the  karyotype  of  A.  jacare  from  that  of  A.  chrysolepis  by 
centromeric  fissions  in  the  last  pair  of  macrochromosomes  of  the 
latter,  leading  to  two  pairs  of  microchromosomes  with  terminal 
centromeres.  This  process  would  result  in  a  complement  with 
six  pairs  of  macrochromosomes  separable  into  three  distinct 
groups,  and  in  ten  pairs  of  microchromosomes,  exactly  as  in  /I. 
jacare.  The  osteological  evidence,  however,  does  not  support  any 
close  relationships  between  these  two  species. 

The  chromosome  analysis  thus  indicates  that  Anolis  jacare  is  an 
alpha  Anolis  that  has  departed  significantly  from  other  members 
of  this  group  in  chromosome  number  and  structure,  though  main- 
taining the  standard  iguanid  karyotypic  feature  of  six  pairs  of 
macrochromosomes. 
Observations  in  life  (C.  Rivero-Blanco  and  E.  E.  Williams): 

Since  no  information  of  any  ecological  sort  had  ever  been  pro- 
vided for  Anolis  jacare,  it  was  as  important  an  objective  of  the 
expedition  to  Merida  to  provide  this  information  as  to  obtain 
chromosome  data. 

Only  twelve  anoles  were  collected  during  a  period  of  three  days 
of  active  search.  All  were  obtained  on  medium  and  large-sized 
trees  bordering  the  small  Rio  Milla  just  outside  the  city  of  Merida 
(1639  meters  above  sea  level).  Several  other  areas  within  and 
outside  the  city  of  Merida  were  carefully  examined. 

The  general  area  is  classified  as  Premontane  Humid  Forest  in 
the  scheme  of  L.  R.  Holdridge  (J.  J.  Ewel  and  A.  Madriz.  1968). 
The  mean  annual  temperature  is  19.1°  C  and  the  annual  rainfall 
1791  mm. 

The  two  actual  collection  sites  (Fig.  2)  were  roadside  localities 
and  were  subject  to  more  or  less  penetration  by  the  sun,  especially 
so  in  site  1  where  trees  were  partly  separated,  less  so  in  site  2 
where  the  canopy  was  closed.     In  the  first  site,  the  anoles  were 


8 


BREVIORA 


No.  353 


seen  and  collected  on  the  branches  of  "majagua"  (Heliocarpus 
popoyensis,  Tiliaceae)  and  "guamo"  {Inga  sp.,  Leguminosae),  at 
the  second  on  "anime"  {Montanea  quadrangularis,  Compositae) 
and  on  a  very  large  tree  10-15  meters  high,  not  identified,  since 
leaves  and  flowers  were  not  collected. 


Figure   2.   Map   of  the   collecting   sites  for   A  nulls  jacarc  along   the   Rio 
Milia  outside  Merida. 


Collecting  was  done  with  the  aid  of  a  5  meter  long  telescopic 
fishing  rod  with  a  nylon  noose.  The  animals  were  not  shy  but 
avoided  the  noose  by  moving  around  the  branch  or  further  along 
the  branch  or  to  other  branches  along  the  trunk  or  out  on  the  finer 
twigs.     Two  escaped  high  into  the  canopy;  others  did  not  move  at 


1970  ANOLIS    JACARE  9 

all.    The  number  of  animals  seen  varied  from  none  on  many  trees 
to  four  on  one  guamo  tree.     Few  of  those  seen  escaped  the  noose. 

We  have  no  belief  that  we  have  even  the  beginning  of  knowledge 
of  the  population  density  of  this  species.  The  animals  were  difficult 
to  see  and  commonly  lay  along  branches,  and  only  twice  were 
they  seen  on  the  main  trunk  of  the  trees.  They  obviously  ranged 
widely  within  the  trees  they  inhabited,  including  very  high  in  the 
crown.  The  first  specimen  taken  came  from  a  guamo  tree  that 
was  examined  several  times  every  day  and  even  one  night.  It  was 
this  tree  that,  on  the  last  afternoon,  provided  three  additional  ani- 
mals to  give  a  final  result  of  two  males  and  two  females  on  a 
tree  no  more  than  six  meters  high  and  not  especially  complex. 
This  result  was  possible  only  because,  during  the  last  afternoon, 
we  had  the  help  of  a  young  local  boy  who  was  an  excellent  climber 
and  who  was  able  to  spot  from  a  higher  position  animals  that  could 
not  be  seen  from  below  because  of  their  resting  position  on 
branches. 

In  summary,  this  is  an  animal  inhabiting  primarily  the  crown 
and  its  branches,  though  not  avoiding  the  trunk.  It  is  not  re- 
stricted to  shade;  several  individuals  seen  were  in  partial  sun  or 
moved  into  sun  without  reluctance.  It  has  no  evident  competitors. 
No  other  lizards  were  seen  in  the  collecting  area  either  on  the 
trees  or  on  the  ground.  Elsewhere  in  the  vicinity  other  lizards 
were  found:  Polychrus,  in  a  hedge,  and  Aiueiva  and  Cnemido- 
phorus,  on  the  ground. 

Discussion  (E.  E.  WiUiams): 

The  karyotypic  evidence  clearly  demonstrates  a  strong  separa- 
tion between  jacare  and  either  of  the  stocks  of  Lesser  Antillean 
anoles.  Equally  there  is  sharp  difference  between  jacare  and  the 
few  mainland  alphas  that  have  been  studied  thus  far  (Gorman, 
personal  communication).  On  the  face  of  the  evidence,  A.  jacare 
seems  to  occupy  a  rather  isolated  phyletic  position. 

It  may  be  of  interest  and  importance  here  that  A .  jacare  is  dis- 
tributionally  isolated  also  and  that,  very  unusually  for  South 
American  anoles,  it  is  not  known  to  be  sympatric  with  any  con- 
geners in  any  part  of  its  known  range. 

There  are  other  South  American  species  that  extend  beyond 
the  range  of  their  congeners  somewhere  at  the  periphery  of  their 
range.  A.  jacare  is  special  in  that  so  far  as  known  its  whole  range 
is  outside  contact  with  any  other  anole. 

Recent  studies  by  T.  Schoener  (1970)  have  shown  that  in  the 
Lesser  Antilles,  "solitary"  species,  i.e.,  species  without  sympatric 


10  BREVIORA  No.    353 

congeners,  tend  to  be  very  similar  in  size  and  habitus.  There  also 
appears  to  be  a  broadened  unsp:ciaiized  ecology  characteristic 
of  these  "solitary"  anoles.  We  have  noted  above  that  the 
bimaculatiis  and  roquet  species  groups  are  extraordinarily  similar 
in  scale  characters.  We  emphasize  now  that  they  are  so  in  spite 
of  the  fact  that  they  are  products  of  two  quite  separate  invasions 
of  the  West  Indies  and  are  very  distinct  in  karyotype  and  bio- 
ci'icm'stry. 

Schoener  infers,  and  we  may  agree  with  him,  that  some  common 
selective  factor  must  be  at  work  to  keep  (or  evolve)  external 
similarity  when  wide  underlying  differences  exist.  That  common 
selective  factor  would  appear  to  be  the  negative  one  of  the  absence, 
or  extreme  limitation,  of  the  number  of  congeners. 

Certainly  on  the  larger  islands  of  the  Greater  Antilles  a  con- 
trary rule  exists:  syntopic  anoles  are  very  diverse  in  morphology 
or  size  or  both. 

The  modification  of  a  species  in  the  absence  of  congeners  or 
other  competitors  in  its  general  niche  is  sometimes  spoken  of  as 
"release."  In  morphology,  at  least,  it  is  proper  to  speak  of  a  more 
positive  selection  than  that  implied  by  that  essentially  negative 
term.  A  certain  size  seems  clearly  optimal  and  presumably  the 
features  of  squamation  must  likewise  be  held  under  selective 
control. 

In  ecological  behavior,  "release"  seems  a  more  descriptive  term, 
since  the  wider  range  of  habitat  permitted  a  species  in  the  absence 
of  close  competitors  concords  better  with  our  intuitive  sense  of  the 
meaning  of  release. 

In  the  Lesser  Antilles,  there  is  often  only  one  species  per  island 
and,  except  for  instances  of  very  recent  importation  and  their  very 
local  occurrence  (e.g.,  wattsi  on  St.  Lucia,  Underwood,  1959. 
1962),  there  is  a  maximum  of  two  species  per  island.  These  are 
relatively  old  islands  and  the  species  on  them  are  well  differen- 
tiated. They  afford  the  classic  and  best  examples  of  "solitary" 
anoles. 

A.  jo.care,  however,  is  as  isolated  in  the  Andes  of  Merida  as  the 
solitary  anoles  of  the  Lesser  Antillean  islands.  It  is  effectively  on 
a  mainland  island;  it  is  interesting  therefore,  but  not  unexpected, 
however,  to  find  it  resembling  and  behaving  like  an  island  anole — 
a  solitary  anole  of  an  old  small  island. 

The  resemblances,  then,  of  A.  jacare  to  A.  leachii  or  A.  luar- 
moratus  are  to  be  explained  in  terms  of  adaptation  to  similar  selec- 
tive pressures.  We  need  not,  in  fact,  seek  any  complex  zoogeo- 
graphic  solution  to  the  similarity  of  one  anole  on  island  mountains 


1970 


ANOLIS   JACARE 


11 


to  one  on  a  distant  island;  the  similarity  is  non-phyletic,  strictly 
convergent. 


TABLE 

1 

snout-vent 
length  of 
adult  -' 

jacarc 

73  mm 

leach  a 
96  mm 

intirnioraliis 
77  mm 

scales  acioss 
snout 

6-8 

4-5 

4-5 

scales  between 
semicircles 

0-2 

0-1 

0-1 

loreal  rows 

4-5 

4-5 

4-5 

scales  between 
interparietal 
and  semi- 
circles 

1-3 

1-2 

1-2 

supralabials  to 
center  of  eye 

6-9 

7-8 

7-8 

mental 

number  of 
sublabials  in 
contact  with 
infralabials 

not  deeper 
than  wide 

3-5 

not  deeper 
than   wide 

2-4 

deeper  than 
wide 

2-4 

scales  between 
sublabials  in 
contact  with 
mentals 

4 

4-6 

3-4 

ventrals 

smooth 

smooth 

feebly  keeled 

lamellae  under 
phalanges  ii  and 
iii  of  fourth  toe 

tail 


dewlap 
color 


19-25 

compressed 
but  without 
crest,  2 
dorsal  rows 

large 

green  with 
variable  dark 
vermiculations 


26-32 

compressed, 
with  strong 
crest  in 
males 

small 


24-30 

Compressed,  with 
weak  dorsal  crest 
in    males 


large 


green  with  dark      green   with   light 
vermiculations         vermiculations 
but  these  on  head  in  males 

stronger  on   head   only 
than  on  body 


12  BREVIORA  No.    353 

ACKNOWLEDGMENTS 

The  expedition  to  obtain  and  study  A  uoUs  jaccire  was  supported 
by  the  Instituto  de  Zoologia  Tropical,  Universidad  Central  de- 
Venezuela,  and  by  National  Science  Foundation  Grant  GB  6944 
to  Ernest  E.  Williams.  Thanks  are  also  due  to  Ingrid  LcJbig  for 
help  in  laboratory  work,  and  to  Pedro  Durand  for  facilities  provided 
at  the  Universidad  de  los  Andes  during  the  work  in  Mcrida.  We 
are  indebted  to  George  Gorman  for  communicating  to  us  data  on 
the  karyotypes  of  two  female  A .  jacare. 

REFERENCES 

BouLENGER,  G.  A.  1903.  On  some  batrachians  and  reptiles  from 
Venezuela.  Ann.  Mag.  Nat.  Hist.,  ser.  7.   11:  481-484. 

Etheridge,  R.  1960.  The  relationships  of  the  anoles  ( Reptilia:Saiiria: 
Iguanidae)  an  interpretation  based  on  skeletal  morphology.  Ann  Arbor, 
Michigan:   University  Microfilms,  xiii  -f  236  pp. 

Ewel,    J.    J.,    AND    A.    Madriz.      1968.     Zonas    de    Vida    de    Venezuela. 
Ediciones  del  Fondo  Nacional  de  Investigaciones  Agropecuarias. 
Caracas.  265  pp  +  Mapa  Ecologico  de  Venezula. 

Gorman,  G.  C.  1965.  Interspecific  karyotypic  variation  as  a  systematic 
character  in  the  genus  Anolis  (Sauria: Iguanidae).    Nature  208:  95-97. 

Gorman,  G.  C,  and  L.  Atkins.  1966.  Chromosomal  heteromorphism 
in  some  male  lizards  of  the  genus  Anolis.    Amer.  Nat.   100:   579-583. 

1967.     The  relationships  of  the  Anolis  of  the  roquet  species 

group  (Sauria;  Iguanidae).  II.  Comparative  chromosome  cytology. 
Syst.  Zool.  16:    137-143. 

1968a.     New    karyotypic    data    for    16    species    of    Anolis 


(Sauria:    Iguanidae)    from    Cuba.   Jamaica    and    the   Cayman    Islands. 
Herpetologica  24:    13-21. 
1968b.     Confirmation    of   an    X-Y    sex    determining    mech- 


anism in  lizards  (Anolis).    Copeia  1968:    159-160. 
1968c.     Natural    hybridization   between   two   sibling   species 


of  Anolis  lizards:   chromosome  cytology.    Science   159:    1358-1360. 
1969.     The     zoogeography     of     Lesser     Antillean     Anolis 


lizards  —  an  analysis  based  upon  chromosomes  and  lactic  dehydro- 
genases.   Bull.  Mus.  Comp.  Zool.    138:   53-80. 

Gorman,  G.  C,  L.  Atkins,  and  T.  Holzinger.  1967.  New  karyotypic 
data  on  15  genera  of  lizards  in  the  family  Iguanidae,  with  a  discus- 
sion of  taxonomic  and  cytological  implications.  Cytogenetics  6: 
286-299. 


1970  ANOLIS   JACARE  13 

Gorman.  G.  C.  R.  Thomas,  and  L.  Atkins.  1968.  Intra-  and  inter- 
specific chromosome  variation  in  the  lizard  Anolis  cristate  I  Ins  and  its 
closest  relatives.    Breviora  293:    1-13. 

Levan,  a..  K.  Fredga.  and  A.  A.  Sandberg.  1964.  Nomenclature  for 
centromeric  position  on  chromosomes.  Hereditas  52:  201-220. 

Schmidt,  K.  P.  1939.  A  new  lizard  from  Mexico  with  a  note  on  the 
genus  Norops.    Zool.  Ser..  Field  Mus.  Nat.   Hist.    24:   7-10. 

ScHOENER,  T.  W.  1970.  Size  patterns  in  West  Indian  Anolis  Lizards.  II. 
Correlations  with  sizes  of  particular  sympatric  species  displacement 
and  convergence.  Amer.  Nat.  104:    155-173. 

Underwood,  G.  1959.  The  anoles  of  the  Eastern  Caribbean  (Sauria, 
Iguanidae).  Part  III.  Revisionary  notes.  Bull.  Mus.  Comp.  Zool. 
121:    187-226. 

___.      1962.     Reptiles     of     the     Eastern     Caribbean.      Caribbean 

Affairs   (N.S.)    1:    1-192. 

(Received    17   April    1970.) 


14  BREVIORA  No.    353 

A^  A2  A3  ^       -*\      »    U     ^ 

XX    XX    ..    ^^W 


B1  B2  CI 


•      •  • 


Figure    3.    Spermatogonia!    metaphase    and   karyotype   of   AiioUs  jacarc. 
Specimen  no.  MCNC  5601.  cell  no.  A-167  T5  C2.  Scale:    10  micra. 


M    }t    n  «V^ 


•      • 


«       » 


Figure    4.    Spermatogonial    metaphase   and    karyotype   of   Aiiolis  jacare. 
Specimen  no.  MCNC  5604.  cell  no.  A-)71  T.^  C2.  Scale:    10  micra. 


970 


ANOLIS   JACARE 


LS 


w*- 


Figure    5.   Diakinesis  of  Aiuilis   hicarc.    Specimen   no.   MCNC   5603,  eel 
no.  A-170  T7  CI. 


•    ..^    \^IX-'' 


^■^-rj.^*^ 


W~'f'^' 


-^ml 


^: 


■%,. 


~  "^' 


j^;;.-.k. 


Figure  6.  Rio  Milla.  Merida  (site  1  of  Fig.  2).  To  the  right  of  the  hght 
pest  is  the  guamo  (Inga  sp.)  in  which  two  males  and  two  females  were 
collected.  The  other  trees  to  the  right  are  majagua  (Heliocarpus 
pupayensis)    where  other   specimens  were  collected 


BREVIORA 


Musenaiiii   of   Compsirative    Zoology 

Cambridge,  Mass.  18  September,  1970  Number   354 

TAXONOMIC  AND  ECOLOGICAL  NOTES  ON  SOME 

MIDDLE  AND  SOUTH  AMERICAN  LIZARDS  OF  THE 

GENUS  Ameiva  (TEIIDAE) 

Arthur  C.  Echternacht 


Abstract.  The  taxonomy  of  two  Middle  American  and  one  South 
American  Ameiva  (Sauria,  Teiidae)  is  discussed.  Ameiva  festiva  niceforoi 
Dunn  is  accorded  species  rank,  A.  f.  miadis  Barbour  and  Loveridge  is  for- 
mally designated  a  subspecies  of  A.  undiilata.  and  A.  iiiuliilata  thomasi 
Smith  and  Laufe  is  placed  in  the  synonymy  of  A.  chaitzami  Stuart.  Diag- 
noses and  statements  of  range  are  provided  for  each,  and  ecological  in- 
formation is  presented  for  miadis.  The  condition  of  the  median  parietal 
(divided  or  not)  is  shown  to  be  unstable  in  Ameiva  and  useless  for  diag- 
nosing species  in  Middle  America. 

INTRODUCTION 

In  the  course  of  my  studies  of  geographic  variation  in  the 
Middle  American  species  of  the  lizard  genus  Ameiva,  I  have  found 
that  certain  taxa  require  reallocation  and  that  diagnoses  presented 
with  the  original  descriptions  of  some  are  either  in  error  or  mis- 
leading. It  is  the  purpose  of  this  paper  to  clarify  the  taxonomic 
positions  of  three  of  these  taxa.  A  diagnosis  is  presented  for 
each,  and  ecological  information  is  included  where  warranted. 

Acknowledgements.  I  am  indebted  to  the  following  persons 
for  the  loan  of  specimens  in  their  care:  W.  E.  Duellman,  Univer- 
sity of  Kansas  Museum  of  Natural  History  (KU);  R.  F.  Inger 
and  H.  Marx,  Field  Museum  of  Natural  History  (FMNH);  E.  V. 
Malnate,  Academy  of  Natural  Sciences  of  Philadelphia  (ANSP); 
J.  R.  Meyer  (Private  Collection);  J.  A.  Peters  and  G.  R.  Zug, 
United  States  National  Museum  (USNM);  C.  F.  Walker  and  L. 
C.  Stuart,  University  of  Michigan  Museum  of  Zoology  (UMMZ); 
R.  G.  Zweifel,  American  Museum  of  Natural  History  (AMNH); 


2  BREVIORA  No.    354 

and  E.  E.  Williams,  Museum  of  Comparative  Zoology  (MCZ). 
W.  E.  Duellman  and  E.  E.  Williams  read  and  criticized  the  manu- 
script. 

Ameiva  niceforoi  Dunn 

Ameiva  f estiva  niceforoi  Dunn,  Notulae  Naturae  no.  126:  1-2,  1943 
(Holotype:  ANSP  24300.  Type  Locality:  "Sasaima,  in  the  eastern  Andes, 
75  km  northwest  of  Bogota,  altitude  1200  meters,"  Colombia.  Collector: 
Hermano  Niceforo  Maria). 

Diagnosis.  Ameiva  niceforoi  can  be  distinguished  from  its 
congeners  by  the  following  combination  of  characters:  Small  size 
(maximum  observed  snout-vent  length  |SVL]  82  mm  for  males, 
75  mm  for  females) ;  central  gular  scales  much  enlarged,  surround- 
ing scales  diminishing  in  size  gradually  toward  the  periphery  of 
the  gular  region;  frontal  and  frontoparietal  scales  entire;  three 
parietal  scales;  total  number  of  femoral  pores  moderate;  number 
of  dorsal  granules  around  the  body  (GAB)  and  occiput  to  rump 
(GOR)  low;  no  preanal  spurs;  broad  middorsal  stripe  bordered 
laterally  by  a  fine  white  stripe;  black  dorsolateral  stripe  bordered 
ventrally  by  a  fine  white  stripe;  no  narrow,  light-colored  vertebral 
stripe. 

Range.  Knovv'n  only  from  the  type  locality  and  from  Honda, 
Departamento  Tolima,  Colombia. 

Remarks.  Dunn  (1943)  diagnosed  Ameiva  f estiva  niceforoi 
(  =A.  niceforoi)  as  "A  form  of  f estiva,  identical  with  it  in  size, 
proportions,  and  in  scalation,  but  remarkably  different  in  mark- 
ings." In  addition  to  color  pattern  (Fig.  lA),  niceforoi  differs 
from  fesiiva  in  a  number  of  characters  of  scutellation.  In  color 
pattern,  niceforoi  is  virtually  identical  to  female  or  subadult  male 
A.  leptophrys  but  differs  from  leptoplvys  in  numerous  scale  char- 
acters. Some  pertinent  differences  among  the  three  species  are 
summarized  in  Table  1.  Because  geographic  variation  is  marked 
(Echternacht,  1970),  means  of  characters  of  scutellation  for  an 
entire  species  tend  to  mask  similarities  between  niceforoi  and 
samples  of  other  species  drawn  from  nearby  localities.  For  this 
reason,  means  for  nearby  samples  are  given  as  well  as  those  for 
the  entire  species.  In  addition  to  the  total  number  of  femoral 
pores,  GAB  and  GOR,  niceforoi  differs  from  leptophrys  in  the 
arrangement  of  scales  peripheral  to  the  enlarged  central  gulars.  In 
leptoplvys  the  posterior  gular  scales  are  much  reduced  in  size 


1970 


NOTES   ON    AMEIVA 


Figure  1.  (A)  Ameiva  niceforoi,  paratype  (ANSP  24303:  Sasaima, 
Depto.  Cundinamarca,  Colombia),  snout-vent  length  77  mm.  (B)  Ameiva 
undulata  miadis,  holotype  (MCZ  26970:  Isla  del  Maiz  Grande,  Depto. 
Zelaya,  Nicaragua),  126  mm.  (C)  Ameiva  chaitzami,  paratype  (MCZ 
52170  [formerly  UMMZ  90642]:  Along  Cahabon-Languin  trail  ca.  2  km 
N  Finca  Canihor,  Depto.  Alta  Verapaz,  Guatemala),  69  mm.    All  males. 


relative  to  the  anterior  gulars.  Ameiva  niceforoi  and  festiva  are 
similar  in  this  respect. 

No  other  South  American  species  of  Ameiva  seems  to  be  closely 
related  to  any  of  the  three  species  discussed  above.  An  Ameiva 
similar  to  niceforoi  could  have  given  rise  to  either  leptophrys  or 
festiva  or  to  both,  but  the  present  chaotic  situation  with  respect 
to  the  taxonomy  of  Ameiva  in  South  America  (Medem,  1969)  pre- 
cludes decisive  conclusions  concerning  phylogenetic  relationships. 
Studies  in  progress  are  designed  to  clarify  this  situation. 

Other  than  the  type  series  (ANSP  22784,  24300-303),  only 
three  specimens  of  Ameiva  niceforoi  are  known:  USNM  93500- 
93501  (Topotypes)  and  AMNH  35300  from  Honda,  Depto. 
Tolima,  Colombia. 


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1970  NOTES   ON    AMEIVA  5 

Ameiva  undulata  miadis  Barbour  and  Loveridge 

Ameiva  f estiva  miadis  Barbour  and  Loveridge,  Bull.  Mus.  Comp.  Zool., 
69:  141-142,  1929  (Holotype:  MCZ  26970.  Type  Locality:  "Great  Corn 
Island"  [=Isla  del  Maiz  Grande],  Depto.  Zelaya.  Nicaragua.  Collector: 
James  L.  Peters). 

Ameiva  undulata  miadis,  Dunn,  Proc.  Acad.  Nat.  Sci.  Philadelphia,  92: 
115,  1940.    Villa,  Rev.  Biol.  Trop.,  15:   119,  1968. 

Diagnosis.  Ameiva  undulata  miadis  (Fig.  IB)  can  be  dis- 
tinguished from  A.  f estiva  and  other  subspecies  of  A.  undulata 
on  the  basis  of  its  unique  color  pattern:  No  narrow,  light-colored 
vertebral  stripe;  lateral  pattern  of  blue  (males)  or  gray-brown 
(females)  bars  on  a  black  background  extending  from  mid- 
dorsal  stripe  to  enlarged  ventral  scutes;  broad  middorsal  stripe 
from  occiput  onto  tail,  much  disrupted  by  transverse  black  blotches 
that  are  often  continuous  with  the  black  background  color  of  the 
flanks;  sexual  dimorphism  in  color,  but  not  pattern,  in  adults. 

Range.  Known  only  from  Islas  del  Maiz,  Depto.  Zelaya,  Nica- 
ragua. 

Remarks.  With  the  exceptions  noted  above,  Ameiva  undulata 
miadis  is  similar  to  other  subspecies  of  undulata  that  have  barred 
flanks  (see  Echternacht,  1970).  Dunn  (1940)  and  Villa  (1968) 
have  briefly  alluded  to  the  relationship  of  miadis  with  undulata 

Barbour  and  Loveridge  (1929)  considered  Ameiva  festiva 
miadis  (  ^A.  undulata  miadis)  to  be  intermediate  between  A. 
festiva  and  A.  ruthveni  (  =A.  leptophrys) .  Color  pattern  alone 
distinguishes  miadis  from  leptophrys,  but  in  addition,  the  peri- 
pheral gular  scales  of  undulata  are  like  those  described  for  niceforoi 
above  and  differ  from  those  of  leptophrys  in  the  same  manner. 
Also,  in  leptophrys  the  postnasals  are  not  in  contact  with  the  pre- 
frontal scales,  whereas  in  undulata  these  scales  are  in  contact. 

The  nearest  known  mainland  populations  of  Ameiva  festiva  are 
at  Bluefields,  Depto.  Zelaya,  Nicaragua,  about  85  kilometers  west 
of  Isla  del  Maiz  Grande.  Ameiva  festiva  from  Bluefields  are 
typical  of  the  species  in  having  a  well-defined  vertebral  stripe  in 
ah  but  large  adults  and  in  having  little  barring  on  the  flanks. 
Nearest  known  populations  of  leptophrys  are  in  the  southeastern 
lowlands  of  Costa  Rica,  and  the  nearest  populations  of  undulata 
are  in  northeastern  Honduras,  western  Nicaragua,  and  northwest- 
ern Costa  Rica.  Four  specimens  of  undulata  (ANSP  15438- 
15441)  from  Huaunta  Haulover,  Depto.  Zelaya,  Nicaragua,  about 


BREVIORA 


No.  354 


150  kilometers  north-northwest  of  Isla  del  Maiz  Grande,  may  in- 
dicate an  isolated  population  there.  In  color  pattern,  the  undulata 
from  Islas  del  Maiz  most  closely  resemble  those  from  near  Cata- 
camas,  Depto.  Olancho,  Honduras.  In  these  Honduranian 
Ameiva,  the  middorsal  stripe  is  heavily  blotched,  but  the  blotches 
are  never  continuous  onto  the  flanks. 

Island  populations  of  Middle  American  Ameiva  (with  the  ex- 
ception of  qiiadnlineata)  tend  to  have  a  relatively  high  GAB  count 
when  compared  to  mainland  samples  of  the  same  species  (see 
Echternacht,  1970).  Although  the  mean  for  this  character  does 
not  differ  statistically  from  those  of  certain  mainland  samples 
examined,  it  is  the  highest  recorded  for  the  species  {A.  undulata: 
X  =    149.5,  standard  deviation  of  the  mean  =   16.5,  range  = 

108-202,  N  =  918.  A.  u.  miadis:  x  =  186.3  ±  9.3,  range  = 
165-202,  N  =  42). 

Nothing  has  been  reported  of  the  ecology  of  Ameiva  undulata 
miadis.  I  was  able  to  make  some  observations  on  June  4-8,  1966. 
The  lizard  is  very  common  on  Isla  del  Maiz  Grande  and  I  found  it 
particularly  abundant  in  clearings  within  the  coconut  groves  that 
cover  the  island  (Fig.  2).    It  was  also  common  in  the  shrub  and 


'i..  -^  *t,. .,  ,.^5^-s. 


Figure  2.     Habitat  of  Ameiva  undulata  miadis  on  Isla  del  Maiz  Grande, 
Depto.  Zelaya,  Nicaragua.    June  1966. 


1970  NOTES    ON    AMEIVA  7 

grassy  vegetation  along  the  airstrip  and  in  clearings  around  build- 
ings. None  were  seen  on  open  beaches.  Individuals  often  were 
encountered  basking  or  foraging  on  or  around  fallen  palm  fronds. 
Activity  extended  from  dawn  until  dusk,  but  more  lizards  were 
seen  early  in  the  day  than  in  late  afternoon.  The  lizards  were  not 
active  in  rain.  Hatchlings  with  clearly  dehneated  umbilical  scars 
were  observed.  The  chin,  gular  region,  and  anteriormost  part  of 
the  chest  of  many  males  was  bright  reddish  orange.  In  others, 
this  area  was  pale  blue.  Such  dichromatism  is  widespread  among 
species  of  Ameiva  and  may  be  associated  with  reproductive  con- 
dition. Evidence  is  lacking  on  this  point.  English-speaking  resi- 
dents of  the  island  refer  to  the  Ameiva  simply  as  "lizard,"  al- 
though they  have  specific  names  for  Iguana  iguana  and  Cteno- 
saura  similis,  both  of  which  are  common. 

Ameiva  chaitzami  Stuart 

Ameiva  chaitzami  Stuart,  Proc.  Biol.  Soc.  Washington,  55:  143,  1942 
(Holotype:  UMMZ  90638.  Type  Locality:  "Along  Cahabon-Languin  trail 
about  2  km  north  of  Finca  Canihor  .  .  .  ,  Alta  Verapaz,  Guatemala."  Col- 
lector: L.  C.  Stuart). 

Ameiva  imdulata  thomasi  Smith  and  Laufe,  Univ.  Kansas  Sci.  Bull.,  31: 
47-50,  pi.  lA,  1946  (Holotype:  FMNH  100006.  Type  Locality:  "La  Liber- 
tad,  Chiapas,  near  Rio  Cuilco  where  it  crosses  the  Guatemalan  border," 
Mexico.    Collector:  Henry  D.  Thomas).    New  synonymy. 

Diagnosis.  Ameiva  chaitzami  (Fig.  IC)  can  be  distinguished 
from  its  congeners  by  the  following  combination  of  characters: 
Small  size  (maximum  observed  SVL  85  mm  for  males,  75  mm  for 
females);  central  gular  scales  enlarged,  in  longitudinal  series; 
gradual  reduction  in  size  of  scales  radiating  outward  from  the 
central  gulars;  prefrontals  in  contact  with  postnasals;  three  parietal 
scales  (four  if  median  parietal  divided);  transverse  row  of  abrupt- 
ly enlarged  mesoptychial  scales;  usually  eight  transverse  rows  of 
ventral  scutes  at  midbody;  moderately  narrow  middorsal  stripe 
(mean  width  in  terms  of  granules  37.1,  N  =  61);  no  narrow, 
well-defined  vertebral  stripe;  often  a  dark  secondary  stripe  medial 
to  the  dorsolateral  light  stripes;  dorsolateral  blotches  of  adult 
males  fused  to  the  dorsolateral  light  stripe  so  that  the  latter  has 
a  well-defined  dorsal  border,  an  irregular  ventral  border.  The 
latter  character  alone  will  distinguish  chaitzami  from  undulata 
with  certainty. 


8  BREVIORA  No.    354 

Range.  Valleys  of  the  upper  tributaries  of  the  Rio  Grijalva 
in  Chiapas,  Mexico,  and  west-central  Guatemala,  from  the  vicin- 
ity of  Finca  Canihor,  Depto.  Alta  Verapaz,  Guatemala,  and  near 
Poptiin,  Depto.  El  Peten,  Guatemala. 

Remarks.  Stuart  (1942)  diagnosed  Ameiva  chaitzami  as  "An 
Ameiva  almost  identical  with  Ameiva  nndulata  stuarti  Smith  from 
which  it  may  readily  be  distinguished  by  the  fact  that  the  median 
parietal  is  divided  longitudinally  to  produce  four  instead  of  three 
parietals."  The  posterior  scales  on  the  dorsal  surface  of  the  head 
is  an  unstable  character  among  Middle  American  species  of 
Ameiva,  and  diagnoses  based  on  scales  in  the  area  are  unreliable 
(Echternacht,  1970).  Considering  nndulata  only,  I  noted  the 
median  parietal  to  be  divided  or  semidivided  in  22.4  per  cent  of 
1043  specimens  obtained  from  throughout  the  range  of  the  species. 
This  is  probably  a  conservative  estimate  of  the  frequency  of  oc- 
currence of  this  condition,  because  the  information  was  not  noted 
early  in  the  study.  There  seem  to  be  no  geographic  trends  as- 
sociated with  the  condition  of  the  median  parietal.  At  least  38 
of  45  samples  contained  individuals  with  divided  or  semidivided 
median  parietals.  Samples  having  a  high  frequency  of  occurrence 
of  division  were  as  follows:  near  Chinandega,  Depto.  Chinandega, 
Nicaragua  (55  per  cent,  N  =  31);  Piedras  Negras,  Depto.  El 
Peten,  Guatemala  (72  per  cent,  N  =  32);  Canihor,  Depto.  Alta 
Verapaz,  Guatemala  (50  per  cent,  N  =  30);  near  Panajachel, 
Depto.  Sololii,  Guatemala  (48  per  cent,  N  =  29);  Sabana  de 
San  Quintin,  Chiapas,  Mexico  (100  per  cent,  N  =  10);  near  Las 
Tazas  and  Florida,  Chiapas,  Mexico  (90  per  cent,  N  =  30). 
Three  samples  of  chaitzami  yielded  the  following  frequencies: 
Comitan,  Chiapas,  Mexico,  3  per  cent  (N  =  30);  near  San  An- 
tonio Huista,  Depto.  Huehuetenango,  Guatemala,  10  per  cent 
(N  =  31 );  near  Finca  Canihor,  Depto.  Alta  Verapaz,  Guatemala, 
and  near  Poptun,  Depto.  El  Peten,  Guatemala,  89  per  cent  (N  = 
9).  Six  of  the  nine  in  the  last  sample  constitute  the  type  series. 
At  the  type  locality  and  at  Poptun,  chaitzami  is  sympatric  with 
A .  imdidata  hartwegi  Smith,  a  large  subspecies  quite  distinct  in  color 
pattern  and  scutellation  from  chaitzami.  The  samples  from  Canihor 
and  Piedras  Negras,  Guatemala,  and  from  Sabana  de  San  Quintin, 
Chiapas,  are  hartwegi.  Elsewhere  within  its  range,  samples  of 
hartwegi  have  from  13  to  30  per  cent  of  individuals  with  divided 
or  semidivided  median  parietals.  It  is  noteworthy  that  the  holo- 
type  of  hartwegi  (FMNH  108600),  obtained  across  the  Rio  Usu- 
macinta  from  Piedras  Negras,  has  a  divided  median  parietal. 


1970  NOTES    ON    AMEIVA  9 

Smith  and  Laufe  (1946)  discussed  the  evolution  of  Aineiva 
undidata  and  recognized  several  new  subspecies,  but  they  ap- 
parently did  not  examine  specimens  of  chaitzami.  The  description 
of  A.  u.  thomasi  (Smith  and  Laufe,  1946)  agrees  with  that  of 
Stuart  (1942)  for  chaitzami  in  most  respects.  I  have  examined 
the  type  specimens  of  both  and  consider  them  to  be  conspecific. 
The  samples  cited  above  from  Comitan  and  near  San  Antonio 
Huista  are  from  within  the  range  of  thomasi  as  described  by 
Smith  and  Laufe  (1946). 

LITERATURE   CITED 

Dunn,  E.  R.  1940.  New  and  noteworthy  herpetological  material  from 
Panama.    Proc.  Acad.  Nat.  Sci.  Philadelphia,  92:    105-122. 

. 1943.    A  new  race  of  Ameiva  f estiva  from  Colombia.   Notu- 

lae  Naturae  no.  126,  2  pp. 

EcHTERNACHT,  A.  C.  1970.  A  review  of  Middle  American  lizards  of  the 
genus  Ameiva  (Teiidae)  with  emphasis  on  geographic  variation.  Un- 
published Ph.D.  Dissertation,  University  of  Kansas,  Lawrence,  Kansas. 

Medem,  F.  1969  (1968).  El  desarrollo  de  la  Herpetologia  en  Colombia. 
Rev.  Acad.  Colombiana  Cienc.  Exactas  Fis.  Natur.,  13(50):    149-199. 

Barbour,  T.,  and  A.  Loveridge.  1929.  Vertebrates  from  the  Corn  Is- 
lands.  Reptiles  and  Amphibians.  Bull.  Mus.  Comp.  Zool.,  69:  138-146. 

Stuart,  L.  C.  1942.  Comments  on  the  iindiilata  group  of  Ameiva 
(Sauria).  Proc.  Biol.  Soc.  Washington.  55:    143-150. 

Smith,  H.  M.,  and  L.  E.  Laufe.  1946.  A  summary  of  Mexican  lizards 
of  the  genus  Ameiva.    Univ.  Kansas  Sci.  Bull.,  31(2):   7-73. 

Villa,  J.  D.  1968.  A  new  colubrid  snake  from  the  Corn  Islands,  Nic- 
aragua.   Rev.  Biol.  Trop.,  15:   117-121. 

(Received  13  June  1970.) 


BREVIORA 

Miasemim    of    Coimpsirsitive    Zoology 

Cambridge,  Mass.        30  November,  1970  Number  355 


GENERIC  RELATIONS  AND 

SPECIATION   PATTERNS  IN  THE  CARACARAS 

(AVES:  FALCONIDAE) 

Francois  Vuilleumier^ 


Abstract.  The  caracaras  are  a  group  of  American  Falconidae  occurring 
from  temperate  and  subtropical  North  America  southward  to  extreme  south- 
ern South  America  and  the  Falkland  Islands.  The  taxa  of  caracaras  appear 
to  be  closely  interrelated.  It  is  suggested  that  they  be  classified  in  two 
genera:  Daptrius  (forest  caracaras;  two  sympatric  species),  and  Polybonis 
(nonforest  caracaras;  two  species-groups:  the  chimachima  and  planciis 
species-groups,  with  two  and  three  species,  respectively).  Former  classifica- 
tion advocated  the  use  of  four  genera.  Speciation  is  long  completed  in 
Daptrius  and  in  the  Polybonis  chimachima  species-group.  In  the  Polybonis 
planciis  species-group,  however,  several  phenomena  are  evidence  of  active 
species  formation.  Geographical  isolates  exist  that  are  morphologically 
differentiated  enough  to  be  considered  borderline  cases  between  species  and 
subspecies.  Some  of  the  cases  of  geographical  isolation  in  the  caracaras  can 
be  related  to  climatic  and  vegetational  changes  following  glacial  events  of 
the  Pleistocene. 

INTRODUCTION 

This  paper  constitutes  the  fourth  of  a  series  stemming  from 
studies  on  speciation  in  Andean  birds  (see  Vuilleumier,  1968, 
1969,  1970). 

I  shall  discuss,  first,  the  generic  classification  of  the  caracaras, 
and  secondly,  the  patterns  of  distribution,  geographical  variation 
and  speciation  in  these  birds,  with  particular  emphasis  on  the 
Andean  taxa.  I  shall  deal  either  with  problems  not,  or  only  litde, 
covered  by  Brown  and  Amadon  (1968)  in  their  recent  book,  or 

1  Biology  Department,  University  of  Massachusetts,  100  Arlington  Street, 
Boston,  Massachusetts  02116. 


2  BREVIORA  No.    355 

with  controversial  issues,  especially  when  my  own  conclusions  differ 
from  theirs. 

The  data  were  obtained  from  examination  of  about  250  skins 
and  some  skeletons;  and  from  field  studies  on  the  habitat  prefer- 
ences, general  behavior,  and  distribution  of  five  taxa  of  caracaras 
made  over  a  period  totaling  thirteen  months  during  trips  to  South 
America  in  1964,  1965,  and  1967-68. 

THE    CARACARAS 

The  7  to  10  or  11  species  of  caracaras  can  be  distinguished 
from  other  Falconidae  more  by  their  vulture-like  external  morpho- 
logical characters  and  associated  scavenging  habits,  than  by  clear- 
cut  anatomical  characters  (Friedmann,  1950:  719).  They  differ 
from  true  falcons,  however,  in  their  habit  of  building  their  own 
nest,  as  pointed  out  by  Brown  and  Amadon  (1968:  23,  104).  The 
problem  of  whether  the  caracaras  should  be  accorded  taxonomic 
rank  within  the  Falconidae,  and  if  so,  which  one  (e.g.,  subfamily, 
tribe),  will  not  be  discussed  here. 

The  species  of  caracaras  have  traditionally  been  placed  in  four 
genera  (see,  e.g.,  Peters,  1931;  Hellmayr  and  Conover,  1949; 
Friedmann,  1950;  de  Schauensee,  1966;  Brown  and  Amadon, 
1968):  Daptrius  Vieillot,  1816,  with  two  species;  Milvago  Spix, 
1824,  with  two  species;  Phalcoboenus  d'Orbigny,  1834,  with  two 
to  four  species;  and  Poly  bonis  Vieillot,  1816,  with  one  to  three 
species.  (The  long  controversy  over  the  names  Polyborus  versus 
Caracara  Merrem,  1826,  was  resolved  by  Amadon  (1954),  who 
showed  that  "Vieillot's  diagnosis  of  Polyborus  applies  to  the  Cara- 
caras," so  that  "the  diagnosis  sustains  the  name."  Caracara  must, 
therefore,  go  into  synonymy,  and  the  issue  can  be  considered 
closed.) 

As  a  group,  the  caracaras  are  distributed  from  temperate  North 
America  southward  to  Central  and  South  America,  ranging  as  far 
south  as  the  Falklands  and  the  islands  off  Tierra  del  Fuego.  Sev- 
eral species  have  very  broad  ranges,  especially  Polyborus  plancus, 
the  distribution  of  which  encompasses  almost  that  of  the  entire 
group.  Other  species  are,  on  the  contrary,  quite  localized  geo- 
graphically. For  example,  the  extinct  Polyborus  lutosus  occurred 
only  on  Guadalupe  Island  off  Baja  California,  and  the  living  Phal- 
coboenus australis  breeds  on  a  handful  of  small  islands  off  the 
southern  coast  of  Tierra  del  Fuego  and  on  the  Falklands. 


1970  SPECIATION    IN    THE    CARACARAS  3 

Correlated  with  the  broad  distribution  of  the  caracaras  is  their 
ecological  diversity.  As  a  group,  these  birds  inhabit  most  vegeta- 
tion formations  found  in  their  geographical  range,  from  desert 
scrub  to  tropical  lowland  wet  forest,  and  including  the  highest 
zones  of  Andean  vegetation.  About  the  only  major  type  of  vegeta- 
tion not  favored  by  caracaras  is  montane  tropical  wet  forest  (or 
cloud  forest). 

All  the  taxa  of  caracaras  are  scavengers,  but  should  perhaps  be 
viewed  as  omnivorous,  since  their  diet  also  includes  live  prey  (ver- 
tebrates and  invertebrates)  and  vegetal  matter  (see,  e.g.,  Hud- 
son, 1920:  62-88;  Wetmore,  1926:  92-96;  Haverschmidt,  1962: 
157-158;  Friedmann,  1927:  157;  Friedmann  and  Smith,  1950: 
450-451,  and  1955:  486-487;  Brown  and  Amadon,  1968).  Among 
the  most  notable  food  specializations  of  the  caracaras  is  the  habit 
of  Polyborus  planciis  of  attacking  domestic  animals  the  size  of 
sheep  (Johnson,  1965:  263),  and  the  marked  predilection  shown 
by  Daptrius  americanus  for  colonial  wasps  (Skutch,  1959). 

Most  caracaras  are  social,  at  least  during  the  nonbreeding  sea- 
son, and  form  intraspecific  flocks  that  appear  to  be  feeding  associa- 
tions. The  larger-sized  species  may  form  smaller  flocks  than  the 
smaller  ones.  Thus  the  largest  flock  of  the  osprey-sized  Polyborus 
plancus  I  have  observed  comprised  about  15  birds,  while  I  have 
often  seen  much  larger  flocks  of  the  kestrel-sized  Milvago  chimango. 
The  intraspecific  gregariousness  of  some  of  the  smaller  species  may 
also  extend  to  the  breeding  season.  Drury  (personal  communica- 
tion )  observed  a  colony  of  Milvago  chimango  where  the  nests  were 
only  about  30  feet  (ten  meters)  apart.  The  caracaras  also  form 
associations  with  vertebrates  other  than  birds.  In  Patagonia,  Mil- 
vago chimango  flocks  are  frequent  near  cattle  and  horses;  I  even 
saw  one  bird  sitting  on  the  flank  of  a  lying  horse,  pecking  from  time 
to  time  at  the  skin,  perhaps  to  eat  ticks.  Hudson  (1920:  70)  men- 
tioned that  M.  chimango  "follows  the  plough,"  thus  playing  the 
part  of  gulls  {Lams)  elsewhere.  The  habit  of  following  moving 
vehicles  from  which  scraps  of  food  can  be  collected  has  been 
observed  in  Phalcoboenus  megalopterus  along  the  Yungas  Road 
in  La  Paz,  Bolivia  (Niethammer,  1953:  265;  personal  observa- 
tion), and  in  Polyborus  plancus  along  a  railroad  in  the  Bolivian 
Chaco  (Eisentraut,  1935:  391).  The  gregarious  behavior  exhib- 
ited by  the  caracaras  may  be  correlated  to  a  large  extent  with  their 
scavenging  habits,  yet,  from  my  own  observations,  I  would  judge 
their  behavior  to  be  much  more  plastic  and  diverse  than  that  of 


4  BREVIORA  No.    355 

other   scavengers   such    as   Old   World  or   New   World    vultures 
(Cathartidae  and  Aegypiinae,  respectively). 

ANALYSIS  OF  SOME  CHARACTERS  OF  THE  CARACARAS 

Size 

The  caracaras  vary  considerably  in  size,  as  several  authors 
(Friedmann,  1950;  Brown  and  Amadon,  1968)  have  already 
pointed  out.  This  variation  is  obvious  if  wing  length,  in  the  ab- 
sence of  data  on  weights,  is  used  as  an  indicator  of  overall  body 
size  (Table  1).  Taxonomists  have  often  been  bothered  by  size 
differences  between  species,  and  have  been  reluctant  to  place  in 
the  same  genus  closely  related  species  which  differed  conspicuously 
in  size  but  in  few,  or  no,  other  characters.  This  attitude  might 
have  been  prevalent  among  the  ornithologists  who  worked  with 
caracaras,  because  the  two  smallest  species  belong  in  the  genus 
Milvago  and  the  largest  species  in  Phalcoboenus  and  Polyborus. 
Yet  the  two  species  of  Daptrius  bridge  the  gap  between  these  ex- 
tremes. I  therefore  believe  that  size  should  not  be  given  undue 
weight  in  the  supraspecific  classification  of  the  caracaras.  In  other 
Falconidae,  notably  in  the  genus  Falco,  similarly  large  size  differ- 
ences between  species  have  not  prevented  their  inclusion  in  the 
same  genus. 

Proportions 

In  a  number  of  bird  taxa,  a  proportionately  short  tarsus  is  cor- 
related with  arboreal  habits,  and  a  long  tarsus  with  more  terrestrial 
habits.  Most  species  of  caracaras  are  both  arboreal  and  terrestrial, 
but  some  definite  trends  toward  one  or  the  other  of  these  habits 
exist,  especially  in  regard  to  feeding  habits.  Thus  Polyborus  and 
Milvago  are  often  seen  perched  on  trees,  and  they  breed  in  trees, 
but  they  do  a  lot,  perhaps  most,  of  their  foraging  for  food  on  the 
ground.  The  species  of  Phalcoboenus  (with  the  possible  exception 
of  P.  albogularis)  seem  to  forage  entirely  on  the  ground,  and  breed 
in  cliffs  and  rocky  slopes;  they  do  on  occasion  perch  on  buildings. 
The  species  of  Daptrius  seem  at  variance  with  the  other  three 
genera  because  they  do  some,  perhaps  even  a  substantial,  portion 
of  their  foraging  for  food  in  trees. 

From  this  summary  one  would  thus  expect  the  species  of  Dap- 
trius, which  are  more  arboreal  than  the  other  caracaras,  to  have 
proportionately  shorter  tarsi  than  other  species.   Figure  1  shows  a 


1970 


SPFXIATION    IN    THE    CARACARAS 


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6  BREVIORA  No.    355 

scatter  diagram  of  tarsus  length  plotted  against  wing  length  (rep- 
resenting body  size  in  the  absence  of  weight  data)  in  the  caracaras. 
The  two  species  of  Milvago,  although  overlapping  considerably  in 
wing  length,  show  little  overlap  in  tarsus  length.  The  southern 
species,  M.  chimango,  is  decidedly  longer-legged  than  the  northern 
one,  M.  chimachima.  This  difference,  especially  in  regard  to  the 
zone  of  sympatry  of  the  two  species,  is  discussed  again  below  in 
the  section  on  speciation  in  these  birds.  Dapthiis  ater  has  somewhat 
longer  wings  than  either  species  of  Milvago,  but  its  tarsal  measure- 
ments overlap  fully  with  those  of  M.  chimachima.  Yet  D.  ater 
would  seem  more  arboreal  than  M.  chimachima.  The  arboreal 
Daptrius  americanus  overlaps  with  the  more  terrestrial  Phalco- 
boenus  megaloptenis,  P.  albogularis,  and  Polyborus  plancus  in 
wing  length,  but  has  a  much  smaller  tarsus.  In  this  case  the  differ- 
ence in  tarsus  size  appears  to  correspond  to  a  difference  in  habits. 


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Figure   1.   Tarsus  length  plotted  against  wing  length  in   seven  taxa  of 
caracaras. 


1970  SPECIATION    IN    THE    CARACARAS  7 

It  is  worthy  of  note  that  the  species  of  Phalcoboemis  closest  to  D. 
americamis  in  tarsus  length  is  P.  albogularis  (see  Fig.  1)  said  by 
Olrog  (1948:  478;  1950:  520)  to  occur  in  forests  and  thus  to 
diverge  from  the  habitat  preferred  by  P.  megalopterus. 

On  the  basis  of  the  proportions  of  tarsus  and  wing  lengths  plotted 
on  Figure  1 ,  Milvago  chimango,  M.  chimachima,  and  Daptrius  ater 
would  form  one  group  of  species  closely  similar  to  each  other,  over- 
lapping greatly  in  both  wing  and  tarsus  length.  A  second  such 
group  would  include  Phalcoboemis  and  Polyborus,  while  Daptrius 
americanus  appears  clearly  distinct  from  all  other  species,  yet  inter- 
mediate between  the  two  groups. 

Interspecific  variation  in  tail  length  is  summarized  in  Table  2. 
When  handling  skins,  Daptrius  americamis  appears  distinctly  longer 
tailed  than  the  other  species  of  caracaras.  If  the  tail/wing  ratios, 
instead  of  the  absolute  tail  lengths,  are  compared  among  the  species 
of  caracaras,  then  a  smooth  variation  is  detected,  from  the  propor- 
tionately short-tailed  Polyborus  plancus  and  Phalcoboemis  mega- 
lopterus to  the  long-tailed  Milvago  chimachima  and  Daptrius 
americamis.  No  groups  of  caracaras  can  be  established  on  the 
basis  of  relative  tail  length. 

TABLE   2 

Variation  in  tail  length,  expressed  in  percent  of  wing  length, 
among  the  caracaras.  The  taxa  are  ranked  in  order  of  increasing 
tail/wing  ratio.   Both  sexes,  and  adult  and  subadult  birds  included. 


Taxon 

Tail/ Wing 

X  100 

Sample  Size 

Range 

Mean 

plancus 

50.8-58.1 

53.9 

42 

megalopterus 

53.1-57.4 

55.5 

13 

carunculatus 

55.6 

1 

chimango 

54.8-58.7 

57.3 

5 

albogularis 

54.1-64.7 

58.4 

5 

australis 

57.5-61.5 

59.4 

4 

ater 

58.4-63.5 

61.1 

6 

lutosus 

62.7 

1 

chimachima 

60.9-70.2 

66.2 

25 

americanus 

62.2-74.6 

68.4 

36 

8  BREVIORA  No.    355 

Plumage  Color  and  Pattern 

Good  descriptions  of  both  adult  and  immature  plumages  of 
caracaras  have  been  given  by  Friedmann  (1950)  and  Brown  and 
Amadon  (1968),  who  should  be  consulted  for  full  details.  The 
main  colors  of  aduh  and  immature  plumages  are  summarized  in 
Table  1. 

Adult  caracaras  vary  from  a  brown,  rather  unpatterned  plumage 
(such  as  is  found  in  a  variety  of  birds  of  prey)  to  a  highly  pat- 
terned plumage.  Thus  Milvago  chimango  has  a  brown  plumage, 
variegated  somewhat  with  barrings,  reminiscent  of  the  plumage  of 
some  kites  of  the  genus  Milvus.  The  plumages  of  both  species  of 
Daptrius,  and  of  the  three  Andean  species  of  Phalcoboenus  (carun- 
culatus,  megalopterus,  and  albogularis)  are  very  different  from 
those  of  the  other  caracaras.  These  birds  are  strikingly  marked 
with  black  and  white  patterns,  and  remind  one  of  gallinaceous 
birds  such  as  Crax. 

Immature  caracaras  are  less  varied  in  their  plumages.  Most  of 
them  are  brownish  with  patterns  of  barring  or  streaking,  with  the 
exception  of  the  immature  Daptrius  americanus,  which  is  like  the 
adult.  The  dimorphism  between  immature  and  adult  can  be  very 
well  marked,  as  in  Phalcoboenus  carunculatus,  P.  megalopterus, 
and  P.  albogularis;  or  poorly  marked,  as  in  Daptrius  americanus 
or  Milvago  chimango;  or  intermediate,  as  in  Polyborus  plancus  and 
P.  lutosus. 

In  spite  of  the  variation  in  plumage  color  and  pattern  exhibited 
by  the  different  species  of  caracaras,  certain  basic  resemblances  are 
evident  in  the  group  as  a  whole  when  adult  and  immature  plumages 
are  compared  together.  For  example,  the  immatures  of  Milvago 
chimachima,  Phalcoboenus  carunculatus,  P.  megalopterus,  P.  albo- 
gularis, Polyborus  lutosus  and  P.  plancus  are  all  very  similar  to 
one  another,  as  they  are  to  the  adult  of  Milvago  chimango.  Thus, 
regardless  of  the  intraspecific  variabihty  between  immatures  and 
adults  on  the  one  hand,  and  the  interspecific  variability  among 
adults  on  the  other,  Milvago,  Phalcoboenus,  and  Polyborus  all 
appear  to  have  similarities  in  plumage  color  and  pattern. 

In  every  genus  except  Polyborus,  there  is  a  dichotomy  between 
one  or  more  species  that  have  different  immature  and  adult  plum- 
ages, and  one  or  more  species  that  have  quite  similar  immature  and 
adult  plumages.     This   dichotomy   is   obvious   in   Milvago,   with 


1970  SPECIATION    IN    THE    CARACARAS  9 

chimanfio  plumages  much  alike,  and  chimachima  unlike;  in  Phal- 
coboenus,  with  australis  plumages  much  alike,  and  with  canincu- 
latus-megalopterus-albogularis  plumages  very  different.  The  dicho- 
tomy is  still  present,  but  much  less  obvious,  in  Daptrius,  with 
americanus  plumages  alike  and  ater  plumages  slightly  different. 
Correlation  between  this  dichotomy  and  patterns  of  geographical 
distribution  among  closely  related  species  is  not  readily  apparent. 
In  Milvago  and  Phalcoboemis ,  the  species  which  differ  least  in  their 
adult  and  immature  plumages  are  the  two  southern  ones;  but  in 
Milvago  alone,  there  is  an  important  geographical  overlap  between 
chimango  and  chimachima,  whereas  there  is  no  or  only  a  very  nar- 
row overlap  between  the  southern  australis  and  the  more  northern 
carunculatus-megalopterus-albogularis  complex.  In  Daptrius  (di- 
chotomy poorly  marked),  there  is  almost  complete  overlap  between 
the  ranges  of  the  two  species,  since  the  range  of  ater  is  almost 
entirely  contained  within  that  of  americanus.  In  Polyborus  (no, 
or  almost  no  dichotomy ) ,  lutosus  and  plancus  are  entirely  allopat- 
ric.  (The  possible  ecological  significance  of  the  immature  and  adult 
dimorphism  is  discussed  below  under  habitat  preferences.) 

If  one  were  to  consider  the  immature-hke  plumage  of  some  sex- 
ually mature  birds  as  being  a  primitive  condition,  and  the  strikingly 
different  plumage  in  other  mature  birds  as  an  advanced  one  (i.e., 
secondarily  developed  during  the  evolutionary  history  of  the  cara- 
caras),  then  Polyborus  and  Daptrius  might  be  thought  to  be  more 
primitive  than  the  other  two  genera.  If  a  brownish,  barred  and 
streaked  immature  plumage  were  considered  a  more  primitive  con- 
dition, then  Daptrius  is  more  advanced  in  this  character  than  the 
three  other  genera,  because  in  that  genus,  immatures  are  hardly 
different  from  adults,  being  also  conspicuously  patterned  in  black 
and  white. 

Naked  Facial  Skin 

Every  species  in  the  genera  Polyborus,  Phalcoboenus,  and  Dap- 
trius has  brightly  colored  naked  skin  between  the  bill  and  the  eye, 
and  often  around  the  eye  or  even  the  throat.  In  the  genus  Milvago, 
only  M.  chimachima  has  naked  facial  skin;  M.  chimango  has  a  fully 
feathered  head.  The  area  of  unfeathered  skin  varies  from  species 
to  species  among  those  that  have  naked  facial  skin.  In  the  species 
of  Phalcoboenus,  this  variation  is  geographical.  In  Phalcoboenus 
carunculatus  (Colombia  and  Ecuador),  the  surface  of  facial  skin 
is  extensive,  and  the  throat  is  even  adorned  by  fleshy  wattles.    In 


10  BREVIORA  No.    355 

p.  megalopterus  (Peru,  Bolivia,  and  northern  Chile-Argentina), 
only  the  lores  are  unfeathered,  while  the  throat  is  largely  feathered. 
In  P.  albogularis  (Patagonia),  the  extent  of  bare  loral  skin  is 
smaller  than  in  megalopterus.  Finally,  in  P.  australis  (southernmost 
islands  of  South  America),  the  facial  skin  is  almost  entirely  feath- 
ered, but  there  are  wattles  on  the  breast  instead.  The  difference 
between  P.  australis  and  P.  carunculatus-megalopterus-albogularis 
may  be  related  to  the  fact  that  australis  is  sympatric  with  Polyborus 
plancus,  a  species  having  extensive  naked  facial  skin,  whereas  the 
other  three  species  of  Phalcoboenus  are  the  only  caracaras  in  their 
respective  ranges. 

The  naked  facial  skin  in  the  caracaras  varies  from  salmon  pink 
to  rose-red  and  from  yellowish  to  bright  red  (see  Table  1).  This 
variation  is  both  intra-  and  interspecific.  I  have  seen  the  facial 
skin  of  one  individual  of  Polyborus  plancus  change,  in  a  few  sec- 
onds, from  pale  yellow  to  salmon-pink  and  finally  to  vivid  red. 
Such  a  rapid  change  cannot  easily  be  ascribed  to  hormonal  influ- 
ences, but  is  more  likely  to  be  due  to  a  sudden  flush  of  blood  to  the 
superficial  vessels  of  the  skin.  Brown  and  Amadon  (1968:  738) 
mention  a  reverse  change  in  P.  plancus:  "bare  facial  skin  carmine 
red,  changing  to  yellow  when  excited." 

The  variation  in  facial  skin  color  in  the  caracaras  (Table  1) 
seems  too  extensive  within  species,  and  too  restricted  between 
species  (differences  between,  say,  yellow  and  orange,  or  orange  and 
red  seem  relatively  slight)  to  be  important  as  a  species-specific 
means  of  recognition.  Presence  or  absence,  together  with  color 
and  area  of  unfeathered  skin  might,  however,  play  such  a  role 
among  true  sympatric  species,  e.g.,  Phalcoboenus  australis  and 
Polyborus  plancus  already  cited,  or  Milvago  chimango  and  M. 
chimachima. 

Nostril  Shape 

I  have  examined  skulls  of  Polyborus  plancus  (several  speci- 
mens), Phalcoboenus  australis  (4),  Daptrius  sp.  (1 ),  and  Milvago 
sp.  (3).  Polyborus  plancus  has  slanted,  elongated  nostrils  (bean- 
shaped),  while  Phalcoboenus  australis,  Daptrius  sp.,  and  Milvago 
sp.  all  have  rounded  nostrils.  This  difference  is  also  visible  on  the 
cere  of  study  skins  and  seems  to  be  confined  to  Polyborus  (Table 
1 ) ,  since  only  P.  lutosus  and  P.  plancus  have  bean-shaped  nostrils. 
Swann  (1925:   66)   and  Friedmann  (1950:   545-546)  used  this 


1970  SPECIATION  IN  THE  CARACARAS  11 

difference  in  nostril  shape,  together  with  other  characters,  as  diag- 
nostic features  to  key  out  the  genera  of  caracaras.  I  do  not  know 
what  the  biological  significance  of  this  difference  may  be. 

Habitat  Preferences 

The  preferred  habitats  of  Milvago,  Phalcoboenus,  and  Polyborus 
include  a  variety  of  nonforest  types:  open  scrub,  grassy  pampas, 
tussock-grassland,  pastures,  treeless  cultivated  farmland,  open 
thorny  chaco,  savanna  woodland,  and  open  plantations.  Phalco- 
boenus albogularis  may  be  an  exception,  since  Olrog  (1948:  478; 
1950:  520)  reports  it  as  a  forest  bird. 

Both  species  of  Daptrius  are  inhabitants  of  tropical  forest  and 
contrast  markedly  with  the  other  caracaras  in  this  feature.  The 
distribution  of  ater  and  americamis  corresponds  to  the  distribution 
of  wet  lowland  rain  forest  in  Central  and  South  America,  but  the 
actual  preference  of  these  species  seems  to  be  less  for  the  forest 
interior  than  for  more  open  situations  within  or  along  the  forest: 
river  banks,  small  clearings,  secondary  growth,  mangroves,  and 
tree-tops.  The  plumage  pattern  of  both  species  of  Daptrius,  espe- 
cially D.  americamis,  is  most  similar  to  that  of  adults  of  Phalco- 
boenus carunculatus  and  P.  megalopterus,  which  inhabit  high 
Andean  steppes,  an  environment  that  differs  in  every  respect  from 
that  of  Daptrius.  This  basic  morphological  similarity  among  taxa 
of  widely  distinct  ecological  preferences  seems  to  be  more  easily 
understandable  on  an  hypothesis  of  close  relationship  than  on  one 
of  convergent  evolution.  The  fact  that  the  species  of  Phalcoboenus 
mentioned  above  have  a  very  different  immature  plumage,  while 
those  of  Daptrius  are  far  less  dimorphic  between  adult  and  imma- 
ture, might  be  a  correlate  of  environmental  differences  between  the 
two  genera.  In  the  open  habitats  of  the  high  Andes  there  is  never 
more  than  one  species  of  caracara  at  any  one  locality  (diversity 
=  1 ) .  Because  congeneric  competitors  are  absent,  the  sharp 
dimorphism  between  adults  and  immatures  of  Phalcoboenus  may 
consequently  reflect  the  results  of  slightly  relaxed  selective  pres- 
sures. In  the  tropical  lowland  forests,  however,  there  are  two 
sympatric  species  of  caracaras  (diversity  =  2),  so  that  selection 
through  interspecific  competition  might  possibly  limit  the  range  of 
intraspecific  variability,  thus  resulting  in  the  evolution  of  similarity 
(monomorphism)  between  immatures  and  adults  of  Daptrius.  The 
difference  in  size  (character  divergence)  between  the  two  species 


12  BREVIORA  No.    355 

of  Daptrius,  which  are  sympatric,  may  be  relevant  here.  Being  so 
different  from  each  other  (no  overlap  in  range  of  wing  lengths), 
they  should  compete  very  little  for  food  (see  Schoener,  1 965 ) .  The 
interspecific  difference  in  size,  together  with  the  lack  of  dimorphism 
between  age  categories  in  Daptrius,  may  be  roughly  equivalent 
ecologically  to  the  striking  dimorphism  within  high  Andean  Phal- 
coboenus,  which  do  not  have  any  sympatric  congeners.  In  Milvago, 
where  the  two  species  are  largely  allopatric,  one  observes  a  con- 
siderable overlap  in  wing  lengths  between  the  two,  but  one  of  the 
species  is  conspicuously  dimorphic  (chimachima) ,  whereas  the 
other  is  not.  Therefore,  the  situation  in  Milvago  appears  inter- 
mediate to  that  in  both  Daptrius  and  Phalcoboenus.  I  beheve  this 
intermediacy  is  also  found  in  the  habitats  occupied  by  Milvago 
(such  as  open  woodland,  savannas)  that  are  more  or  less  inter- 
mediate between  lowland  wet  forest  (occupied  by  Daptrius)  and 
barren  high  Andean  steppes  (occupied  by  Phalcoboenus). 

Summary  of  Character  A  nalysis 

If  the  characters  discussed  above  are  examined  separately,  the 
variation  among  some  of  them  shows  the  following  possible  group- 
ing within  the  caracaras.  (a)  Polyborus  is  distinct  in  nostril  shape 
from  the  other  genera,  (b)  Daptrius  and  Phalcoboenus  are  closer 
to  each  other  than  to  other  genera  since  both  have  a  strikingly 
patterned  black  and  white  adult  plumage,  (c)  The  immature  plum- 
ages of  Milvago,  Phalcoboenus  and  Polyborus  appear  extremely 
similar  to  one  another,  and  differ,  as  a  group,  from  those  of  Dap- 
trius. If  both  adult  and  immature  plumages  are  used,  together  with 
habitat  preferences,  the  two  species  of  Daptrius  appear  to  stand 
out  against  most  other  species.  First,  the  immature  plumage  of 
Daptrius,  when  distinct  from  that  of  the  adult  (as  in  D.  ater),  is 
quite  different  from  the  brownish,  streaked  or  barred  immature 
plumage  of  all  other  species  except  Phalcoboenus  australis.  Sec- 
ondly, the  forest  habitat  of  the  species  of  Daptrius  differs  from  the 
nonforest  habitats  of  the  species  in  the  other  genera,  with  the  pos- 
sible exception  of  Phalcoboenus  albogularis.  (The  remaining  char- 
acters [naked  facial  skin  and  size]  seem  of  httle  or  no  use  in 
estabUshing  groups  within  the  caracaras.) 

I  can  only  conclude  from  this  analysis  that  all  caracaras  appear 
to  be  closely  interrelated,  but  that  Daptrius  is  less  similar  to  the 
other  three  genera  than  these  are  to  each  other. 


1970  SPECIATION  IN  THE  CARACARAS  13 

CLASSIFICATION 

The  splitting  of  the  caracaras  into  four  genera,  endorsed  by  most 
taxonomists,  does  not  seem  to  reflect  properly  the  close  relation- 
ships of  these  birds.  Since  the  lumping  of  all  caracaras  into  a  single 
genus  may  be  going  somewhat  too  far  in  the  opposite  direction,  I 
suggest  here  a  third  possibiUty,  which  is  to  put  the  caracaras  in- 
habiting nonforest  habitats  in  a  single  genus  (Polyborus,  including 
Milvago  and  Phalcoboemis)  and  to  keep  the  forest  caracaras  in  a 
second  genus  (Daptrius).  Further  subdivisions  within  the  non- 
forest  caracaras  can  be  made  by  using  species-groups  and  super- 
species,  which  do  not  burden  the  nomenclature  with  additional 
names  (as  pointed  out  by  Cain,  1954),  yet  permit  a  finer  hierarchy 
between  the  genus  and  species  levels. 

I  present  below  a  classification  outline  of  the  caracaras,  includ- 
ing species-groups  and  superspecies.  Each  species-group  represents 
a  former  genus.  The  grouping  of  some  species  in  a  superspecies 
(included  in  braces)  is  given  here  in  anticipation  of  the  discussion 
on  speciation  in  the  next  section  of  this  paper.  The  sequence  of 
taxa  in  this  list  is  arbitrary,  and  does  not  pretend  to  suggest  that 
some  taxa  are  more  primitive  than  others,  since  such  decisions 
would  be  guess  work. 

Genus  Dap /m/5  Vieillot,  1816  (forest  caracaras) 
D.  ater  Vieillot,  1816 
D.  americanus  (Boddaert,  1783) 

Genus  Polyborus  Vieillot,  1816  (nonforest  caracaras) 

1 .  chimachima  species-group 

P.  chimachima  Vieillot,  1816 
P.  chimango  Vieillot,  1816 

2.  plancus  species-group 

P.   plancus   (Miller,    Mil)    (includes   lutosus  Ridgway, 
1876,  considered  by  some  authors  as  a  separate  species) 

australis  superspecies 
iP.  australis  (Gmelin,  1788) 

\p.  megalopterus  (Meyen,  1834)  (includes  carunculatus 
(Des  Murs,  1853),  and  albogularis  Gould,  1837,  con- 
sidered by  some  authors  as  two  separate  species) 


14  BREVIORA  No.    355 

VARIATION    AND    SPECIATION    IN   DAPTRIUS 

Of  the  two  species  of  Daptrius,  only  D.  americanus  shows  geo- 
graphical variation.  This  variation  seems  to  be  a  cline  of  diminish- 
ing size,  as  measured  by  wing  length,  from  Guatemala  southward 
through  Central  America  to  South  America.  According  to  Brown 
and  Amadon  (1968),  the  populations  from  "southern  Brazil"  may 
show  an  increase  in  wing  length  over  those  from  farther  north  in 
South  America.  This  increase  is  in  fact  quite  sharp,  and  is  illus- 
trated by  Figure  2.  The  disjunction  may  reflect  absence  of  gene 
flow  between  birds  from  the  Amazon  Valley  and  those  from  the 
uplands  of  Brazil.  The  birds  Hving  in  the  coastal  forests  of  south- 
ern Brazil  and  in  the  gallery  forests  of  the  Parana-Paraguay  drain- 
age system  of  south-central  Brazil  may  be  ecologically  isolated 
from  birds  living  in  forests  of  the  Amazon  Valley  by  parts  of  the 
central  Brazilian  plateau,  which  are  covered  by  extensive  open 
savannas  and  campos. 

Any  inferences  that  might  be  drawn  about  the  possible  evolu- 
tionary history  of  this  genus  are  prevented  by  the  considerable 
sympatry  between  ater  and  americanus  (see  map  76  in  Brown  and 
Amadon,  1968). 


320     330      340      350      360     370      360      390      400     4  10 
I \ \ \ \ 1 \ 1 \ 1 


Guatem,,   Hond.Nicar.    Cos,   Rica 


Ecuador.   Peru 


Brazil    (Goias,    Mato    Grosso) 


Figure  2.  Geographical  variation  of  wing  length  in  Daptrius  americanus. 
Measurements  are  in  miHimeters.  Horizontal  bars:  range  of  measurements; 
vertical  bars:  means. 


1970  SPECIATION    IN    THE    CARACARAS  15 

VARIATION   AND   SPECIATION    IN   POLYBORUS 
1.    The  chimachima  Species-Group 

The  two  species  of  this  group,  which  constitute  the  former  genus 
Milvago,  are  largely  allopatric.  Polyborus  chimachima  occurs  in 
southern  Central  America  (Costa  Rica  and  Panama)  and  in  South 
America  from  Colombia  and  Venezuela  in  the  north  to  northern 
Argentina  in  the  south,  and  P.  chimango  from  northern  Argentina 
southward  to  southernmost  South  America.  They  are  sympatric, 
however,  over  a  relatively  broad  zone,  including  Rio  Grande  do 
Sul  in  southern  Brazil,  parts  of  northern  Argentina,  Uruguay,  and 
Paraguay,  and  southern  Bolivia  westward  to  the  foothills  of  the 
Andes. 

Polyborus  chimachima  shows  color  and  size  variation.  Tail  and 
culmen  length  appear  to  vary  clinally,  and  to  increase  from  south 
to  north,  whereas  the  reverse  seems  to  be  true  of  wing  length  (see 
Fig.  3). 

Polyborus  chimango  shows  geographical  variation  that  seems  to 
conform  to  eco-geographical  rules,  since  the  southernmost  birds 
are  the  largest  (Bergmann's  rule),  and  the  birds  occurring  along 
the  wet,  forested  Andean  slopes  are  darker  than  those  living  in  the 
drier,  grassy  and  shrubby  plains  of  central  Argentina  (Gloger's 
rule). 

Geographical  variation  in  P.  chimango  has  been  recognized  tax- 
onomically  by  the  naming  of  three  subspecies.  Two  of  them,  temu- 
coensis  (Andean  slopes  birds)  and  chimango  (open  plains  birds) 
intergrade  broadly.  The  third  subspecies,  juegiensis,  seems  re- 
stricted to  the  island  of  Tierra  del  Fuego,  but  is  probably  merely 
the  southward  end  of  a  north  to  south  cline  of  increasing  size. 
Interestingly,  the  southern  populations,  from  Tierra  del  Fuego  and 
the  mainland  of  southern  Patagonia,  appear  to  leave  their  breeding 
grounds  to  migrate  northward  as  far  as  northern  Argentina  (Olrog, 
1962:  112-113)  in  the  southern  hemisphere  winter. 

Although  P.  chimachima  and  P.  chimango  are  undoubtedly  very 
close  relatives,  they  have  diverged  morphologically  rather  consider- 
ably. One  of  the  differences  has  been  mentioned  earlier:  the  im- 
mature plumage  of  chimango  is  very  similar  to  that  of  the  adults, 
whereas  the  immature  chimachima  is  quite  unlike  the  adult.  An- 
other difference  between  the  two  species  may  be  ecological.   As  I 


16 


BREVIORA 


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1970  SPECIATION    IN    THE    CARACARAS  17 

judge  from  personal  observations  and  literature  records,  P.  chima- 
chima  may  generally  prefer  somewhat  denser,  more  wooded,  habi- 
tats than  P.  chimango,  but  no  study  of  a  possible  habitat  segrega- 
tion has  been  undertaken  in  the  area  of  sympatry.  If  tarsus  length 
reflects  whether  a  bird  is  more  or  less  arboreal,  then  variation 
between  P.  chimachima  and  P.  chimango  in  this  character  is  in- 
structive. That  P.  chimachima  populations  have  shorter  tarsi  than 
those  of  P.  chimango  (see  Fig.  3)  suggests  that  the  latter  may  be 
less  arboreal  than  the  former.  Whether  this  difference  is  true 
character  divergence  should  be  examined  carefully. 

Brown  and  Amadon  (1968:  739)  say  that  the  two  species  "may 
be  regarded  as  a  super-species."  Even  if  a  broad  superspecies  con- 
cept is  embraced,  it  seems  to  me  that  the  zone  of  overlap,  con- 
sidered together  with  the  morphological  differentiation  between 
chimachima  and  chimango,  clearly  suggests  that  these  two  taxa  are 
past  the  species  borderline,  and  that  application  of  the  superspecies 
concept  to  their  case  may  no  longer  be  correct.  As  far  as  I  know, 
hybridization  does  not  take  place  between  the  two  species  where 
they  are  sympatric;  a  field  study  of  the  pair  in  their  overlap  zone 
would  nevertheless  be  rewarding. 

It  seems  most  likely  that  the  pair  of  species  chimachima  and 
chimango  has  originated  by  a  straightforward  process  of  splitting 
of  one  ancestral  population  into  two.  Yet  secondary  sympatry  is 
too  extensive  to  permit  more  speculation  about  the  original 
isolation. 

2.    The  planciis  Species-Group 

This  group  consists  of  P.  plancus  and  the  P.  australis  super- 
species. The  birds  of  this  group  are  medium  to  large,  and  have 
brownish  immature  plumage  with  dark  streaking  and/or  barring. 
The  P.  plancus  species-group  includes  both  the  former  genera 
Polybonis  and  Phalcoboemis.  Brown  and  Amadon  (1968:  730) 
remarked  that  "Phalcoboemis  australis  is  in  all  respects  inter- 
mediate" between  Polyborus  and  Phalcoboenus,  yet  they  kept  the 
two  genera  distinct. 

P.  plancus  is  essentially  a  lowland  species,  while  the  members  of 
the  P.  australis  superspecies  occur  mostly  in  the  Andes,  in  some 
localities  at  high  altitudes.  Where  plancus  meets  members  of  the 
australis  superspecies,  as  on  the  Falkland  Islands  and  on  islands 
off  Tierra  del  Fuego,  the  two  may  live  in  habitat  co-occupancy, 
but  their  ecological  relationships  have  not  been  studied.    In  any 


18  BREVIORA  No.    355 

event,  sympatry  in  the  P.  plancus  species-group  is  very  limited  and 
geographically  peripheral. 

Polyborus  plancus 

Polybonis  plancus  has  a  broad  distribution  from  the  southern 
United  States  and  Mexico  to  Tierra  del  Fuego  and  the  Falkland 
Islands  and  exhibits  extensive  geographical  variation.  The  birds 
from  Florida,  isolated  from  the  remainder  of  the  mainland  North 
American  birds,  are  closer  geographically  and  morphologically  to 
the  Cuban  ones  (both  are  included  in  the  subspecies  auduboni) . 
The  birds  of  the  population  living  on  the  Tres  Marias  Islands  off 
western  Mexico  (subspecies  pallid  us)  are  morphologically  differ- 
entiated from  the  nearest  mainland  populations  (for  a  discussion 
of  the  characters  of  palUdus,  see  Grant,  1965:  12-14).  The  con- 
tinental population  living  from  eastern  Panama  southward  to 
northwestern  Peru  near  the  Upper  Maranon  and  Amazon  Rivers 
(subspecies  cheriway)  are  well  marked.  There  is  intergradation 
between  cheriway  and  southern  South  American  birds  (subspecies 
plancus)  in  Brazil  (see  Hellmayr  and  Conover,  1949:  283-284). 

The  extinct  Polyborus  lutosus  lived  on  Guadalupe  Island  (see 
e.g.,  Abbott,  1933;  Greenway,  1958).  The  adults  looked  very 
similar  to  plancus,  but  white  was  replaced  by  brown,  and  there 
was  no  black  on  the  abdomen;  the  immature  was  brown  and 
streaked.  This  insular  population  was  certainly  well  marked;  it 
is  considered  here  as  having  been  a  strong  subspecies  of  plancus. 
Brown  and  Amadon  (1968:  736)  maintained  lutosus  as  a  separate 
species. 
The  australis  Superspecies 

The  four  nominal  species  (the  former  genus  Phalcoboenus)  in- 
cluded in  this  superspecies  are  Andean  and  Patagonian  in  distribu- 
tion (Fig.  4).  One  of  the  species,  australis,  occurs  only  on  islands 
off  southern  South  America.  The  three  others,  carunculatus,  mega- 
lopterus,  and  albogidaris,  occur  along  the  Andean  cordillera,  from 
Colombia  to  Tierra  del  Fuego. 

Polyborus  australis  is  larger  than  the  three  other  species,  but 
resembles  them  in  several  other  respects.  The  pattern  of  breast  and 
abdominal  streaks  in  the  adults  is  especially  reminiscent  of  the 
geographically  distant  carunculatus.  P.  australis  breeds  on  the 
Falklands,  where,  according  to  Cawkell  and  Hamilton  (1961),  its 
numbers  have  decreased  in  the  recent  past.  It  also  breeds  on  sev- 
eral islands  off  Tierra  del  Fuego  (Staten  and  Navarino),  and  on 
islands  of  the  Cape  Horn  Archipelago  (for  example,  Grevy,  Bayly, 


1970 


SPECIATION    IN    THE    CARACARAS 


19 


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Figure  4.  Geographical  distribution  of  the  Folyborus  aiistralis  superspecies. 
A  question  mark  represents  the  alleged  occurrence  of  albogulans  at  Puente 
del  Inca,  Mendoza  (see  Hellmayr  and  Conover,  1949:  217-218).  Labeled 
localities  are  identified  in  the  text. 


20  BREVIORA  No.    355 

Freycinet,  Hershel:  Olrog:  1950:  520).  Reynolds  (1932)  ob- 
served one  P.  australis  on  Woodcock  Island  in  the  Beagle  Channel, 
and  Olrog  (1948:  478)  saw  it  at  Yendegaia,  along  the  southern 
coast  of  Tierra  del  Fuego,  where  he  also  collected  P.  megalopterus 
albogularis  (see  Fig.  4).  This  observation  (not  mentioned  by 
Brown  and  Amadon,  1968:  731  )  implies  that  P.  australis  and  P. 
megalopterus  albogularis  are  narrowly  sympatric  on  the  main  island 
of  Tierra  del  Fuego,  but  this  suggestion  needs  careful  checking  in 
the  field.  P.  australis  is  sympatric  with  P.  plancus  on  some  islands 
off  Tierra  del  Fuego  and  the  Falklands. 

Polyborus  carunculatus,  megalopterus,  and  albogularis  are  here 
treated  as  three  subspecies  of  a  single  species,  as  previously  advo- 
cated by  Hellmayr  and  Conover  (1949:  276-277),  and  adopted 
later  by  some  students  of  South  American  birds  (e.g.,  Olrog,  1963; 
Koepcke,  1964;  and  Johnson,  1965).  (The  name  megalopterus 
Meyen,  1834,  has  priority  over  albogularis  Gould,  1837,  and 
should  be  used  as  the  specific  name,  contra  Hellmayr  and  Conover, 
1949.)  Other  authors,  however,  have  maintained  the  three  taxa 
as  separate  species  (e.g.,  Amadon,  1964:  14;  de  Schauensee,  1966; 
Brown  and  Amadon,  1968). 

The  divergence  of  opinion  about  the  taxonomic  status  of  these 
three  taxa  has  hinged  on  two  things:  first,  the  striking  interspecific 
adult  plumage  color  differences,  and  secondly,  the  allopatry  of  the 
taxa.  A  third  factor,  namely  the  absence  of  intermediate  specimens 
between  any  two  of  these  forms,  has  been  invoked  by  some  authors 
to  justify  their  treating  the  three  as  species.  Brown  and  Amadon 
(1968:  371),  for  instance,  stated:  "the  two  [taxa]  that  are  the 
most  similar,  albogularis  and  megalopterus,  are  not  known  to  inter- 
grade  rather  [sic]  there  seems  to  be  a  slight  gap  between  their 
ranges,  suggesting  friction."  A  few  specimens,  however,  do  seem 
to  be  intermediate  between  carunculatus  and  tnegalopterus  on  the 
one  hand,  and  between  megalopterus  and  albogularis  on  the  other, 
as  discussed  below. 

The  characters  that  vary  from  one  to  the  other  of  the  three  taxa, 
carunculatus,  megalopterus  and  albogularis,  are:  the  amount  of 
white  at  the  tip  of  the  primaries,  the  degree  of  curliness  of  the  crest 
feathers,  the  extent  of  bare  skin  on  the  throat,  and  the  coloration 
of  the  underparts.  The  two  northern  taxa,  carunculatus  and  mega- 
lopterus, live  in  high  Andean  grassland  and  scrub  above  the  timber 
line,  at  altitudes  usually  higher  than  3000-3500  meters.  Both  of 
these  forms  are  common  birds  where  they  live,  and  can  be  seen 


1970  SPECIATION    IN    THE    CARACARAS  21 

daily  in  small  groups  or  singly  (personal  observation).  The  popu- 
lations of  carunculatus  are  geographically  isolated  from  those  of 
we-^alopterus  by  a  hiatus  that  includes  the  low  Andes  of  northern 
Peru,  the  depression  of  the  Upper  Maranon  Valley  and  other  val- 
leys in  northern  Peru  (see  Fig.  4).  Birds  north  of  this  gap  {carun- 
culatus) have  the  throat  and  breast  black  with  white  longitudinal 
streaks  or  spots,  and  the  abdomen  white.  South  of  the  gap,  birds 
{megalopterus)  have  throat  and  breast  black  without  white  spotting 
or  streaking,  and  a  white  abdomen. 

These  morphological  differences,  considered  in  the  light  of  the 
ecological  barrier  lying  between  the  two  taxa,  might  be  interpreted 
as  reflecting  a  period  of  geographical  isolation  during  which  differ- 
ential selection  acted  on  populations  cut  off  from  free  gene  flow. 
Absence  of  gene  flow,  however,  seems  surprising  in  view  of  the 
good  flying  abilities  and  the  relative  abundance  of  birds  of  this 
group.  It  is  therefore  noteworthy  that  Zimmer  (1930:  248)  found 
three  adult  males  of  megalopterus  from  Peru,  all  showing  "an 
interesting  progression  in  the  direction  of  carunculatus."  Two  of 
the  three  specimens  (from  Macate,  Department  Ancash,  and 
Panao,  Department  Huanuco,  see  Fig.  4),  have  small,  pale  or 
whitish  spots  on  the  lower  breast;  the  third  specimen  (from  Junin, 
farther  south)  lacks  breast  spots.  Zimmer's  description  of  the  three 
birds  should  be  consulted  for  additional  details. 

These  data  seem  to  indicate  that  gene  flow  is  indeed  possible 
between  Ecuadorian  carunculatus  and  Peruvian  megalopterus. 
Further  intensive  collecting  of  these  birds  in  northern  Peru  is  badly 
needed.  The  total  number  of  specimens  of  either  carunculatus  or 
megalopterus  from  areas  close  to  the  barrier  of  northern  Peru  is 
low,  so  hybrid  specimens  might  appear  to  be  much  rarer  than  they 
really  are. 

What  about  the  situation  between  megalopterus  and  albogularis? 
The  northern  megalopterus  is  a  common  bird  in  the  high  Andean 
scrub  vegetation  of  the  Argentine-Chilean  cordilleras.  The  south- 
ern albogularis  seems  to  occur  in  Nothojagus  forests  rather  than 
open  vegetation  types  (see  Olrog,  1948:  478;  1950:  520;  Philippi 
et  al.,  1954:  39).  There  seems  to  be  a  distributional  hiatus  (see 
Fig.  4)  between  the  northernmost  records  of  albogularis  (in 
Neuquen,  fide  Olrog,  1963:  116)  and  the  southernmost  ones  of 
megalopterus  (in  Talca,  fide  Johnson,  1965:  265).  We  do  not 
know,  however,  whether  this  gap  is  real  or  not,  because  of  the 
general  scarcity  of  collections  made  in  the  "hiatus"  area.   In  any 


22  BREvioRA  No.  355 

event,  what  is  real  is  the  fact  that  no  ecological  barrier  interrupts 
the  distribution  of  megalopterus  and  that  of  alhogularis  in  the  way 
the  northern  Peruvian  low  does  between  megalopterus  and  carun- 
culatus.  The  situation  seems  therefore  more  complex  ecologically, 
and  deserves  field  study. 

From  these  considerations,  contact  should  be  possible  between 
megalopterus  and  alhogularis,  and  if  they  are  not  reproductively 
isolated,  gene  flow  should  occur  between  them.  In  February,  1965, 
at  1950  m  on  Cerro  Catedral,  near  Nahuel  Huapi,  Rio  Negro, 
Argentina  (see  Fig.  4),  I  observed  two  adult  Polyborus  that  were 
attracted  by  a  small  garbage  dump  near  the  Refugio  Lynch.  One 
of  them  had  the  throat  and  breast  black,  in  contrast  with  the  white 
of  the  abdomen  (megalopterus-likQ  phenotype).  The  second  had 
both  a  white  throat  and  breast,  with  only  the  sides  of  the  breast 
black,  not  forming  a  black  pectoral  band  (albogularis-YikQ  pheno- 
type). This  observation  might  have  been  of  a  mixed  pair,  but 
unfortunately  the  birds  could  not  be  collected. 

The  possibility  of  mixed  pairs  and  of  offspring  from  them,  seems 
to  be  shown  by  two  adult  birds  that  exhibit  what  appears  to  be 
intermediacy  between  megalopterus  and  alhogularis.  One  of  these 
birds,  an  adult  male  taken  in  February,  1 896,  in  Chubut,  southern 
Argentina,  was  described  by  Scott  (1910)  as  Ihycter  circumcinctus. 
The  underparts  of  this  specimen  are  as  follows:  the  throat  is  white, 
followed  by  "a  band  of  black  below  the  throat  patch  more  or  less 
variegated  by  white  on  some  of  the  feathers;  this  band  is  about  an 
inch  in  width;  lower  part  of  the  under  neck  pure  white,  the  black 
of  the  sides  of  the  neck  confining  the  white  of  this  region  to  a 
narrow  area,  widening  into  the  pure  white  of  the  breast."  This  bird 
appears  to  be  like  a  specimen  of  alhogularis  with  a  narrow  black 
breast  band.  The  second  of  these  birds,  an  adult  male  from  Nahuel 
Huapi  (see  Fig.  4),  is  mentioned  by  Hellmayr  and  Conover  (1949: 
277).  This  specimen  (British  Museum  99.1.27.229)  has  a  distinct, 
interrupted  breastband. 

The  same  conclusion  seems,  therefore,  to  follow  from  these 
scanty  data  as  from  those  on  carunculatus  and  megalopterus:  con- 
tact between  megalopterus  and  alhogularis  seems  a  reality  since  at 
least  two  specimens  are  somewhat  intermediate  between  the  two 
taxa,  and  since  birds  from  the  two  phenotypes  were  sighted  to- 
gether. Amadon,  however,  speaking  of  Scott's  "circumcinctus," 
said  that  it  "may  be  a  mutant  rather  than  a  true  genetic  intergrade" 
(1964:  15).  This  hypothesis  seems  unlikely  to  me.  Since  speci- 
mens of  alhogularis  are  relatively  rare  in  museums,  the  two  birds 


1970  SPECIATION    IN    THE    CARACARAS  23 

with  a  black  pectoral  band  represent  a  relatively  high  frequency  of 
the  black-banded  phenotype,  perhaps  as  many  as  1  in  10  or  1  in 
15 — a  number  too  high  to  be  accounted  for  solely  on  the  basis  of 
recurrent  mutation.  A  third  possible  interpretation  would  be  that 
there  is  a  polymorphism  involving  breast  color.  If  this  were  true, 
then  obviously  megalopterus  and  albogidaris  should  be  considered 
members  of  the  same  species. 

For  the  time  being,  I  believe  the  best  interpretation  of  the  situa- 
tion in  this  complex  to  be  that  the  three  taxa,  although  clearly  dif- 
ferentiated morphologically  as  adults,  have  not  achieved  compbte 
reproductive  isolation,  so  that  when  two  of  them  come  in  contact, 
whether  across  a  barrier  (carunculatus  with  megalopterus)  or  not 
(megalopterus  and  albogularis) ,  they  produce  hybrids.  The  tax- 
onomic  solution  I  propose  in  this  paper  is  to  consider  all  three 
taxa  conspecific,  although  I  realize  that  this  lumping  may  be  a 
little  premature  in  view  of  the  paucity  of  data.  If  additional  study 
should  reveal  that  hybridization  is  very  limited,  even  though  there 
may  be  plenty  of  opportunity  for  it  to  take  place,  then  it  would  be 
justified  to  maintain  the  three  taxa  as  species,  although  it  would 
be  necessary  to  emphasize  that  they  are  really  semispecies:  a  truly 
intermediate  stage  in  the  speciation  process. 

DISCUSSION 

The  caracaras  are  interesting  to  the  student  of  speciation,  be- 
cause they  offer  a  variety  of  phenomena  that  are  interpreted  as 
intermediate  in  the  process  of  species  formation  (see  Table  3). 
They  can  be  summarized  as  follows.  In  Daptrius  americanus,  the 
populations  from  southern  Brazil  may  be  geographically  isolated 
from  other  populations  farther  north  in  South  America.  In  Poly- 
borus  plancus  can  be  seen  phenomena  of  incipient  spsciation. 
Isolated  populations,  both  insular  (Tres  Marias  Islands,  Cuba) 
and  continental,  exist,  showing  varying  degrees  of  morphological 
differentiation.  The  most  differentiated  population  (lutosus)  was 
wholly  insular,  yet  was  of  no  evolutionary  significance  for  further 
speciation  since  it  is  now  extinct.  The  other  insular  populations, 
on  the  Tres  Marias  Islands  and  Cuba,  are  much  less  differentiated 
than  lutosus,  the  Cuban  one  even  being  similar  morphologically  to 
the  Florida  population.  On  the  continent,  populations  from  north- 
em  South  America  (cheriway)  are  sufficiently  differentiated  from 
southern  South  American  ones  (plancus)  for  some  ornithologists 


24 


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1970  SPECIATION    IN    THE    CARACARAS  25 

to  have  treated  them  as  species.  There  is  some  evidence  that  (sec- 
ondary? )  hybridization  takes  place  near  the  mouth  of  the  Amazon 
where  they  come  into  contact. 

The  taxa  of  the  Polyborus  australis  superspecies  present  another 
"stage"  of  the  speciation  process,  in  that  one  of  the  members  of 
the  superspecies,  australis,  is  sufficiently  distinct  to  be  considered 
unhesitatingly  as  a  species.  The  three  remaining  members,  how- 
ever, present  interesting  situations.  In  one  instance,  differentiation 
seems  to  have  taken  place  across  an  ecological  barrier  (the  low 
area  of  the  northern  Peruvian  Andes),  yet  hybridization  appears 
to  occur  in  spite  of  this  gap.  In  the  second  instance,  no  barrier  is 
evident  today,  and  some  hybridization  seems  to  occur.  The  south- 
ernmost taxon  of  this  complex  {albogularis)  apparendy  meets 
australis  in  Tierra  del  Fuego. 

In  the  Polyborus  chimachima  species-group,  speciation  is  com- 
pleted, and  the  two  species  overlap  now  over  a  considerable  area, 
although  they  are  allopatric  over  the  major  portions  of  their  respec- 
tive ranges.  Finally,  the  two  species  of  the  genus  Daptrius  are  so 
different  morphologically  and  show  so  much  sympatry  that  recon- 
struction of  their  history  is  impossible. 

Although  six  of  the  seven  species  I  recognize  in  the  caracaras 
have  extensive  geographical  distributions,  the  existing  patterns  of 
speciation,  or  incipient  speciation,  seem  to  indicate  that  multiphca- 
tion  of  species  has  occurred  mostly  through  the  formation,  and 
subsequent  differentiation,  of  small  or  relatively  small  peripheral 
isolates.  The  present  isolates  of  Daptrius  americanus  and  Polyborus 
plancus  are  restricted  to  small  areas  around  the  periphery  of  the 
range  of  the  species,  and  the  geographical  location  of  Polyborus 
australis  relative  to  Polyborus  megalopterus  seems  to  suggest  for- 
mer peripheral  isolation  of  the  first  named  species.  Differentiation 
within  P.  megalopterus  does  not  seem  to  correspond  as  clearly  to 
a  pattern  of  isolation  in  peripheral  areas,  although  the  central 
populations  {megalopterus)  do  have  a  much  broader  distribution 
than  either  the  northern  (carunculatus)  or  southern  (albogularis) 
ones. 

The  previous  summary  of  speciation  in  the  caracaras  shows  that 
this  process  is  most  actively  taking  place  along  the  Andes,  where 
the  various  members  of  the  Polyborus  australis  superspecies  live. 
In  the  other,  lowland,  taxa,  the  speciation  process  is  either  com- 
pleted (as  in  Daptrius  or  the  Polyborus  chimachima  species-group) 
or  is  not  as  pronounced  {Polyborus  plancus,  Daptrius  americanus) . 


26  BREVIORA  No.    355 

It  is  tempting  to  relate  the  apparently  greater  evolutionary  activity 
in  the  Andean  caracaras  to  the  recent  geological  history  of  this 
Cordillera.  The  high  Andean  grasslands  and  scrub  habitats  (paramo 
and  puna)  where  Polyborus  megalopterus  now  lives  are  undoubt- 
edly the  most  recent  environments  of  the  Andes,  and  cannot  be 
older  than  the  latest  phases  of  uplift,  which  brought  the  mountains 
to  their  present  tremendous  altitudes  during  the  Pho-Pleistocene 
(see  Childs  and  Beebe,  1963;  Steinmann,  1930;  Ahlfeld  and 
Branisa,  1960;  and  Briiggen,  1950;  for  summaries  of  the  geological 
development  of  the  Andes).  The  differentiation  within  P.  megalop- 
terus most  probably  occurred  during  the  Pleistocene  glaciations, 
although  to  attempt  the  dating  of  such  processes  is  almost  complete 
guess  work.  However,  if  we  recall  that  during  glacial  episodes,  the 
temperature  depression  lowered  the  altitude  of  the  upper  vegeta- 
tion zones,  where  P.  megalopterus  lives,  then  it  becomes  possible 
to  envision  the  separation  of  a  northern  isolate  (proto-carunculatus) 
in  Ecuador  at  interglacial  time,  when  the  altitudinal  raising  of  this 
treeless  zone  occurred,  thus  increasing  the  effectiveness  of  a  natural 
barrier  such  as  the  Upper  Maranon  Valley  and  northern  Peruvian 
low  for  birds  living  on  either  side  of  it.  The  isolation  of  caruncu- 
latus  from  megalopterus,  or,  rather,  of  proto-carunculatus  from 
proto-me galopterus,  might,  then,  have  happened  during  an  inter- 
glacial. It  is,  of  course,  not  possible  to  suggest  which  of  the  several 
interglacial  periods  was  responsible  for  such  an  event. 

Similar  glacial-interglacial  oscillations  may  have  permitted  the 
separation  of  proto-megalopterus  and  proto-australis  in  extreme 
southern  South  America.  During  the  maximum  glacial,  extreme 
southern  South  America  was  covered  with  an  ice-sheet  (Caldenius, 
1932;  Polanski,  1965)  which  probably  forced  Andean  biota  to 
"retreat"  considerably  northward.  At  the  same  time,  however,  the 
Falkland  Islands  were  left  unglaciated,  and,  furthermore,  were  of 
greater  area  than  today  because  of  a  concurrent  lowering  in  sea- 
level.  It  seems  therefore  possible  that  during  the  maximum  glacia- 
tion  the  southernmost  populations  of  the  stock  common  to  mega- 
lopterus and  australis  remained  on  a  Falkland  refuge,  where  they 
were  geographically  isolated  from  mainland  populations  by  the  ice 
barrier,  added  to  the  sea  barrier.  If  such  a  separation  did  indeed 
take  place  during  the  maximum  glaciation,  which  is  attributed  to 
the  late  Pleistocene  (Wiirm  or  Wisconsin)  (see  Polanski,  1965), 
then  the  splitting  of  an  ancestral  stock  into  the  modern  australis 
(having  evolved  from  a  population  in  a  southern  insular  refuge) 


1970  SPECIATION  IN  THE  CARACARAS  27 

and  megalopterus  (having  remained  in  Andean  Patagonia,  but  con- 
siderably farther  north  than  its  present-day  southernmost  limit) 
may  have  taken  place  as  recently  as  50,000  to  80,000  years  ago. 
Of  course,  it  is  also  possible  that  the  original  separation  took  place 
during  an  earlier,  somewhat  less  extensive,  glacial  episode,  but 
since  the  maximum  glaciation  apparently  obliterated  earlier  re- 
mains, it  is  futile  to  speculate  any  further  about  the  possible  course 
of  this  event. 

ACKNOWLEDGMENTS 

I  thank  Ernst  Mayr  for  his  continued  advice  throughout  my 
studies  of  speciation  in  Andean  birds.  He  and  Dean  Amadon 
criticized  an  earlier  version  of  this  paper.  W.  John  Smith  and 
William  H.  Drury,  Jr.  kindly  allowed  me  to  use  their  field  notes 
on  several  species. 

Field  work  was  financed  by  the  Frank  M.  Chapman  Memorial 
Fund  of  the  American  Museum  of  Natural  History,  the  National 
Science  Foundation  (grants  G-19729  and  GB-3167  to  the  Com- 
mittee on  Evolutionary  Biology  of  Harvard  University),  the  Society 
of  the  Sigma  Xi,  and  the  Bourse  federate  de  voyages  of  the  Societe 
helvetique  des  sciences  naturelles  (Switzerland). 

I  am  grateful  to  the  following  persons,  who  helped  me  in  various 
ways  during  my  examination  of  specimens:  Jean  Dorst  (Museum 
national  d'histoire  naturelle,  Paris),  I.  C.  J.  Galbraith  (British 
Museum,  Natural  History),  Father  Antonio  Olivares  (Instituto  de 
Ciencias  Naturales,  Bogota),  Raymond  A.  Paynter,  Jr.  (Museum 
of  Comparative  Zoology),  and  the  late  R.  A.  Philippi  (Museo 
Nacional,  Santiago).  Finally,  I  acknowledge  the  assistance  of 
Warren  Hubley  during  the  course  of  this  study. 

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Their    Distribution.     Narberth,    Pennsylvania,    Livingston    Publ.    Co. 

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BREVIORA 


Mnaseiiamn    of    Coimparative    Zoology 

Cambridge,  Mass,  30  November,  1970  Number  356 

On  new  species  in  a  new  earthworm  genus 
from  Puerto  Rico^ 

G.  E.  Gates2 


Abstract.  A  new  genus  of  earthworms,  Estherella  (family  Glossosco- 
lecidae),  with  new  species  montana  (type  species)  and  nemoralis,  is 
described  from  Puerto  Rico,  and  its  remarkable  structural  modification  is 
discussed. 

A  seemingly  impossible  evolutionary  modification  was  shown 
by  several  worms  received  25-30  years  ago.  Immaturity,  amputa- 
tion, maceration,  and  paucity  of  specimens  prevented  completion 
of  species  descriptions  to  desired  standards.  Unfortunately  subse- 
quent material  never  became  available.  Various  attempts  to  secure 
it  were  futile.  This  contribution  now  is  proferred  in  hope  of 
awakening  interest  in:  1)  An  evolutionary  development  that  some 
zoologists  categorically  maintain  is  impossible.  2 )  The  mostly 
unknown  earthworm  faunas  of  Caribbean  Islands. 

Glossoscolecidae 
Estherella  gen.  nov. 

Definition.  Digestive  system,  with  a  gizzard  in  iii,  three  pairs  of 
calciferous  glands  in  v-vii,  each  gland  sausage-shaped,  vertically 
placed  alongside  gut,  with  a  short  duct  from  dorsal  end  opening 
into  esophagus  just  lateral  to  the  supra-esophageal  vessel,  in- 
testinal origin  in  region  of  xix-xx,  with  a  lamelliform  typhlosole, 
without  caeca  and  supra-intestinal  glands.  Vascular  system,  with 
a  single  dorsal  trunk  aborted  in  front  of  hearts  of  iv,  complete 
ventral  and  subneural  trunks,  the  latter  adherent  to  parietes,  a 
supra-esophageal  trunk  in  v-xiv,  paired  latero-esophageal  trunks 

1  From  research  financed  by  the  National  Science  Foundation. 

2  Zoology  Department,  University  of  Maine,  Orono. 


2  BREVIORA  No.    356 

in  iii-ix  with  connectives  to  supra-esophageal  in  v-vii.  Hearts,  in 
iv-vii  lateral,  in  viii  latero-esophageal.  Nephridia,  holoic  and 
vesiculate.  Nephropores,  obvious,  in  a  regular  longitudinal  rank 
on  each  side  in  region  of  CD.  Pigment,  none.  Septa,  present  from 
3/4.  Prostomium,  none,  replaced  by  a  protrusible  proboscis.  Setae, 
eight  per  segment,  in  regular  longitudinal  ranks. 

Quadrithecal,  spermathecae  adiverticulate,  pores  in  region  of 
CD,  at  5/6-6/7. 

Type  species,  E.  montana  n.  sp. 

Distribution.    Puerto  Rico. 

Estherella  montana  sp.  nov. 

Puerto   Rico,   El   Yunque   Mountain.    Wet  cloud   forest  at 
±  2500  feet.  May   1938.  3-0-0.    P.  J.  Darlington  per  G.  E. 
Pickford.    (Mus.  Comp.  Zool.)    About  2200  feet,  an  anterior 
fragment,  C.  W.  Richmond  &  L.  Stejneger.    (U.  S.  Nad.  Mus.) 
External  characteristics.    Length,  50-60  mm  (juveniles),   175 
mm    (posterior   amputee   of    148    segments).     Diameter,   4   mm 
(juveniles),   12  mm   (amputee).    Segments  of  54  mm  juvenile, 
188.    Color,  white   (long  alcoholic  preservation).    Peristomium, 
much  shorter  than  ii  but  of  about  the  same  appearance  externally 
as  subsequent  segments.    Intersegmental  furrows,  distinct.    Seg- 
mental length,  gradually  increasing  posteriorly  to  region  of  vii-ix. 
Secondary  annulation,  a  presetal  and  a  postsetal  secondary  furrow 
in   each   of   ix-xxvi,   postsetal   secondaries    unrecognized   behind 
xxvi.    Nephropores,  obvious,  present  from  ii,  well  behind  inter- 
segmental furrows  but  usually  less  than  half  way  toward  segmental 
equators,  at  or  near  C.  Setae,  paired,  ventral  couples  first  certainly 
recognizable  in  v,  lateral  couples  in  region  of  xv,  in  region  of  xxx 
CD  slightly  <  AB  much  <  AA   <  BC,  posteriorly  A  A  ca.  -  BC, 
still  further  back  AA  ^  BC.   Dorsal  pores,  none. 

Quadrithecal,  spermathecal  pores,  minute,  superficial,  in  CD, 
at  5/6-6/7.  Other  genital  apertures,  unrecognizable.  Genital 
tumescences,  transversely  and  shortly  elliptical,  indistinctly  de- 
limited, each  with  two  circular  areas  of  epidermal  translucence  at 
center  of  which  is  a  follicle  aperture,  a,b/xw-\xi\.  Region  ot  AA, 
rather  deeply  depressed  through  xv-xxiv. 

Internal  anatomy.  Septa,  4/5-13/14  thickly  muscular  to 
muscular,  funnel-shaped,  large,  apices  well  posteriorly,  14/15  and 
following  septa  slightly  strengthened  by  muscular  fibers.  Septum 
3/4,  a  delicate  transparent  membrane  bearing  on  its  posterior  face 


1970  NEW    EARTHWORM    GENUS  3 

one  pair  of  nephridia  and  on  its  anterior  face  two  other  pairs  of 
tubules,  with  insertion  on  gut  immediately  behind  gizzard.  Pig- 
ment, if  once  present  in  body  wall,  completely  leached  by  pre- 
servative. A  large,  empty  canal,  ellipitical  in  cross  section, 
apparently  completely  circumferential,  in  anterior  portion  of  body 
wall  in  each  of  i-x.  Canal  size,  decreasing  posteriorly.  Brain,  in 
ii.  Nerve  cord  sheath,  massively  muscularized  (Fig.  1)  anteriorly 
but  so  as  to  leave  a  greyish  translucent  line  visible  at  mD  and 
mV  in  the  cord  between  segmental  ganglia  (Fig.  2). 

Buccal  cavity,  in  i  dorsally  of  small  juveniles,  seemingly  pro- 
vided, though  only  temporarily,  with  a  suckerlike  pad  somewhat 
resembling  the  withdrawn  and  depressed  condition  of  the  prosto- 
mium  in  various  megadriles,  in  ii  dorsally  with  a  circular  aperture 
into  a  tunnel  containing  a  presumably  protrusible  proboscis  1-2 
mm  long.  Gut  from  level  of  intersegmental  furrow  2/3  to  septum 
4/5,  ca.  30  mm  long,  sigmoid,  comprising  a  pharynx  (4  mm 
long),  a  bulb  (5  mm  thick  dorsoventrally  and  with  a  glandular 
chamber  anteriorly),  a  slender  esophagus  (14+  mm  long)  with 
closely  crowded,  low  longitudinal  ridges  on  its  inner  wall,  a  sort 
of  conical  crop  (5  mm  long)  with  circular  ridges  on  its  inner  wail, 
and  a  powerful  gizzard  (6  mm  long)  referable  to  iii. 

Calciferous  glands,  in  contact  with  each  other  mesially  under 
the  gut,  in  vii  ducts  longer  but  concealed  by  adherence  of  7/8 
(near  apex  of  its  funnel)  to  the  gut.  Typhlosole,  present  from 
region  of  xxiv-xxvi,  10  mm  high  (3  mm,  small  juvenile),  rolled 
up  on  itself  like  a  scroll,  ending  in  region  of  125th  segment  (132d 
of  188).  Lateral  typhlosoles,  not  lamelliform,  rounded  and  pro- 
tuberant ridges  in  first  one  or  two  typhlosolar  segments. 

Ventral  blood  vessel,  high  up  in  coelom  and  near  gut  in  v-xi  at 
least.  Extra-esophageals.  interconnected  by  a  transverse  vessel 
just  in  front  of  4/5  and  just  under  the  ventral  trunk,  anteriorly 
passing  up  and  branching  among  nephridia  associated  with  3/4. 
Supra-esophageal,  with  a  large  branch  on  each  side  in  v  and  vi 
that  bifurcates,  one  branch  to  a  calciferous  gland  near  the  duct, 
the  other  passing  down  along  anterolateral  aspect  of  the  gland  to 
an  extra-esophageal  trunk,  connected  also  with  extra-esophageals 
by  a  pair  of  vessels,  seemingly  on  posterior  face  of  7/8  but  mostly 
within  the  septum.  Hearts,  of  iv-vii  slender  and  lateral,  of  viii 
apparently  latero-esophageal — posterior  bifurcations  to  dorsal 
trunk  slender  and  empty,  anterior  branches  filled  with  blood  and 
obviously  joining  the  supra-esophageal. 


4  BREVIORA  No.    356 

Nephridial  ducts  (of  anterior  segments),  passing  down  through 
longitudinal  muscle  layer  and  then  turning  forward  to  cross  the 
circumferential  intra-parietal  canal,  thence  anteriorly  widened  and 
with  more  opaque  (muscularized?)  wall. 

Spermathecae,  rudimentary,  adiverticulate,  within  the  longi- 
tudinal muscle  layer.  , 

Remarks.  Small  juveniles  are  assumed  to  be  of  the  same  species 
as  the  large  worm  from  the  same  mountain. 

Rudimentary  state  of  the  spermathecae  and  absence  of  macro- 
scopically  recognizable  gonads,  funnels,  and  seminal  vesicles,  in- 
dicate that  even  the  large  worm  was  juvenile  though  maximum 
diameter  for  the  species  may  have  been  attained. 

The  parietal  insertion  of  the  delicate  septum  3/4  had  become 
unrecognizable  presumably  as  a  result  of  pinning  out  the  specimen 
after  a  longitudinal  incision  had  been  made  near  the  mid-dorsal 
line. 

Any  connection  between  nephridial  ducts  and  the  circumferential 
intraparietal  canals  would  have  been  too  small  to  recognize  in 
dissection,  and  microtome  sections  were  unsatisfactory.  The 
canals  were  crossed  diagonally  by  delicate  fibers  (or  septa?). 
Similar  canals  had  been  observed  at  least  once  before,  but  records 
were  destroyed  during  World  War  II. 

Abortion  of  dorsal  trunk  in  front  of  hearts  of  iv  and  posteriorly 
in  that  segment  was  found  in  each  dissected  specimen  considered 
herein.  That  and  other  characters  already  mentioned  in  the  generic 
definition  do  not  need  mention  again  in  species  descriptions. 

Photographs  of  nerve  cord  sections  were  provided  by  Prof.  E. 
Carpenter. 

E.  nemoralis  sp.  nov. 

Puerto  Rico.    Luquillo  Forest  (Caribbean  National  Forest), 
La  Mina  Recreational  Area,  at  1800  feet,  February  22,  1947., 
2  macerated  specimens  (several  younger  specimens  possibly  of 
the  same  species,  also  macerated.)    R.  Kenk.  (U.  S.  Natl.  Mus.) 
External  characteristics.    Length,  250  mm.    Diameter,  9  mm. 
Segments,  220  (at  195/196  a  tail  regenerate  with  terminal  anus). 
Color,  possibly  red  originally,  even  after  long  alcoholic  preserva- 
tion  dorsum   with   a   slight   reddish   tinge,  except  in   regenerate. 
Nephropores,   obvious,   present  from   ii,    in   CD.    Setae,   closely 
paired  throughout,  AB  =  CD,  AA  >  BC,  DD  ca.  =  VzC,  ventral 


1970  NEW    EARTHWORM    GENUS  5 

couples  of  some  segments  modified  (?  but  genital  tumescences  not 
recognized). 

Clitellum,  perhaps  represented  by  a  dark  brown  coloration  in 
xv-xxii,  xxiii/eq,  which  is  conspicuously  lacking  in  a  small  area 
around  each  nephropore,  no  epidermal  tumescence  recognizable. 
Ouadrithecal,  pores  minute,  superficial,  each  at  center  of  a  small 
tubercle  at  C  and  at  or  immediately  in  front  of  5/6-6/7.  Female 
pores,  postsetal  in  AB  of  xii(?). 

Internal  anatomy.  Septa,  4/5-6/7  very  thickly  muscular,  a 
transparent,  funnel-shaped  membrane  bearing  three  pairs  of 
nephridia  inserted  on  the  gut  just  behind  the  gizzard  almost  im- 
mediately in  front  of  4/5  presumably  being  3/4,  7/8  lacking  or 
else  inserted  on  parietes  over  intersegmental  furrow  8/9. 

Calciferous  glands,  without  a  central  lumen  but  with  a  honey- 
comb appearance  in  cross  sections,  each  with  a  small  distal 
appendage. 

Supra-esophageal,  bifurcating  posteriorly  in  xiv,  giving  off  two 
pairs  of  vessels,  one  immediately  behind  the  other  and  both  just 
in  front  of  the  septum  in  each  of  v-vii,  the  posterior  of  each  pair 
giving  ofl"  branches  to  the  calciferous  gland  and  ventrally  joining 
the  extra-esophageal  trunk  of  it^  side,  the  anterior  vessels  passing 
onto  stalks  of  calciferous  glands  and  down  through  the  glands  into 
the  terminal  appendages.  Extra-esophageal,  first  visible  in  region 
of  3/4  as  a  result  of  union  of  several  large  vessels,  with  several 
branches  to  each  calciferous  gland  of  its  side.  Subneural  trunk, 
large,  zigzag-looped,  closed  ends  of  loops  visible  beyond  both  sides 
of  the  nerve  cord,  bifurcating  just  in  front  of  subpharyngeal  gang- 
lion (one  specimen)  or  in  region  of  xvii  (one),  each  branch 
passing  anteriorly  in  a  zigzagged  course  lateral  to  the  cord  but 
connected  with  its  twin  on  the  opposite  side  by  numerous  trans- 
verse vessels.  Ventral  trunk,  high  up  in  coelom  as  in  E.  montana. 
Hearts,  large,  two  pairs,  possibly  latero-esophageal  and  attributable 
to  viii-ix  (?). 

Testis  sac  (or  sacs?)  filled  with  coagulum,  surrounding  or 
including  hearts  belonging  in  viii  (?). 

Spermathecae,  sessile,  ducts  confined  to  body  wall,  ampullae 
small,  protruding  only  slightly  into  coelomic  cavities  of  vi  and  vii. 

Remarks.  Intersegmental  furrows,  in  spite  of  the  maceration, 
are  distinct,  and  septa  4/5-6/7  are  inserted  on  the  parietes  directly 
over  intersegmental  furrows  4/5-6/7. 

Thickness  of  the  subneural  trunk  is  greater  than  that  of  the  nerve 
cord  even  in  regions  of  segmental  ganglia. 


6  BREVIORA  No.    356 

The  cuticle  was  loose  and  setae  had  been  pulled  out  of  their 
follicles. 

Repetition  in  the  description  of  characters  shared  identically 
with  E.  montana  seems  unnecessary.  Mention  should  be  made  of 
the  fact  that  a  proboscis  and  circumferential  parietal  canals  were 
not  seen. 

This  species  is  distinguished  from  E.  montana  by  absence  of  the 
marked  muscularity  in  the  nerve  cord  sheath. 

Estherella  sp. 

Puerto  Rico.    Luquillo  Forest  (Caribbean  National  Forest), 

La  Mina  Recreational  Area,  1800  feet,  February  22,  1947,   1 

macerated  specimen.   R.  Kenk.    (U.  S.  Natl.  Mus.) 

External  characteristics.    Size,    150  by  7   mm.    Nephropores, 

obvious,  present  from  ii,  in  CD.  Setae,  paired  throughout  (ventral 

couples  modified  in  some  clitellar  segments?). 

Qitellum,  xv-xxii  (and  xxiii?).  Tubercula  pubertatis,  longi- 
tudinal bands  of  translucence,  just  lateral  to  B,  each  demarcated 
laterally  by  a  deep  furrow.  Female  pores,  postsetal  in  /4B  of  xii(?). 
Internal  anatomy.  Male  funnels,  one  pair,  iridescent,  imbedded 
in  coagulum  apparently  also  containing  hearts  of  viii  and  possibly 
in  sacs  (or  a  testis  sac?).  Spermathecal  ampullae,  spheroidal, 
without  spermatozoal  iridescence,  slightly  protuberant  into 
coelomic  cavities  from  the  angles  of  septal  insertions  and  parietes. 
Remarks.  Setae  had  been  pulled  out  of  their  follicles  as  in  the 
types  of  nemoralis.  Gonads  and  female  funnels  were  not  found. 
Structure,  so  far  as  could  be  determined,  is  the  same  as  is  shared 
by  the  two  preceding  species. 

The  reason  for  anticipating  a  third  species  is  the  maturity  at  a 
size  smaller  than  is  expected  for  the  other  two. 

SYSTEMATICS 

Cephalization  has  had  little  attention  from  oligochaetologists 
and  perhaps  least  of  all  in  connection  with  a  family  in  which  one 
manner  of  evolutionary  modification  seemingly  had  its  most  ex- 
tensive, as  well  as  perhaps  least  appreciated  development. 

Metamerism  in  oligochaetes  sometimes  has  been  said  to  be 
homonomous,  i.e.,  similar  throughout  the  body.  Typically,  the 
soma  is  in  anteroposterior  segments,  each  of  which,  at  least  in 
earlier  stages  of  evolution,   has  four  pairs   of  setae,   a  pair  of 


1970  NEW    EARTHWORM    GENUS  7 

nephridia.  and  a  section  of  the  gut.  Such  a  segment  is  demarcated 
externally  from  each  of  its  two  contiguous  neighbors  by  inter- 
segmental furrows,  circumferential  lines  where  the  epidermis  is 
thinnest.  Internally,  a  segment  is  deUmited  by  transverse  parti- 
lions,  the  intersegmental  septa.  The  latter,  typically,  are  in  exactly 
the  same  anteroposterior  levels  as  the  intersegmental  furrows. 
Peristomium  and  periproct,  according  to  such  definitions,  are  not 
segments,  though  for  practical  purposes  are  counted  as  such. 

Differentiation  in  a  relatively  short  anterior  portion  of  the  soma 
of  special  digestive  organs  such  as  gizzards,  calciferous  glands, 
etc.,  and  localization  of  gonads  are  aspects  of  oligochaete  cephali- 
zation  so  universal  as  not  even  to  have  been  thought  to  be  involved. 
More  usually  considered  were  abortions,  as  of  follicle  and  nephri- 
dial  anlage,  and  disappearance  of  septa  and  intersegmental  fur- 
rows, i.e.,  those  structures  existence  of  which  enables  recognition 
of  segments.  Slight  (or  at  least  seeming)  diplacements  of  septal 
insertions  on  the  parietes  have  been  known  for  some  time.  Recog- 
nized but  recently  (Gates,  1943:  92)  was  a  seemingly  posterior 
dislocation  of  the  parietal  insertion  of  septum  9/10,  in  Pontoscolex 
corethrurus  (Miiller,  1857),  to  a  position  over  site  of  inter- 
segmental furrow  10/11.  Failure  to  recognize  that  dislocation  was 
responsible  in  part  for  assignment  of  certain  organs  in  systematic 
descriptions  to  wrong  segments.  How  many  other  errors  of  that 
sort  were  made  in  past  characterizations  of  glossoscolecids  remains 
to  be  learned. 

Appearance  of  deep,  secondary,  and  even  tertiary  furrows  hardly 
distinguishable  from  the  primary  intersegmentals,  in  association 
with  abortions  of  setae  and  nephridia,  also  has  been  responsible 
for  errors  in  determination  of  organ  locations.  Such  mistakes  are 
unfortunate,  as  knowledge  of  exact  organ  position  along  the  ante- 
roposterior axis  is  of  first  importance  for  megadrile  systematics 
and  phylogeny.  Absence  of  data  as  to  segmental  location  of  the 
gonads  in  the  Puerto  Rico  species  is  not  so  regrettable  as  would 
formerly  have  been  thought  since  it  is  now  known  that  "andry" 
often,  and  sometimes  even  "gyny,"  does  vary  intragenerically. 

Fortunately,  the  worms  now  under  consideration,  in  spite  of 
the  poor  condition,  are  free  of  external  modifications  that  might 
lead  to  wrong  determinations  of  organ  locations.  Sctal  follicles, 
to  be  sure,  have  been  aborted  in  some  of  the  anteriormost  seg- 
ments, but  compensation  is  provided  by  the  nephropores  which 
not  only  are  all  present  but  also   are  obvious.    Secondary   and 


8  BREVIORA  No.    356 

tertiary  furrowing  is  lacking,  and  the  anterior  segments  are  clearly 
demarcated  by  unmistakable  intersegmental  furrows.  The  first 
two  segments  have  the  normal  appearance  of  externally  exposed 
epidermis.  No  evidence  was  found  for  the  existence  of  an  actual 
pre-oral  vestibule  comprising  one  or  two  rudimentary  segments 
no  longer  exposed  regularly  to  the  external  environment.  Further- 
more, the  unusual  condition  next  to  be  discussed  characterizes 
every  individual  of  two,  or  possibly  even  three,  species.  Individual 
abnormality  or  defective  anterior  regeneration  accordingly  cannot 
be  invoked  as  was  contended  when  a  single  Panama  specimen  was 
described  (Gates,  1968)  with  a  similar  condition. 

The  powerful  gizzard,  being  in  front  of  a  membrane  that,  be- 
cause of  nephridial  relationships,  must  be  regarded  as  septum  3/4, 
is  unusually  anterior.  With  the  single  exception  of  the  above- 
mentioned  Panama  species,  a  megadrile  gizzard  has  not  hitherto 
been  found  in  front  of  segment  v  and  often  is  further  back  in  the 
esophagus.  Other  organs  also  are  too  far  forward.  The  last  pair 
of  hearts  is  in  viii,  whereas  the  first  pair  of  real  hearts  usually  is 
in  ix.  Calciferous  glands  are  present  in  v  only  in  the  Panamanian 
Thamnodriloides  yimkeri  Gates,  1968.  Lastly,  testes  are  at  least  two 
segments  in  front  of  where  they  would  normally  be  expected. 

Accordingly,  much  more  is  involved  than  forward  displacement 
(homoeosis)  of  a  single  organ  but  rather  a  condition  in  which 
all  organs  of  the  cephalic  region  from  gizzard  posteriorly  are  three 
segments  in  front  of  their  expected  positions  (regional  homoeosis). 

An  initial  or  very  early  stage  in  an  evolutionary  development 
that  may  have  reached  its  climax  in  the  Puerto  Rico  and  Panama 
worms  is  provided  by  P.  corethrurus.  In  that  species  an  inter- 
segmental furrow  between  the  first  and  second  segments  has  di- 
appeared  along  with  the  prostomium.  The  now  rather  flaccid 
fusion  metamere  is  small.  Proof  of  what  happened  is  provided  in 
many  specimens  by  retention  of  the  setae  belonging  to  ii  which  are 
now  near  the  first  intersegmental  furrow  that  morphologically  is 
2/3.  With  loss  of  those  setae,  as  in  some  individuals  of  the  species, 
the  gizzard  would  have  to  be  referred  to  v  instead  of  vi.  Organs 
behind  the  gizzard  also  would  be  one  segment  anterior  to  their 
usual  position.  Abortion  of  two  further  segments  by  the  same 
process  under  way  in  P.  corethrurus  would  provide  the  regional 
homoeoses  of  the  Puerto  Rico  and  Panama  genera.  Although 
body  wall  and  associated  nephridia  were  markedly  reduced  or 
deleted,  the  digestive  system  was  not  correspondingly  shortened. 


1970  NEW    EARTHWORM    GENUS  9 

On  the  contrary,  there  has  been  so  much  elongation  as  to  require 
very  considerable  enlargement  of  associated  septa  into  posteriorly 
directed  funnel-shapes.  What  happened  in  the  nervous  system  may 
prove  to  be  interesting  also. 

Although  homoesoses  are  identical,  the  digestive  systems  and 
especially  structure  of  the  calciferous  glands  show  that  the  two 
fore-shortened  genera  are  not  closely  related.  Puerto  Rican  worms 
may  have  evolved  from  a  stock  with  calciferous  glands  in  viii-x. 
Genera  so  characterized  are  unknown.  Related  forms  should  be 
sought  to  the  south  as  the  glossoscolecids  evolved  in  tropical  South 
America.  Puerto  Rico  now  appears  to  be  the  northern  limit  of 
generic  endemism. 

Completion  of  a  development  somewhat  hke  that  now  under 
way  in  P.  corethrurus  may  be  responsible  for  attribution  of  testes 
in  Thamnodriliis  matapi  Righi,  1969,  to  segments  ix  and  x  instead 
of  the  expected  x  and  xi. 

REFERENCES 

Gates,    G.    E.     1943.     On    some    American    and    Oriental    earthworms. 

Ohio  Jour.  Sci.,  43:   97-116. 
. 1968.     On  a  glossoscolecid  earthworm  from   Panama  and 

its  genus.    Megadrilogica,   1:    1-15. 


10 


BREVIORA 


No.  356 


1970  NEW    EARTHWORM    GENUS  11 


LIST   OF    ILLUSTRATIONS 


Figure  1.  E.  montana.  Transverse  section  of  nerve  cord  anteriorly  to 
show  muscularization  of  the  sheath. 

Figure  2.  E.  montana.  Transverse  section  of  nerve  cord  anteriorly  to 
show  the  condition  responsible  for  the  appearance  of  a  greyish  translucent 
line  at  mD  and  mV. 

Figure  3.  E.  montana.  Transverse  section  of  nerve  cord  anteriorly  to 
show  giant  cells  ventrally. 


BREVIORA 

MiLiiseiiinn   of   Coimpsirsitive    Zoology 

Cambridge,  Mass.        30  November,  1970  Number  357 

A  review  of  the  fossil  Pelomedusidae  (Testudines, 
Pleurodira)  of  Asia 

Roger  Conant  Wood 


Abstract.  The  taxonomic  status  of  the  three  Asiatic  chelonian  genera 
that  have  been  described  as  pelomedusids  is  reviewed.  Of  these,  "Podoc- 
neinis"  imiica,  although  possibly  a  member  of  the  family,  is  so  poorly  known 
that  familial  assignment  is  not  presently  possible.  Carteremys  leithii  and 
Shwehoemys  pilgrimi  both  appear  to  be  valid  palomedusid  species.  On 
the  basis  of  new  material  S.  pilgrimi  is  redescribed  and,  in  addition,  a  new 
species  of  this  genus  from  the  Miocene  of  Baluchistan,  S.  gaffneyi,  is 
proposed. 

INTRODUCTION 

Living  pelomedusid  turtles  are  restricted  to  sub-Saharan  Africa, 
Madagascar,  and  South  America.  But  paleontological  evidence 
indicates  that  pelomedusids  formerly  had  a  much  more  cosmo- 
politan distribution;  fossil  representatives  of  this  family  occur  in 
North  and  South  America,  Europe,  Africa,  and  Asia. 

The  purpose  of  the  present  paper  is  to  review  the  extinct  Asiatic 
chelonian  genera  that  have  been  described  as  pelomedusids  as 
well  as  to  put  on  record  two  new  fossil  pelomedusid  skulls  from 
Asia,  one  referable  to  Shwehoemys  pilgrimi  and  the  other  repre- 
senting a  new  species  of  the  same  genus. 

Abbreviations  used  in  this  paper  are: 
ANSP — Academy  of  Natural  Sciences,  Philadelphia 
BMNH — British  Museum  (Natural  History) 
GSI — Geological  Survey  of  India 
MCZ — Museum  of  Comparative  Zoology,  Harvard  University 

I  have  not  seen  the  material  described  by  Lydekker,  Swinton, 
and  Williams  that  is  contained  in  the  collections  of  the  Geological 
Survey  of  India,  but  it  is  for  the  most  part  well  figured  in  the 
literature.  Photographs  of  the  type  of  Shwehoemys  pilgrimi 
Swinton  have  been  available. 


2  BREVIORA  No.    357 

PREVIOUSLY   DESCRIBED   ASIATIC   PELOMEDUSIDS 

Very  few  fossil  pelomedusids  have  been  described  from  any- 
where in  Asia,  and  none  of  these  is  particularly  well  known  on  the 
basis  of  published  material. 

"Podocnemis*"'  indica  Lydekker  1887.  This  species  was  de- 
scribed on  the  basis  of  a  fairly  complete  carapace  and  on  some 
miscellaneous  plastral  fragments  found  at  Nila  in  the  Salt  Range 
of  West  Pakistan.  Lydekker  was  uncertain  about  the  age  of  "P". 
indica  but  concluded  (1887:  59)  that  it  was  probably  of  ".  .  .  low- 
est eocene  .  .  .  and  may  .  .  .  correspond  to  the  Cemaysian  stage 
of  Reims,  and  the  Puerco  group  of  the  United  States."  Since  it 
is  now  generally  recognized  that  the  Cernay  beds  are  of  late 
Paleocene  age  and  the  Puerco  beds  of  early  Paleocene  age,  "P." 
indica  may  actually  be  of  Paleocene  rather  than  Eocene  age.  Both 
Paleocene  and  early  Eocene  deposits  occur  in  the  Tertiary  sequence 
of  the  Salt  Range  (Krishnan,  1960:  494),  and  too  much  uncer- 
tainty exists  as  to  the  exact  stratigraphic  horizon  from  which  the 
only  known  specimen  of  "P."  indica  was  obtained  to  resolve  the 
question  of  its  age  beyond  all  doubt.  Invertebrates  found  in 
association  with  the  two  chelonians  {"Podocnemis"  and  Hemi- 
chelys)  described  from  this  locality  ".  .  .  indicate  that  the  bed 
in  which  they  were  found  is  either  of  marine  or  estuarine  origin; 
and  this  is  confirmed  by  the  chelonians,  one  of  which  is  covered 
with  the  'spaf  of  oysters,  while  sharks'  teeth  are  embedded  in  the 
matrix  of  the  other"  (Lydekker,  1887;  59-60). 

Preservation  of  the  carapace  of  "P."  indica  is  rather  poor; 
Lydekker  noted  (1887:  60)  that  ".  .  .  both  specimens  [from 
Nila]  .  .  .  were  in  a  much  broken  condition,  and  .  .  .  required  all 
[the  preparator's]  skill  to  render  them  fit  for  description." 
Lydekker's  restoration  of  the  carapace  (1887,  plate  13)  indicates 
that  its  most  distinctive  feature  is  a  peak  along  the  midline  of  the 
neurals,  with  the  pleurals  on  either  side  apparently  sloping  away 
flatly  rather  than  on  a  curve.  The  nuchal  bone  appears  to  be 
unusual  in  that  its  postero-lateral  sides  are  considerably  longer 
than  its  antero-lateral  ones.  The  nuchal  is  rather  small  and  does 
not  transgress  the  lateral  boundaries  of  the  first  vertebral  scute. 
There  are  seven  neurals;  the  first  five  are  all  longer  than  broad, 
whereas  the  last  two  are  broader  than  long.  Two  pleurals  (the 
seventh  and  eighth)  meet  in  the  midline  between  the  last  neural 
and  the  suprapygal.    No  indentation  occurs  at  the  midline  along 


1970  ASIATIC    FOSSIL    PELOMEDUSIDAE  3 

the  anterior  margin  of  the  carapace  and  a  cervical  scute^  is  lacking. 
Whereas  the  first  vertebral  is  nearly  twice  as  wide  as  it  is  long, 
the  second  and  third  vertebrals  are  both  longer  than  broad. 
Lydekker  estimated  (1887:  63)  that  the  overall  length  of  the 
carapace  must  have  been  approximately  35  inches  (87  centi- 
meters), exceptionally  large  for  a  fossil  pelomedusid.  Critical 
taxonomic  evidence,  such  as  whether  or  not  the  pelvis  was  fused  to 
the  shell,  the  presence  or  absence  of  mesoplastra,  and  the  scute 
pattern  on  the  anterior  plastral  lobe,  is  not  preserved.  Conse- 
quently, there  is  no  assurance  that  "P."  indica  is  actually  a  pelo- 
medusid, let  alone  a  member  of  the  genus  Podocnemis.  Neverthe- 
less, its  midline  ridge  and  straight  loping  sides  are  somewhat  remi- 
niscent of  the  carapace  structure  of  a  recently  discovered  shell  of 
Shweboemys  from  Egypt  (see  p.  00),  and  the  number,  shape,  and 
arrangement  of  its  neurals  is  typical  of  many  pelomedusids,  as  is 
its  lack  of  a  cervical  scute.  Therefore,  it  does  not  seem  altogether 
unlikely  that  "P."  indica  may  represent  the  remains  of  some  kind 
of  pelomedusid,  although  it  probably  is  not  a  member  of  the  genus 
Podocnemis.  Until  more  complete  specimens  of  this  taxon  are 
discovered,  I  do  not  think  that  a  better  identification  of  this  speci- 
men is  possible  than  Pelomedusidae?  incertae  sedis. 

Cartereniys  leithii  (Carter  1852).  A  second  Asiatic  pelome- 
dusid taxon,  "Hydraspis"  leithii,  was  recovered  from  Intertrappean 
beds  near  Bombay,  India.  Some  uncertainty  exists  as  to  the  age  of 
these  sediments.  Lydekker  (1887:  60)  regarded  them  as  "lower 
eocene."  Referring  to  the  age  of  the  volcanics  within  which  the 
Intertrappean  beds  occur,  Wadia  (1953:  302)  stated  that  "...  it 
is  quite  apparent  that  the  Deccan  Traps  cannot  be  older  than  the 
Danian  stage  of  the  uppermost  Cretaceous  [now  Paleocene],  while 
.  .  .  they  cannot  be  much  younger  than  the  Eocene."  According 
to  Krishnan  (1960:  483-486),  paleontological  evidence  afforded 
by  fossils  contained  within  the  Intertrappean  beds  is  not  par- 
ticularly helpful  for  dating,  but  on  other  grounds  he  concluded 
that  the  Deccan  Traps  ranged  in  age  from  late  Cretaceous  to, 
perhaps,  Ohgocene.  Robinson  (1970:  245)  has  expressed  similar 
views,  stating  that  the  Intertrappeans  are  ".  .  .  probably  mainly  early 


ij  have  here  adopted  the  term  suggested  by  Zangerl  (1969:  315)  for 
this  particular  scute  to  avoid  the  confusing  redundancy  arising  from  the 
conventional  procedure  of  referring  to  both  it  and  the  underlying  bone  as 
the  nuchal. 


4  BREVIORA  No.    357 

Tertiary  in  age.  .  ."  Since  the  Intertrappeans  of  the  Bombay 
region  are  confined  to  the  upper  part  of  the  Deccan  Traps  (Pascoe, 
1964:  1385),  their  attribution  to  the  Eocene  would  not  be  unrea- 
sonable. Krishnan  (1960:  482),  Pascoe  (1964:  1385)  and 
Robinson  (1970:  245)  all  agree  that  the  Bombay  Intertrappeans 
were  laid  down  in  fresh  water,  Pascoe  further  suggesting  (1964: 
1386)  that  the  depositional  environment  was  a  shallow  marsh. 

Carteremys  leithii  was  a  small  species;  the  only  two  complete 
carapaces  for  which  measurements  have  been  recorded  are  IVk 
and  8  inches  (18-20  centimeters)  in  length  (Carter,  1852:  187; 
Williams,  1953:  6).  Carter's  original  description  was  based  on 
material  that  is  now  unfortunately  lost  (Williams,  1953:  2).  Only 
three  other  specimens  that  can  be  referred  to  this  species  with 
reasonable  confidence  have  subsequently  been  discovered 
(Williams,  1953:  6,  and  plate  3).  The  total  number  of  neurals 
is  uncertain,  although  there  are  at  least  five.  Evidently  no  cervical 
scute  was  present,  and  the  first  vertebral  was  much  smaller  than 
the  second.  The  outer  surface  of  the  shell  is  covered  with  fine 
sculpturing.  In  several  respects  the  plastron  is  quite  distinctive: 
it  is  relatively  narrow,  with  a  semicircular  anterior  lobe  projecting 
well  forward  of  the  front  of  the  carapace;  between  the  broadly 
rounded  xiphiplastral  tips  is  a  very  shallow  anal  notch,  not  com- 
parable in  its  shape  to  those  of  any  pelomedusid  with  which  I  am 
familiar;  and  the  outlines  of  the  pelvic  scars  on  the  xiphiplastron 
are  also  unusual.  In  spite  of  Williams'  suggestion  (1953:  4)  that 
small,  laterally  placed  mesoplastra,  a  characteristic  pelomedusid 
feature,  may  have  been  present,  there  is  no  conclusive  evidence 
bearing  on  this  point.  None  of  the  three  existing  specimens  (all 
belonging  to  the  collections  of  the  Geological  Survey  of  India)  is 
sufficiently  complete  to  demonstrate  the  presence  or  absence  of 
these  structures  (WiUiams,  1953:  6).  Trapeziform  gulars  were 
widely  separated  by  an  extremely  broad  intergular  scute  that 
extended  posteriorly  to  the  humero-pectoral  sulcus  and  thus  pre- 
vented the  humerals  from  meeting  in  the  midline  also.  The  most 
notable  feature  of  the  skull  is  the  extensive  emargination  of  the 
roof  from  behind,  a  condition  typical  of  most  pelomedusids.  A 
well-developed  jugal-quadratojugal  bar  is  present.  Although  the 
extremity  of  the  mandibular  rostrum  was  broken  off  in  the 
material  Carter  described,  it  is  clear  from  what  was  preserved 
that  there  must  have  been  a  broad,  robust  symphysis  at  the  mid- 
line of  the  lower  jaw. 


1970  ASIATIC    FOSSIL    PELOMEDUSIDAE  5 

Long  regarded  as  a  chelid,  "Hydraspis"  leithii  was  eventually 
redescribed  and  designated  as  the  type  of  a  new  pelomedusid  genus 
by  Williams  (1953:  3-4).  A  combination  of  several  characters — 
the  absence  of  a  cervical  scute,  the  relative  proportions  of  the  first 
and  second  vertebrals,  the  remarkably  large  intergular,  and  the 
lack  of  a  parieto-squamosal  arch  combined  with  the  presence  of 
a  jugal-quadratojugal  bar — led  Williams  to  conclude  that  this 
species  could  not  be  a  cheHd.  These  characters,  together  with  the 
inferred  existence  of  small,  laterally  placed  mesoplastra,  per- 
suaded him  that  Carteremys  was  in  fact  a  pelomedusid.  On  the 
basis  of  the  data  presented  in  Table  1,  I  agree  with  Williams' 
conclusion.  If  we  disregard  for  a  moment  the  question  of  whether 
or  not  mesoplastra  were  present  in  Carteremys,  then  we  see  that 
for  all  the  characters  tabulated,  this  genus  and  pelomedusids  agree. 
In  contrast,  none  of  the  other  families  share  more  than  two 
characters  with  Carteremys.  This  comparison  strongly  suggests 
that  Carteremys  is  a  pelomedusid.  Should  it  eventually  be  possible 
to  determine  that  Carteremys  had  mesoplastra,  the  evidence  would 
overwhelmingly  favor  this  determination. 

Lydekker  (1890:  22-23,  fig.  2)  referred  an  epiplastral  frag- 
ment, probably  from  Intertrappean  beds  and  therefore  possibly 
of  Eocene  age,  to  "Hydraspis"  leithii.  Differing  from  Carteremys 
in  size  and  in  gular-intergular  proportions,  this  specimen  may  well 
represent  an  unknown  taxon,  but  too  little  is  known  of  it  to  permit 
useful  discussion. 

Shweboemys  pilgrimi  Swinton  1939.  The  type,  and  until  now 
only  known  specimen,  of  this  species  is  a  partial  skull  of  Pliocene 
or  Pleistocene  age  from  Burma  (Swinton,  1939).  Swinton  be- 
lieved that  nasal  bones,  although  not  preserved  on  the  specimen 
he  described,  must  have  been  present  originally.  Were  this  sup- 
position true,  his  placement  of  the  genus  in  the  Pelomedusidae 
would  be  suspect  because  one  of  the  diagnostic  characters  of  the 
family  is  the  absence  of  nasals  (cf.  Romer,  1956:  515).  Evidently 
Swinton  was  either  unaware  of  the  significance  of  this  character 
or  else  he  did  not  consider  it  to  be  of  great  importance;  at  any 
rate,  he  did  not  discuss  its  bearing  on  taxonomy.  Nevertheless, 
other  observations  led  him  to  conclude  (1939:  551)  that 
Slnveboetnys  is  a  pelomedusid:  'in  brief,  the  interest  of  the  speci- 
men is  that  in  superior  and  lateral  aspect  there  is  little  to  dis- 
tinguish it  from  the  genus  Podocnemis,  while  in  palatal  view  it 
has  much  similarity  to  Stereogenys.    There  is  no  doubt  that  it 


BREVIORA  No.    357 


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1970  ASIATIC    FOSSIL    PELOMEDUSIDAE  7 

differs  from  both  genera  and  is  a  new  form  belonging  to  the  family 
Peiomedusidae." 

NEW   ASIATIC    PELOMEDUSID    MATERIAL 

The  recent  recognition  of  a  second,  slightly  more  complete 
specimen  of  Shweboemys  pilgrimi  by  Mr.  C.  A.  Walker  in  the 
collections  of  the  British  Museum  (Natural  History)  has  provided 
new  information  which  confirms  Swinton's  familial  determination. 
Further  supporting  evidence  is  furnished  by  the  new  species  of 
Shweboemys  from  the  Miocene  of  Baluchistan  (West  Pakistan) 
described  below.  In  addition,  recent  Yale  University  paleonto- 
logical  expeditions  to  the  Fayum  Depression  of  Egypt  have  pro- 
duced conclusive  evidence  showing  that  "Podocnemis"  antiqua 
Andrews  1903  from  the  late  Eocene  Qasr  el-Sagha  Formation  is 
referable  to  Shweboemys.  A  detailed  description  of  this  species, 
the  only  one  represented  by  both  skull  and  shell  material,  is  being 
prepared  for  publication  elsewhere,  but  I  include  the  diagnostic 
characters  of  its  shell  in  the  emended  diagnosis. 

Shweboemys  Swinton  1939 

Type  species.   Shweboemys  pilgrimi  Swinton  1939. 

Emended  diagnosis.  Skull  with  broad  secondary  palate  formed 
by  medial  expansion  of  maxillae  and  palatines,  with  narrow  median 
cleft  extending  posteriorly  from  behind  premaxillae;  outer  border 
of  palatines  not  parallel  to  midline  axis,  but  diverging  from  it  at 
an  angle  of  approximately  thirty  degrees;  laterally  projecting, 
prominent  ectopterygoid  processes;  enlarged  carotid  charmels; 
basisphenoid  not  covered  by  pterygoids  ventrally.  Carapace  cordi- 
form  in  outline,  tapering  to  a  point  posteriorly;  pleurals  flat  rather 
than  curved,  sloping  away  from  continuous  midline  ridge  at  gentle 
angle;  ventral  surface  of  plastron  completely  flat;  anterior  lobe  of 
plastron  very  short  and  semicircular;  posterior  lobe  narrower  and 
approximately  one  and  one-half  times  longer  than  anterior; 
outer  margin  of  posterior  lobe  straight  rather  than  curved,  slanting 
inward  toward  rear. 

Referred  species.  Shweboemys  antiqua  (Andrews)  1903,  S. 
gaffneyi  sp.  no  v. 

Distribution.  Late  Eocene,  Fayum  Depression,  Egypt;  early 
Miocene,  Bugti  HiUs,  West  Pakistan;  Pliocene  or  Pleistocene, 
Burma. 


8  BREVIORA  No.    357 

The  skull  of  Shweboemys  is  very  similar  to  that  of  Stereogenys 
but  differs  in  several  significant  respects:  the  pterygoids  do  not 
completely  cover  the  basisphenoid  ventrally;  the  lateral  margins  of 
the  palatines  are  not  parallel  to  the  midline  axis;  and  the  secondary 
palate  is  less  elongate,  not  extending  back  as  far  as  the  ectoptery- 
goid  processes. 

Swinton's  decision  to  base  a  new  pelomedusid  genus  and  species 
on  his  Burmese  specimen  was  founded  on  his  belief  that  the  skull 
combined  features  of  both  Podocnetnis  and  Stereogenys  without 
being  more  like  one  than  the  other  (see  p.  5).  That  the  palatal 
structure  of  Shweboemys  is  very  similar  to  that  of  Stereogenys  and 
different  from  that  of  Podocnemis  is  indisputable,  but  Swinton's 
remark  that  the  dorsal  and  lateral  aspects  of  Shweboemys  are 
virtually  identical  to  the  comparable  regions  of  Podocnemis  and 
unlike  those  of  Stereogenys  is  an  overstatement.  Swinton  (1939: 
550)  evidently  compared  the  type  of  Shweboemys  pilgrimi  only 
with  Andrews'  original  description  (1901:  442)  of  the  type  skull 
of  Stereogenys  cromeri,  which  is  somewhat  crushed  dorso-ventrally 
in  the  facial  region  as  Andrews  himself  noted  (1901 :  443n).  An- 
other specimen  (BMNH — R.3189),  which  Andrews  later  (1906: 
301  and  plate  25,  fig.  1 )  referred  to  this  species,  is  not  flattened' 
and  reveals  that  virtually  all  of  the  characters  used  by  Swinton 
(1939:  550)  to  differentiate  Stereogenys  from  Shweboemys — the 
relative  positions  of  the  orbits  and  external  nares,  shape  of  the 
orbits,  and  breadth  as  well  as  flatness  of  the  skull — are  artifacts 
of  preservation  rather  than  taxonomically  significant  features. 
Swinton  also  claimed  (1939:  550)  that  the  facial  bones  of 
Stereogenys  were  more  slender  than  those  of  Shweboemys.  The 
difference  in  thickness  is  easily  explained,  however.  The  type  of 
Shweboemys  pilgrimi  is  considerably  larger  than  that  of  Stereogenys 
cromeri  (12.5  versus  slightly  more  than  8  centimeters  from  the 
snout  to  the  occipital  condyle)  and  the  thicker  bones  merely  reflect 
greater  size.  In  dorsal  and  lateral  aspects,  therefore,  the  skuU  of  a 
Shweboemys  does  not  resemble  that  of  Podocnemis  more  than  it 
does  that  of  Stereogenys. 


1  If  anything,  in  terms  of  distortion,  this  skull  may  perhaps  be   some- 
what compressed  laterally. 


1970  ASIATIC    FOSSIL    PELOMEDUSIDAE  9 

Shweboemys  pilgrimi  Swinton  1939 
(Plates  I,  IIA,  IIIA,  IVA) 

Type.  GSI  17255,  an  incomplete  skull.  The  original  description 
of  this  specimen  was  accompanied  only  by  some  rather  crude 
sketches  (Swinton,  1939,  text-figures  1  and  2).  Photographs  of 
the  type  showing  comparable  views  are  therefore  reproduced  as 
Plate  I. 

Hypodigm.  The  type  and  BMNH— R.  8432,  a  slightly  more 
complete  skull  lacking  the  anterior  portions  of  the  premaxillae, 
both  ectopterygoid  processes,  part  of  the  left  and  all  of  the  right 
paroccipital  process,  and,  to  whatever  extent  it  may  have  been 
developed,  the  supratemporal  roof. 

Horizon  and  locality.  Pliocene  or  Pleistocene,  Irrawaddy  beds, 
one  mile  NNE  of  Mauktet,  Shwebo  District,  Burma. 

Swinton's  determination  of  a  Pliocene  age  for  the  type  (1939: 
548)  is  questionable  because  he  failed  to  state — perhaps  because 
the  information  did  not  exist — at  what  level  within  the  Irrawaddy 
sediments  the  specimen  was  found.  It  is  generally  recognized  that 
there  are  two  faunal  horizons  within  the  Irrawaddy  beds,  a  lower 
one  of  Pliocene  age  and  an  upper  one  of  Pleistocene  age  (Stamp, 
1922:  498;  Colbert,  1938:  267;  Krishnan,  1960:  554).  Un- 
determined chelonian  remains  have  been  reported  from  the  lower 
beds  near  Yenangyaung  (Stamp,  1922:  498),  but  these  have  never 
been  formally  described.  Fossil  turtle  fragments  have  also  been 
recovered  from  the  upper  Irrawaddy  beds  (Colbert,  1943:  417). 
One  of  these,  MCZ  1890  (MCZ  6305  in  Colbert)  represents  the 
left  epiplastron  of  a  very  large  tortoise  while  another  (ANSP 
14644)^  according  to  Colbert,  may  be  a  trionychid.  No  pelome- 
dusid  remains  have  been  recognized  among  these  specimens. 
Whether  the  Irrawaddy  beds  of  the  Shwebo  District,  whose  admin- 
istrative center,  the  municipality  of  Shwebo,  lies  some  130-140 
miles  to  the  northeast  of  Yenangyaung,  represent  only  the  upper 
part  or  the  lower  part  of  this  sedimentary  unit,  or  a  mixture 
of  both,  is  unknown.  Consequently,  the  absence  of  any  reasonably 
precise  stratigraphic  data  for  Swinton's  specimen  does  not  permit 
a  decision  as  to  its  age.  Unfortunately,  nothing  is  known  about 
the  provenance,  other  than  "Burma,"  of  BMNH — R.  8432.  Its 
morphological  identity  with  the  type  of  5.  pilgrimi  leads  me  to 
believe  that  the  two  skulls  are  of  essentially  the  same  age. 


10  BREVIORA  No.    357 

Emended  diagnosis.  Interorbital  width  slightly  greater  than  di- 
ameter of  orbits;  orbits  circular,  directed  forward;  maxillary  tomia 
curving  upwards  toward  midline  to  form  broad,  semicircular  notch; 
medial  borders  of  palatine  flanges  nearly  parallel  to  each  other  as 
far  back  as  the  opening  for  internal  nares;  little  or  no  contact  be- 
tween pterygoids  at  midline;  precondylar  fossa  lunate;  trigeminal 
foramen  facing  antero-laterally,  situated  low  on  wall  of  brain  case; 
breadth  between  postero-lateral  corners  of  palatines  equal  to  40 
per  cent  of  skull  length  from  snout  to  occipital  condyle. 

Not  only  does  the  British  Museum  specimen  provide  new  infor- 
mation about  parts  of  the  skull  that  were  not  preserved  in  the 
type,  but  it  also  permits  an  important  correction  of  Swinton's 
description.  The  snout  region  of  BMNH — R.  8432  is  little  dam- 
aged and  it  is  possible  to  determine  unequivocally  that,  contrary 
to  his  belief,  nasals  were  lacking,  as  in  all  pelomedusids. 

The  type  as  preserved  is  4V2  inches  (11.4  centimeters)  long 
according  to  Swinton.  A  comparable  portion  of  the  British 
Museum  specimen  measures  9.3  centimeters  in  length.  The  total 
length  of  this  skull  (from  snout  to  occipital  condyle)  is  approxi- 
mately 10.2  centimeters.  With  this  information  it  is  possible  to 
calculate  the  total  estimated  length  of  the  type  skull,  assuming  that 
there  were  no  significant  ontogenetic  changes  in  proportion,  as 
12.5  centimeters.  Such  large  skulls  indicate  that  adult  representa- 
tives of  Shweboemys  pilgrimi  must  have  been  imposing  creatures, 
roughly  equivalent  in  size  to  Podocnemis  expansa,  the  largest  of 
the  living  pelomedusid  species. 

The  most  persuasive  indication  that  Swinton  adduced  to  support 
his  contention  that  Shweboemys  was  a  pelomedusid  is  its  palatal 
structure,  which  resembles  that  of  Stereogenys  more  than  that  of 
any  other  known  turtle.  This,  however,  is  not  a  diagnostic 
character,  since  it  occurs  elsewhere  within  the  family  only  in 
Bothremys  and  is  rather  widespread  among  cryptodires. 

For  taxonomic  purposes,  therefore,  the  most  significant  addi- 
tional information  provided  by  the  British  Museum  skull  is  the 
evidence  that  enlarged  carotid  channels  were  present  (Fig.  lA). 
Such  structures  are  known  only  in  the  pelomedusid  genera 
Podocnemis  and  Stereogenys  and  are  not  known  in  any  other 
turtle  group.  Much  more  substantial  grounds  now  exist,  con- 
sequently, to  confirm  Swinton's  belief  that  Shweboemys  is  truly  a 
pelomedusid. 


1970 


ASIATIC    FOSSIL    PELOMEDUSIDAE 


11 


Figure  1.  Palatal  views  of:  A — Shweboemys  pilgrimi  (BMNH — R. 
8432);  B— Shweboemys  gaffneyi  (BMNH— R.  8570).  Solid  parallel  lines 
represent  areas  of  breakage.  Matrix  is  indicated  by  randomly  arranged 
Vs.  Stippled  areas  cover  region  in  which  thin  sheets  of  surface  bone  have 
broken  off,  thus  making  exact  determination  of  position  of  sutures  difficult. 
Abbreviations:  PM  =  premaxilla;  M  =  maxilla;  Pal  =  palatine;  Pt  = 
pterygoid;  Bs  =  basisphenoid;  Bo  =  basioccipital;  Eo  =  exoccipital;  So  = 
supraoccipital;  Etp  =  ectopterygoid  process;  cc  =  carotid  channel. 


12  BREVIORA  No.    357 

There  does  not  appear  to  be  any  contact  between  the  pterygoids 
at  the  midHne,  although  less  than  perfect  preservation  on  the 
ventral  surface  of  the  basicranium  of  BMNH — R.  8432  necessi- 
tates consideration  of  the  possibility  that  these  bones  may  have 
barely  met  in  an  undamaged  specimen  (see  Plate  II A  and  Fig. 
lA).  Even  if  the  pterygoids  actually  did  meet  at  the  midline, 
their  junction  was  clearly  not  extensive.^  Among  pelomedusids, 
this  particular  configuration  is  found  only  in  this  species  and  its 
African  relative,  Shweboetuys  antiqua.  Another  distinctive  char- 
acter is  the  position  of  the  foramen  for  the  trigeminal  nerve 
(Plate  IIIA),  which  Swinton  (1939:  551)  was  unable  to  detect 
in  the  type  specimen  because  of  poor  preservation.  Instead  of 
being  situated  above  the  floor  of  the  brain  case  and  directed  later- 
ally, as  in  nearly  all  other  pelomedusids,  it  is  positioned  much 
lower  and  faces  antero-laterally.  In  Bothremys  cooki  this  foramen 
is  evidently  situated  as  far  down  on  the  side  of  the  brain  case  as 
in  Shweboemys  pHgrimi,  but  it  does  not  seem  to  have  been  directed 
antero-laterally  (Galfney  and  Zangerl,  1968:  220,  figs.  13,  14, 
and  16). 

Breakage  of  the  anterior  ends  of  the  premaxillae  prevents  an 
exact  determination  of  the  shape  of  the  external  nares  (Fig.  2A). 
As  preserved,  the  narial  opening  is  ellipical,  with  its  transverse 
axis  the  longest.  Damage  to  this  same  region  also  leaves  some 
question  as  to  the  actual  shape  of  the  upper  jaw.  Conceivably,  it 
may  have  had  a  downward  curving  beak,  as  in  adult  specimens  of 
Pelusios  niger,  or  have  simply  been  notched,  as  in  many  other 
pelomedusids.  Alternatively,  its  present  rounded  contour  may 
actually  reflect  its  original  shape.  Whatever  the  case,  it  is  clear 
that  there  was  a  strong  median  indentation  of  some  kind  at  the 
midline. 

Although  the  scroll-like  outer  portion  of  the  laterally  projecting 
ectopterygoid  processes  have  not  been  preserved  in  either  speci- 
men of  Shweboemys  pilgrimi,  these  structures  did  exist.  Evidence 
to  this  effect  is  preserved  on  BMNH — R.  8432,  where  the  basal 
portion  of  these  protuberances  can  be  seen  on  both  sides. 


1  Contrary  to  Swinton's  statement  (1939:  550),  no  portion  of  the 
pterygoids  is  preserved  on  the  holotype.  What  he  evidently  interpreted  as 
the  palatine-pterygoid  suture  appears  to  be  a  transverse  crack  across  the 
ventral  surface  of  the  palatines  (Plate  lA). 


1970 


ASIATIC    FOSSIL    PELOMEDUSIDAE 


13 


3  CM 


3  CM 


Figure  2.  Facial  views  of:  A — Shweboemys  pilgrimi  (BMNH — R. 
8432);  B—Shweboemys  gaffneyi  (BMNH— R.  8570).  Solid  parallel  lines 
represent  areas  of  breakage. 


♦ 


14 


BREVIORA 


No.  357 


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1970  ASIATIC    FOSSIL    PELOMEDUSIDAE  15 

Scute  sulci  can  be  detected  on  the  roof  of  the  British  Museum 
skull  (Fig.  3).  The  anterior  border  of  the  interparietal  overlapped 
slightly  onto  the  postero-lateral  corners  of  the  frontal  bones  and 
was  bow-shaped,  more  like  that  of  Podocnemis  sextiiberculata 
{cj.  Siebenrock,  1902,  fig.  9)  than  any  other  pelomedusid  known 
to  me.  Behind  the  orbit  a  scute  intervened  between  the  maxillary 
and  frontal  scutes.  Whether  this  was  an  enlarged  masseteric  scute, 
as  in  Podocnemis  diimeriliana,  or  a  subocular  scute,  as  in  most  of 
the  other  species  of  Podocnemis  (Williams,  1954),  is  uncertain. 

Shweboemys  gaffneyi  sp.  nov.^ 
(Plates  MB,  IIIB,  IVB) 

Type.  BMNH — R.  8570,  a  partial  skull  lacking  the  premaxillae, 
most  of  the  prefrontals,  the  bones  of  the  cheek  region,  the  quad- 
rates and  squamosals,  the  supraoccipital  crest,  and  whatever 
supratemporal  roofing  there  may  have  been. 

Hypodigm.   The  type,  only. 

Horizon  and  locality.  Early  Miocene,  Bugti  Hills,  Baluchistan, 
West  Pakistan. 

No  locahty  or  stratigraphic  data  are  associated  with  this  speci- 
men, but  apparently  it  was  obtained  by  C.  Forster-Cooper  during 
one  of  his  two  expeditions  to  the  area  around  Dera  Bugti  during 
the  years  1910  and  1911  and  would  therefore  be  of  the  age  and 
from  the  general  region  cited  above.  It  was  subsequently  given  to 
Professor  D.M.S.  Watson  for  description,  who  in  turn  passed  it 
on  to  Dr.  E.  E.  Williams  for  the  same  purpose.  Other  commit- 
ments having  prevented  either  from  formally  describing  this 
interesting  skull,  the  task  has  now  fallen  to  me. 

Pilgrim  (1908:  144)  briefly  mentioned  that  chelonian  remains 
are  not  uncommon  in  the  Miocene  sediments  of  the  Bugti  region. 
Unfortunately,  none  of  these  have  ever  been  described.  Knowl- 
edge of  their  existence  nevertheless  reinforces  the  probabihty  that 
the  skull  under  consideration  is  of  the  age  of  and  from  the  locality 
given  above. 

Diagnosis.  Differing  from  S.  pilgrimi  in :  interorbital  width  less 
than  diameter  of  orbits;  tomial  margins  of  upper  jaw  (so  far  as 
preserved)    horizontal,  not  notched;  medial  borders  of  palatine 


1  The   species  is   named  for  Dr.  Eugene  Gaffney  in  recognition  of  his 
work  on  pelomedusid  turtles. 


16  BREVIORA  No.    357 

flanges  curving  away  from  midline;  breadth  between  postero- 
lateral corners  of  palatines  equal  to  50  per  cent  of  skull  length 
from  snout  to  occipital  condyle;  broad  contact  between  pterygoids 
at  midline;  precondylar  fossa  semicircular;  foramen  for  trigeminal 
nerve  situated  relatively  higher  on  ascending  wall  of  brain  case 
and  directed  laterally.  Differing  from  S.  antiqua  in:  lack  of  fore- 
head groove;  orbits  round  rather  than  oval;  no  median  notch  in 
upper  jaw;  broad  contact  between  pterygoids  at  midline;  size 
much  greater. 

In  total  length,  this  skull  is  slightly  longer  than  the  smaller  of 
the  two  specimens  of  Shweboemys  pilgrimi  (10.5  versus  10.2 
centimeters  for  the  distance  from  the  snout  to  the  occipital 
condyle).  The  width  at  the  postero-lateral  corners  of  the  palatines 
is  significantly  greater,  however,  indicating  that  the  skull  of  S. 
gaffneyi  was  proportionately  wider.  Compared  to  S.  pilgrimi,  the 
orbits  of  the  new  species  are  also  proportionately  much  larger. 
The  increase  has  been  achieved  primarily  by  dorsal  emargination 
of  the  external  face  of  the  maxilla.  The  diameter  of  the  orbits  in 
S.  pilgrimi  is  essentially  the  same  as  the  distance  across  the  maxilla 
from  the  base  of  the  orbit  to  the  tomium.  In  contrast,  the  diameter 
cf  the  orbits  in  S.  gaffneyi  is  nearly  twice  as  great.  Because  the 
premaxillae  are  missing,  it  is  impossible  to  reconstruct  the  shape 
of  the  upper  jaw  at  the  midline.  There  may  have  been  some  kind 
of  median  notch,  but  if  so  it  must  have  been  relatively  small  and 
thus  quite  unlike  that  of  S.  pilgrimi  (see  Fig.  2B). 

The  two  Asiatic  species  differ  somewhat  in  the  structure  of  their 
secondary  palates.  In  S.  gaffneyi,  the  secondary  palate  is  broader 
than  it  is  long,  whereas  in  S.  pilgrimi  this  region  is  slightly  longer 
than  wide  (cf.  Figs.  lA  and  B).  For  analyzing  proportional  dif- 
ferences, direct  comparisons  may  be  made  between  comparable 
measurements  of  the  two  British  Museum  skulls  of  Shweboemys, 
each  representing  one  of  the  Asiatic  species,  since  they  are  both 
of  nearly  the  same  length  and  are  equally  well  preserved  in  the 
region  under  consideration.  At  the  point  where  the  sutures  be- 
tween the  maxillae  and  the  palatines  reach  the  outermost  extent 
of  the  secondary  palates,  the  distance  across  the  secondary  palate 
of  the  type  of  S.  gaffneyi  is  7.2  centimeters,  whereas  this  same 
distance  in  BMNH — R.  8432  is  6.1  centimeters.  But  the  length 
of  this  structure  is  5.3  centimeters  in  the  former  and  6.7  in  the 
latter.  Another  difference,  of  unknown  biological  significance, 
involves  the  pitting  on  the  ventral  surface  of  the  secondary  palate. 


1970  ASIATIC    FOSSIL    PELOMEDUSIDAE  17 

In  both  species,  these  pits  appear  to  be  more  abundant  on  the 
maxillae  than  on  the  palatines.  The  maxillary  pits,  however,  seem 
to  be  deeper,  larger  in  diameter,  and  fewer  in  number  in  5. 
gaffneyi  (see  Plate  II). 

No  scute  sulci  are  clearly  discernible  on  the  preserved  part  of 
the  skull  roof  of  5.  gaffneyi.  Linear  depressions,  which  might  be 
interpreted  as  scute  furrows,  follow  the  courses  of  the  fronto- 
parietal and  fronto-postorbital  bone  sutures.  But  a  similar  groove 
running  antero-posteriorly  along  the  midline  does  not  have  a 
homologue  in  any  other  pelomedusid.  Thus  I  am  dubious  that  any 
of  these  indentations  necessarily  corresponds  in  position  to  the 
actual  boundaries  between  scutes. 

The  position  of  the  trigeminal  nerve  foramina  and  the  extent 
to  which  the  pterygoids  meet  on  the  ventral  surface  of  the  skull  in 
5.  gaffneyi  are  typically  pelomedusid  and  clearly  serve  to  differenti- 
ate this  species  from  5.  pilgrimi,  which  is  specialized  in  these 
characters.  The  skull  of  S.  gaffneyi  exhibits  no  features  that  would 
bar  the  species  from  the  ancestry  of  S.  pilgrimi. 

The  skull  of  S.  gaffneyi  differs  from  that  of  5.  antiqua  in  a  num- 
ber of  respects,  of  which  a  few  may  be  mentioned  here,  pending 
detailed  description  of  the  Fayum  species.  Size  is  the  most  obvious 
(although  not  necessarily  the  most  significant  taxonomically )  dif- 
ference between  the  two:  the  distance  from  the  snout  to  the 
occipital  condyle  in  S.  gaffneyi  is  more  than  one  and  one-half 
times  longer  than  in  5.  antiqua  ( 10.5  versus  6.6  centimeters).  The 
orbits  of  S.  gaffneyi  are  round  and  directed  forward,  those  of  S. 
antiqua  are  oval  and  face  laterally.  There  is  a  forehead  groove 
between  the  orbits  of  the  latter  but  not  of  the  former.  As  in  S. 
pilgrimi,  and  in  strong  contrast  to  5.  gaffneyi,  there  is  little  or  no 
contact  between  the  pterygoids  at  the  midline  in  5.  antiqua. 

DISCUSSION 

Of  the  small  number  of  Asiatic  fossil  pelomedusids  hitherto 
described,  one,  "Podocnemis"  indica,  is  not  well  enough  known 
at  the  present  time  to  merit  formal  taxonomic  assignment.  How- 
ever, Carteremys  probably  was  a  pelomedusid,  and  Shwebuemys 
certainly  was. 

The  relationships  of  Carteremys  within  the  Pelomedusidae  are 
uncertain.  On  the  basis  of  skull  structure,  Shweboemys  appears 
to  have  been  more  closely  related  to  Stereogenys  than  to  any  other 


18  BREVIORA  No.    357 

pelomedusid.  Within  the  genus,  Shweboemys  pilgrimi  may  well 
have  been  derived  more  or  less  directly  from  5.  gaffneyi,  and 
there  is  no  reason  why  this  latter  species  could  not  in  turn  have 
been  directly  descended  from  S.  antiqua.  Occurrences  of  this 
genus  are  separated  by  such  great  distances  and  represented  by 
such  a  paucity  of  material,  however,  that  future  discoveries  may 
reveal  that  this  interpretation  is  overly  simplistic. 

Shweboemys  is  the  only  pelomedusid  genus  so  far  known  to 
have  established  a  successful,  enduring  lineage  outside  of  Africa 
or  South  America.  The  Shweboemys  lineage  appears  to  have  been 
restricted  to  southern  Asia  and  Africa;  no  pelomedusid  has  thus 
far  been  reported,  even  questionably,  from  central  or  eastern  Asia. 
The  localities  where  the  two  Asiatic  species  of  this  genus  occur 
are  very  widely  separated  geographically  and  no  representative 
has  been  recorded  from  the  intervening  (and  considerably 
younger)  Siwalik  deposits  of  India.  Nothing,  however,  has  been 
published  on  Siwalik  fossil  turtles  for  more  than  three-quarters  of 
a  century.  Those  described  by  Lydekker  (1885),  apart  from  the 
large  testudinids,  show  relationships  to  the  recent  turtle  fauna  of 
India,  but  available  collections  need  to  be  examined  thoroughly 
with  an  eye  to  the  possible  presence  of  pelomedusid  remains. 

Some  inferences  are  possible  concerning  the  ecology  of  the  two 
Asiatic  species  of  Shweboemys:  the  Irrawaddy  beds  are  fluviatile 
in  origin  (Krishnan,  1960:  498),  so  that  this  species  was  evidently 
not  a  marine  form.^  In  view  of  the  fact  that  all  pelomedusids 
(except  for  one  or  possibly  two  undescribed  fossil  genera  from 
Africa)  are  aquatic,  S.  pilgrimi  was  probably  a  freshwater  rather 
than  a  terrestrial  turtle.  Pilgrim  (1908:  159)  referred  to  the 
Bugti  beds  from  which  S.  gaffneyi  was  presumably  recovered  as 
a  '^freshwater  formation"  and  Krishnan  (1960:  492)  regarded 
them  as  being  fluviatile,  so  that  this  species  was  in  all  likelihood 
also  a  freshwater  rather  than  a  marine  form.  Moreover,  the 
specialized  palatal  structures  of  these  two  species  have  definite  im- 
plications regarding  their  feeding  habits.  Like  some  living  triony- 
chids  with  enlarged  secondary  palates,  their  diet  may  have  con- 
sisted largely  or  perhaps  even  exclusively  of  molluscs  of  one  sort 
or  another. 


1 1  am  suggesting  elsewhere  that  the  pelomedusids  were  of  marine  origin. 


1970  ASIATIC    FOSSIL    PELOMEDUSIDAE  19 

ACKNOWLEDGMENTS 

I  am  particularly  grateful  to  Mr.  C.  A.  Walker  of  the  British 
Museum  (Natural  History)  for  bringing  to  my  attention  the  skull 
of  Shweboemys  pilgrimi  belonging  to  that  institution.  To  the 
authorities  of  the  British  Museum  (Natural  History)  I  am  indebted 
for  permission  to  describe  this  specimen  as  well  as  the  type  of 
S.  gaffneyi.  I  am  also  much  obliged  to  Professor  Bryan  Patterson 
and  Dr.  E.  E.  Williams  for  critically  reading  this  manuscript,  to 
Professor  B.  Kummel  for  help  concerning  the  stratigraphy  of  West 
Pakistan  and  Burma,  and  to  Mr.  A.  D.  Lewis  for  his  skillful 
preparation  work  on  both  of  the  British  Museum  skulls.  The 
photographs  of  the  type  of  5.  pilgrimi  reproduced  in  Plate  1  were 
sent  to  Dr.  E.  E.  Williams  by  the  authorities  of  the  Geological 
Survey  of  India.  The  figures  were  drawn  by  Mr.  Laszlo  Meszoly. 
Finally,  I  would  like  to  express  my  appreciation  to  the  National 
Geographic  Society  for  their  generous  financial  support  of  my 
research  on  pelomedusid  turtles. 

LITERATURE  CITED 

Andrews,  C.  W.     1901.     Preliminary  note  on  some  recently  discovered 

extinct  vertebrates  from  Egypt.   (Part  II.)   Geol.  Mag.,  8:  436-444. 
. 1906.     A  descriptive  catalog  of  the  Tertiary  Vertebrata  of 

the  Fayum,  Egypt.    Brit.  Mus.  (Nat.  Hist.),  London.  324  pp. 
Carter,  H.  J.     1852.     Geology  of  the  Island  of  Bombay.    Jour.  Bombay 

Branch  Roy.    Asiatic  Soc,  4,   16:    161-215. 
Colbert,  E.  H.     1938.     Fossil  mammals  from  Burma  in  the  American 

Museum  of  Natural  History.    Bull.  American  Mus.  Nat.  Hist.  74,  art. 

6:  255-436. 
1943.     Research    on    early     man    in     Burma,     Part     III: 

Pleistocene  vertebrates  collected  in  Burma  by  the  American  Southeast 

Asiatic   expedition.    Trans.    American    Phil.    Soc,    n.s.,    32,   part    3: 

395-429. 
Gaffney,   E.   S..   and   R.   Zangerl.      1968.     A   revision   of   the    chelonian 

genus  Bothremys  (Pleurodira:  Pelomedusidae),  Fieldiana  (Geol.),  16 

(7):  193-239. 
Krishnan,  M.  S.     1960.     Geology  of  India  and  Burma  (4th  ed.).  Madras. 

Higgenbothams  (Private)  Ltd.  604  pp. 

Lydekker,     R.     1885.     Indian     Tertiary    and     post-Tertiary    Vertebrata. 

Siwalik  and   Narbada  Chelonia.    Mem.  Geol.  Surv.   India,   Palaeont. 

Indica,  sen  10,  3,  part  6:   155-208,  pis.  18-27. 
1887.     Indian     Tertiary     and     post-Tertiary     Vertebrata. 

Eocene   Chelonia    from   the    Salt   Range.     Mem.    Geol.    Surv.   India, 

Palaeont.  Indica,  ser.  10,  4,  part  3:   59-65,  pis.  12-13. 


20  BREVIORA  No.    357 
1890.     Note  on  certain  vertebrate  remains  from  the  Nagpur 


District.  Records  Geol.  Surv.  India,  23:  20-24. 
Pascoe,   E.   H.     1964.     A  manual   of  the   geology   of   India   and    Burma, 
3  (3rd  ed.).  Geol.  Surv.  India:  XXIV  and  pp.  1345-2130. 

Pilgrim,  G.  E.  1908.  The  Tertiary  and  post-Tertiary  freshwater  de- 
posits of  Baluchistan  and  Sind,  with  notices  of  new  vertebrates. 
Records  Geol.  Surv.  India,  37,  part  2:    139-166,  pis.  2-4. 

Robinson,  P.  L.  1970.  The  Indian  Gondwana  formations — a  review. 
l.U.G.S.  First  Symposium  on  Gondwana    Stratigraphy:   201-268. 

RoMER,  A.  S.      1956.     Osteology  of  the  Reptiles.  Chicago,  The  University 

of  Chicago  Press.  772  pp. 
SiEBENROCK,    F.      1902.     Zur    systematik    der    schildkroten-gattung    Podoc- 

nemis  Wagl.  Sitz.  der  kaiserl.  Akad.  der  Wiss.  in  Wien,  Math.-Naturw. 

Classe,  111,  abt.  1:   1-14. 
Stamp,  L.  D.     1922.     An  outline  of  the  Tertiary  geology  of  Burma.  Geol. 

Mag.,  59  (11):  481-501. 
SwiNTON,  W.  E.     1939.     A  new  fossil  fresh-water  tortoise  from  Burma. 

Rec.  Geol.  Surv.  India,  74,  pt.  4:  548-551. 
Wadia,   D.   N.     1953.     Geology   of  India    (3rd  ed.).   London,   Macmillan 

and  Co.  531  pp. 
Williams,   E.  E.     1953.     Fossils  and  the   distribution  of  chelyid  turtles, 

1.  "Hydraspis  leithii"  (Carter)  in  the  Eocene  of  India  is  a  pelomedusid. 

Breviora,  no.  13:   1-8,  pis.  1-3. 
^__ 1954.     A  key  and  description  of  the  living  species  of  the 

genus    Podocnemis    {sensii    Boulenger)    (Testudines,    Pelomedusidae). 

Bull.  Mus.  Comp.  Zool.,  Ill,  (8):  279-295. 
Zangerl,    R.      1969.      The    turtle    shell.     In    Biology    of    the    Reptilia,    /. 

Morphology  A  (C.  Gans,  ed.)  London  and  New  York,  Academic  Press. 

311-339. 


970 


ASIATIC    FOSSIL    PELOMEDUSIDAE 


21 


-'-r^np^ 


.^i*^^*^"^' 


»>• 


B 


I.  Type  specimen  oi  SJnveboemys  pilgrimi  (GSI  17255):  A — 
palatal  view  of  skull;  B — dorsal  view.  Approximately  Va  natural 
size. 


22 


BREVIORA 


No.   357 


! 

■ 

1    11 

Hj    CM 

■ 

■1 

^^^^1                                  •  •'\^'  " 

A 

*^"^^^^§L^^- 

^''   -«<■•■  >^^o|^^3H|^t^ 

k 

b 

"**         "***  ^^BSiBt 

ilraMI^T'^ 

^^^^s 

»^«w 

■J^ 

■J^^^Pk 

'^^^^^^m^B^^-,    «-v»  --t^^t    "•»          '^^H 

' 

II.     Palatal   views    of:    A — Shweboemys   pilgrimi    (BMNH- 
R.   8432);  "R— Shweboemys  gafjneyi  (BMNH— R.  8570). 


1970 


ASIATIC    FOSSIL    PELOMEDUSIDAE 


23 


III.     Lateral  views  of:    A — Shweboemys  pilgrimi   (BMNH- 
R.  8432);  B— Shweboemys  gaffneyi  (BMNH— R.  8570).    tgf 
trieeminal  nerve  foramen. 


24 


BREVIORA 


No.  357 


CM 


IV.     Dorsal  views  of:  A — Siiweboemys  pilgiimi  (BMNH — R. 
8432);  B—Shweboemys  gaffneyi  (BMNH— R.  8570). 


BREVIORA 


Miaseium    of    Comparative    Zoology 

Cambridge,  Mass.        30  November,  1970  Number  358 

South  American  anoles:  Anolis  apollinoris  Boulenger  1919, 
a  relative  of  A.  biporcatus  Wiegmann  (Sauria,  Iguanidae) 


Ernest  E.  Williams 

Abstract.  Anolis  apollinaris  is  a  central  Andean  derivative  of  A.  bipor- 
catus, probably  from  an  earlier  invasion  of  South  America  than  that  which 
has  provided  the  present  Colombian,  Ecuadorian,  and  western  Venezuelan 
populations  of  the  latter  species. 

Anolis  apollinaris  Boulenger  1919  was  described  from  a  unique 
type,  a  female,  said  to  come  from  "near  Bogota."  The  description 
made  no  mention  of  relationships. 

The  next  mention  of  the  species  was  made  by  Burt  and  Burt 
(1931:  255),  who  referred  numerous  Colombian  specimens  in  the 
American  Museum  to  this  species.  They  suggested  that  the  species 
belonged  to  the  "chrysolepis  stock"  but  also  said  that  their  speci- 
mens closely  resembled  A.  gemmosus  of  Ecuador  with  which  they 
believed  A .  apollinaris  "may  prove  to  be  identical  or  subspecifically 
allied."  An  examination  of  the  type  of  apollinaris  in  the  British 
Museum  shows  that  these  statements  of  relationships  are  entirely 
mistaken  and  that  the  specimens  referred  to  the  species  by  Burt 
and  Burt — one  specimen  received  in  exchange  from  the  American 
Museum  by  the  Museum  of  Comparative  Zoology — are  mis- 
identified.^ 


1  The  type  of  A.  gemmosus  O'Shaughnessy  has  also  been  examined.  It 
is  not  of  chrysolepis  stock  nor  related  at  all  closely  to  the  two  species  mis- 
identified  by  Burt  and  Burt  as  A.  apollinaris.  The  affinities  of  A.  gemmosus 
are  with  A.  fasciatus  Boulenger  and  A.  andianus  Boulenger. 


2  BREVIORA  No.    358 

A  correct  judgment  on  the  affinities  of  A.  apollinaris  was  made 
by  E.  R.  Dunn  in  1944  (p.  25),  who  at  that  time  reported: 

"The  Instituto  de  La  Salle  has  a  specimen  of  this  lizard  (de- 
scribed from  'near  Bogota')  from  Paime,  Cundinamarca,  1038 
meters.  A  number  of  students  have  overlooked  the  statement  that 
this  is  a  large  Anolis  (type  head-body  length  106  mm)  and  mis- 
applied the  name.  Thus  the  "Anolis  apollinaris"  of  Burt  and  Burt 
(1921  I  sic  J,  p.  255)  is  not  Boulenger's  species  but  a  composite  of 
two  smaller  species,  incomperliis  Barbour  from  Villavicencio  and 
mariaruin  Barbour  from  Medellin^  True  apollinaris  is  allied  to 
solijer  of  Santa  Marta  and  copei  of  Central  America." 

The  two  latter  names  are  now  regarded  as  synonyms  of  bipor- 
catus  (see  Williams,  1966)  and  it  is  with  this  species,  which  ranges 
from  Mexico  to  Ecuador,  that  apollinaris  requires  comparison. 

Brother  Niceforo  Maria  of  the  Instituto  La  Salle  tells  me  that 
Dunn's  specimen  of  A.  apollinaris  was  one  of  many  specimens 
destroyed  in  a  fire  at  the  Institute  in  1948.  Fortunately,  a  number 
of  previously  unreported  specimens  have  been  discovered,  one  in 
the  Institut  Royale  (Brussels),  a  series  in  the  Zoologische  Staat- 
sammlung  (Munich)  and  three,  indeed,  in  more  recent  collections 
of  the  Instituto  La  Salle  (ILS),  and  two  more  in  the  American 
Museum  of  Natural  History  (AMNH). 

On  the  basis  of  these  new  specimens  and  the  type  specimen  at 
the  British  Museum  (BM),  I  present  a  revised  standard  descrip- 
tion of  the  species: 

Anolis  apollinaris  Boulenger 

Type.  BMNH  1919.3.6.7  (1946.8-13.22),  from  near  Bogota, 
Cundinamarca,  Colombia. 

Referred  specimens.  (All  Colombia.)  Antioquia  (all  Cauca 
Valley):  AMNH  38725,  Sabanalarga;  ILS  81,  Puerto  Antioquia. 
Caldas:  ILS  101,  Pueblo  Rico.  Cundinamarca:  Brussels  3580,  La 
Esperanza,  1250  m;  ILS  65,  Paime;  ILS  106,  Quipile;  Munich 
427-432,  San  Pablo,  west  side  of  cordillera  between  Bogota  and 
La  Dorada.   "Western  Colombia":  AMNH  4844. 


1  A.  incompertus  Barbour  is  a  composite  species:  specimens  from 
Villavicencio  are  A.  chrysolepis  scypheus  Cope  and,  from  near  Bogota.  A. 
tropidogaster  Hallowell.  A.  mariaruin  Barbour  is  a  synonym  of  A.  antonii 
Boulenger.    All  types  have  been  examined. 


1970 


ANOLIS    APOLLINARIS 


u 


d 

Z, 

B 

Xi 

o 

c 

3 


2 


BREVIORA 


No.  358 


Diagnosis.  Allied  to  biporcatus  Wiegmann  and  its  subspecies 
parvauritus  Williams  but  differing  in  color,  in  one  or  no  scales 
separating  nasal  from  rostral,  and  in  a  modally  higher  number  of 
lamellae  under  phalanges  ii  and  iii  of  the  fourth  toe. 

Head.  Head  scales  small,  sharply  uni-  or  tricarinate.  Ten  to 
thirteen  scales  across  snout  between  second  canthals.  A  distinct 
frontal  depression,  scales  within  it  not  smaller  than  surrounding 
scales.  Five  to  nine  scales  border  rostral  posteriorly.  Circumnasal 
scale  separated  from  rostral  by  one  small  scale  or  in  contact.  Six 
to  seven  scales  between  circumnasals  dorsally. 

Supraorbital  semicircles  separated  from  each  other  by  2-4  scales, 
from  the  supraocular  disk  by  one  row  of  smaller  scales.  Supra- 
ocular disk  not  very  distinct,  of  4-12  keeled  scales  grading  laterally 
into  granules.  One  to  three  overlapping  elongate  supraciliary  scales, 
continued  posteriorly  by  granules.  Anterior  corner  of  supraocular 
filled  by  larger  subgranular  scales.  Canthus  sharp,  of  6-7  over- 
lapping scales,  the  first  and  second  or  second  and  third  the  largest. 
Five  to  seven  loreal  rows,  subequal  or  the  uppermost  largest.  Tem- 
poral scales  granular.  A  distinct  double  line  of  enlarged  inter- 
temporal scales.    Supratemporals  granular,  slightly  smaller  than 


Figure  2.     Anolis  apollinaris  Munich  No.  422.   Dorsal  view  of  head. 


1970  ANOLIS    APOLLINARIS  5 

temporals.  Scales  surrounding  interparietal  moderately  to  abruptly 
enlarged,  swollen,  largest  anteriorly  and  laterally.  Interparietal  less 
than  or  greater  than  ear,  separated  from  semicircles  by  3-4  scales 
on  each  side. 

Suboculars  separated  from  supralabials  by  one  row  of  scales  (or 
narrowly  in  contact),  anteriorly  separated  from  canthal  ridge  by 
one  scale,  posteriorly  continued  by  an  indistinct  double  row  of 
smaller  scales.   Seven  to  eight  supralabials  to  center  of  eye. 

Mental  slightly  wider  than  long,  in  contact  with  4-8  scales  be- 
tween supralabials  posteriorly.  Sublabials  not  well  differentiated. 
Central  throat  scales  quadrangular,  swollen,  gradually  increasing 
in  size  laterally. 

Dewlap.  Dewlap  in  male  large  with  close-packed  scales.  A 
gular  fold  only  in  female,  moderate,  scales  rather  closely  packed. 

Trunk.  Middorsals  slightly  enlarged,  swollen,  keeled.  Dorsal 
and  flank  scales  keeled,  subequal.  Ventrals  larger,  weakly  keeled, 
imbricate,  not  mucronate. 

Limbs.  Largest  fore  and  hind  limb  scales  strongly  unicarinate, 
except  at  knee  and  elbow,  smaller  than  largest  ventrals.  Supra- 
digital  scales  multicarinate.  Twenty-four  to  twenty-seven  lamellae 
under  phalanges  ii  and  iii  of  fourth  toe. 

Tail.  Slightly  compressed,  almost  evenly  scaled  all  round.  Ver- 
ticils indistinct.   All  scales  keeled.   Enlarged  postanals  in  male. 

Size.     Type:   106  mm  snout-vent  length. 

Comparison.  Table  1  lists  the  major  features  differentiating  A. 
apollinaris  and  A.  biporcatus.  I  comment  on  each  of  these  features 
below: 

1.  Scales  in  narial  area.  The  exact  pattern  of  the  scales  sur- 
rounding the  naris  and  their  relation  to  the  rostral  have  been 
repeatedly  used  in  lizards  generally  (e.g.,  geckos),  and  this  pattern 
has  also  proved  empirically  very  useful  at  the  species  level  in 
Anclis.  Published  examples  of  the  utility  of  this  character  at  the 
species  level  are  Ruibal  and  Williams  (1961 )  and  Lazell  (1964). 
Although,  like  all  squamation  characters  in  Anolis,  these  patterns 
are  subject  to  some  intraspecies  variation,  they  are  rather  surpris- 
ingly constant.  Frequently  a  single  pattern  is  consistently  main- 
tained; this  is  usually  a  simple  one.  More  complex  patterns  tend 
to  greater  variation  but  the  variations  are  readily  derivable  from 
the  modal  condition  (Fig.  3).  The  pattern  of  apollinaris  is  always 
simpler  than  that  of  biporcatus  and  may  be  more  primitive.  (The 
judgment  that  this  pattern  may  be  more  primitive  is  based  not  upon 


BREVIORA 


No.  358 


Figure  3.  Nasal  rostral  relationships.  Upper  left:  Anolis  biporcatus 
biporcatiis,  MCZ  15426.  Upper  right:  A.  b.  parvaiiritus,  MCZ  78942. 
Lower  left:  A.  apollinaris,  Munich  422.  Lower  right:  A.  fraseri,  MCZ 
43772. 


its  simplicity  but  upon  its  association  with  other  characters  re- 
garded as  primitive  and  on  its  occurrence  in  species  regarded  on 
other  grounds  as  primitive.)  The  variation  in  apollinaris  is  in  the 
direction  of  the  pattern  in  biporcatus,  but  there  is  no  overlap.  This 
is  a  sharp  and  clear  distinction. 

2.  Supraciliary  scales  (Fig.  4).  Again  the  pattern  of  this  area 
tends  to  be  species  specific  and  again  the  condition  in  apollinaris 
tends  to  be  simpler  and  perhaps  more  primitive  than  that  of  bipor- 
catus. The  common  pattern  in  biporcatus  is  indeed  unusual  (though 
not  unique).  Two  patterns  are  common  for  the  supracihary  region 
of  anoles:  (1)  one  or  more  elongate  supraciliaries  followed  by  un- 
differentiated granules;  (2)  one  or  more  elongate  supraciliaries 
followed  by  a  double  series  of  enlarged  scales  rather  even  in  size. 


970 


ANOLIS    APOLLINARIS 


Figure  4.     Supraciliary    area.     Top:    Anolis    apoUinaris,    Munich    422. 
Lower  left:   A.  b.  biporcatiis,  MCZ   15426.    Lower  right:  A.  fraseri,  MCZ 

43772. 


A.  biporcatiis,  exhibiting  several  rather  short  supraciharies  grading 
into  large  scales  that  tend  to  grade  again  into  granules,  presents  a 
condition  hardly  more  frequent  than  that  of  A .  fraseri  with  its  series 
of  quadrate  scales  along  the  whole  supraciliary  margin,  the  first  of 
these  sometimes  elongate. 

3.  Scales  around  interparietal.  In  general,  the  degree  of 
enlargement  of  scales  around  the  interparietal  is  a  good  specific 
character  in  Anolis.  Particularly  valuable  may  be  the  degree  of 
enlargement  of  the  scales  posterior  to  the  interparietal  as  compared 
with  the  adjacent  dorsal  or  supratemporal  scales.  There  may  be 
rapid  intergradation  of  enlarged  scales  lateral  to  the  interparietal 
into  much  smaller  dorsal  and  supratemporal  scales,  or  the  scales 
behind  the  interparietal  may  be  sharply  and  conspicuously  larger 
than  dorsal  or  supratemporal  scales  (as  in  some  apoUinaris).  The 
two  subspecies  of  A.  biporcatus  difl'er  in  this  regard.  A.  apoUinaris 
is  variable;  perhaps  the  variation  is  geographic,  but  there  is  not 
enough  material  to  say. 

4.  Ear  shape  and  position.  The  ear  of  apoUinaris  is  quite  dif- 
ferent from  that  of  either  southern  or  northern  biporcatus.    It  is 


8  BREVIORA  No.    358 

closer  in  size  to  that  of  southern  biporcatus  but  quite  distinct  in  its 
obliquity,  a  rather  unusual  feature. 

5.  Ventral  keeling.  This  character  is  minor.  Keeled  ventrals 
may  be  a  good  species  character,  but  there  are  many  instances  of 
intraspecies  variability,  both  geographic  and  (typically  qualitatively 
less  extreme)  at  a  single  locality.  A.  apollinaris  has  the  ventrals 
more  weakly  keeled  than  either  subspecies  of  biporcatus. 

6.  Toe  lamellae.  The  number  of  toe  lamellae  is  an  extremely 
useful  character  in  Anolis  and  very  characteristic  of  species.  It  is, 
however,  subject  to  variability  (a  range  of  6  or  7  is  quite  usual) 
and  overlap  is,  as  in  the  present  case,  frequent.  A.  apollinaris 
tends  to  a  higher  number  of  toe  lamellae  than  either  subspecies 
of  biporcatus. 

7.  Color.  I  have  no  descriptions  of  color  in  life  of  apollinaris 
and  the  varying  colors  of  biporcatus  as  preserved  (it  is  uniform 
green  in  life)  do  not  make  comparison  very  easy.  Boulenger  de- 
scribed the  type  female  as  "Dark  olive  above  and  on  the  sides, 
with  a  fine  blackish  network,  head  and  a  vertebral  band  pale,  the 
latter  with  narrow  transverse  processes;  small  round  light  spots  on 
the  sides  and  tail;  forearm,  tibia  and  lower  parts  pale  green." 

The  Brussels  specimen  has  preserved  its  pattern  rather  well. 
Description  follows:  Head  greyish.  A  dark  streak  from  back  of 
eye  to  shoulder,  there  merging  with  dark  flanks.  Below  this,  labials 
and  nape  lighter,  their  color  continuous  with  the  smudged  grey  of 
the  throat.  A  hght  brown  middorsal  zone,  irregularly  darker  lat- 
erally, bordered  on  each  side  by  a  narrow  grey  line.  Flanks  dark 
brown  with  indications  of  white  spots  or  broken  narrow  vertical 
white  bars.  Forelimbs  obscurely  annulate,  hind  limbs  boldly  so. 
Tail  above  with  longitudinally  oval  light  spots  with  irregularly  dark 
centers.  Belly  lighter  than  any  part  of  dorsum  but  still  heavily 
infuscated.   Tail  below  lighter  still. 

The  new  specimens  resemble  the  Brussels  specimen  in  head 
coloration,  as  the  British  Museum  type  now  does;  presumably  the 
latter  differs  from  Boulenger's  description  as  a  result  of  change 
during  preservation. 

A.  apollinaris,  when  compared  with  A.  biporcatus,  differs  in  few 
and  superficially  trivial  ways.  The  ventrals  are  less  strongly  keeled. 
There  are  fewer  scales  between  nostril  and  rostral:  one  or  more 
rather  than  two  or  three.  The  color  is  quite  unlike  anything  1  have 
seen  in  biporcatus.   I  am  neither  confident  that  this  form  is  a  full 


1970  ANOLIS    APOLLINARIS  9 

species  nor  convinced  that  it  is  not.  It  is  certainly  not  to  be  con- 
fused with  Mexican  or  Central  American  biporcatus,  nor  with  the 
south  Colombian-Ecuadorian  population,  nor  does  it  resemble  the 
two  Venezuelan  specimens  of  that  species.  Whether  it  is  distinct 
from,  or  intergrades  with,  some  of  the  other  Colombian  or  the 
Ecuadorian  populations  is  a  matter  for  future  discovery.  Provi- 
sionally, since  it  was  described  as  a  species,  it  may  remain  so 
allocated. 

A.  biporcatus  has  the  distribution  of  a  recent  immigrant  into 
South  America,  extending  from  Panama  through  the  Choco  region 
of  Colombia  down  into  Ecuador  west  of  the  Andes  and  extending 
eastward  through  the  Santa  Marta  Mountains  into  western  Vene- 
zuela. A.  apollinaris,  now  recorded  from  Antioquia,  Caldas,  and 
Cundinamarca,  may  be  supposed  to  have  arisen  from  A.  bipor- 
catus by  isolation  and  subsequent  minor  modification  in  the  central 
Andean  regions  of  Colombia.  Since  it  has  some  primitive  features 
(e.g.,  nasal-rostral  relationship)  and  since  it  has  reached  species 
status,  it  may  represent  an  earlier  invasion  of  South  America  than 
that  which  resulted  m  A.  b.  parvauritus  Williams  and  the  Vene- 
zuelan specimens  oi  A.  b.  biporcatus. 

REFERENCES 

BouLENGER,  G.  A.  1919.  Descriptions  of  two  new  lizards  and  a  new  frog 
from  the  Andes  of  Colombia.    Proc.  Zool.  Soc.  London,  1919:  79-80. 

Burt,  C.  E.,  and  M.  D.  Burt.  1931.  South  American  lizards  in  the  col- 
lection of  the  American  Museum  of  Natural  History.  Bull.  American 
Mus.  Nat.  Hist.  61:  227-395. 

Dunn,  E.  R.  1944.  Herpetology  of  the  Bogota  area.  Revista  Acad.  Co- 
lombiana  Cienc.  6:  68-81. 

Lazell.  J.  D.,  Jr.  1964.  The  anoles  (Sauria,  Iguanidae)  of  the  Guade- 
loupeen  Archipelago.    Bull.  Mus.  Comp.  Zool.  131:  359-401. 

RuiBAL.  R.,  AND  E.  E.  Williams.  1961.  The  taxonomy  of  the  Anolis 
honwlechis  complex  of  Cuba.    Bull.  Mus.  Comp.  Zool.  125:  209-246. 

Williams,  E.  E.  1966.  South  American  anoles:  Anolis  biporcatus  and 
Anolis  fraseri  (Sauria,  Iguanidae)  compared.  Mus.  Comp.  Zool., 
Breviora  No.  239:   1-14. 

(Received  9  June  1970.) 


10 


BREVIORA 


No.  358 


■10 


O' 


-:^/0' 


Figure  5.     Map    of    the    distribution    of    Anolis    apollinaris    in    central 
Colombia. 


1970 


ANOLIS    APOLLINARIS 


11 


TABLE   1 


apollinaris  b.  biporcatus 

scales  across  snout  9-13  7-11 


b.  parvauritus 
8-13 


scales  between  nasal 
and  rostral 


0-1 


2-3 


2-3 


scales  between  supra- 
orbital semicircles 


2-4 


1-4 


0-3 


supraciliaries 


1-2  elongate  plus     usually  3-4  short      as  in  biporcatus 
series  of  small         supraciliaries 
scales  of  rather        plus  a  series  of 
uniform  size  small  scales  of 

variable  size 


scales  behind 
interparietal 


variable,  slightly       abruptly  larger 
to  abruptly  larger    than  dorsals 
than  dorsals 


grading  gradually 
into  dorsals 


scales  separating 
interparietal  from 
semicircles 


3-5 


3-6 


3-7 


loreal  rows 


5-8 


5-10 


6-9 


supralabials  to 
center  of  eye 


ear 


7-8 


8-11 


small  to  moderate    moderate  to 
large,  vertical 


7-12 


small 


ventrals 


weakly  keeled 


strongly  keeled, 
mucronate 


strongly  keeled, 
mucronate 


lamaellae  under 
phalanges  ii  and  iii 
of  fourth  toe 


25-27 


22-26 


22-26 


BREVIORA 


MiaseiLaitii    of    Comparative    Zoology 

Cambridge,  Mass.        30  November,  1970  Number  359 

The  Swimbladder  as  a  Juvenile  Organ 
in  Stromateoid  Fishes 

Michael  H.  Horn^ 


Abstract.  The  swimbladder  regresses  in  14  of  the  15  genera  of  strom- 
ateoid fishes  and  apparently  in  each  case  before  maturity  is  reached.  In 
one  genus  the  swimbladder  is  absent.  The  organ  appears  to  be  completely 
functional  and  is  present  in  juvenile  fishes  that  inhabit  the  surface  layers 
of  the  ocean,  often  in  association  with  jellyfish  medusae  or  floating  objects. 
In  the  transition  from  the  juvenile  to  the  adult  habitat  and  mode  of  life, 
the  swimbladder  regresses  to  a  nonfunctional  state,  and  other  morphological 
changes  occur. 

A  detailed  study  in  progress  of  the  state  and  structure  of  the 
swimbladder  in  stromateoid  fishes  in  relation  to  their  evolution 
and  ecology  shows  that  the  organ  regresses  with  age  in  14  of  the 
15  genera  comprising  this  suborder  of  perciform  teleosts.  The 
regression  of  the  swimbladder  occurs  at  different  ages,  depending 
upon  the  species  in  question  and  seems  to  be  correlated  with  other 
morphological  changes  and  with  certain  changes  in  mode  of  life. 
Thus,  the  state  of  the  swimbladder  may  be  useful  in  predicting 
or  determining  at  what  age  or  size  a  particular  species  undergoes 
a  shift  in  habitat  or  way  of  life. 

The  suborder  Stromateoidei  consists  of  six  families  (Haedrich 
&  Horn,  1969),  the  members  of  which  range  in  maximum  size 
from  about  30  to  about  120  centimeters.  It  is  a  fairly  diverse 
group  of  temperate  and  tropical  marine  fishes,  which,  as  adults, 
variously  occupy  a  wide  range  of  depths  in  coastal  and  oceanic 
waters.  The  Stromateidae  occur  at  all  depths  over  the  continental 
shelf.  The  Ariommidae  are  benthic  or  benthopelagic  on  the  shelf. 


1  Present   address:     Department   of   Biological   Science,   California  State 
College,  Fullerton,  California  92631. 


2  BREVIORA  No.    359 

The  Centrolophidae  are  either  coastal,  as  in  Hyperoglyphe  and 
Seriolella,  or  oceanic  at  various  depths,  as  in  Centrolophiis  and 
Icichthys.  The  Nomeidae,  Tetragonuridae,  and  Amarsipidae  are 
oceanic  usually  in  epi-  or  mesopelagic  layers.  However,  as  occurs 
in  many  other  marine  fishes,  the  larvae  and  juveniles  of  stroma- 
teoids  are  pelagic  in  the  surface  layers,  mostly  in  the  upper  100 
meters. 

Stromateoid  fishes  commonly  undergo  marked  changes  when 
approaching  maturity,  and  these  changes  are  often  associated  with 
the  migration  from  the  surface  layers  to  the  deeper  layers  where 
the  fishes  live  as  adults  (Haedrich,  1969).  Along  with  certain 
changes  in  body  proportions  (see  Haedrich,  1967;  and  Horn, 
1970),  including,  frequently,  changes  in  the  length  of  paired  fins, 
the  swimbladder  regresses.  This  regression  and  the  significance  of 
the  swimbladder  in  the  life  of  young  fishes  are  discussed  below. 

MATERIALS   AND    METHODS 

Specimens  examined  are  from  the  collections  of  the  British 
Museum  (Natural  History);  the  Zoological  Museum,  Copen- 
hagen; and,  the  Woods  Hole  Oceanographic  Institution.  The 
fishes  from  the  last  institution  will  ultimately  be  deposited  in  the 
Museum  of  Comparative  Zoology,  Harvard  University.  Specimen 
data  will  be  included  in  a  forthcoming  comprehensive  paper  on 
stromateoid  swimbladders. 

Swimbladder  volumes  were  calculated  treating  the  bladder  as 
an  ellipsoid.  Body  volumes  were  determined  by  displacement  in 
water.  Ten  per  cent  was  allowed  for  shrinkage  of  the  preserved 
material,  and  volume  determinations  were  made  from  swimblad- 
ders that  were  in  most  cases  well  expanded.  The  number  of  retial 
capillaries  was  estimated  from  thin  sections  of  swimbladders. 

RESULTS   AND    DISCUSSION 

Very  little  mention  has  been  made  of  the  swimbladder  in 
stromateoids.  Jordan  &  Evermann  (1896)  stated  that  the  organ 
was  "usually  absent"  in  the  Stromateidae.  Fowler  (1936)  indi- 
cated that  it  was  "present  or  absent"  in  his  treatment  of  several 
stromateoid  genera.  Grey  (1955)  reported  it  to  be  absent  in 
Tetragonurus.  Haedrich  (1967)  cited  its  presence  in  Ariomma. 
While  I  have  not  yet  examined  every  species,  I  have  found  a 
swimbladder  to  be  present  in  all  genera  except  Pampus. 


1970 


SWIMBLADDER    OF    JUVENILE    STROMATEOIDS 


The  swimbladder  in  stromateoids  (Fig.  1)  is  euphysoclystous, 
i.e.,  with  a  distinct  gas-resorbing  area — a  posterior  chamber 
separated  from  the  anterior  by  a  diaphragm — and  has  unipolar 
retia  that  are  either  medial  or  posterior  in  position.  It  is  generally 
of  a  relatively  simple  type  found  in  a  number  of  perciform  fishes 
(N.  B.  Marshall,  personal  communication). 


Figure  1.  Ventral  (slightly  flattened)  view  of  the  swimbladder  of 
Nomeus  gronovii,  26.4  mm  SL;  rm  =  rete  mirabile;  rv  =  retial  vein; 
ra  =  retial  artery;  gg  =  gas  gland;  ac  =  anterior  chamber;  dm  =  dia- 
phragm; pc  =  posterior  chamber.  (X  33) 


The  swimbladder  in  these  fishes  is  relatively  small  and  fre- 
quently below  the  3.1-5.7  range  of  percentage  volumes  calculated 
by  Alexander  (1966)  to  be  necessary  for  neutral  buoyancy  in 
sea  water  (Table  1).  Measurements  of  swimbladder  percentage 
volume  for  Hyperoglyphe,  Cubiceps,  and  Ariomma  show  the 
organ  to  be  within  the  above  range,  but  in  other  genera,  notably 
Schedophiliis  and  Nomeus,  the  percentage  volume  may  be  as  low 
as  0.5  or  0.6  per  cent.  Some  calculated  values  may  be  lower 
than  normal  because  of  the  swimbladder  being  in  a  slightly  con- 
tracted state.  The  organ  does  appear  to  be  completely  developed 
and  almost  certainly  functional.  The  blood  supply  is  complete, 
and  the  surface  area  of  the  gas  gland  and  the  length  of  the  retia 
in  relation  to  swimbladder  size  (Table  1 )  compare  closely  with 
the  range  of  values  calculated  by  Marshall  (1960:  tables  3,  4,  & 
5)  for  deep-sea  fishes  with  well-developed  swimbladders.  The 
organ  is  fully  formed  in  the  smallest  individuals  (9  mm  SL)  that 
have  been  examined.  Regression  to  a  nonfunctional  state  occurs, 
apparently  in  all  species,  before  maturity  is  reached. 


BREVIORA 


No.  359 


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1970  SWIMBLADDER    OF    JUVENILE    STROMATEOIDS  5 

Being  fully  developed  and  certainly  capable  of  hydrostatic  ad- 
justment, the  stromateoid  swimbladder  seems  very  unlikely  to  be 
merely  an  evolutionary  remnant.  The  clue  to  its  significance 
appears  to  lie  in  the  behavior  of  the  juveniles.  The  young  of  all 
or  nearly  all  of  the  species  live  in  the  surface  layers  and  fre- 
quently in  association  with  jellyfish  medusae  or  other  animate  or 
inanimate  floating  objects.  Protection  is  presumably  provided  by 
the  medusae  or  floating  objects,  and  the  fishes  feed  upon  the 
small  invertebrates  concentrated  around  the  objects  or  upon  the 
jellyfishes  themselves.  This  existence  seems  to  require  both  con- 
siderable maneuverability  and  the  ability  to  hover  and  remain 
motionless  in  midwater.  I  have  observed  young  Peprilus  triacan- 
thus  hovering  beneath  and  near  the  tentacles  of  the  sea  nettle, 
Chrysaora  qiiinquecinha,  and  they  show  little  locomotor  activity 
except  for  backing  of  water  by  the  pectoral  fins.  Mansueti  (1963) 
has  made  similar  observations  on  Peprilus  alepidotus  {=  P. 
paru.).  Few,  if  any,  of  the  stromateoid  genera  which  consort 
with  medusae  are  completely  immune  to  jellyfish  toxins  but  merely 
avoid  the  tentacles,  according  to  observations  made  by  Mansueti 
(1963)  on  P.  alepidotus,  by  Maul  (1964)  on  Mupus  {-Schedo- 
philus),  and  myself  on  P.  triacanthus.  Lane  (1960)  reports  that 
Nomeus  gronovii  can  survive  doses  of  Physalia  toxin  as  much  as 
ten  times  that  which  would  kill  other  fishes  of  the  same  general 
size  and  type;  however,  Nomeus  still  exhibits  considerable  agility 
in  avoiding  the  tentacles  of  Physalia. 

The  swimbladder,  even  if  smaU,  would  provide  a  degree  of 
buoyancy,  although  not  necessarily  complete  neutral  buoyancy. 
During  the  period  of  life  in  which  the  fishes  have  a  gas  bladder, 
the  skeleton  is  not  well  ossified  and  the  musculature  may  not  be 
completely  developed;  thus,  the  juveniles  probably  have  a  lower 
specific  gravity  than  the  adults.  In  those  adults  with  soft  muscula- 
ture and  light  ossification,  such  as  Schedophilus,  the  swimbladder 
probably  becomes  unimportant  and  uneconomical  because  of  a 
change  in  mode  of  life,  even  though,  as  in  juveniles,  a  small  volume 
of  gas  would  provide  nearly  neutral  buoyancy.  Using  Alexan- 
der's (1966)  formula  for  calculating  the  percentage  swimbladder 
volume  necessary  to  achieve  hydrostatic  equilibrium,  I  find  that 
only  a  1  per  cent  reduction  in  specific  gravity  of  the  fish  lowers  the 
required  percentage  volume  from  3.1  per  cent,  the  lower  figure 
in  Alexander's  calculated  range,  to  2.2  per  cent.  The  latter  figure 
is  within  or  near  the  range  of  volumes  for  most  of  the  stromateoid 


6  BREVIORA  No.    359 

genera  (Table  1).  Also,  the  more  firmly  muscled  and  more 
heavily  ossified  fishes,  such  as  Hyperoglyphe,  have  greater  swim- 
bladder  volumes  than  those  with  softer  muscles  and  lighter  bones, 
such  as  Schedophiliis  (Table  1  ).  An  exception  is  Nomeus,  which 
has  relatively  firm  musculature  but  a  small  swimbladder. 

The  regression  of  the  swimbladder  is  a  gradual  process,  with 
the  sac  diminishing  and  the  gas  gland  becoming  a  small  yellowish 
mass  before  being  completely  resorbed.  The  mass  representing 
the  regressed  gas  gland  may  persist  in  the  mesentery  beneath  the 
kidney  for  a  considerable  period  of  time  after  the  swimbladder 
becomes  nonfunctional.  In  none  of  the  stromateoids  does  the 
swimbladder  appear  to  become  fat-filled  upon  regression  as  it 
does  in  some  deep-sea  fishes  (Marshall,  1960). 

It  is  meaningful  to  consider  the  duration  that  the  swimbladder 
remains  functional  in  the  different  stromateoid  genera  in  rela- 
tion to  the  time  of  change  in  habitat  and  mode  of  life.  Nomeus 
among  the  stromateoids  appears  to  have  the  most  intimate  and 
enduring  association  with  jellyfishes,  usually  with  the  siphono- 
phore,  Physalia.  The  fish  may  remain  with  Physalia  throughout 
its  life,  although  this  is  uncertain.  Significantly,  Nomeus  retains 
what  seems  to  be  a  functional  swimbladder  longer  than  any  other 
stromateoid  that  has  been  examined.  The  largest  specimen  I  have 
studied  (142.7  mm  SL)  had  a  relatively  large  sac  with  a  some- 
what contracted  gas  gland  and  was  captured  at  the  surface  with 
Physalia.  It  has  not  been  possible  to  determine  whether  or  not 
the  large  specimens  that  have  been  found  with  Physalia  were 
mature. 

The  swimbladder  of  Peprilus  triacanthus  is  usually  completely 
regressed  by  the  time  the  fish  reaches  a  length  of  100  mm  SL, 
and  this  is  about  the  size  at  which  it  has  completely  abandoned 
jellyfish  medusae.  Large  individuals  (>  100  mm  SL)  of  P.  tria- 
canthus do  not  hover  as  do  the  juveniles  but  swim  continuously. 
The  pecioral  fins  increase  in  relative  length  with  age  and  are  used 
more  extensively  for  propulsion  in  adults  than  in  juveniles.  The 
angle  through  which  the  pectorals  are  adducted  apparently  pro- 
vides lift.  (The  locomotion  and  buoyancy  of  P.  triacanthus  are 
being  considered  in  a  separate  study.)  Continuous  swimming 
with  some  degree  of  pectoral  propulsion  is  probably  the  rule  in 
adult  stromateoids. 

In  Stromateus  fiatola,  the  swimbladder  is  greatly  regressed  at 
a  fish  length  of  75  mm  SL,  a  size  at  which  the  fish  seems  to  have 


1970  SWIMBLADDER    OF    JUVENILE    STROMATEOIDS  7 

ended  its  association  with  medusae  (Mansueti,  1963:  60).  In 
the  size  interval  of  75  to  100  mm  SL,  this  species  loses  the  pelvic 
fins,  and  its  coloration  changes  from  a  vertically-banded  pattern 
to  a  more  uniform  one  in  which  there  are  often  dorsal  spots. 

Tetragoniirus  is  a  strictly  oceanic  genus  (Grey,  1955),  and  its 
swimbladder  is  considerably  regressed  when  the  fish  reaches  a 
size  of  50  mm  SL.  The  young  have  been  found  associated  with 
medusae  in  the  surface  waters  (Mansueti,  1963:  60).  According 
to  Haedrich  ( 1967),  the  adults  are  probably  members  of  the  meso- 
or  bathypelagic  fauna. 

Finally,  Pampus,  a  coastal  genus  and  the  one  considered  by 
Haedrich  (1967)  to  be  the  most  advanced  of  the  stromateids, 
evidently  has  no  swimbladder.  Whether  fishes  of  this  genus  as- 
sociate with  medusae  as  frequently  as  other  stromateids  is  not 
known.  There  are  indications  that  they  do  not.  According  to 
Suyehiro  (1942),  P.  argenteus  does  feed  to  a  certain  extent  on 
jellyfishes  in  Japanese  waters.  However,  studies  by  Kuthalingam 
(1963)  and  Nath  (1966)  show  that  both  juveniles  and  adults  of 
this  species  off  the  Indian  coast  are  macroplankton  feeders  whose 
diet  largely  depends  upon  seasonal  changes  in  abundance  of  crus- 
taceans and  polychaetes;  this  may  indicate  that  the  young  do 
not  regularly  associate  with  medusae.  Also,  the  pectoral  fins  of 
Pampus  become  quite  long  early  in  life  and  do  not  greatly  increase 
in  relative  length  with  age  as  they  do  in  Peprilus,  another  stro- 
mateid,  and  certain  other  genera.  At  a  fish  size  of  30  mm  SL, 
the  pectoral  length  of  Pampus  argenteus  is  about  40  per  cent  of 
the  standard  length  compared  to  only  about  30  per  cent  in  Pep- 
rilus paru,  which  has  a  very  similar  body  shape.  The  pectoral 
length  in  Peprilus  triacanthus  of  the  same  size  is  about  25  per 
cent  of  standard  length.  The  relative  length  of  the  pectorals  has 
increased  to  40  per  cent  in  P.  paru  and  to  about  35  per  cent  in 
P.  triacanthus  at  a  size  of  80  mm  SL.  Thus,  assuming  that  hover- 
ing beneath  objects  and  possession  of  a  swimbladder  are  related 
and  that  increased  pectoral  length  is  important  in  continuous  swim- 
ming, it  seems  that  members  of  the  genus  Pampus  acquire  the  adult 
mode  of  locomotion  and  habit  at  an  earlier  stage  than  most  other 
stromateoids  and,  in  so  doing,  completely  dispense  with  the  swim- 
bladder. 

A  number  of  other  fishes  have  regressed,  age-dependent  swim- 
bladders.  These  include  such  shallow-water  marine  fishes  as  cer- 
tain gobies,  blennies,  flatfishes,  and  most  muraenid  eels  (N.  B. 


8  BREViORA  No.   359 

Marshall,  personal  communication )  and  also  some  deep-sea  fishes, 
such  as  certain  species  of  Cyclothone  and  Stomias,  whose  swim- 
bladders,  upon  regressing,  become  invested  with  fat  (Marshall, 
1960).  As  in  stromateoids,  the  regression  of  the  organ  in  these 
fishes  is  probably  associated  with  habitat  and/or  internal  changes. 
Swimbladder  regression  is  eventually  to  be  the  subject  of  a  general 
review. 

Yet  to  be  examined  is  the  state  of  development  of  the  swim- 
bladder  in  newly-hatched  stromateoid  larvae.  Since  it  is  fully 
formed  in  fishes  as  small  as  9  mm  SL,  the  organ  must  develop 
quite  early.  The  swimbladder  may  be  of  considerable  importance 
to  larvae  in  orientation  and  in  positioning  the  body  for  food- 
capturing,  although  it  is  not  known  when  the  larvae  begin  to  feed. 
Indeed,  the  swimbladder,  as  I  judge  from  its  particularly  early 
regression  in  some  stromateoids,  may  have  its  greatest  functional 
significance  in  the  larvae  and  smallest  juveniles. 

ACKNOWLEDGMENTS 

1  sincerely  thank  N.  B.  Marshall  and  Richard  L.  Haedrich  for 
reading  and  ofi'ering  suggestions  on  the  manuscript.  I  am  also 
grateful  to  Dr.  Marshall  for  valuable  advice  on  swimbladders 
and  for  providing  space  and  facilities  in  the  British  Museum  (Na- 
tural History).  This  work  was  supported  by  a  NATO  Postdoctoral 
Fellowship  awarded  by  the  National  Science  Foundation. 

LITERATURE  CITED 

Alexander,   R.   McN.      1966.     Physical  aspects  of  swimbladder  function. 

Biol.  Rev.,  41  (1):    141-176. 
Fowler,  H.  W.     1936.     The  marine  fishes  of  West  Africa,  based  on  the 

collection    of   the    American    Museum    Congo   Expedition,    1909-1915. 

Part  11.    Bull.  American  Mus.  Natur.  Hist.,  70(2):   607-1493. 
Grey,  M.      1955.     The  fishes  of  the  genus   Tetragoniirus  Risso.    DANA- 

Report  No.  41:    1-75. 
Haedrich,  R.  L.     1967.     The  stromateoid  fishes:   systematics  and  a  classi- 
fication.   Bull.  Mus.  Comp.  Zool.,   135(2):    31-139. 
1969.     A  new  family  of  aberrant  stromateoid  fishes  from 

the  equatorial  Indo-Pacific.    DANA-Report  No.  76:    1-14. 
Haedrich,  R.  L.,  and   M.  H.   Horn.     1969.     A   key   to  the   stromateoid 

fishes.    WHOl     Tech.    Rept.    No.    69-70,    46     pp.     UNPUBLISHED 

MANUSCRIPT. 


1970  SWIMBLADDER    OF    JUVENILE    STROMATEOIDS  9 

Horn,  M.  H.  1970.  Systematics  and  biology  of  the  stromateid  fishes  of 
the  genus  Peprilii.s.  Bull.  Mus.  Comp.  Zool.,  140(5):    165-262. 

Jordan.  D.  S.,  and  B.  W.  Evermann.  1896.  The  fishes  of  North  and 
Middle  America:  a  descriptive  catalogue  of  the  species  of  fish-like 
vertebrates  found  in  the  waters  of  Ncrlh  America  north  of  the  Isthmus 
of  Panama.    Part  1.    Bull.  U.  S.  Nat.  Mus.,  No.  47:    1-1234. 

KuTHALiNGAM,  M.  D.  K.  1963.  Observations  on  the  fishery  and  biology 
of  the  silver  pomfret,  Pampiis  argenteiis  (Euphrasen),  from  the  Bay 
of  Bengal.    Indian  J.  Fish..  10(1):   59-74. 

Lane,  C.  E.  1960.  The  Portuguese  man-of-war.  Sci.  Amer.,  202(3): 
158-168. 

Mansueti,  R.  1963.  Symbiotic  behavior  between  small  fishes  and  jelly- 
fishes,  with  new  data  on  that  between  the  stromateid,  Pepriliis  alepi- 
dotus,  and  the  scyphomedusa,  Chrysaora  qiiinqiiecirrha.  Copeia,  1963 
(1):  40-80. 

Marshall,  N.  B.  1960.  Swimbladder  structure  of  deep-sea  fishes  in  rela- 
tion to  their  systematics  and  biology.    Discovery  Rept.,  31:    1-122. 

Maul,  G.  E.  1964.  Observations  on  young  live  Miipus  tnaculatus 
(Giinther)  and  Miipiis  oralis  (Valenciennes).  Copeia,  1964  (1): 
93-97. 

Nath,  p.  R.  1966.  Biology  and  seasonal  distribution  of  the  pelagic  food 
fishes  of  Travancore  coast.    Kerala  Univ.   Pub.,  India,   1-140. 

SuYEHiRO,  Y.  1942.  A  study  on  the  digestive  system  and  feeding  habits 
of  fish.    Japan.  J.  Zool.,  10  (1):   1-303. 


BREVIORA 


Muisenajnini    of   Comparative    Zoology 

Cambridge,  Mass.        30  November,  1970  Number  360 


MAMMALS  FROM  THE  EARLY  CENOZOIC  OF 
CHUBUT,  ARGENTINA 

George   Gaylord   Simpson 

Abstract.  Angelocabrenis  daptes,  new  genus  and  species  (Mammalia, 
Marsupialia,  Borhyaenidae),  Coelostylodon  florentinoameghinoi,  new  genus 
and  species  (Mammalia,  Notoungulata,  ?Isotemnidae)  and  Coelostylodon 
caroloameghinoi,  new  species,  are  described  from  the  Casamayor  forma- 
tion, probably  early  Eocene.  Knowledge  of  upper  premolars  of  Didolodiis 
(Mammalia,  Condylarthra.  Didolodontidae)  is  increased  and  the  status  of 
Acoelodiis  (Mammalia,  Notoungulata,  Acoelodidae)  is  discussed.  The  latter 
genus  and  the  family  based  on  it  are  essentially  indeterminate,  and  previous 
usage  of  the  names  is  unjustified. 

INTRODUCTION 

A  visit  to  Mar  del  Plata,  Provincia  de  Buenos  Aires,  Argentina, 
early  in  1970  enabled  me  for  the  second  time  to  examine  parts  of 
the  important  collections  of  fossil  mammals  in  the  Museo  Munici- 
pal de  Ciencias  Naturales  of  that  municipality.  In  collections  from 
the  Casamayoran  Stage  of  Chubut,  three  specimens  were  found  to 
be  of  particular  interest  and  to  make  especially  important  con- 
tributions to  knowledge.  The  Director  of  the  Museo,  Sr.  Galileo 
J.  Scaglia,  very  kindly  permitted  me  to  study  those  specimens  and 
to  publish  descriptions  and  discussions  of  them,  presented  here- 
with. I  am  again  and  increasingly  indebted  to  Sr.  Scaglia  and  to  the 
whole  staff  of  the  Museo  for  their  courtesy  and  cooperation.  The 
accompanying  illustrations  were  prepared  by  RaVae  Marsh. 

In  the  following,  MMP  precedes  catalogue  numbers  of  the 
Museo  Municipal  de  Ciencias  Naturales  de  Mar  del  Plata  and 
MACN  those  of  the  Museo  Argentino  de  Ciencias  Naturales  "Ber- 
nardino Rivadavia,"  Buenos  Aires. 

While  carrying  out  the  research  for  this  paper  I  was  employed 
jointly  by  the  Museum  of  Comparative  Zoology  and  the  Univer- 
sity of  Arizona. 


2  BREVIORA  No.    360 

Order  Marsupialia  lUiger 

Family  Borhyaenidae  Ameghino 

Angelocabrerus,  new  genus 

Etymology.  For  the  late  Angel  Cabrera,  a  great  mammalogist, 
who,  among  many  other  things,  wrote  an  important  study  of  bor- 
hyaenids.  This  kind  of  nomenclature  is  Ameghinian  and  is  con- 
sonant with  the  related  Arminiheringia.  I  have  ventured  to  give 
the  compound  an  appropriately  mascuUne  ending. 

Type-species.     Angelocabrerus  daptes,  new  species,  infra. 

Known  distribution.     Casamayoran,  Argentine  Patagonia. 

Diagnosis.  Specialized  borhyaenines.  Canines  with  closed, 
rapidly  tapering  roots;  short,  heavy,  fully  enameled  crowns.  P., 
one-cusped,  heavy,  with  small  distinct  talonid.  M  1.4  essentially 
two-cusped,  with  paraconid  anterior  and  only  slightly  lingual  to 
the  larger  protoconid.  No  trace  of  metaconid.  Talonids  un- 
basined,  reduced  to  very  slight,  simple  ledges.  Protoconids  and 
paraconids  truncated  with  wear  on  M^.g,  becoming  sharp  points  on 
M4  with  protoconid  a  high  slender  needle. 

Discussion.  As  far  as  known,  the  dentition  is  similar  to  that 
of  the  much  later  (Santacrucian)  Borhyaena  and  by  the  same  token 
is  also  similar  to  the  contemporary  Casamayoran  Arminiheringia. 
The  talonid  reduction  seems  to  have  gone  even  further  in  Angelo- 
cabrerus than  in  the  other  genera.  The  lower  canine  is  unlike  that 
of  Arminiheringia,  with  a  shorter  closed  root  and  more  fully 
enameled  crown.  The  way  in  which  M^  wears,  quite  distinctive 
from  either  Arminiheringia  or  Borhyaena,  would  seem  to  imply 
different  occlusion  and  hence  different  structure  in  the  unknown 
upper  teeth,  M^.^ ,  with  which  M^  occluded.  This  wear  is  much 
as  in  Plesiofelis,  considered  by  Cabrera  (1927:  274-278)  Des- 
eadan  in  age  and  synonymous  with  Pharsophorus  but  almost  cer- 
tainly Mustersan  and  probably  distinct  from  Pharsophorus.  How- 
ever, in  Plesiofelis  the  molar  talonids  are  considerably  less  re- 
duced than  in  Angelocabrerus. 

In  Arminiheringia  auceta,  the  only  adequately  known  species 
of  its  genus,  there  is  a  rapid  increase  in  size  of  the  molars  pos- 
teriorly, M4  being  about  twice  as  large  as  M^.  The  figures  (some- 
how omitted  in  Simpson,  1948)  are  here  given  in  Table  1.  It  is 
there  shown  that  the  increase  is  much  less  in  Angelocabrerus  dap- 
tes, with  M4  only  about  half  again  as  large  as  M^.    The  increase 


1970  EARLY  CENOZOIC CHUBUT  3 

is  even  less  in  Borhyaena.  As  far  as  the  evidence  goes,  Angeloca- 
hrerus  could  be  ancestral  to  Borhyaena,  and  in  that  case  the  rate 
of  evolution  in  known  parts  must  have  been  extremely  slow. 
Knowledge  of  the  present  genus  is  too  incomplete,  however,  to 
warrant  a  firm  conclusion. 

As  in  Arminiheringia  and  Borhyaena  but  to  even  more  marked 
degree,  Pg  is  a  large  and  heavy  tooth.  It  here  approximates  M ,  in 
dimensions.  It  has  a  single  main  cusp,  with  a  long  anterior  and 
short,  nearly  vertical  posterior  slope.  There  is  a  minute  cuspule 
at  the  anterior  base.  There  is  a  distinct  but  small,  shelflike  talonid 
with  a  single  cuspule.  This  is  absent  in  Borhyaena  and  also  in  the 
only  known  specimen  of  Arminiheringia  that  might  show  it,  but 
the  latter  is  so  worn  that  a  small  talonid  could  have  been  present 
originally.  Except  for  the  points  already  mentioned,  the  lower 
molars  are  like  Arminiheringia  and  Borhyaena  in  structure. 

Angelocabrerus  daptes,  new  species. 

Etymology.  Greek  daptes,  eater,  gnawer,  from  the  inferred 
carnivorous,  possibly  ossifragous  habits  of  the  animals. 

Holotype.  MMP  967M,  part  of  right  mandibular  ramus  with 
M2.4,  left  Pg,  Ml,  and  M.  probably  of  the  same  individual,  two 
lower  canines  somewhat  broken,  and  small  caniniform  tooth  and 
tip  of  another  doubtfully  associated. 

Hypodigm.     Holotype  only. 

Horizon  and  locality.  Casamayoran,  south  of  Lago  Colhue- 
Huapi,  Chubut,  Argentina.  The  specimen  was  a  surface  find  high 
in  the  beds,  and  derivation  from  an  overlying  formation  is  pos- 
sible but  quite  improbable. 

Diagnosis.  Only  known  species  of  the  genus  as  diagnosed 
above. 

Discussion.  The  loose  left  M.  has  somewhat  darker  enamel 
and  is  slightly  less  worn  than  the  right  M.  in  the  mandibular  frag- 
ment. Its  color  and  wear  are  more  consonant  with  those  of  the 
loose  teeth  identified  as  left  Pg  and  M^.  However,  there  can  be 
little  serious  doubt  that  those  and  the  two  loose  lower  canines  do 
in  fact  belong  to  the  same  individual  as  the  mandibular  fragment. 
All  were  found  together,  they  are  congruent  in  size  and  structure, 
and  they  add  up  to  a  unique  specimen  of  a  group  extremely  rare 
in  these  beds.  The  two  slender  caniniform  teeth  are  dubious  and 
I  do  question  whether  they  belong  to  the  same  animal. 


BREVIORA 


No.  360 


The  diagnosis  and  discussion  of  the  genus  and  the  illustrations 
make  further  description  unnecessary. 


Figure  1.  Angelocabrerus  daptes,  new  genus  and  species.  Holotype, 
MMP  967M.  Right  M2-4.  A,  buccal  view.  B,  occlusal  view.  C,  lingual 
view.  X  1. 


Order  Condylarthra  Cope 

Family  Didolodontidae  Scott 

Didolodus  sp.  indet. 

Specimen.     MMP    696M,    fragment    of    right    maxilla    with 


2-4 


Horizon  and  locality.  Casamayoran  of  Caiiadon  Vaca,  tribu- 
tary to  the  left  (northwest)  bank  of  the  Rio  Chico,  Chubut,  Ar- 
gentina. 


1970 


EARLY   CENOZOIC CHUBUT 


Figure  2.  Angelocabrerus  daptes,  new  genus  and  species.  Holotype, 
MMP  967M.  Left  P^  -  M,.  A,  lingual  view.  B,  occlusal  view.  C,  buccal 
view.  XI. 


Figure  3.     Angelocabrerus   daptes,   new   genus   and   species.     Holotype, 
MMP  967M.   Lower  canine.  X  1. 


BREVIORA 


No.  360 


Discussion.  This  specimen  is  interesting  because  it  shows  the 
coronal  structure  of  P^'^  of  Didolodus  in  relatively  little  worn 
condition  and  because  the  proportions  of  these  teeth  are  distinctive. 

Comparison  is  mainly  with  MACN  10690,  holotype  of  Didolo- 
dus multicuspis  Ameghino,  the  only  other  specimen  of  Didolodus 
known  to  me  that  includes  P^^.  It  is  figured  in  Simpson,  1948, 
text  figures  25  and  26  and  plate  10,  figures  1  and  2.  MACN  10738 
includes  P-,  which  has  not  been  figured  but  was  included  in  my 
description  of  D.  multicuspis  (Simpson,  1948:  101).  AMNH 
2847  is  a  P'^  referred  to  D.  minor  by  me  (Simpson,  1948:  103) 
but  not  separately  described  or  figured. 

As  shown  in  Table  2,  P-  and  P^  are  each  shorter  than  in  the 
holotype  by  7  per  cent,  which  does  not  in  itself  suggest  specific  dis- 
tinction, and  P^  has  almost  the  same  length  in  the  two  specimens. 
However,  all  three  teeth  are  more  notably  narrower  in  MMP 
696M,  by  16  per  cent,  20  per  cent,  and  19  per  cent  for  P-,  P^, 
and  P^  respectively.  A  result  is  that  all  three  teeth  are  longer 
relative  to  their  widths  in  MMP  696M.    This  is  especially  notice- 


Figure  4.     Didolodus  sp.  MMP  696M.    Right  PS-i,  occlusal  view.  X  3. 


able  in  P"^,  which  is  distinctly  transverse  in  MACN  10690  but 
equidimensional  in  MMP  696M.  P=^  of  AMNH  28471,  referred 
to  D.  minor,  is  even  more  transverse  than  in  the  holotype  of  D. 
multicuspis.  Its  width  slightly  exceeds  that  of  P^  in  MMP  696M, 
although  its  length  is  decidedly  (25  per  cent)  shorter.  The  in- 
dividual represented  by  MMP  696M  was  probably  closer  to  D. 
multicuspis  in  over-all  size,  but  the  differences  in  some  dimensions 
and  in  proportions  make  reference  doubtful  either  to  that  species 
or  to  D.  minor.  At  the  same  time,  they  do  not  warrant  definition 
of  a  new  species,  which  in  any  case  should  preferably  not  be  based 
on  upper  premolars,  for  which  there  is  so  little  comparative 
material. 


1970  EARLY   CENOZOIC CHUBUT  7 

Specimens  of  known  origin  referable  to  D.  midticiispis  without 
much  doubt  are  all  from  south  of  Lago  Colhue-Huapi,  and  those 
similarly  referable  to  D.  minor  are  from  Canadon  Vaca.  MMP 
696M  is  from  Canadon  Vaca  but  probably  does  not  belong  to  D. 
minor.  Specimens  and  field  data  for  Didolodus  are  still  far  from 
sufficient  for  identification  of  populations  within  the  genus  and  for 
determination  of  their  distribution. 

P-  of  MMP  696M,  unlike  the  less  well-preserved  specimens 
previously  known,  is  seen  to  have  two  distinct  external  cusps,  con- 
nate above  the  tips  but  still  separated  by  grooves.  These  are  at 
least  descriptively  paracone  and  metacone,  and  the  metacone  is 
only  slightly  lower  and  smaller  than  the  paracone.  The  tooth  is 
completely  surrounded  by  a  cingulum,  but  this  is  feeble  on  the 
middle  of  the  labial  face.  The  lingual  slope  from  paracone  plus 
metacone  to  the  labial  cingulum  is  sUghtly  uneven,  but  is  without 
really  distinct  cusps.  P^  and  P^  also  have  distinct  paracone  and 
metacone  but,  unusually,  the  metacone  is  lower  and  smaller  rela- 
tive to  the  paracone  progressively  from  P-  to  P^.  P^  and  P^  have 
well-developed  protocones,  and  the  cingula  do  not  cross  their  lin- 
gual faces.  A  distinct  cingular  cusp  or  style  is  present  on  each 
tooth  anterior  and  slightly  labial  to  the  paracone  and  there  is  a 
similar  but  smaller  and  less  distinct  cuspule  posterior  to  the  meta- 
cone. Each  tooth  has  a  distinct  protoconule  but  no  metaconule. 
There  is  no  hypocone.  It  is  also  unusual  that  P^  is  distinctly 
shorter  than  P-^  although  wider. 

The  structure  of  P-  in  this  specimen  seems  to  be  rather  different 
from  that  in  the  holotype  of  D.  multicuspis  and  more  molariform. 
Except  for  dimensions  and  proportions,  apparent  differences  in 
structure  of  P  ^"^  are  possibly  due  only  to  the  more  worn  condition 
of  the  holotype  of  D.  multicuspis. 

Although  far  from  identical,  there  is  considerable  resemblance 
between  P^-^  of  MMP  696M  and  the  homologous  teeth  of  North 
American  Phenacodus.  A  fairly  close  ancestral  relationship  is  con- 
firmed to  that  extent.  However,  considerable  independent  evolu- 
tion is  also  suggested.  For  example,  P^-^^  especially,  of  MMP 
696M,  are  more  distinctly  molariform  than  their  homologues  in 
Phenacodus. 


8 


BREVIORA 


No.  360 


Order  Notoungulata  Roth 

Family  Isotemnidae  Ameghino 

Coelostylodon,  new  genus 

Etymology.  Greek  koilos,  hollow,  stylos,  pillar,  odon,  tooth. 
The  name  is  meant  to  recall  former  reference  to  Acoelodiis  and 
resemblance  to  Pleurostylodon.  It  is  also  consonant  with  much 
Ameghinian  nomenclature. 

Type-species.  Coelostylodon  florentinoameghinoi,  new  species, 
injra. 

Known  distribution.     Casamayoran,  Argentine  Patagonia. 

Diagnosis.  Primitive  notoungulates  with  complete,  nearly 
closed  dentition.  Upper  canine  small  and  fully  incisiform.  Cheek 
teeth  brachydont,  P--M^  soon  wearing  so  that  crown  presents  a 
single  fossa,  without  complex  folds  or  anterior  opening.  M^-^ 
with  flattened,  slightly  bifid  lingual  faces.  M^^  with  slight  para- 
style  and  paracone  folds  and  very  feeble  metacone  swelling  on 
ectolophs,  no  mesostyle.  M^  subtriangular,  with  short  but  distinct 
metaloph,  longer  than  M'  or  M-  and  almost  as  long  as  broad. 


Figure  5.     Coelostylodon   florentinoameghinoi,    new   genus   and    species. 
Holotype,  MMP  1723M.   Right  C  and  pa  -  M^.  X  W2. 


Discussion.  This  genus  is  essentially  that  called  Acoelodus 
by  Ameghino  (1901:  467)  and  discussed  by  me  (Simpson,  1967: 
57)  under  that  name,  but  that  apphcation  of  the  name  can  no 
longer  be  sustained.  The  type-species  of  Acoelodus  is  A.  oppositus 
Ameghino,  1897  (p.  454).  The  holotype  of  that  species  is  MACN 
10770,  a  fragment  of  a  left  mandibular  ramus  with  much  worn 
P  2.3  and  part  of  Pj.  That  specimen  is  essentially  indeterminate. 
In  1901  Ameghino  referred  to  the  species  a  poorly  preserved  skull, 
MACN  10753,  and  redefined  the  genus  essentially  on  the  basis  of 


1970  EARLY  CENOZOIC — CHUBUT  9 

that  specimen.  Desiring  to  validate  as  much  as  possible  of  Ame- 
ghino's  nomenclature,  I  accepted  the  reference  and  redefinition, 
taking  MACN  10753  as  essentially  a  neotype  in  Ameghino's  usage 
and  designating  it  as  such  (Simpson,  1967:  58).  However,  that 
action  is  invalid  under  the  present  code  of  nomenclature  (Stoll 
et  al.,  1964,  Article  75)  because  in  fact  the  holotype,  MACN 
10770,  has  not  been  lost  or  destroyed. 

If  now  there  were  a  reasonable  probability  that  the  referred  skull 
and  the  holotype  belong  to  the  same  genus  and  species,  the  type 
designation  would  have  no  practical  importance  and  one  could 
continue  to  use  the  name  Acoelodus  for  the  genus  and  A.  oppositus 
for  the  species  represented  by  the  referred  skull.  In  fact,  however, 
as  I  already  mentioned  in  previous  discussion  (1967),  there  is  no 
good  evidence  that  the  two  specimens  are  of  the  same  genus  and 
species,  and  there  is  some  contrary  evidence.  The  contrary  evi- 
dence is  weightier  than  I  previously  indicated.  If  the  comparative 
sizes  of  P  2.3  and  P^-^  jn  Acoelodus  were  approximately  as  in 
Pleurostylodon,  a  reasonable  assumption,  then  P  ^-s  of  the  skull 
MACN  10753  are  some  22  to  44  per  cent  larger  in  various  dimen- 
sions than  would  be  expected  from  the  holotype  of  Acoelodus 
oppositus  and  are  also  different  in  relative  sizes  and  proportions. 
It  is  thus  highly  improbable  that  the  two  specimens  are  conspecific, 
and  if  they  are  not  conspecific,  there  is  no  reason  to  consider  them 
congeneric. 

The  genus  represented  by  the  holotype  of  Acoelodus  oppositus 
is  indeterminate,  a  notoungulate  incertae  sedis  as  far  as  my  knowl- 
edge and  judgment  go.  The  genus  represented  by  MACN  10753 
is  determinate  and  is  distinct  from  any  other  for  which  there  is 
comparable  material  known  to  me.  This  conclusion  is  reinforced 
by  discovery  of  another  specimen,  MMP  723M,  that  can  be  re- 
ferred to  the  same  genus  as  MACN  10753  but  is  specifically  dis- 
tinct. In  order  to  avoid  possible  further  confusion  with  Acoelodus, 
the  species  represented  by  MMP  723M  is  made  type-species  for 
the  new  generic  name. 

In  order  to  avoid  still  another  confusion,  it  must  be  noted  that 
none  of  Ameghino's  figures  labeled  "Acoelodus  oppositus"  in  sev- 
eral of  his  publications  are  conspecific  or  congeneric  either  with 
the  holotype  of  that  species  or  with  MACN  10753  (for  details  and 
discussion  see  Simpson,  1967:  58-59). 

Ameghino  considered  Acoelodus  as  closely  related  to  Oldfield- 
thomasia  and  so  placed  the  latter  in  his  family  Acoelodidae,  but 


10  BREVIORA  No.    360 

that  was  based  on  specimens  dubiously  or  incorrectly  referred  to 
Acoelodus,  including  at  least  one  that  in  fact  belongs  in  Oldfield- 
thomasia.  Since  the  holotype  of  the  type-species  of  Acoelodus  is 
not  identifiable  as  to  family,  the  name  Acoelodidae  has  no  estab- 
lished significance.  For  that  reason,  I  named  a  family  Oldfield- 
thomasiidae  for  Oldfieldthomasia  and  its  probable  relatives  (Simp- 
son, 1945:  126).  In  revision  of  the  Casamayoran  fauna,  I  put 
MACN  10753,  under  the  incorrect  reference  name  Acoelodus 
oppositus,  in  the  Oldfieldthomasiidae.  The  genus  Coelo  stylo  don, 
to  which  that  specimen  is  now  referred  as  holotype  of  C.  caro- 
loameghinoi,  is  of  uncertain  family  position.  It  differs  from  all 
adequately  characterized  previously  named  genera  of  both  the 
Oldfieldthomasiidae  and  the  Isotemnidae,  but  has  resemblances  to 
both  families.  Present  reference  to  the  Isotemnidae  is  very  tentative. 
The  upper  molar  structure  is  most  nearly  similar  to  that  of  Pleu- 
rostylodon,  an  isotemnid,  among  adequately  known  genera,  but 
Coelostylodon  differs  from  Pleurostylodon  and  other  isotemnids  in 
its  small,  incisiform  canine  and  various  other  details.  The  canine 
is  more  like  that  of  Oldfieldthomasia,  but  the  molars  are  quite 
different. 

Coelostylodon  florentinoameghinoi ,  new  species 

Etymology.  For  Florentino  Ameghino,  famed  describer  of 
most  of  the  Casamayoran  fauna.  Combination  of  given  and  family 
names  is  a  nomenclatural  device  that  he  often  used. 

Holotype.  MMP  723M,  nearly  complete  but  badly  crushed 
skull. 

Hypodigm.     The  holotype  only. 

Horizon  and  locality.  Lowest  Casamayoran  beds  in  the  bar- 
ranca south  of  Lago  Colhue-Huapi,  Chubut. 

Diagnosis.  Significantly  larger  than  C.  caroloameghinoi  (see 
Table  3 ) .   Posterolabial  angle  of  M^  less  projecting. 

Discussion.  The  teeth  are  deeply  worn  in  both  of  the  holo- 
types  now  referred  to  this  genus.  As  preserved,  there  is  no 
marked,  discernible  difference  in  structure  of  the  cheek  teeth. 
MMP  723M  clearly  has  the  small  canine  considered  characteristic 
of  the  genus.  P^^^are  almost  completely  fragmented,  but  seem  to 
have  been  quite  small,  perhaps  more  so,  relatively,  than  in  MACN 
10753.  The  posterolabial  corner  of  M^  does  not  project  so  dis- 
tinctly as  in  MACN  10753. 


1970  EARLY  CENOZOIC CHUBUT  1  1 

The  skull  is  too  badly  crushed  to  make  out  much  significant  de- 
tail. It  seems  to  have  been  a  primitive,  unspecialized  notoungulatc 
skull  generally  similar  to  that  of  Pleurostylodon. 

Coelostylodon  caroloameghinoi ,  new  species. 

Acoelodus  oppositus,  in  error,  Ameghino,  1901:  365;  Simpson, 
1967:  58  and  plate  11,  fig.  1. 

Etymology.  For  Carlos  Ameghino,  who  discovered  the  Casa- 
mayoran  fauna  and  found  the  holotype  of  this  species. 

Holotype.  MACN  10753,  poorly  preserved  anterior  part  of 
skull. 

Hypodigm.     The  holotype  only. 

Horizon  and  locality.  Casamayoran,  barranca  south  of  Lago 
Colhue-Huapi. 

Diagnosis.  Significantly  smaller  than  C.  florentinoameghinoi 
(see  Table  3).  Posterolabial  angle  of  M^  sharply  produced 
posteriorly  (or  distally). 

Discussion.  In  1901  and  thereafter  Ameghino  based  his  con- 
cept of  Acoelodus  oppositus  mainly  on  this  specimen,  but  he  did 
not  figure  it,  and  none  of  the  specimens  figured  by  him  as  Acoe- 
lodus oppositus  belong  to  the  present  genus  or  species.  The  holo- 
type is  adequately  figured  in  my  previous  memoir,  as  cited  above. 

REFERENCES 

Ameghino,  F.  1897.  Mammiferes  cretaces  de  I'Argentine.  Deuxieme 
contribution  a  la  connaissance  de  la  fauna  mammalogique  des  couches 
a  Pyrotherium.    Inst.  Geog.  Argentina,   18:  406-429,  431-521. 

.      1901.     Notices  preliminaires  sur  des  ongules  des  terrains 

cretaces  de  Patagonia.   Bol.  Acad.  Nac.  Cien.   Cordoba,  16:  350-426. 

Cabrera,  A.  1927.  Datos  para  el  conocimiento  de  los  dasiuroideos  fosiles 
argentinos.   Rev.  Mus.  La  Plata,  30:  271-315. 

Simpson,  G.  G.  1945.  The  principles  of  classification  and  a  classification 
of  mammals.   Bull.  American  Mus.  Nat.  Hist.,  85:  i-xvi,  1-350. 

.      1948.     The  beginning  of  the  Age  of  Mammals  in  South 

America.    Part  1.    Bull.  American  Mus.  Nat.  Hist.,  91:   1-232. 

.      1967.     The   beginning  of  the  Age  of  Mammals  in  South 


America.    Part  2.    Bull.  American  Mus.  Nat.  Hist.,  137:   1-259. 

Sinclair,  W.  J.  1906.  Marsupialia  of  the  Santa  Cruz  beds.  Repts.  Prince- 
ton Univ.  Exped.  Patagonia,  1896-1899,  vol.  IV,  part  III:  333-460. 

Stole,  N.  R.,  et  al.  1964.  International  code  of  zoological  nomenclature 
adopted  by  the  XV  International  Congress  of  Zoology.  International 
Trust  for  Zoological  Nomenclature,  London. 


12  BREVIORA  No.    360 


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1970 


EARLY    CENOZOIC CHUBUT 


13 


TABLE   2 


Measurements  in  millimeters  of  upper  premolars  of  Didolodus. 


p2 


p3 


p4 


Length 

Width 

L/W 

Length 

Width 

L/W 

Length 

Width 

L/W 


D.  luulticuspis 
MACN  10690 

7.6 
7.4 
1.03 

7.5 
9.5 
.79 

7.0 
10.0 
.70 


D.  minor 
AMNH  28471 


5.7 
7.8 
.58 


D.  sp. 
MMP696M 

7.1 
6.2 
1.15 

7.6 
7.6 

1.00 

6.5 

8.1 
.80 


TABLE   3 

Comparative  measurements  in  millimeters  of  dentitions  of  holo- 
types  of  Coelostylodon  florentinoameghinoi  and  C.  carolo- 
ameghinoi. 


p4 


Ml 


M2 


M3 


Length 
Width 

Length 
Width 

Length 
Width 

Length 
Width 


C  florentinoameghinoi 

C  caroloameghinoi 

MMP723M 

MACN  10753 

9.9 

7.5 

12.5 

9.9 

Ca.lO 

8.0 

15.4 

11.5 

12.6 

8.5 

17.0 

11.8 

15.1 

10.0 

15.4 

10.7 

BREVIORA 

Mnaseiam    of    Compsirative    Zoology 


Cambridge.  Mass.  30  November,  1970  Number  361 

ADDITIONS  TO  KNOWLEDGE  OF  THE  ARGYROLAGIDAE 

(MAMMALIA,  MARSUPIALIA)  FROM  THE  LATE 

CENOZOIC  OF  ARGENTINA 

GEORGE   GAYLORD   SIMPSON 

Abstract.  A  recent  monograph  of  the  Argyrolagidae  is  supplemented 
by  observations  on  specimens  not  previously  seen  by  the  author.  The 
holotype  of  Argyrolagiis  palineri  confirms  previously  published  data.  An 
additional  specimen  of  Argyrolagiis  scagliai  adds  to  i<nowledge  of  the 
coronal  pattern  of  lower  molars.  Argyrolagiis  parodii  is  a  hitherto  dubious 
species  the  holotype  of  which  was  destroyed.  A  second  specimen  is  made 
neotype;  it  validates  the  species  and  permits  redefinition. 

A  monograph  of  the  Argyrolagidae  (Simpson,  1970)  was  com- 
pleted early  in  1968  and  an  addendum  included  late  in  that  year. 
Early  in  1970  a  visit  to  Argentina  made  possible  the  study  of 
several  specimens  not  available  or  not  known  to  me  when  the 
monograph  and  addendum  were  written.  These  add  significantly 
to  knowledge  of  the  family. 

For  the  facilities  for  making  and  the  privilege  of  publishing 
these  observations  I  am  greatly  indebted  to  the  authorities  of  the 
Museo  de  La  Plata  and  especially  to  Dr.  Rosendo  Pascual  and 
Sr.  Jorge  Zetti.  The  accompanying  photographs  were  made  under 
the  direction  of  Sr.  Zetti  and  provided  for  this  publication  by  the 
Museo.  In  Buenos  Aires  Sr.  Guillermo  del  Corro  courteously 
made  available  the  type  of  Argyrolagiis  palmeri.  The  drawing  was 
made  by  RaVae  Marsh  from  a  sketch  by  me.  While  making  this 
study  I  was  employed  jointly  by  Harvard  University  and  the  Uni- 
versity of  Arizona. 

In  the  following  all  measurements  are  in  miUimeters:  L  r=z  length 
(anteroposterior  or  mesiodistal).  W  =  width  (bucco-lingual). 
Ljj  =  length  of  trigonid.  Lp  =  length  of  talonid.  W^  =r  width  of 
trigonid.  Wj,  =  width  of  talonid.  MACN  =  Museo  Argentino  de 


2  BREVIORA  No.    361 

Ciencias  Naturales  "Bernardino  Rivadavia."  MLP  ■=.  Facultad 
de  Ciencias  Naturales  y  Museo  de  La  Plata.  MM?  =  Museo 
Municipal  de  Ciencias  Naturales  de  Mar  del  Plata. 

Family  Argyrolagidae  Ameghino,  1904 

Genus  Argyrolagus  Ameghino,  1904 

Argyrolagus  palmeri  Ameghino,   1904 

Holotype.  MACN  A53-4,  part  of  left  mandibular  ramus,  ori- 
ginally with  I J  and  M  ^.4,  collected  by  Carlos  Ameghino  at  Monte 
Hermoso  in  1904. 

Remarks.  For  other  formal  data  see  Simpson,  1970:  11. 
When  that  account  was  written  I  had  not  seen  the  type,  which  is 
in  the  Ameghino  Collection  in  Buenos  Aires  and  catalogued  as 
above.  I^  has  been  lost  since  the  specimen  was  figured  by  F. 
Ameghino  (1906,  fig.  221)  and  L.  Kraglievich  (1931,  fig.  2). 
Both  of  those  figures  represent  the  specimen  accurately.  New 
measurements  on  the  specimen  agree  reasonably  well  with  those 
taken  from  the  earlier  figures  (given  in  Simpson,  1970,  Table  1 ), 
see  present  Table  1. 

Argyrolagus  scagliai  Simpson,  1970 

Addition  to  hypodigni.  MPL  49-1X-7-1,  right  mandibular  la- 
mus  with  alveoli  of  I  ,0  and  P.  and  all  of  Mi,.  "Miramar,  prov. 
de  Bs.  Aires,"  probably  Chapadmalal  formation.  Presented  to 
the  MLP  by  the  widow  of  Dr.  Santiago  Roth  in  August,  1924. 

Description.  For  formal  data  on  the  species  see  Simpson, 
1970:  12.  This  specimen  has  M^.^  beautifully  preserved  and  less 
worn  than  in  others  known.  In  this  genus  the  hypselodont  molars 
rapidly  lose  the  coronal  pattern  by  wear  and  become  columns  with 
characteristic  outline  but  no  internal  structure.  Here  even  Mj, 
although  somewhat  worn,  preserves  some  coronal  features.  M^ 
is  also  fully  erupted  and  beginning  to  wear.  The  teeth  do  not 
taper  in  the  alveoli  and  would  not  increase  in  size  with  wear.  The 
dimensions  of  the  exposed  ends  of  these  young  teeth  are  com- 
parable with  those  of  old  individuals  of  the  species  (see  Table  2). 
All  the  molars  retain  traces  of  a  fossettid  in  the  trigonid.  M,  has 
a  somewhat  more  complex  outline  than  in  other,  individually  older 
specimens  considered  to  be  of  the  same  species  (see  Fig.  2). 
Most  of  the  crown  is  horizontally  truncated  by  wear,  but  there  is 
a  steeply  sloping  anterolingual  wear  facet.    On  the  anterior  face 


1970 


ARGYROLAGIDAE 


there  is  a  well-developed  cingulum,  not  yet  worn,  enclosing  a  small 
pocket.  The  preservation  makes  possible  separate  trigonid  and 
talonid  measurements  in  Table  3. 


A. 


B. 


C. 


Figure  1.  Argyrolagus  scaglicii  Simpson,  1970.  M.L.P.  No.  49-1X-7-1. 
right  mandibular  ramus  with  M  ^,^  .  A,  buccal  view.  B.  occlusal  view. 
C,  lingual  view.    Approximately  X  4i/4. 


BREVIORA  No.    361 


Figure  2.     Argyrolagus   scagliai   Simpson,    1970.     M.L.P.    No.49-IX-21, 
right  M^.    Occlusal  view,  diagrammatic  sketch.    Approximately   X    10. 


Argyrolagus  parodii  Rusconi,  1933 

Neotype.  MLP  62-V11-27-81,  right  mandibular  ramus  with 
I^,  alveolus  of  I.,  and  PfM,,  from  the  Playa  las  Palomas,  near 
the  Balneario  Chapadmalal.  Collected  by  the  personnel  of  MLP 
in  August,  1961. 

Revised  diagnosis.  Smaller  than  A.  palmeri  or  A.  scagliai. 
Trigonids  somewhat  more  triangular,  paraconids  medial.  Talonids 
relatively  short.  Labial  and  lingual  sulci  directly  opposite.  Talonid 
of  Mj  somewhat  reduced,  but  decidedly  larger  than  in  Microtra- 
gulus.  Buccal  extension  of  coronoid  crest  strong. 

Discussion.  In  a  letter  written  shortly  before  his  lamented 
death,  Sr.  Rusconi  informed  me  that  the  holotype  of  this  species, 
in  his  private  collection,  had  been  destroyed.  The  available  figures 
and  description  of  that  holotype  are  somewhat  equivocal,  as  dis- 
cussed in  Simpson,  1970:  14-15.  There  is  little  doubt,  however, 
that  MLP  62-Vn-27-81  does  belong  to  the  same  species.  It  is 
very  close  to  the  size  indicated  by  Rusconi  in  text  and  figures,  as 
here  shown  in  Table  4,  and  it  also  shares  the  most  likely  morpho- 
logical distinctions  of  the  holotype.  The  present  specimen  can 
be  confidently  referred  to  Argyrolagus  and  it  shows  that  A.  parodii 
is  distinct  from  any  other  known  species — both  points  left  in 
some  doubt  by  the  destruction  of  the  holotype.  This  case  meets 
all  the  conditions  for  designation  of  a  neotype  set  forth  in  Article 
75(a)  of  the  International  Code  of  Zoological  Nomenclature 
adopted  by  the  XV  International  Congress  of  Zoology,  and  the 
present  treatment  supplies  all  the  qualifying  conditions  specified  in 
Article  75(c)  of  the  Code. 

The  locality  where  the  holotype  was  found  is  not  precisely 
known  but  was  somewhere  along  the  shore  four  or  five  kilometers 


1970 


ARGYROLAGIDAE 


Figure  3.  Argyrolagiis  parodii  Rusconi,  1933.  Neotype,  M.L.P.  No. 
62-V!!-27-81.  right  mandibular  ramus  with  I^  and  P.^  -  M,.  A,  buccal 
view.    B,  occlusal  view.    C,  lingual  view.    Approximately  X   6. 


BREVIORA 


No.   361 


northeast  of  Miramar,  Buenos  Aires  Province.  The  neotype  is 
from  the  same  sequence  of  exposures  on  the  shore  about  llVz 
to  13V2  kilometers  farther  northeast.  The  holotype  was  probably 
from  the  Chapadmalal  formation,  as  restricted,  but  possibly 
Vorohue.     (See   J.   L.   Kraglievich,    1952.)     There  is  no  clearly 


/   '-*'S 


n 
^ 


'I 


,i.r 


I""*' 


A. 


B. 


c. 


D. 


Figure  4.  Argyrolagidae,  genus  and  species  undetermined.  M.L.P.  No. 
59-IX-28-98,  right  tibiofibula  lacking  unfused  portion  of  fibula.  A,  lateral 
view.  B,  anterior  view.  C,  medial  view.  D,  posterior  view.  Approximately 
X  2. 


1970  ARGYROLAGIDAE  7 

established  difference  between  the  faunas  of  the  two  formations. 
The  neotype  is  almost  certainly  from  the  restricted  Chapadmalal 
formation.  The  two  are  probably  of  the  same  age,  and  in  any 
case  can  hardly  have  a  faunally  appreciable  difference  in  age. 

The  specimen  now  made  neotype  of  Argyrolagus  parodii  is  the 
one  figured,  without  catalog  reference,  as  Microtragulus  argentinus 
by  Ringuelet  (1966,  plate  X,  figs.  I,  J)  and  used  as  a  basis  {Ibid., 
pp.  58-59)  for  redefinition  of  the  genus  Microtragulus  (taken  as 
a  synonym  of  Argyrolagus)  and  the  family  Microtragulidae 
(equated  with  Argyrolagidae).  As  previously  pointed  out  (Simp- 
son, 1970:  65-67),  the  redefinitions  are  valid  for  the  specimen  in 
question  but  are  too  restricted  for  the  genus  and  family  as  wholes. 

The  preceding  diagnosis  and  accompanying  measurements 
(Table  4)  and  photographs  (Fig.  3)  make  detailed  description 
unnecessary. 

Argyrolagidae  gen.  et  sp.  indet. 

MLP  59-IX-28-98  is  a  tibiofibula  lacking  the  free  part  of  the 
fibula,  collected  by  Dr.  J.  Frenguelli  from  the  "Chapadmalense" 
of  Baliza  Chica,  northeast  of  Miramar.  At  this  locality  it  would  be 
either  from  a  very  high  level  in  the  Chapadmalal  formation,  re- 
stricted, or  from  the  overlying  Vorohue  formation.  Its  length  is 
53.5  mm,  compared  with  60.4  mm  for  MMP  7855,  holotype  of 
Argyrolagus  scagliai.  It  also  differs  from  the  latter  in  that  the 
proximal  part  of  the  cnemial  crest  ends  abruptly  slightly  below 
rather  than  at  the  articular  surfaces  and  also  ends  abruptly  distally 
rather  than  passing  gradually  into  the  shaft.  This  specimen  may 
belong  to  Microtragulus  reigi,  but  association  cannot  now  be  estab- 
lished. 


REFERENCES 

Ameghino,  F.  1906.  Les  formations  sedimentaires  du  Cretace  superieur 
et  du  Tertiaire  de  Patagonie.  Ann.  Mus.  Nac.  Buenos  Aires,  ser.  3,  8: 
1-568.  Also  published,  with  Spanish  translation,  as  volume  16  of  the 
Obras  (Ameghino,   1913-1936). 

Kraglievich,  L.  1931.  Cuatro  notas  paleontologicas,  sobre  Octomylodon 
aversus  Amegh.,  Argyrolagus  palmeri  Amegh.,  Tetrastyhis  montanus 
Amegh.,  y  Munizia  paranensis.  Rev.  Soc.  Argentina  Cien.  Nat.,  10: 
22-266.    Also  in  the  Obras  (Kraglievich,  1940:  581-602). 


8  BREVIORA  No.    361 

Kraglievich,  J.  L.      1952.     El  perfil  geologico  de  Chapadmalal  y  Miramar, 

Provincia  de  Buenos  Aires.    Rev.  Mus.  Municipal  Cien.  Nat.  y.  Tradic. 

Mar  del  Plata,  1 :  8-37. 
RiNGUELET,  A.  B.  DE.     1953.     Marsupialia.    In  A.  V.  Borello,  ed.,  Paleon- 

tografia  Bonaerense,  Comis.  Invest.  Cien..  Prov.  Buenos  Aires,  La  Plata, 

fascicule  IV:  46-59. 

RuscoNi,  C.     1933.     New  Pliocene  remains  of  diprotodont  marsupials  from 

Argentina.    Jour.  Mammal.,   14:  244-250. 
__.  1936.     La  supuesta  afinidad  de  Argyrolagiis  con  los  Typotheria. 

Bol.  Acad.  Nac.  Cin.  Cordoba,  33:  173-182. 

Simpson,  G.  G.     1970.     The  Argyrolagidae,  extinct  South  American  Mar- 
supials.   Bull.  Mus.  Comp.  Zool.,  139:   1-86. 


1970  ARGYROLAGIDAE  9 

TABLE    1 
Measurements  of  teeth  of  holotype  of  Ar^yrola^us  palmeri 

M,  M,.  M3  M4  LMu4 

L       W  L       W  L       VV  L       W 

MACN  A53-4  1.9      1.1  2.1      1.3         2.0     1.3         2.0     1.1  7.8 

TABLE   2 
Comparative  measurements  of  teeth  of  Argyrolagus  scagUai 

M,  M2  Ma  M4  LMi^ 

L       W         L       W         L       W         L        VV 
Holotvpe,  MMP  7855         1.7     1.4       2.0     1.7       2.0     1.6       2.2     1.2  8.5 

MLP49.  IX.  7.1  1.8     1.7       2.3     1.9       2.3     1.8       2.2      1.4  8.6 


TABLE   3 

Trigonid  and  talonid  measurements  of  Argyrolagus  scagliai,  MLP 

49.IX.7.1. 

Ml  M-.  Ms  M4 

La     Lp     Wa    Wp       La     Lp     W^    Wp      L^     Lp     Wa    Wp      L^     Lp     W^   Wp 

1.2    0.6     1.6     1.7      1.4    0.9     1.9     1.9      1.5    0.8     1.8     1.6      1.3    0.9     1.4     1.3 


TABLE   4 

Measurements  of  destroyed  holotype  of  Argyrolagus  parodii,  from 
text  and  figures  of  Rusconi,  and  of  neotype  MLP  62-VII.27.81. 


Holotype: 

Rusconi,  1933,  te.xt 

Rusconi,  1933,  fig.  la 

Rusconi,  1936,  fig.  12  — 

Neotype  1.6    1.4        1.8    1.5        1.7    1.4        1.7    1.1  6.7 


M, 

M-. 

M3 

A 

^4 

LM, 

L      W 

L      \V 

L      W 

L 

\v 

—    — ■ 

—     — 

1.9     — 

1.3 

— 

— 

—    — 

—     — 

1.8    1.6 

1.6 

1.2 

— 

—     — 

—     — 

1.6    1.4 

1.6 

1.2 

— 

BREVIORA 

Mmseiuiiiii    of    Compsirative    Zoology 


Cambridge,  Mass.  30  November,  1970  Number  362 

ADDITION  TO  KNOWLEDGE  OF  GROEBERIA 

(MAMMALIA,  MARSUPIALIA)  FROM  THE 

MID-CENOZOIC  OF  ARGENTINA 

George   Gaylord   Simpson 

Abstract.  Groeberia  pattersoni,  new  species,  from  the  Divisadero 
Largo  formation,  is  based  on  the  second  known  specimen  of  that  genus. 
Some  information  on  the  hitherto  unknown  skull  of  genus  and  family  is 
provided.  Reference  to  the  Marsupialia  is  supported,  but  affinities  within 
the  Marsupialia  remain  dubious. 

The  extraordinary  fossil  marsupial  genus  Groeberia  has  hitherto 
been  known  from  a  single  specimen,  a  fragmentary  mandible, 
named  and  described  by  Patterson  (1952).  A  second  specimen 
was  found  by  Dr.  Edgardo  Rolleri  of  the  Yacimientos  Petroliferos 
Fiscales  (Argentine  government  petroleum  bureau)  and  deposited 
in  1968  in  the  Museo  de  La  Plata.  Dr.  Rosendo  Pascual  kindly 
referred  it  to  me  for  study,  which  I  carried  out  in  La  Plata  early 
in  1970,  and  for  publication,  here  presented.  Sr.  Jorge  Zetti,  as- 
sistant to  Dr.  Pascual,  facilitated  the  study  and  arranged  for  photo- 
graphs, provided  by  the  Museo  for  this  publication.  The  accom- 
panying drawings  were  made  by  RaVae  Marsh  on  the  basis  of 
sketches  by  me.  I  am  also  indebted  to  Dr.  A.  J.  Amos,  Dean  of 
the  Faculty  of  Natural  Sciences  and  the  Museum  of  La  Plata,  and 
to  Sr.  G.  J.  Scaglia,  Director  of  the  Museo  Municipal  de  Ciencias 
Naturales  of  Mar  del  Plata,  who  sent  the  holotype  of  G.  minoprioi 
on  loan  to  La  Plata  for  direct  comparison  with  the  present  speci- 
men. 

The  research  for  this  paper  was  performed  while  I  was  employed 
jointly  by  the  University  of  Arizona  and  the  Museum  of  Com- 
parative Zoology. 


2  BREVioRA  No.  362 

Class  Mammalia  Linnaeus,   1758 

Order  Marsupialia  Illiger,    1811 

Family  Groeberiidae  Patterson,   1952 

Genus  Groeberia  Patterson,   1952 

Groeberia  pattersoni,  new  species 

Etymology.  For  Bryan  Patterson,  who  named  and  described 
the  genus  and  its  type-species,  G.  ininoprioi. 

Holotype.  Museo  de  La  Plata  No.  68-VI-27-1,  partial  skull 
and  mandible. 

Hypodigm.     Holotype  only. 

Horizon  and  locality.  Divisadero  Largo  formation,  [in  the 
general  vicinity  of]  Mina  Atala,  Mendoza,  Argentina. 

Diagnosis.  Anterosuperior  part  of  symphysis  much  more 
slender  and  incisors  smaller  than  in  G.  minoprioi.  M  3.4  also,  but 
less,  smaller.   See  Table  1. 

Identification.  The  holotype  of  the  type-species  Groeberia 
minoprioi  includes  most  of  the  mandibular  symphysis  and  incisors, 
left  Mo. .J ,  and  broken  bases  of  M,  and  M,  (see  Patterson,  1952). 
The  present  specimen  also  preserves  most  of  the  symphysis  and 
lower  incisors  and  has  the  broken  bases  of  left  M  3.4.  These  parts 
are  morphologically  closely  similar  in  the  two  specimens  and  quite 
unlike  any  other  animal  known  to  me.  Reference  to  the  same  genus 
is  indicated.    Both  are  from  the  Divisadero  Largo  formation  and 


'&'- 


TABLE   1 


Comparative  measurements  in  millimeters  of  holotypes  of 
Groeberia  minoprioi  and  G.  pattersoni. 


G.  minoprioi 

G.   pattersoni 

Transverse  at  narrowest 

part  of  symphysis,  at 

postincisive  diastema 

ca.   5.8 

ca.   3.4 

Transverse,  across  both 

incisors  at  alveoli 

ca.  5.8 

ca.   3.4 

M3         Length 

2.3 

ca.  1.8 

M.,         Width 

1.6 

ca.    1.4 

M^         Length 

ca.  2.3 

ca.   1.5 

M^         Width 

ca.   1.8 

ca.     1.3 

Measurements  of  M..  of  G.  pattersoni  and  of  M^  of  both  speci- 
mens are  on  broken  bases  of  teeth  and  are  rough  approximations. 


1970  GROEBERIA  3 

near  the  same  locality:  the  holotype  of  G.  minoprioi  from  one-half 
kilometer  east  of  the  Cerro  Divisadero  Largo  (Patterson,  1952: 
3)  and  that  of  G.  pattersoni  recorded  as  "Mina  Atala,"  which 
would  be  about  IVi  kilometers  northeast  of  the  previous  locality 
but  which  must  be  a  rough  approximation,  as  the  Mina  Atala  is 
not  on  the  Divisadero  Largo  formation. 

The  holotype  of  G.  minoprioi  is  from  Minoprio's  stratum  F 
(see  map  and  stratigraphic  discussion  in  Simpson,  Minoprio,  and 
Patterson,  1962).  The  level  of  the  present  specimen  is  not  so 
precisely  known.  Although  no  faunal  change  has  been  demon- 
strated within  the  formation,  its  deposition  may  have  covered  a 
considerable  span  of  time  and  the  two  specimens  may  not  be  very 
closely  contemporaneous.  There  is  some  presumption  that  speci- 
mens so  similar  in  morphology  and  provenience  are  conspecific, 
but,  as  far  as  I  know,  the  difference  in  slenderness  of  the  sym- 
physis and  sizes  of  the  teeth  are  greater  than  within  adults  of 
any  one  species  of  marsupials.  This  difference  can  hardly  be  due 
to  greater  age  of  the  holotype  of  C.  minoprioi.  The  incisors  of  the 
holotype  of  G.  pattersoni  do  not  taper  in  the  alveoli,  hence  they 
could  age  considerably  without  increasing  in  diameter  at  the  alveoh. 
Although  measurements  are  imprecise,  the  length  of  M^  is  about 
50  per  cent  longer  in  the  holotype  of  G.  minoprioi,  and  these 
brachydont  teeth  do  not  grow  after  eruption.  The  holotype  of  G. 
pattersoni  evidently  had  all  teeth  erupted  and  some  skull  sutures 
closed,  as  in  fully  adult  animals.  Thus  specific  separation  is  in- 
dicated. 

Age.  Simpson,  Minoprio,  and  Patterson  (1962:  290)  con- 
cluded that  "the  age  of  the  Divisadero  Largo  fauna  is  approxi- 
mately early  Deseadan  or  latest  pre-Deseadan,"  but  that  knowledge 
at  that  time  did  not  warrant  basing  on  it  the  apparently  missing 
mammalian  age-stage  between  Mustersan  and  Deseadan.  How- 
ever, on  evidence  not  fully  stated,  Pascual,  Ortega,  Gondar,  and 
Tonni  (1965)  proposed  a  "Divisaderense"  (in  English,  Divisa- 
deran)  mammal  age-stage  as  intermediate  between  Mustersan  and 
Deseadan  and  separated  from  each  by  a  hiatus.  They  tentatively 
correlated  it  with  the  Ludian  of  Europe  and  Duchesnian  of  North 
America  as  latest  Eocene.  As  those  authors  also  did  recosnize. 
the  data  do  not  really  permit  close  correlation,  and  I  believe  that 
all  one  can  now  say  is  that  the  age  in  terms  of  the  European  epochs 
may  be  somewhere  around  late  Eocene  or  early  Oligocene,  hence, 
in  terms  of  absolute  age,  more  or  less  middle  Cenozoic. 


4  BREVIORA  No.    362 

Description.  As  found,  the  specimen  included  at  least  the 
anterior  part  of  the  skull  and  most  of  the  mandible  in  articulation. 
Some  time  before  the  specimen  came  into  the  control  of  the  Museo 
de  La  Plata,  the  skull  and  mandible  were  separated  and  both  were 
severely  damaged.  Nevertheless,  what  remains  adds  considerably 
to  knowledge  of  this  remarkable  and  enigmatic  genus. 

The  two  lower  incisors  are  preserved  for  a  length  of  about  12 
mm  within  their  alveoli.  The  anterior  ends  are  broken  and  the 
posterior  ends  have  been  ground  smooth,  presenting  the  appear- 
ance seen  in  Figure  IB.  The  pulp  cavity  is  here  open,  and  there 
is  no  sign  of  root  formation,  so  these  teeth  were  clearly  hypselo- 
dont/  as  in  G.  minoprioi.  The  teeth  curve  so  that  the  posterior 
parts  were  nearly  horizontal,  in  an  odd  medial  posterior  projection 
of  the  symphsis,  and  the  extra-alveolar  parts  would  have  been 
nearly  vertical.  Enamel  is  lacking  on  the  medial  and  dorsal  faces, 
and  at  this  depth  in  the  alveoli  even  the  dentine  has  not  quite 
closed  the  pulp  cavity  dorsally.  Heavy  enamel  occurs  ventrally, 
and  this  extends,  thinning  as  it  goes,  onto  the  lateral  faces,  more 
so  than  in  the  extra-alveolar  parts  of  the  incisors  of  the  holotype 
of  G.  minoprioi. 

There  is  a  short  diastema  posterior  to  the  lower  incisors  and 
then  a  series  of  cheek  teeth,  probably  four  as  in  G.  minoprioi,  al- 
though here  they  cannot  be  definitely  counted.  The  bases  of  what 
are  almost  certainly  the  last  two  cheek  teeth  can  be  made  out,  but 
the  crowns  are  not  visible.  These  teeth  are  brachydont  as  in  G. 
minoprioi  and  similar  in  outline  but  perhaps  slightly  less  elongate. 
There  are  two  pairs  of  upper  incisors,  here  designated  I'  and  1- 
for  convenience,  although  their  ancestral  homologies  are  unknown. 


1  Dictionaries  give  "hypselodont"  as  a  variant  of  "hypsodont,"  and  the 
most  recent  authoritative  odontology,  Peyer  (1968),  uses  "hypselodont" 
in  place  of  "hypsodont."  It  is,  however,  more  convenient  to  adopt  a  dis- 
tinction sometimes  made  by  mammaiogists,  especially  paleomammalogists. 
I  define  as  hypsodont  a  tooth  that  eventually  develops  one  or  more  roots 
but  that  has  a  crown  definitely  higher  than  those  roots  or  than  any  of  its 
horizontal  dimensions  and,  as  hypselodont,  a  tooth  that  never  forms  a 
root  but  continues  to  grow  and  to  extrude  new  parts  from  the  alveolus 
throughout  life.  Peyer  was  not  a  mammalogist  and  devoted  relatively 
little  attention  to  mammal  teeth.  Other  odontologists  have  often  oriented 
their  work  on  groups,  especially  Homo,  in  which  hypselodont  teeth  (in 
my  sense)  do  not  occur.   The  distinction  is  of  great  functional  importance. 


1970 


GROEBERIA 


B. 


bone 

enamel 

dentine 

matrix  in 
pulp  cavity 


Figure  I.  Grocheria  pattersoni,  new  species.  Holotype,  M.L.P.  No. 
68-VI-27-1.  A,  sketch  and  measurements  of  wear  surface  of  P,  approxi- 
mately X  6.  B,  sketch  of  posterior  (intra-alveolar)  exposure  of  paired 
lower  incisors,  approximately  X  5. 


P  is  a  large,  strongly  curved  tooth  with  an  alveolus  extending 
posterodorsally  far  back  in  the  facial  region  to  above  the  infra- 
orbital foramen.  It  and  I-  are  probably  both  hypselodont.  The 
cross  section  is  peculiar,  with  an  oblique,  long,  slightly  convex, 
buccal,  enamel-covered  face;  a  flat,  anteroposterior,  enamelless, 
anteromedial  face;  and  a  likewise  enamelless,  concave,  postero- 
medial face.  The  three  faces  meet  at  definite  angles,  approximately 
right  angles  at  both  ends  of  the  anteromedial  face  but  strongly 
acute  between  the  buccal  and  posteromedial  faces.  (See  Fig.  lA.) 
The  enamel  is  nearly  smooth  but  with  slight  wavy  longitudinal  rib- 
bing. Right  and  left  P  are  close  to  each  other  on  their  medial 
faces. 

I-  is  much  smaller  than  P,  measuring  about  1.1  mm  across  the 
buccal  face  as  compared  with  about  2.5  mm  for  P.  I-  is  also 
enameled  on  the  buccal  face,  and  probably  not  elsewhere.  The 
cross  section  cannot  be  clearly  determined  as  the  specimen  is 
preserved.    I-  is  less  curved  longitudinally  than  P  and  although 


BREVIORA 


No.  362 


the  extra-alveolar  parts  of  the  two  are  in  contact,  the  alveoli  di- 
verge. In  the  most  probable  orientation  of  the  skull,  the  extruded 
part  of  P  is  slightly  recumbent  and  that  of  I-  is  nearly  vertical. 


Figure  2.  Groeheria  pattersoni.  new  species.  Hololype.  M.L.P.  No. 
68-VI-27-1.  Fragment  of  symphysis  with  parts  of  lower  incisors.  A, 
supero-pcsterior  or  lingual  view.  B,  infero-anterior  or  genial  view.  C,  right 
lateral  view  (in  more  anatomical  orientation  the  anterior  parts  of  the  in- 
cisors would  be  nearly  vertical).    Approximately  X  4. 


1970 


C.ROEBERIA 


'mx-mx 
suture? 


IFO 
foramen  ? 


Buccal 
to  M^ 


Mx- Ju 
suture  ? 


Figure  3.  Groehcria  pcittersoni.  new  species.  Holotype.  M.L.P.  No. 
68-VI-27-1.  Anterior  part  of  skull,  left  lateral  view,  photograph  and  ex- 
planatory sketch.  "Buccal  to  M-^"  indicates  a  point  on  matrix,  formerly 
covered  by  the  zygoma,  medial  to  which  is  a  broken  cheek  tooth  identi- 
fied as  probably  M'\  IFO  =  infraorbital.  Mx-Ju  =  maxillo-jugal.  NA 
=  nasal.  OR  =  orbit.  Pmx-mx  =  premaxillo-maxillary.  Approximately 
X  4. 


8 


BREVIORA 


No.  362 


IFO   forame 


HR 


Mx-Ju 
suture  ? 


Figure  4.  Groeberia  pattersoni,  new  species.  Holotype.  M.L.P.  No. 
68-VI-27-1.  Anterior  part  of  skull,  right  lateral  view,  photograph  and 
explanatory  sketch.  CO  =  fragment  of  coronoid  process  of  mandible.  DPZ 
=  descending  plate  of  zygoma.  HR  =  fragment  of  horizontal  ramus  of 
mandible.  IFO  =  infraorbital.  Mx-Ju  i=:  maxillo-jugal.  OR  =  orbit. 
Approximately  X  4. 


1 970 


GROEBERIA 


4"'; 


'^ 


•^i 


B. 


Figure  5.  Groeheria  pattersoni,  new  species.  Holotype  M.L.P.  No. 
68-VI-27-1.  Anterior  part  of  slcull.  A,  dorsal  view.  B.  palatal  view.  Ap- 
proximately X  4. 


10 


BREVIORA 


No.  362 


There  is  a  diastema  posterior  to  I-  and  then  cheek  teeth,  but  noth- 
ing definite  can  be  made  out  for  the  latter,  except  that  they  are 
small  and  brachydont. 

The  preorbital  part  of  the  skull  is  notably  short  and  deep.  In 
the  most  probable  orientation,  it  (or  the  snout)  is  convex  dor- 
sally  as  a  whole  and  curves  downward  anteriorly.  The  nasals  are 
accordingly  downcurved  and  end  shortly  anterior  to  P.  The  infra- 
orbital foramen  is  not  definitely  visible  as  the  specimen  is  pre- 
served, but  must  be  of  moderate  size  and  in  a  normal  position  on 
the  face  anteroventral  to  the  orbit  and  about  half  way  between  it 
and  1-,  where  there  is  a  depression  obscured  by  matrix  on  the 
specimen.  On  the  left  side,  what  is  probably  part  of  the  pre- 
maxillo-maxillary  suture  is  visible  just  anterior  to  that  depression. 

The  orbit  is  rather  small  and  relatively  anterior  in  position,  its 
anterior  rim  probably  in  advance  of  the  cheek  teeth  and  certainly 
well  in  advance  of  what  is  identified  as  M-\  The  stout  root  of  the 
zygoma  below  the  orbit  had  an  expanded  suborbital  process  or 
plate,  the  full  extent  of  which  cannot  be  determined.  On  both 
sides,  a  possible  but  uncertain  maxillo-jugal  suture  can  be  seen 


Figure    6.     Groeberia   pattersoni,    new    species.     Holotype,    M.L.F.    No. 
68-VI-27-1.    Anterior  part  of  skull,  anterior   view.     Approximately    X    4. 


1970  GROEBERIA  I  1 

below  the  ventral  border  of  the  orbit.  Posterior  to  this,  and  hence 
on  the  jugal  if  the  possible  suture  is  such,  is  a  small  ventral  postor- 
bital  process.  Uncertainly  but  probably,  there  was  no  dorsal  post- 
orbital  process,  and  the  orbit  was  therefore  probably  open. 

The  palatal  surface  is  both  poorly  exposed  and  poorly  preserved, 
so  that  little  can  be  made  out  there  with  sufficient  probability. 
However,  its  dorsal  (intranasal)  surface  is  partly  exposed,  and 
some  details  can  be  made  out  in  cross  section  at  the  broken  pos- 
terior surface  of  the  specimen.  A  palatal  vacuity  was  probably 
absent  or  small  if  present.  It  appears  that  the  palate  between  the 
cheek  teeth  was  deeply  arched  (concave  ventrally).  The  coro- 
noid  process  of  the  mandible  can  be  seen  lateral  to  a  posterior 
tooth,  perhaps  M''  or  M^,  and  lateral  to  that  a  section  of  a  deep 
(vertically)  but  thin  (laterally)  zygoma.    (See  diagram,  Fig.  7.) 

palate  {^probable 
zygoma      \^  K^    cartilage 


mandible 


Figure  7.  Groeberia  pattersoni,  new  species.  Holotype,  M.L.P.  No. 
68-VI-27-1.  Rough  diagram  of  section  at  posterior  break  of  specimen  as 
preserved.    Not  to  scale. 


Affinities.  This  specimen  adds  considerably  to  data  bearing 
on  affinities  of  the  genus,  without  settling  the  matter.  Patterson's 
(1952:  3)  judgment  that  Groeberia  should  be  distinguished  at  the 
family  level,  as  Groeberiidae,  is  strongly  confirmed. 

Patterson's  evidence  that  Groeberia  is  a  marsupial  was  in  small 
part  positive,  largely  negative,  and  partly  indirect.  The  present 
specimen  adds  no  positive  evidence,  strengthens  the  negative  evi- 
dence, and  does  not  change  the  indirect  evidence.  The  only 
really  positive  evidence  from  the  holotype  of  G.  ininoprioi  for 
marsupial  affinities  in  general  (as  distinct  from  caenolestoid  affin- 
ities in  particular,  see  below)  is  the  probably  inflected  angle  of 
the  mandible.  Even  this  is  not  quite  certain,  because  the  angle 
itself  is  not  known,  but  a  crest  that  would  have  led  to  it  does 
decidedly  suggest  inflection.  An  inflected  angle  is  strong,  but  not 
conclusive,  evidence,  as  a  few  marsupials  do  not  have  the  angle 
inflected  and  a  few  placentals  do.   G.  minoprioi  may  have  had  four 


12  BREVIORA  No.    362 

lower  molars,  and  that  would  again  be  strong  but  not  fully  con- 
clusive evidence,  but  the  possibility  that  its  cheek  teeth  include 
one  premolar  and  three  molars  is  not  entirely  excluded.  The 
known  parts  of  the  skull  of  C  pattersoni  have  no  evident  features 
strongly  characteristic  either  of  marsupials  or  of  placentals.  The 
absence  of  palatal  vacuities  would  be  more  like  most  placentals, 
but  it  is  uncertain  and  there  are  a  number  of  marsupials  without 
such  vacuities. 

The  negative  evidence  is  that  Groeberia  has  no  known  features 
that  would  make  reference  to  the  Marsupia'ia  impossible  or  highly 
improbable  but  does  have  known  features  that  make  reference 
to  any  other  order  highly  improbable.  Here  the  new  specimen 
confirms  and  adds  somewhat.  The  habitus  is  more  or  less  rodent- 
like, but  the  two  upper  incisors  are  unlike  those  of  any  rodent. 
They  are  somewhat  like  those  of  lagomorphs,  but  the  cheek  teeth, 
even  what  little  can  be  seen  of  them  in  this  specimen,  definitely 
rule  out  pertinence  to  that  group.  Limited  resemblances  of  the 
mandible  to  those  of  certain  primates,  such  as  the  early  Cenozoic 
Chiromyoides,  as  mentioned  by  Patterson,  or  the  living  Daiiben- 
tonia,  become  even  less  possibly  significant  in  the  light  of  what  is 
now  known  of  the  skull.  The  skull  is  unknown  in  Chiromyoides, 
but  its  upper  incisors  are  entirely  unlike  those  now  known  in  Groe- 
beria and  the  skulls  of  other  plesiadapids  are  also  quite  dilTerent 
(see  especially  Russell,  1964).  There  is  an  interesting  resemblance 
between  the  short,  deep  faces  of  Daubentonia  and  Groeberia,  but 
this  is  quite  clearly  functionally  convergent  and  the  two  diff'er 
markedly  in  other  respects  and  in  facial  details.  Almost  all  other 
placental  orders  have  basic  diagnostic  features  absent  in  Groe- 
beria or  strongly  contradicted  in  this  genus. 

If  Groeberia  was  a  placental,  it  must  almost  perforce  have 
evolved  independently  and  uniquely  from  ancestors  as  primitive 
and  undifferentiated  as  those  now  known  from  the  late  Cretaceous 
and,  in  decreasing  numbers  and  generality,  quite  early  Cenozoic. 
Here  one  turns  to  the  indirect  and  yet  cogent  evidence:  that  no 
such  placentals  are  known  from  South  America;  that  equally  pri- 
mitive and  undifferentiated  marsupials  are  known  from  there;  that 
those  marsupials  did  diverge  in  independent  and  unique  lines;  and 
that  derivation  of  Groeberia  from  a  potent  and  definitely  South 
American  source  is  at  least  a  likely  hypothesis. 

Patterson's  views  on  the  affinities  of  Groeberia  were  buttressed 
by  evidence  for  referring  it  to  the  Caenolestoidea.    That  evidence. 


1970  GROEBERIA  13 

from  the  single  poorly  preserved  fragment  of  mandible  then  known, 
was  as  follows: 

1 .  One  greatly  enlarged  lower  incisor,  with  enamel  on  an- 
terior  face   and   alveolus    (or    "parte  basal")    parallel   to 

median  line  of  symphysis  (not  to  the  horizontal  ramus  or 
tooth  row). 

2.  Strong  salient  coronoid  process. 

3.  Molars  with  short  talonids  with  posterior  entoconid  and 
hypoconid,  united  by  a  transverse  crest,  a  short  crista 
obliqiia,  and  a  shallow  basin. 

4.  Molar  trigonids  with  one  lingual  (probable  metaconid) 
and  two  labial  cusps  (probable  paraconid  and  protoco- 
nid),  as  in  caenolestoids  except  Caenolestinae. 

5.  Trigonids  and  talonids  subequal,  as  in  Palaeothentinae 
and  Abderitinae. 

6.  Masseteric  crest  absent;  very  poorly  defined  in  Palaeothen- 
tinae. 

7.  Inflection  of  lower  border  beginning  anterior  to  cheek 
teeth;  usually  posterior  to  cheek  teeth  in  Caenolestoidea 
but  beneath  M^  in  Parabderites  bicrispatus. 

This  was  a  valid  analysis  of  the  admittedly  deficient  evidence, 
but  the  conclusion  may  be  retroactively  queried  in  the  light  of 
present  knowledge.  As  to  (1 ),  no  unquestioned  caenolestoids  have 
hypselcdont  incisors  comparable  to  these  in  form  or  function,  but 
the  placing  of  the  alveoli  is  an  interesting  point.  (2)  is  not  par- 
ticularly diagnostic.  Regarding  (3)-(5),  the  molar  structure  is 
difiicult  to  make  out  on  the  specimen,  but  I  believe  that  Patterson 
has  correctly  interpreted  it.  However,  it  diff'ers  characteristically 
from  probably  ancestral  didelphid  structure  in  litde  more  than  the 
more  labial  position  of  the  paraconid,  an  occlusal  adjustment  that 
could  well  arise  more  than  once.  (6)  is  somewhat  dubious  and 
is  not  diagnostic  for  caenolestoids.  (7)  dift'ers  from  caenolestoids 
more  than  it  resembles  them. 

A  reasonable  but  inconclusive  case  was  presented  on  the  basis 
then  available  and  pending  acquisition  of  further  knowledge.  The 
still  quite  limited  further  knowledge  now  acquired  does  not  flatly 
contradict  that  case,  but  neither  does  it  strengthen  it,  and  it  even 
weakens  it  to  some  extent.  I  see  no  special  resemblance  of  known 
parts  of  G.  pattersoni  to  any  unquestionable  caenolestoid.  On  the 
contrary,  the  extreme  abbreviation  of  the  face,  the  reduction  of 
the  incisors  to  two,  and  their  truly  gliriform,  hypselodont  nature 


14  BREVIORA  No.    362 

are  almost  the  opposite  of  known  trends  in  the  Caenolestoidea. 
Even  the  Polydolopidae,  superficially  most  seemingly  rodentlike 
of  undoubted  caenolestoids,  are  not  really  very  rodentlike  in  habi- 
tus and  evolved  in  a  direction  very  unlike  that  of  Groeberia  (see 
especially  Simpson,  1948;  Paula  Couto,  1952). 

Patterson  (1952:  6)  who  com'pdL^td  Groeberia  \n\\\\  Argyrokiiius 
and  concluded  that  they  are  not  specially  related  beyond  their  both 
being  marsupials.  With  greatly  increased  information  on  Argyro- 
logiis,  I  agreed  (Simpson,  1970),  and  the  present  addition  to 
knowledge  of  Groeberia  does  not  change  that  opinion.  Indeed,  the 
contrasts  between  Argyrolagiis  and  Groeberia,  both  somewhat 
rodentlike,  are  remarkable.  Argyrolagiis  has  an  extremely  elon- 
gate, shallow  rostrum  and  face,  very  posterior  orbit,  short,  shal- 
low zygoma,  hypselodont  cheek  teeth.  Groeberia  has  extremely 
short,  deep  rostrum  and  face,  very  anterior  orbit,  long  deep 
zygoma,  brachydont  cheek  teeth. 

Almost  complete  knowledge  of  dentition  and  skeleton  of  Argyro- 
lagiis contradicted  previous  opinion  that  it  might  be  a  caenolestoid 
and  required  placing  it  in  a  separate  superfamily.  I  suspect  that 
the  same  might  happen  if  we  had  equally  good  information  on 
Groeberia,  but  we  do  not.  This  knowledge  is  still  so  scanty  that 
I  believe  it  would  be  unreasonable  or,  at  best,  premature  at  this 
point  to  classify  the  Groeberiidae  other  than  as  Marsupialia  in- 
certae  sedis. 

Proposals  have  long  been  made  to  divide  the  marsupials  into 
suborders,  and  recently,  to  divide  them  into  two  or  more  orders. 
If  suborders  Polydactyla  and  Syndactyla  were  recognized,  I  would 
predict  that  discovery  of  foot  bones  would  aline  Groeberia  with 
the  polydactyls.  If  Polyprotodonta  and  Diprotodonta  were  recog- 
nized, Groeberia  would  be  descriptively,  typologically,  or  pheneti- 
cally  diprotodont,  but  I  believe  that  would  be  profoundly  mis- 
leading because  it  inevitably  suggests  connection  with  the  Austral- 
ian diprotodonts,  and  Groeberia  is  not  so  incertae  sedis  as  all 
that.  It  has  no  suggestion  at  all  of  Australian  affinities.  The 
ordinal  system  of  Ride  ( 1964)  has  no  sure  ordinal  place  for  it,  as 
the  evidence  that  it  may  be  a  "paucituberculate"  (caenolestoid) 
is  insufficient,  but  reference  to  the  Marsupicarnivora  would  be 
rather  anomalous  (although  like  all  marsupials  it  doubtless  arose 
from  the  group  so  named  by  Ride),  and  pertinence  to  the  Pera- 
melina  or  Diprotodonta  (seiisii  Ride)  is  out  of  the  question. 
Kirsch's  (1968)  arrangement  also  has  no  sufficiently  likely  place 
for  Groeberia  in  any  one  of  his  orders. 


1970  GROEBERIA  15 

Bioloij;}'.  In  the  absence  of  postcranial  remains,  nothing  can 
be  safely  inferred  as  to  body  build,  hmb  proportions,  or  locomo- 
tion in  Groeberia.  Biological  inferences  are  further  limited  by  the 
absence  of  specimens  of  the  neurocranium  and  by  the  imperfec- 
tions of  the  only  two  specimens  known.  The  following  are  the 
principal  characters  of  probable  functional  importance  that  are 
known: 

1 .  Face  and  snout  short. 

2.  Face  and  mandible  deep. 

3.  infraorbital  foramen  small. 

4.  Orbit  relatively  anterior. 

5.  Orbit  of  moderate  size. 

6.  Masseteric  origin  on  zygoma. 

7.  Heavy  hypselodont  incisors  with  labial  enamel. 
(S.     1'  recumbent. 

9.  Short  lower  diastema  near  alveolar  level. 

10.  Comparatively  small,  brachydont  cheek  teeth. 

1  I .  Large  coronoid  process. 

12.  Small  (no?)  masseteric  crest. 

13.  Inverted  angle. 

The  habitus  is  rodentlike  at  first  sight,  but  no  living  rodent  and 
in  fact  no  other  animal,  living  or  fossil,  known  to  me  combines 
all  those  characteristics.  3,  6,  11,  and  13  are  usual  and  4,  5,  and 
10  common  in  marsupials;  all  but  13  are  also  fairly  common  in 
placentals.  1,  2,  7  and  8  occur  in  the  other  known  marsupials 
that  are  most  rodentlike,  the  Australian  wombats.  They  are  lack- 
ing in  caenolestoids,  also  somewhat  but  much  less  rodentlike  in 
some  genera.  With  only  the  partial  exception  of  13,  all  these 
characters  occur  in  one  placental  rodent  or  another,  but  not  in 
this  combination.  For  example  some  caviomorphs,  such  as 
Echbnys,  have  characters  5,  7,  8,  10  and  a  functional  modification 
of  13.  but  notably  differ  in  3,  6.  9.  11  and  12.  Aplodontia  has 
3,  4,  6,  7,  moderate  8,  I  1  and  moderate  12,  but  differs  markedly 
in  1,2,  5,  9,  10,  and  13.  Xenis  (a  sciurid)  agrees  well  in  1, 
3,  4,  7,  8,  and  10,  but  less  well  in  2  and  9,  and  not  at  all  in 
5,  6,  11,  12,  and  13. 

There  is  no  doubt  that  Groeberia  was  a  powerful  gnawer,  at 
least  as  much  so  as  hares,  rodents,  wombats,  or  Daubentonia.  Its 
incisors  were  not  merely  a  pincer  apparatus  as  in  all  known  caeno- 
lestoids and  all  diprotodonts  (phalangeroids)  except  the  wombats. 
They  are  decidedly  more  adapted  to  gnawing  than  in  the  argyro- 
lagoids,  even  though  the  latter,   unlike  caenolestoids,   also  have 


16  BREVIORA  No.    362 

hypselodont  incisors.  Gnawing  is  strongly  connected  with  food 
gathering  in  recent  animals,  but  not  exclusively  so.  On  the  other 
hand,  Groeheiias  small  area  of  brachydont  cheek  teeth  is  very 
different  from  the  hypselodont  teeth  of  wombats,  argyrolagoids, 
and  many  rodents,  and  is  more  nearly  comparable  with  the  cheek 
dentition  of  caenolestoids,  squirrels,  and  Daubentonia.  The  com- 
bination suggests  a  food  obtained  by  gnawing  but  prepared  for 
deglutition  by  crushing  or  comminution  without  grinding.  Pos- 
sibilities are  bark  or  wood-boring  insects  or  fruits  or  nuts  with 
hard  shells.  However,  some  murids  with  strong  gnawing  apparatus 
and  limited,  brachydont  cheek  teeth  are  virtually  omnivorous  or 
even  carnivorous.  I  see  no  way  to  correlate  Groeberias  unique 
combination  of  characters  with  an  equally  unique  diet  or  with 
any  closely  specific  way  of  life. 

No  rodents  are  known  in  the  Divisadero  Largo  or  any  earlier 
South  American  formation.  Simpson,  Minoprio,  and  Patterson 
(1962:  289)  mentioned  the  possibility  that  the  presence  of  the 
rodentlike  marsupial  Groeberia  indicated  age  before  rodents 
reached  that  area,  hence  pre-Deseadan.  The  ecological  aspect  of 
that  suggestion  would  still  hold  even  if  the  determination  of  the 
relative  time  of  entry  of  rodents  proved  to  be  incorrect.  (There 
is  still  no  opposing  evidence.)  The  rodent  habitus  surely  evolved 
elsewhere  and  was  in  being  when  the  first  rodents  entered  South 
America,  whether  in  the  Deseadan  or,  as  is  quite  likely,  somewhat 
earlier.  On  the  other  hand,  the  ancestral  habitus  of  Groeberia 
almost  certainly  evolved  in  South  America  before  rodents  reached 
there,  convergent  to  some  extent  toward  the  absent  rodents  and 
entering  niches  with  some  points  of  similarity. 

Zoogeography.  It  is  the  most  reasonable  hypothesis  that  the 
Groeberidae  did  evolve  in  South  America,  even  though  their  pos- 
sible relationship  to  the  Caenolestoidea  is  quite  dubious,  and  there 
is  no  suggestion  of  special  descendant  relationship  (involving 
specialization)  to  any  other  South  American  group.  Origin  from 
South  American  didelphoids  is  as  likely  as  any  other,  if  not  more 
so.  There  is  no  special  resemblance  to  any  Australian  marsupials 
suggestive  of  genetic  affinity  beyond  the  remote  ancestry  of  all 
marsupials.  No  marsupials  are  known  from  Africa  and  any  idea 
of  connection  there  would  be  purely  gratuitous  at  present. 

Nevertheless  it  is  strange  that  three  of  the  most  peculiar,  most 
specialized  known  groups  of  South  American  marsupials  appear 
in  the  presently  available  record  without  known  ancestors,  only  to 


1970  GROEBERIA  17 

vanish  again  immediately  (geologically  speaking)  or  soon  there- 
after: Groeberiidae,  only  in  the  Divisadero  Largo  formation;  Nec- 
rolestidae,  only  in  the  Santa  Cruz  formation;  and  Argyrolagidae, 
only  from  Huayquerian  to  Uquian.  A  possible  clue  is  that  all 
these  faunas  are  in  Temperate  Zone  Argentina  and  that  earlier 
faunas  are  as  yet  very  inadequately  known  farther  north  on  the 
continent.  It  is  a  reasonable  hypothesis,  as  yet  without  direct 
evidence,  that  these  groups  evolved  in  what  are  now  (and  quite 
likely  were  then)  the  tropics  and  are  picked  up  in  our  record  only 
when  they  spread  rather  briefly  to  what  was  for  them  a  marginal 
area. 

REFERENCES 

KiRSCH,  J.  A.  W.  1968.  Prodromus  of  the  comparative  serology  of 
Marsupialia.    Nature,   217:   418-420. 

Pascual,  R..  E.  J.  Ortega  Hinojosa,  D.  Gondar,  and  E.  Tonni.  1965. 
Las  Edades  del  Cenozoico  mamalifero  de  la  Argentina,  con  especial 
atencion  a  aquellas  del  Territorio  Bonaerense.  Prov.  de  Buenos  Aires, 
Sep.  An.  Com.  Invest.  Cient.  Bs.  As.,  VI:    165-193. 

Patterson.  B.      1952.     Un  nuevo  y  extraordinario  marsupial  deseadiano. 

Rev.  Mus.  Municipal  Cien.  Nat.  y  Tradic,  Mar  del  Plata,   1:  49-44. 
Paula   Couto,    C.    de.     1952.     Fossil   mammals    from    the    beginning   of 

the  Cenozoic  in  Brazil.  Marsupialia:  Polydolopidae  and  Borhyaenidae. 

American  Mus.  Novitates.  No.   1559:    1-27. 

Peyer,  B.  1968.  Comparative  Odontology.  (R.  Zangerl.  ed.)  Chicago, 
Univ.  of  Chicago  Press. 

Ride.  W.   D.  L.      1964.     A  review  of  Australian  fossil  marsupials.    Jour. 

Roy.  Soc.  Western  Australia,  47:  97-131. 
Russell,  D.  E.     1964.     Les  Mammiferes  Paleocenes  d'Europe.    Memoires 

du   Mus.   Nat.   D'Histoire  Nat..  Serie   C,  Sciences  de  la  Terre,   XIII: 

1-324. 

Simpson,  G.  G.  1948.  The  beginning  of  the  Age  of  Mammals  in  South 
America.  Bull.  American  Mus.  Nat.  Hist.,  91:   1-232. 

,     1970.     The    Argyrolagidae.    extinct    South    American 

marsupials.    Mus.  Comp.  Zool..   139  (1):    1-86. 

Simpson.  G.  G.,  J.  L.  Minoprio,  and  B.  Patterson.  1962.  The  mam- 
malian fauna  of  the  Divisadero  Largo  formation,  Mendoza,  Argentina. 
Bull.   Mus.  Comp.   Zool..    127   (4):   239-293. 


BREVIORA 


Miiseiuiiti    of    Compsirative    Zoology 

Cambridge,  Mass.         8  January,  1971  Number  363 

NON-SPECIFICITY  OF  HOST-SELECTION  IN  THE 

ECTOPARASITIC  SNAIL  ODOSTOMIA  (MENESTHO) 

BISUTURALIS  (SAY)  (GASTROPODA:  PYRAMIDELLIDAE) 

Robert  C.  Bullock  and  Kenneth  J.  Boss 


Abstract.  Ectoparasitic  pyramidellid  gastropods  have  often  been 
considered  host-specific,  although  a  few  species  have  been  reported  to  feed 
on  a  variety  of  hosts  under  laboratory  conditions.  A  large  population  of 
Odostomia  (Menestho)  bisuturalis  (Say)  at  Duxbury  Beach,  Massachu- 
setts, provided  an  ideal  opportunity  to  study  the  association  of  this  ecto- 
parasite with  the  various  moUusks  found  in  the  vicinity.  Our  results  re- 
vealed that  O.  bisuturalis  was  associated  with  seven  species  of  moUusks, 
most  commonly  Nassariiis  obsoletiis  (Say)  and  Mytilus  editlis  Linnaeus. 
The  great  abundance  of  O.  bisuturalis  and  the  fact  that  Crassostrea  vir- 
ginica  (Gmelin),  its  usual  natural  host,  was  absent  from  the  study  area, 
appear  to  account  for  the  non-host-specificity  observed. 

INTRODUCTION 

The  host-specificity  of  the  ectoparasitic  snails  of  the  family 
Pyramidellidae  has  been  the  subject  of  several  papers  during  the 
last  decade.  Early  observations  led  some  workers,  notably  Fretter 
and  Graham  (1949;  1962),  to  state  that  these  ectoparasites  were 
host-specific.  More  recent  studies  have  revealed  that  under  labora- 
tory conditions  certain  pyramidellids  actually  feed  on  a  variety  of 
hosts  (Ankel  and  Christensen,  1963;  Scheltema,  1965;  Robertson, 
personal  communication),  although  possible  host-preference  may 
be  a  factor  (Boss  and  Merrill,  1965).  The  observations  reported 
here  suggest  that  some  species  of  pyramidellids  are  not  host- 
specific. 

What  actually  constitutes  a  true  parasitic  relationship  has  been 
questioned  (Robertson  and  Orr,  1961;  Dehlinger,  unpublished 
MS).     While    observations    of    pyramidellids     associated    with 


2  BREViORA  No.   363 

various  organisms  indicate,  by  their  proximity  or  physical  contact, 
possible  parasite-host  relationships,  most  authors  have  been 
wary  of  such  evidence.  Robertson  (personal  communication) 
stated  that  the  presence  of  an  Odostomia  on  a  possible  host  may 
only  reflect  the  pyramidelUd's  need  for  a  suitable  substrate.  This 
view  is  supported  by  some  of  our  observations  and  those  of  Schel- 
tema  (1965),  who  noted  O.  bisuturalis  clinging  to  the  under  sur- 
faces of  stones  in  a  region  where  Littorina  littorea  L.,  a  "labora- 
tory host"  for  this  species,  was  abundant.  Recent  workers  have 
indicated  what  constitutes  a  true  parasitic  relationship:  insertion 
of  the  proboscis  and  action  of  the  buccal  pump  (Robertson,  per- 
sonal communication;  Scheltema,  1965)  or  when  the  parasite  is 
"less  than  V&  in.  from  the  edge  of  the  mantle  of  the  host" 
(Boss  and  Merrill,  1965).  Although  the  former  is  a  more  exact 
method,  we  have  necessarily  followed  Boss  and  Merrill  (1965), 
since  our  observations  were  made  during  the  low  tide  period  when 
the  ectoparasites  were  not  actively  feeding  on  exposed  hosts. 

OBSERVATIONS 

An  abundance  of  Odostomia  (Menestho)  bisuturalis  (Say, 
1822)  was  noted  on  the  tidal  flat  on  the  harbor  side  of  Duxbury 
Beach,  Massachusetts,  in  June,  1969.  Sampling  at  several  stations 
along  the  beach  during  a  -1.6  tide  on  3  June  and  subsequent 
visits  to  the  study  area  provided  ample  field  evidence  of  the  occur- 
rence of  this  snail  on  numerous  intertidal  moUuscan  hosts. 

The  Odostomia  were  not  limited  to  a  particular  region  of  the 
tidal  flat,  for  they  were  found  from  below  the  low-water  mark  to 
the  upper  portion  of  the  intertidal  zone.  Quantitative  samples 
were  taken  in  the  region  at  the  east  end  of  the  Duxbury  Beach 
bridge.  All  moUusks  collected  were  carefully  examined  for  the 
presence  of  Odostomia.  O.  bisuturalis,  the  only  pyramidellid 
found,  was  collected  from  seven  different  species  of  moUusks: 
Littorina  littorea  (L.),  Urosalpinx  cinereus  (Say),  Crepidula  con- 
vexa  Say,  Crepidula  fornicata  (L.),  Nassarius  obsoletus  (Say), 
Nassarius  trivittatus  (Say),  and  Mytilus  edulis  Linnaeus.  They 
were  also  observed  on  the  egg  capsules  of  Nassarius  sp.  and  Poli- 
nices  sp.,  and  on  empty  shefls. 

O.  bisuturalis  was  most  abundant  on  three  hosts:  Mytilus  edulis, 
which  formed  large  mats  on  the  mud  flats,  and  on  the  snails  Nas- 
sarius obsoletus   and  Littorina   littorea,   which   occasionally  had 


1970  ECTOPARASITIC  ODOSTOMIA  3 

from  one  to  three  ectoparasites  on  the  operculum  or  on  the  Hp  of 
the  shell.  The  Mytilus  that  were  observed  in  water  often  had  a 
number  of  ectoparasites  situated  on  the  margins  of  the  mantle, 
away  from  the  hinge,  similar  to  the  position  assumed  in  Odostomia 
scalaris  MacGillivray  on  Mytilus  in  Europe.  However,  most  of 
the  Mytilus  population  at  Duxbury  was  exposed  at  low  tide  and 
the  ectoparasites  had  migrated  to  moist  areas  within  the  Mytilus 
mat.  In  the  laboratory  we  have  observed  O.  bisuturalis  feeding 
on  Mytilus. 

Table  I  shows  the  relative  abundance  of  Odostomia  on  three 
hosts.  In  the  case  of  Nassarius  obsoletus  several  items  should  be 
noted:  1)  the  parasites  occurred  on  samples  with  a  large  mean 
length  in  a  frequency  of  one  Odostomia  to  three  or  four  Nassarius; 
2)  smaller  individuals  of  Nassarius  were  significantly  less  para- 
sitized, with  only  one  parasite  per  ten  individuals.  This  latter  ob- 
servation was  also  noted  in  studies  of  O.  impressa  (Say)  (Hop- 
kins, 1956)  and  O.  dianthophila  Wells  and  Wells  (Wells  and 
Wells,  1961).  At  one  station  A',  obsoletus  was  present  in  large 
numbers,  possibly  12,000/m-,  with  an  equally  high  concentration 
of  O.  bisuturalis,  7,000/m-.  These  figures  indicate  that  at  times 
O.  bisuturalis,  a  usually  overlooked  organism,  must  play  a  mod- 
erately significant  role  in  the  flow  of  energy  in  a  tidal  flat  com- 
munity. In  other  species,  not  quantitatively  sampled,  the  occur- 
rence of  Odostomia  was  even  greater,  in  some  cases  amounting 
to  two  ectoparasites  per  host,  e.g.,  Littorina. 

Previous  published  records  of  field  observations  have  not  re- 
vealed O.  bisuturalis  in  association  with  any  of  the  seven  species 
of  moUusks  reported  in  this  study.  In  the  laboratory,  O.  bisutu- 
ralis is  known  to  feed  on:  Littorina  littorea  (L.)  (Scheltema, 
1965;  Robertson,  1967);  Bittium  altematum  (Say)  (Scheltema, 
1965);  Crucibulum  striatum  (Say)  and  Crepidula  fornicata  (L.) 
(Boss  and  Merrill,  1965).  Previously,  the  only  known  natural 
host  of  O.  bisuturalis  was  the  American  oyster,  Crassostrea  vir- 
ginica  (Gmelin)  (Loosanoff,  1956;  Boss  and  Merrifl,  1965),  a 
species  not  present  at  Duxbury  Beach. 

DISCUSSION 

These  observations  demonstrate  that  at  least  one  pyramideflid 
is  not  host-specific.  Further,  laboratory  studies  have  shown  that 
certain  Odostomia  may  have  numerous  hosts.   Thus,  should  these 


4  BREVIORA  No.    363 

species  actually  be  non-host-specific,  as  O.  bisiituralis  seems  to 
be,  an  examination  of  all  environmental  factors  involved  in  host- 
specificity  and  host-preference  becomes  imperative. 

The  great  abundance  of  O.  bisiituralis  led  to  the  consideration 
of  the  question  of  density-dependent  factors  in  feeding  behaviour. 
While  our  observations  show  the  non-specific  host-selection  of 
O.  bisuturalis,  they  do  not  reveal  any  specific  information  con- 
cerning host-preference.  An  abnormally  large  population  of  O. 
bisuturalis  or  a  diminished  preferred  food  source  might  force 
many  individuals  to  feed  on  hosts  they  would  otherwise  reject. 

The  biological  relationship  between  a  motile  ectoparasite  and 
host-species  can  be  likened  to  that  between  a  predator  and  its 
prey.  The  odostomia-type  of  predator-prey  relationship  with  re- 
spect to  food  preference  is  commonly  observed  in  animals  not 
totally  dependent  on  one  organism  for  survival.  It  has  been 
demonstrated  that  total  food  abundance,  relative  abundance  of 
food  types,  spatial  distribution  of  foods  and  predator  satiation 
afl'ect  feeding  preferences  in  some  animals  (Ivlev,  1961).  In  mol- 
lusks,  for  example.  Wells  (1958)  found  that  although  the  oppor- 
tunistic gastropod  Fasciolaria  hunter ia  (Perry)  prefers  to  eat  the 
small  oyster  drill,  Urosalpinx,  it  will  eat  oysters  if  only  a  minimal 
number  of  the  more  desirable  gastropods  are  present.  Further,  in 
a  study  of  the  relationship  between  time  and  energy  in  food  pref- 
erences, Emlen  (1966:  617)  suggested  that:  1)  ''Animals  should 
be  more  selective  in  their  choice  of  foods  when  satiated  or  when 
food  is  common,  more  indiscriminate  when  starved  or  when  food 
is  scarce";  and,  2)  "Food  preferences  appear  to  change  readily 
and  appropriately  to  changes  in  the  environment." 

The  particular  circumstances  in  which  the  ectoparasitic  popula- 
tion existed  were  unusual  in  that:  1 )  there  was  a  very  large  popula- 
tion of  ectoparasites;  and,  2)  the  preferred  natural  host  for  this 
species,  Crassostrea  virginica,  was  not  present  in  the  local  eco- 
system. Thus,  our  observations  corroborate  the  hypotheses  of 
Emlen  and  indicate  that  Odostomia  bisuturalis  may  have  various 
host-species  under  natural  conditions. 


1970  ECTOPARASITIC   ODOSTOMIA  5 

ACKNOWLEDGMENTS 

The  manuscript  was  critically  read  by  Messrs.  R.  I.  Johnson 
and  M.  K.  Jacobson  and  Dr.  R.  D.  Turner.  Mr.  W.  Baranowski 
brought  our  attention  to  the  occurrence  of  great  numbers  of  Odo- 
stomia  at  the  Duxbury  site,  and  Mr.  S.  Britz  measured  the  speci- 
mens. 


BREVIORA 


No.  363 


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REFERENCES  CITED 

Ankel,  F.,  and  a.  M.  Christensen.  1963.  Non-specificity  in  host  selec- 
tion by  Odostomia  scalaris  MacGillivray.  Vidensk.  Medd.  fra  Dansk 
naturh.  Foren.,   125:    321-325. 

Boss,  K.,  AND  A.  Merrill.  1965.  Degree  of  host  specificity  in  two  species 
of  Odostomia  (Pyramidellidae:  Gastropoda).  Proc.  Malac.  Soc.  Lon- 
don, 36:  349-355. 

Dehlinger,  R.  1969.  Host  specificity  and  the  feeding  ecology  of  the 
ectoparasitic  family   Pyramidellidae.    Unpublished  manuscript,   55  pp. 

Emlen,  J.  M.  1966.  The  role  of  time  and  energy  in  food  preference. 
Amer.  Nat.,  100:   611-617. 

Fretter,  v.,  and  a.  Graham.  1949.  Feeding  and  reproduction  in  pyra- 
midellids.    Nature,  163:  361-362. 

.     1962.     British    Prosobranch    Molluscs.     London,    Ray 

Society,  755  pp. 

Hopkins,  S.  H.  1956.  Odostomia  impressa  parasitizing  southern  oysters. 
Science,  124:  628-629. 

Ivlev,  V.  S.  1961.  Experimental  Ecology  of  the  Feeding  of  Fishes.  New 
Haven,  Yale  Univ.  Press,  302  pp. 

Loosanoff,  V.  L.  1956.  Two  obscure  oyster  enemies  in  New  England 
waters.   Science,  123:  1119-1120. 

Robertson,  R.  1967.  The  life  history  of  Odostomia  bisiitiualis,  and 
Odostomia  spermatophores  (Gastropoda:  Pyramidellidae).  Year  Book 
Amer.  Phil.  Soc,  1966:  368-370. 

Robertson,  R.,  and  V.  Orr.  1961.  Review  of  pyramidellid  hosts,  with 
notes  on  an  Odostomia  parasitic  on  a  chiton.    Nautilus,  74:  85-91. 

Scheltema,  a.  H.  1965.  Two  gastropod  hosts  of  the  pyramidellid  gas- 
tropod Odostomia  bisiitiiralis.    Nautilus,   79:   7-10. 

Wells,  H.  W.  1958.  Predation  of  pelecypods  and  gastropods  by  Fas- 
ciolaria  hunteria  (Perry).  Bull.  Mar.  Sci.  Gulf  and  Caribbean,  8: 
152-166. 

Wells,  H.  W.,  and  M.  J.  Wells.  1961.  Three  species  of  Odostomia 
from  North  Carolina,  with  description  of  new  species.  Nautilus,  74: 
149-157. 


BREVIORA 

MiaseitairM    of    Comparative    Zoology 

Cambridge,  Mass.         8  January,  1971  Number   364 

A  NEW  SCINCID  LIZARD  FROM  BOUGAINVILLE, 
SOLOMON   ISLANDS 

Allen  E.  Greer  and  Fred  Parker^ 


Abstract.  The  relationships  of  Sphenomorphus  transversus,  n.  sp., 
from  Bougainville,  Solomon  Islands,  are  obscure,  but  in  squamation  it  is 
most  similar  to  inaciilatiis,  boiilengcri,  forinosensis,  Uneopiinctiilatiis.  and 
indiciis  from  eastern  Asia;  nielanochlorus  from  New  Guinea;  and  sanctiis 
from  Sumatra  and  Java.  S.  transversus  differs  most  noticeably  from  these 
species  and  from  other  Bougainville  skinks  in  its  dorsal  pattern  of  trans- 
verse dark  brown  bands  on  a  light  olive  ground  color. 

During  investigations  in  1960-1963  by  Parker  on  Bougain- 
ville, Solomon  Islands,  a  single  individual  of  a  previously  unde- 
scribed  species  of  skink  was  collected.  Since  one  subsequent  trip 
(1966)  has  failed  to  uncover  other  specimens  of  the  species,  and 
as  the  possibilities  of  a  second  return  trip  to  Bougainville  in  the 
near  future  are  slim,  it  seems  best  to  describe  the  new  species  from 
the  single  specimen  at  hand. 

On  the  basis  of  current  generic  concepts,  the  species  is  assigned 
to  the  genus  Sphenomorphus  and  may  be  known  as 

Sphenomorphus  transversus^  new  species 

Holotype.  Museum  of  Comparative  Zoology  76485;  collected 
by  a  native  for  Fred  Parker  at  about  2000  feet  above  sea  level  in 
an  area  approximately  five  miles  east  of  Kunua,  northeastern 
Bougainville  (Fig.  1),  on  9  September  1962. 


1  P.  O.  Box  52,  Daru,  Western  District,  Territory  of  Papua  and  New 
Guinea. 

-  The  species  name  calls  attention  to  the  dark  transverse  bars  on  the 
dorsum. 


BREVIORA 


No.  364 


155°  E 


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■6°S 


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Figure  1.  Map  of  Bougainville  showing  the  location  approximately  5 
miles  east  of  Kunua  where  the  type  and  only  known  specimen  of  Spheno- 
morphiis  transversus  was  collected. 


Diagnosis.  Similar  in  squamation  to  those  skinks  of  the  genus 
Sphenomorphus  (Table  1  )  that  have  a  single  anterior  loreal,  the 
frontal  in  contact  with  3  or  more  of  the  5  or  more  supraoculars, 
frontoparietals  and  interparietal  distinct,  no  nuchals  or  trans- 
versely enlarged  scales  in  the  two  vertebral  rows  (Figs.  2  and  3), 


I97' 


A    NEW    SOLOMON    ISLANDS    SKINK 


and  the  digits  and  limbs  well  developed  and  overlapping  when 
adpressed  to  the  body,  but  differing  from  other  skinks  with  this 
diagnosis  in  having  the  following  combination  of  characters:  pre- 
frontals separated  medially,  36  rows  of  smooth  scales  around  mid- 
body,  28-29  smooth  subdigital  lamellae  on  the  4th  toe,  and  a 
color  pattern  of  brown  transverse  bands  on  a  light  olive-green 
ground  color  (Figs.  4  and  5)  — a  color  pattern  most  similar  to 
those  of  the  distantly  related  Sphenomorphus  flavipes,  Scincella 
prehensicaiida,  and  Leiolopisma  semoni  of  New  Guinea. 

Description.  Body  form  relatively  slender;  well-developed  pen- 
tadactyl  digits  and  Umbs  that  overlap  when  adpressed  to  the  body 
(tip  of  4th  toe  reaches  middle  of  forearm);  snout-vent  length  68 
mm,  tail  92  mm. 


Figure  2.     Dorsal  view  of  the  head  of  the  holotype  of  Sphenomorphus 
transversus  (MCZ  76485). 


BREVIORA 


No.   364 


Head  not  depressed,  snout  somewhat  pointed;  rostral  slightly 
wider  than  deep,  projecting  slightly  onto  dorsal  surface  of  snout 
between  nasals;  external  naris  in  single  nasal;  no  supranasals; 
single  anterior  and  posterior  loreals;  frontonasal  slightly  wider 
than  long,  forming  a  short  suture  with  the  rostral  and  a  very 
short  suture  with  the  frontal;  prefrontals  large,  barely  separated  at 
their  inner  angles;  frontal  1%  times  as  long  as  wide,  in  contact 
with  the  three  anteriormost  supraoculars;  5  supraoculars,  the 
first  smallest,  but  in  no  way  to  be  confused  with  the  anterior  super- 
ciliaries;  lower  eyelid  scaly;  6th  supralabial  most  directly  below 
eye;  a  complete  row  of  subocular  scales  separates  scales  of  lower 
eyelid  from  supralabial  series;  frontoparietals  paired  and  subequal 
in  size  with  the  single  interparietal  that  is  sharply  pointed  pos- 
teriorly; parietals  meeting  behind  interparietal  and  bordered 
posteriorly  by  a  single  large  temporal  on  either  side  and  5  large 
dorsal  scales  between  the  temporals;  no  symmetrical  series  of 
nuchals. 

External  ear  opening  vertically  elliptic,  without  auricular  lobes; 
tympanum  sunk  slightly  below  level  of  skin;  36  smooth  scales 
around  midbody,  the  scales  of  the  two  vertebral  rows  not  larger 
than  those  of  the  immediately  adjacent  rows;  a  pair  of  enlarged 
preanals;  scales  of  three  median  subcaudal  rows  subequal  in  size. 

Digits  rather  long  and  slender;  subdigital  lamellae  smooth  and 
undilated  throughout  length  of  digit;  28-29  lamellae  beneath  4th 
(longest)   toe;  upper  surface  of  4th  toe  covered  by  one  or  two 


Figure   3.     Lateral   view  of  head   of  Sphenoworpliiis  tnnisversus    (holo- 
type). 


1971  A    NEW    SOLOMON    ISLANDS    SKINK  5 

single  scales  at  distal  end,  3  rows  of  scales  throughout  center  part 
and  4  rows  near  base  (see  Brongersma,  1942). 

Dorsal  ground  color  light  olive  with  a  series  of  complete  and 
incomplete  transverse  dark  brown  bands  from  nape  to  base  of 
tail,  the  brown  bands  terminating  in  slightly  expanded  blotches 
on  sides  (Fig.  5),  an  effect  especially  pronounced  at  midbody;  a 
horizontal  brown  stripe  from  anterior  loreal  through  eye  to  tem- 
poral region;  brown  blotches  on  anterior  and  upper  surfaces  of 
limbs  as  well  as  on  upper  surface  of  tail;  venter  immaculate  except 
for  a  few  faint  brown  spots  on  throat  and  underside  of  tail. 

In  life  the  undersides  of  the  limbs,  body,  and  tail  were  bright 
yellow. 

Field  Notes.  The  only  known  specimen  of  S.  transversus  was 
taken  by  a  native  collector  under  a  decaying  log  on  the  steep  side 
of  a  montane  river  valley  covered  with  tall  primary  forest.  The 
natives  did  not  recognize  it  as  being  distinct  from  S.  concinnatus, 
a  species  common  at  the  type  locality  of  5.  transversus. 

Morphological  Comparisons  with  Other  Bougainville  Skinks. 
S.  transversus  is  immediately  distinguishable  from  S.  concinnatus 
by  its  more  sharply  tapered,  longer  snout;  the  absence  of  a  dark 
blotch  between  the  ear  opening  and  the  forellmb;  the  smaller  ex- 
ternal ear  opening;  and,  the  regular  transverse  barring. 

Only  two  other  Bougainville  skinks,  S.  taylori  and  S.  cranei — 
both  very  different  from  S.  transversus  in  squamation  —  have 
transverse  bands  on  the  dorsum.  In  both  these  species,  however, 
the  dorsal  pattern  consists  of  very  light  transverse  bands  on  a  dark 
ground  color,  whereas  in  S.  transversus  the  transverse  bands  are 
darker  than  the  ground  color.  S.  transversus  also  has  a  more 
noticeably  pointed  snout  than  either  S.  taylori  or  S.  cranei. 

Skull  Characters.  It  is  extremely  difficult,  if  not  impossible, 
to  remove  the  skull  of  most  skinks  without  severely  damaging  the 
skin  of  the  head.  For  this  reason  we  have  not  attempted  to  pre- 
pare a  skull  from  the  type  and  only  known  specimen  of  S.  trans- 
versus. We  have,  however,  had  a  palatal  view  of  the  skull,  and 
the  salient  features  are  as  follows:  there  are  9  premaxillary  teeth; 
the  palatine  and  pterygoid  bones  meet  along  the  midhne  to  form 
a  fairly  extensive  secondary  palate;  there  is  no  ectopterygoid  pro- 
cess; and,  there  are  no  pterygoid  teeth.  Unfortunately,  these 
characteristics  are  not  particularly  diagnostic,  for  they  would  not 
exclude  S.  transversus  from  close  relationship  with  any  number 


6  BREVIORA  No.    364 

of  other  lygosomines,  including  those  discussed  below  that  are 
most  like  S.  transversiis  on  the  basis  of  external  morphology. 

Comparison  with  Morphologically  Similar  Species.  In  squama- 
tion  S.  transversus  is  most  similar  to  those  species  of  Sphenomor- 
phus  (Table  1)  that  have  a  single  anterior  loreal,  the  frontal  in 
contact  with  3  or  more  of  the  5  or  more  supraoculars,  the  fronto- 
parietals and  interparietal  distinct,  no  nuchals  or  transversely  en- 
larged scales  in  the  two  vertebral  rows,  and  the  digits  and  limbs 
well  developed  and  generally  overlapping  when  adpressed  to  the 
body.  This  assemblage,  which  is  almost  surely  not  monophyletic, 
is  distributed  from  southern  Asia  through  the  Indo-Australian 
archipelago  and  Philippines  to  New  Guinea,  but  not  Australia. 

Seven  species  in  this  group  have  the  prefrontals  separated  me- 
dially (in  all  or  some  individuals),  as  is  the  case  in  the  single 
specimen  of  S.  transversus.  Six  of  these  seven  species  (maculatus, 
boulengeri,  jormosensis,  lineopimctulatus ,  and  indiciis  from 
southern  Asia  and  melanochlorus  from  New  Guinea)  have  sub- 
stantially fewer  subdigital  lamellae  on  the  4th  toe  (16-22)  than 
does  transversus  (28-29),  and  the  seventh  {sanctus  from  Suma- 
tra and  Java)  has  finely  striated  body  scales  to  distinguish  it  from 
the  smooth-scaled  transversus.  Furthermore,  none  of  these  seven 
species  have  a  dorsal  body  pattern  consisting  of  well-defined  dark 
crossbars  as  does  transversus. 

This  very  characteristic  dorsal  body  pattern  of  dark  crossbars 
on  a  light  ground  color  is  most  similar  to  the  patterns  of  the  cross- 
banded  color  morph  of  Sphenomorphus  fiavipes,  the  females  of 
Scincella  prehensicauda,  and  of  all  Leiolopisma  semoni.  These 
three  species  are  endemic  to  neighboring  New  Guinea  and  might, 
therefore,  seem  to  be  likely  relatives  of  Sphenomorphus  trans- 
versus. Current  work  on  scale  and  palatal  characters,  however, 
indicates  that  while  fiavipes,  prehensicauda  and  semoni  are  them- 
selves closely  related  (in  spite  of  current  generic  allocations),  they 
are  only  distantly  related  to  SphenomorpJius  transversus. 

ACKNOWLEDGEMENTS 

Dr.  Ernest  E.  WiUiams  of  the  Museum  of  Comparative  Zoology 
read  the  manuscript  in  several  drafts  and  offered  several  helpful 
suggestions.  Mr.  Laszlo  Meszoly  did  the  drawings  for  Figures  2 
and  3,  and  Mr.  Tan  T.  Riddell  took  the  photographs  for  Figures 


1971  A    NEW    SOLOMON    ISLANDS    SKINK  7 

4  and  5.  Part  of  Greer's  work  on  this  paper  was  done  while  he 
was  a  postdoctoral  fellow  of  the  National  Science  Foundation. 
Partial  support  was  provided  by  National  Science  Foundation 
grant  GB  6944  to  Ernest  E.  Williams. 

LITERATURE   CITED 

Brongersma,  L.  D.  1942.  On  the  arrangement  of  the  scales  on  the 
dorsal  surface  of  the  digits  in  Lygosoma  and  allied  genera.  Zoologische 
Mededeelingen.  24  (1-2):   153-158. 


BREVIORA 


No.   364 


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BREVIORA 


No.  364 


Figure  4.  Dorsal  view  of  the  holotype  of  Splicnomorphiis  transvcrsus 
(MCZ  76485)  showing  the  dark  transverse  bands  which  give  the  species 
its  name. 


1971 


A    NEW    SOLOMON    ISLANDS    SKINK 


11 


Figure  5.     Lateral  view  of  Sphenomorphiis  transversiis   (holotype). 


BREVIORA 

Me  seem   of   Comparative    Zoology 

Cambridge,  Mass.        15    January,  1971  Number  365 


CHARACTERS  AND  SYNONYMIES  AMONG  THE  GENERA 

OF  ANTS.    PART  IV.    SOME  GENERA  OF  SUBFAMILY 

MYRMICINAE  (HYMENOPTERA:  FORMICIDAE) 

William  L.  Brown,  Jr.^ 

Abstract.  Archaeomyrmex  is  a  new  junior  synonym  of  Myrmecina, 
and  tribe  Archaeomyrmicini  accordingly  is  a  synonym  of  Myrmecinini. 
Dodoiis  is  a  new  junior  synonym  of  Pristomyrmex,  and  the  synonymy  of 
Hylidris  under  Pristomyrmex  is  reaffirmed.  Limnomyrmex  is  a  new  junior 
synonym  of  Leptothorax  subgenus  Nesomyrmex. 

The  genera  considered  in  this  part  all  belong  to  subfamily  Myr- 
micinae.  My  main  purpose  here  is  to  explain  briefly  why  some 
new  synonymy  should  be  proposed.  The  taxa  concerned  have  all 
been  studied  during  the  course  of  the  project  "a  reclassification  of 
the  Formicidae,"  supported  by  National  Science  Foundation  Grants 
G-23680,  GB-2175,  and  GB-5574.  The  taxonomic  conclusions 
will  eventually  be  embodied  in  a  synopsis  and  illustrated  keys  to 
the  ant  genera  of  the  world.  I  feel  that  justification  for  revisionary 
changes  should  be  published  as  the  need  for  the  changes  becomes 
clear.  In  this  way,  important  findings  of  the  study  are  made  avail- 
able for  use  by  all  ant  taxonomists  without  undue  delay,  and  the 
synoptic  parts  can  be  freed  from  the  clutter  of  many  detailed 
taxonomic  arguments. 

Myrmecina 

Myrmecina  Curtis,  1829,  Brit.  Entom.  6:  226,  pi.  265,  male.  Type 
species  by  original  designation  Myrmecina  latreillii  :=  Formica  graminicola. 

Arclweomyrmex  Mann,  1921:  448-451.  Type  species:  Archaeomyrmex 
cacabau,  by  original  designation.    NEW  SYNONYMY. 

1  Department  of  Entomolo{!;y,  Cornell  l'ni\  ersity,  Ithaca,  New  York,  14850. 


2  BREVIORA  No.    365 

The  unique  type  of  A.  cacabau  has  been  searched  for  in  vain  in 
the  U.  S.  National  Museum  and  Museum  of  Comparative  Zoology 
ant  collections,  and  must  be  considered  lost.  Fortunately,  Mann's 
description  and  figures  are  reasonably  detailed.  From  them,  it  is 
clear  that  the  species  is  essentially  a  Myrmecina,  a  fact  acknowl- 
edged by  Mann  when  he  wrote:  "The  epinotal  and  petiolar  struc- 
ture are  not  unlike  certain  species  of  Myrmecina."  Mann  empha- 
sized the  ventrolateral  carina  on  each  side  of  the  head,  probably 
without  realizing  that  this  is  an  invariable  character  of  Myrmecina. 
He  also  cited  the  partly  smooth,  partly  costate  sculpture  of  the 
body,  especially  the  trunk,  which  does  set  this  species  off  from  the 
"average"  Myrmecina.  But  Myrmecina  forms  with  more  or  less  of 
the  head  and  trunk  smooth  have  not  been  completely  unknown, 
and  they  even  occur  as  phenetic  variants  in  species  that  are  usually 
heavily  sculptured  in  these  regions. 

Several  Myrmecina  species  (at  least  three  of  them  still  unde- 
scribed)  with  predominantly  smooth  and  shining  head  and  trunk 
are  in  the  MCZ  collection.  Two  of  the  undescribed  species  are 
from  the  New  Hebrides;  in  each  of  these,  the  posterior  pair  of 
propodeal  teeth  is  spiniform,  but  the  coarse  costate  sculpture  of 
the  lower  pleural  areas  is  preserved,  as  it  is  in  cacabau.  Another 
smooth  species  has  come  to  me  from  the  Philippines.  The  geo- 
graphical and  morphological  gaps  are  thus  closed  between  the 
Fijian  and  Indo-Australian  representatives  of  what  is  obviously  a 
single  stock.  A  complete  examination  of  the  A.  cacabau  descrip- 
tion fails  to  reveal  any  character  that  will  separate  it  from  Myrme- 
cina at  generic  level.  Together  with  the  two  New  Hebrides  species, 
cacabau  should  be  taken  to  represent  no  more  than  a  weak  species- 
group  of  Myrmecina. 

Incidentally,  an  interesting  characteristic  of  some  of  these  species 
is  the  extreme  reduction  of  antennomere  III,  just  distal  to  the 
pedicel.  The  distinction  between  "  1 1 -segmented"  and  "12-seg- 
mented"  antennae  in  these  forms  may  prove  impossible  to  maintain 
as  a  key  character. 

Mann's  tribe  Archaeomyrmecini  of  course  falls  as  a  new 
synonym  of  Myrmecinini. 

Pristomyrmex 

Pristomyrmex  Mayr,  1866:  903.  Type  species:  Pristomyrmex  piingens, 
monobasic. 


1971  SOME    GENERA    OF    MYRMICINE    ANTS  3 

Hylidris  Weber,  1941:  190.  Type  species:  Hylidris  myersi,  by  original 
designation.  —  1952:   15-22.    Synonymized  by  Brown,  1953:  9-10. 

Dodous  Donisthorpe,  1946:  145;  worker,  male,  larva.  Type  species: 
Dodous  trispinosus,  by  original  designation.    NEW  SYNONYMY. 

Dodous  was  based  on  the  single  species  trispinosus,  from  Cocotte 
Mountain,  Mauritius.  Syntypes  of  this  species  deposited  in  the 
British  Museum  and  in  the  Museum  of  Comparative  Zoology  are 
basically  Pristomyrmex  in  form,  but  they  have  an  extra  pair  of 
small  teeth  on  the  mesonotum,  and  the  head  and  trunk  are  finely 
and  regularly  costulate  (=  striate).  The  larva,  rather  vaguely 
figured  in  the  original  description  (fig.  4),  has  the  elongate,  pro- 
tuberant head  characteristic  of  Myrmecina  and  Pristomyrmex. 
Donisthorpe  also  figured  the  male,  which  is  like  known  Pristomyr- 
mex males  in  general  habitus.  The  genitalia  as  very  briefly  de- 
scribed may  be  aberrant,  but  then  the  genitalia  have  not  been 
studied  at  all  in  most  other  Pristomyrmex  species. 

A  second  species  of  Dodous,  D.  bispinosus,  was  described  from 
Mauritius  by  Donisthorp)e  in  1949.  I  collected  a  small  sample  of 
strays  of  this  species  at  the  type  locality,  Le  Pouce  (Mountain)  on 
1  April  1969,  the  last  day  of  a  short  stay  on  Mauritius.  The  speci- 
mens were  all  foraging  workers  taken  on  trees  and  on  the  main 
path  through  the  scrubby  native  forest  at  about  800  m  elevation 
on  the  "plateau^'  near  the  summit.  (A  sudden  storm  prevented  my 
finding  any  nests.)  D.  bispinosus  differs  from  D.  trispinosus  in 
lacking  the  mesonotal  teeth  (though  actually  some  of  my  bispinosus 
specimens  have  low  mesonotal  tubercles  in  place  of  the  teeth)  and 
in  having  predominantly  smooth  and  shining  sculpture.  In  fact, 
D.  bispinosus  is  a  rather  ordinary,  if  slightly  long-legged,  Pristo- 
myrmex, and  D.  trispinosus  goes  only  one  step  beyond.  It  seems 
absurd  to  put  these  two  closely  related  species  in  different  genera. 
Discovery  of  the  annectant  D.  bispinosus  makes  it  clear  to  me  that 
Dodous  is  only  the  Mauritian  complement  of  the  widespread  Old 
World  genus  Pristomyrmex.  The  concept  of  Dodous  as  a  separate 
genus  is,  as  far  as  1  am  concerned,  as  dead  as  its  namesake. 

I  have  already  (Brown,  loc.  cit.)  placed  Weber's  Hylidris  as  a 
synonym  of  Pristomyrmex.  Weber  opposed  this  synonymy,  main- 
taining that  Hylidris  is  a  distinct  genus.  But  when  he  described 
Hylidris,  Weber  took  no  note  of  the  African  species  of  Pristomyrmex 
described  previously  by  Santschi,  Arnold,  and  Karavaiev,  at  least 
some  of  which  are  senior  synonyms  of  his  own  Hylidris  species  and 


4  BREVIORA  No.    365 

subspecies  (Weber,  1952).  Weber  has  never  produced  a  charac- 
terization of  Hylidris  that  will  separate  it  as  a  genus  from  Pristo- 
myrmex,  and  particularly  from  the  long-synonymized  "subgenus" 
Odontomyrmex.  \  have  collected  P.  orbiceps  in  the  Ivory  Coast, 
and  can  affirm  that  colony  behavior  (lethisimulation),  larval  form, 
and  general  adult  morphology  are  fully  those  of  Asian  and  Aus- 
tralian Pristomyrmex  as  I  have  seen  them  in  nature. 

Pristomyrmex  is  a  sharply  defined  and  compact  genus,  and  there 
is  no  reason  that  I  know  of  to  set  the  African  species  apart  from  it. 
In  fact,  the  African  species  are  as  nearly  "average"  for  the  genus 
Pristomyrmex  as  one  is  likely  to  find. 

Some  other  misconceptions  expUcit  or  implied  in  Weber's  dis- 
cussion of  1952  need  correction.  The  petiole  of  Pristomyrmex  has 
a  distinct  anterior  peduncle,  though  it  is  short  in  some  species.  In 
contrast,  the  related  genus  Myrmecina  has  a  sessile  petiole  of  more 
or  less  prismatic  shape.  Pristomyrmex  and  Myrmecina  are  not 
very  closely  related  to  tribe  Tetramoriini,  though  two  species  have 
been  wrongly  placed  in  tetramoriine  genera  in  the  past.  The  larvae, 
for  one  thing,  are  very  different,  and  it  seems  that  they  may  furnish 
the  best  tribal  character  for  the  Myrmecinini  if  we  limit  the  tribe 
to  Pristomyrmex,  Myrmecina,  Acanthomyrmex,  and  possibly  the 
little-known  Perissomyrmex  of  Guatemala,  the  larvae  of  which  have 
not  yet  been  found.  Tribe  Tetramoriini  is  not  "worldwide"  in  dis- 
tribution, if  one  ignores  obvious  introductions  by  man.  The  tribe 
has  no  native  species  in  South  or  Central  America,  and  only  a  single 
species  of  Xiphomyrmex  occurs  in  (Sonoran)  North  America. 

Leptothorax  subgenus  Nesomyrmex 

Nesomyrmex  Wheeler,  1910,  Bull.  Amer.  Mus.  Nat.  Hist.,  28:  259. 
Type  species  Nesomyrmex  clavipilis,  monobasic. 

Leptothorax  (Goniothorax)  aiict.,  preoccupied. 

Leptothorax  (Caulomyrma)  Forel,  1914,  Bull.  Soc.  Vaudoise  Sci.  Nat., 
50:  233. 

Limnomyrmex  Arnold,  1948,  Occas.  Pap.  Nat.  Mus.  S.  Rhodesia,  2(14): 
222. —  1952,  Ibid.,  2(17):  460,  discussion.  Type  species  Limiioiuyrmex 
stramineiis,  monobasic.    NEW  SYNONYMY. 

Soon  after  its  description,  the  late  Dr.  Arnold  and  I  engaged  in 
correspondence  on  the  question  of  the  distinctness  of  Limnomyr- 
mex from  the  subgenus  Nesomyrmex  of  Leptothorax.  He  stoutly 
maintained  that  Limnomyrmex  was  a  good  genus,  and  in  1952  {loc. 
cit.)  he  argued  again  in  print  for  this  stand.  Now  that  I  have  finally 


1971  SOME    GENERA    OF    MYRMICINE    ANTS  5 

seen  the  unique  worker  type  of  L.  stramineiis  in  the  Arnold  Collec- 
tion at  Bulawayo,  I  can  only  place  this  species  among  the  other 
known  African  Nesomyrmex.  I  have  searched  in  vain  for  any 
characters  that  might  set  Limuomyrmex  apart  as  a  genus.  In  the 
form  of  the  trunk  and  both  petiolar  and  postpetiolar  nodes,  it  is 
about  "average"  for  a  Nesomyrmex  from  Africa,  and  resembles  in 
a  subdued  way  some  neotropical  members  of  the  group.  Sculptural 
and  a  few  other  differences  mark  stramineus ,  but  these  do  not  seem 
to  be  more  than  species  characters.  The  antennae  of  stramineus 
are  12-segmented;  Nesomyrmex  can  have  either  11  or  12  segments. 
The  status  of  Nesomyrmex  as  a  subgenus  of  Leptothorax  is  main- 
tained for  the  time  being,  pending  the  proper  study  of  both  taxa. 

REFERENCES 

Brown,  W.  L..  Jr.    1953.    Characters  and  synonymies  among  the  genera 

of  ants.    Parti.    Breviora  No.   11:    1-13. 
DoNisTHORPE,  H.  St.  J.  K.     1946.     A  new  genus  and  species  of  Formicidae 

(Hym.)    from  Mauritius.    Proc.   Roy.   Entomol.  Soc.   London,  ser.  B, 

15:   145-147. 
Mann,   W.   M.     1921.     The  ants  of  the   Fiji   Islands.    Bull.  Mus.  Comp. 

Zool.,  64:  401-499. 
Mayr,    G.      1866.     Diagnosen    neuer    und    wenig    gekannter    Formiciden. 

Verhandl.  Zool.-bot.  Ges.  Wien,  16:  885-908,  pi.  20. 
Weber,   N.   A.     1941.     Four  new  genera   of  Ethiopian   and   Neotropical 

Formicidae.   Ann.  Entomol.  Soc.  Amer.,  34:   183-194. 
.     1952.     Studies    on    African    Myrmicinae,    I    (Hymenoptera, 

Formicidae).  Amer.  Mus.  Novitates  1548:   1-32. 


JBREVIORA 

Mmseuinni    of    Comparsitive    Zoology 

Cambridge.  Mass.  15  January,  1971  Number  366 


PULSED    SOUNDS    OF  THE  PORPOISE 
LAGENORHYNCHUS  AUSTRALIS 

William  E.  Schevil!  and  William  A.  Watkins^ 


Abstract.  Pulsed  sounds  of  the  porpoise  Lagenorhynchns  aiistmlis  of 
southern  Chile  were  recorded  and  analyzed.  Most  were  low-frequency 
clicks;  some  had  a  2-kHz  bandwidth  centered  near  1  kHz,  and  others  had 
a  10-  or  12-kHz  bandwidth  with  the  principal  frequency  in  the  lower  5  kHz. 
These  porpoises  also  produced  a  rapidly  pulsed  tonal  sound.  All  these 
sounds  were  very  low-level  and  rarely  audible  at  a  distance  as  great  as  20  m. 
We  heard  none  of  the  whistlelike  squeals  characteristic  of  many  delphinids. 

From  12  November  to  II  December  1968  the  research  ship 
HERO  of  the  National  Science  Foundation  (Antarctic  Research 
Program)  cruised  between  Valparaiso  and  Cape  Horn,  searching 
for  cetaceans  and  pinnipeds,  mostly  in  the  sheltered  inland  water- 
ways of  southern  Chile.  We  were  concerned  with  listening  for  and 
recording  the  underwater  sounds  of  these  animals. 

The  species  most  frequently  seen  and  collected  was  Lcigeno- 
rhynchus  australis  (Peale,  1848  ),  which  has  been  reported  from  the 
west  coast  of  Chile  south  of  about  S  Lat.  40°  around  Cape  Horn 
to  the  Falkland  Islands.  We  heard  them  much  less  often  than  we 
saw  them. 

Methods.  The  recordings  that  are  analyzed  here  were  made  on 
23  November  in  Canal  Messier  (at  48°  10'  S)  and  1,  3,  5,  and  6 
December  west  and  south  of  Navarino  Island  behind  Cape  Horn. 
An  Atlantic  Research  LC-34  hydrophone  was  used  to  pick  up  the 
sounds.  An  impedance-matching  pre-amplifier  (WHOI)  was  in- 
serted in  the  cable  30  cm  from  the  hydrophone.   Two  cable  lengths 


1  Contribution  No.  2562  from  the  Woods  Hole  Oceanographic  Institution. 


2  BREVIORA  No.    366 

were  used,  125  m  from  R/V  HERO  and  30  m  from  HERO's  whale- 
boat.  The  hydrophone  depth  varied  with  local  conditions  and  ex- 
periments, from  2  m  to  nearly  125  m;  it  was  usually  suspended  6-8 
m  from  a  surface  float  (a  rubber  balloon)  and  allowed  to  drift  as 
far  from  ship  or  boat  as  cable-length  permitted. 

Tape  recordings  were  made  with  either  a  modified  Uher  4400 
recorder  or  a  WHOI-built  springwound  recorder,  using  a  hydro- 
phone amplifier  (Watkins,  1963).  When  the  Uher  was  in  use,  the 
system-response  was  limited  to  a  bandwidth,  within  4  db,  of  40  to 
20,000  Hz;  with  the  WHOI  machine,  system-response  was  20  to 
32,000  Hz  (within  Vz  db  from  30  to  30,000  Hz).  Playback  for 
analysis  was  on  Crown  800  tape  recorders.  Spectrographic  analy- 
ses were  made  on  a  Kay  Electric  model  7029A  analyzer  and  ampli- 
tude analyses  on  a  Tektronix  5 35 A  oscilloscope. 

The  porpoises  were  approached  as  closely  and  as  unobtrusively 
as  possible,  but  even  so,  often  the  only  sounds  heard  from  the  ani- 
mals were  within  the  first  5  seconds  of  the  listening  attempts.  Un- 
fortunately, because  of  the  disturbance  of  the  water  by  arrival  of 
the  boat  and  the  motion  of  the  hydrophone,  a  longer  time  than 
this  usually  was  required  before  local  ambient  noise  could  settle 
down  enough  for  faint  sounds  to  be  recorded.  Usually  nothing  was 
heard  from  the  porpoises,  partly  because  they  were  generally  taci- 
turn and  seemed  to  produce  sounds  only  occasionally,  and  partly 
because  their  sounds  were  too  faint  to  be  audible  except  on  close 
approach,  within  a  few  meters  of  the  animals.  They  appeared  to 
be  silent  when  disturbed. 

Sounds.  The  sounds  heard  from  Lagenorhynchus  aiistralis  were 
all  pulsed.  Mostly  they  were  clicks  produced  in  short  series  or  slow 
bursts,  but  sometimes  a  rapidly  pulsed  sound  (a  buzz)  that  had  a 
tonal  quality  was  heard.  The  buzz  was  the  only  sound  heard  from 
L.  australis  at  any  distance,  and  it  was  produced  only  occasionally; 
consequently  most  attempts  to  listen  to  these  porpoises  were  entirely 
unsuccessful.  No  squeals  (whistles)  were  heard;  this  was  unex- 
pected since  we  have  heard  squeals  from  other  Lagenorhynchus 
(L.  albirostris,  acutus,  obliquidens,  and  the  obscurus  of  New 
Zealand). 

These  sounds  of  L.  australis  were  low  level  and  generally  in- 
audible beyond  about  10-20  m.  We  estimate  that  the  loudest 
chcks  were  no  more  than  -20  db  re  1  dyne/cm-  at  1  m,  from 
known  hydrophone  sensitivities   and   tape   saturation  levels,   and 


1971  PORPOISE    SOUNDS  3 

assumed  supply  voltages  and  amplifier  gains.  On  only  a  few  occa- 
sions were  we  convinced  that  we  knew  which  individual  produced 
the  sounds  that  we  heard,  and  therefore  our  estimates  of  signal 
strength  and  of  distance  from  the  hydrophone  are  but  guesses. 

The  click-sounds  were  of  two  types:  a  broadband  click,  and  a 
relatively  restricted-bandwidth  click  (narrowband)  at  predomi- 
nantly low  frequencies.  These  two  clicks  never  seemed  to  be 
mixed.  Both  types  were  heard,  we  thought,  from  any  one  individ- 
ual, with  no  obvious  separation  between  the  different  kinds  of 
clicks,  and  no  gradual  transition.  Though  both  types  of  clicks 
were  sometimes  heard  at  slow  rates  (1  or  2  per  sec),  the  broad- 
band click  was  usually  produced  at  a  more  rapid  repetition-rate 
(20  to  80  per  sec.)  than  the  narrowband  click  (5  to  25  per  sec.). 
The  broadband  click  was  shorter  and  had  less  energy  at  low  fre- 
quencies than  the  narrowband  click.  See  the  table  for  a  comparison 
of  these  two  clicks. 

The  broadband  click  (Figs.  lA  and  2)  was  characterized  by  a 
sharp  onset,  a  short  duration,  as  well  as  a  more  or  less  continuous 
spectrum  to  10  or  12  kHz,  occasionally  to  16  kHz.  Analyses  of 
clicks  showed  a  general  drop  in  intensity  of  1  to  2  db  per  1000  Hz 
above  5  or  6  kHz.  This  drop  was  greater  than  is  consistent  with 
normal  frequency-selective  absorption  for  these  distances  and  fre- 
quencies, so  we  assume  that  this  attenuation  is  characteristic  of  the 
click  of  L.  australis.  The  duration  of  the  broadband  click  was 
consistently  a  little  less  than  1  msec.  Because  of  the  general  low 
level  of  the  sounds  as  well  as  their  usual  reduction  in  intensity  at 
higher  frequencies,  the  clicks  were  easily  masked  by  background 
ambient. 

The  narrowband  click  (Figs.  IB  and  2)  was  restricted  in  fre- 
quency to  the  lower  2000  Hz  and  appeared  to  have  its  greatest  in- 
tensity at  or  below  1000  Hz.  Harmonics  did  exist,  though  at  greatly 
reduced  levels.  Analysis  at  high  gain  (but  still  undistorted)  showed 
some  of  the  narrowband  clicks  with  harmonic  frequencies  to  5  or 
6  kHz.  The  narrowband  click,  with  a  duration  of  1.5  to  3  msec, 
usually  occurred  at  slower  repetition-rates  (5  to  25  per  sec),  and 
consistently  had  higher  intensity  at  low  frequencies  than  the  broad- 
band click.  Perhaps  because  of  its  lower-frequency  emphasis  and 
therefore  better  transmission  characteristics,  the  narrowband  click 
was  the  one  most  commonly  heard. 

The  third  type  of  sound,  the  buzz  (Fig.  3)  was  heard  on  a  few 


4  BREVIORA  No.    366 

occasions.  This  buzz  had  emphasis  at  discrete  higher  frequencies, 
such  that  both  the  fundamental  and  high  frequency  overtones  were 
predominant  in  the  aural  impression  of  the  sound.  The  buzzes 
varied  in  duration  from  0.6  to  1.1  sec.  They  were  composed  of  a 
pulsed  fundamental  near  300  Hz  (Fig.  4)  and  strong  overtones  at 
4  to  5  kHz.  Two  or  three  sidebands  of  the  pulse  repetition-rate 
(modulation.  Fig.  IC)  may  be  noted  grouped  around  the  4-  to 
5-kHz  overtone  in  spectral  analysis  (Fig.  3)  of  these  buzzes  (see 
Watkins,  1967).  The  fundamental  frequency  of  the  buzz  was  more 
intense  than  the  overtones,  yet  at  greater  distances  only  the  4-  to 
5-kHz  tone  (with  its  associated  sideband  structure)  was  audible. 
This  was  probably  because  of  higher  background  ambient  at  the 
lower  frequencies.  The  buzz  appeared  to  be  produced  at  a  higher 
level  than  the  clicks. 

Discussion.  Because  of  both  the  pulsed  quality  of  the  buzz  and 
its  restricted  frequency,  we  suppose  that  this  sound  was  formed  by 
rapidly  repeated  narrowband  clicks.  Singly,  the  narrowband  clicks 
had  few  higher  frequency  components,  but  in  a  rapid  series  the 
overtones  were  prominent.  This  is  somewhat  similar  to  sounds  pro- 
duced by  Phocoena  phocoena,  composed  of  a  rapid  repetition  of 
narrowband  clicks  to  form  a  continuous  sound  with  selected  higher 
frequency  emphases  (Schevill,  Watkins,  and  Ray,  1969).  We  did 
not  find  the  variation  in  the  overtones  of  the  buzz  of  L.  australis 
that  we  noted  for  Phocoena,  but  this  may  have  been  due  to  the 
limited  number  of  the  former's  buzz  sounds  that  were  recorded  well 
enough  for  such  detailed  analysis. 

Perhaps  the  buzz  was  used  in  communication  and  it  may  have 
been  associated  with  stress.  This  could  explain  its  relatively  infre- 
quent occurrence.  The  only  time  that  the  buzz  was  heard  when 
we  thought  we  knew  which  porpoises  were  producing  it  (in  Paso 
Micalvi  outside  of  Seno  Grandi,  Navarino  Island,  6  December),  a 
group  of  three  animals  15  to  20  m  distant  suddenly  seemed  to  be 
in  a  scuffle,  darting  at  and  away  from  each  other.  This  sudden  un- 
usual activity  coincided  with  the  production  of  four  buzzes,  two  of 
them  concurrently  (Figs.  3  and  4),  and  so  we  assume  that  these 
sounds  were  produced  by  these  porpoises. 

We  have  no  evidence  that  Lagenorhynchus  australis  echolocates. 
If  the  click  sounds  were  used  for  echolocation  as  in  some  other 
species  ( Tursiops  truncatus,  Steno  bredanensis,  Orcinus  orca, 
Phocoena  phocoena) ,  it  must  have  been  at  relatively  close  ranges 


1971  PORPOISE    SOUNDS  5 

because  of  the  low  level  of  the  clicks.  We  did  not  hear  any  "ac- 
celerando" in  click  series  such  as  is  typical  of  echolocation  runs 
during  feeding  by  these  other  animals;  however,  we  had  no  sugges- 
tion that  the  L.  aiistralis  were  feeding  when  the  clicks  were  heard. 
In  fact,  the  clicks  were  not  consistently  associated  with  apparently 
investigatory  behavior  by  the  animals.  Porpoises  sometimes  passed 
within  a  meter  of  the  hydrophone  and  even  appeared  to  return  and 
examine  it  without  our  detecting  any  sounds.  On  the  other  hand, 
clicks  were  never  heard  unless  a  porpoise  was  close  by. 

The  two  click-types  perhaps  are  equivalent  to  the  two  basic 
click-categories  noted  for  Tursiops  by  Norris,  Evans,  and  Turner 
(1967).  They  name  these  clicks  by  their  function,  ''discrimination 
clicks"  and  "orientation  clicks."  The  discrimination  click  of  Tur- 
siops has  a  reduced  bandwidth  and  emphasis  of  lower  frequencies, 
while  the  orientation  click  has  a  wide  bandwidth.  In  these  respects 
they  match  the  sounds  heard  from  L.  australis,  though  no  be- 
havioral correlation  was  possible. 

Although  two  types  of  clicks  were  heard,  one  with  a  relatively 
restricted  low  frequency  and  other  with  broadband  characteristics, 
it  suggests  the  possibility  that  only  one  click  type  exists  in  reality 
and  the  variations  noted  result  from  changing  orientation  by  an 
animal  possessing  a  directional  sound  system.  Other  cetaceans  have 
been  shown  to  have  such  a  directional  sound  field  ( Tursiops,  Nor- 
ris, Prescott,  Asa-Dorian,  and  Perkins,  1961;  Orcinus,  Schevill  and 
Watkins,  1966;  Steno,  Norris  and  Evans,  1967;  and,  Platanista, 
Evans  in  Herald  et  al.,  1969).  Our  data  is  insufficient  to  rule  out 
this  possibility  completely,  but  the  evidence  that  we  have  seems  to 
argue  instead  for  two  distinct  click  types: 

1 .  The  click  durations  of  the  two  types  are  different.  High  fre- 
quency emphasis  in  a  low  frequency  click  would  not  shorten  the 
length  of  the  pulse  but  would  simply  extend  the  bandwidth. 

2.  The  two  click-types  suddenly  interchange  with  no  pause  be- 
tween. We  have  no  examples  of  a  gradual  shift  from  one  type 
to  the  other  and  we  have  very  few  individual  clicks  whose  char- 
acteristics are  intermediate  in  form.  Some  of  the  subtle  varia- 
tions observed  in  the  higher  frequency  components  of  successive 
clicks  of  both  types,  however,  may  result  from  such  direction- 
ality, though  we  did  not  have  opportunity  to  observe  any  cor- 
relation of  orientation  with  bandwith. 


6  BREVIORA  No.    366 

Because  of  the  difficulties  we  encountered  in  hearing  the  por- 
poises, we  were  impressed  with  the  low  level  of  their  sounds.  We 
also  were  acutely  aware  that  it  was  not  high  background  that 
obscured  their  sounds,  since  the  ambient  noise  levels  in  this  region 
were  actually  very  low.  Without  carefully  and  recently  calibrated 
equipment,  such  low  sound-levels  are  difficult  (and  probably  mean- 
ingless) to  assess;  however,  our  limitation  much  of  the  time  ap- 
peared to  be  the  self-noise  of  the  equipment  rather  than  the  local 
ambient  background.  Perhaps  the  land  barriers  shielded  the  inland 
channels  from  the  usual  open  sea  sounds  and  at  the  same  time 
provided  enough  shelter  so  that  very  little  local  wind  and  wave 
noise  was  generated.  In  addition,  we  recognized  very  little  contri- 
bution of  sound  from  other  biological  sources,  and  certainly  these 
porpoises  had  but  small  influence  on  the  local  ambient  sound. 

ACKNOWLEDGEMENTS 

We  thank  the  Antarctic  Research  Program  of  the  National 
Science  Foundation  for  support  and  good  help  during  the  cruise 
on  board  R/V  HERO.  The  acoustic  analysis  and  preparation  of 
this  report  were  supported  by  the  Office  of  Naval  Research  (Biol- 
ogy branch)  under  contract  Nonr  4446  and  Nonr  241.09,  and  by 
the  National  Science  Foundation  grant  GA  1475.  Experience  and 
observation  were  shared  with  the  other  members  of  the  scientific 
party  aboard  HERO;  Kenneth  S.  Norris  as  chief  scientist  and 
George  Harvey  were  particularly  involved  and  helpful.  We  thank 
Elizabeth  T.  Bunce  and  Paul  T.  McElroy  for  criticism  of  the  manu- 
script. 

LITERATURE    CITED 

Herald,  E.  S.,  R.  L.  Brownell,  Jr.,  F.  L.  Frye,  E.  J.  Morris,  W.  E.  Evans, 
AND  A.  B.  Scott.  1969.  Blind  river  dolphin:  first  side-swimming  ceta- 
cean.   Science.   166   (3911):    1408-1410. 

NoRRis,  K.  S.,  AND  W.  E.  Evans.  1967.  Directionality  of  echolocation  clicks 
in  the  rough-tooth  porpoise,  Steno  hredanensis  (Lesson).  In  W.  N. 
Tavolga  (ed.),  Marine  Bio-Acoustics,  vol.  2.  Oxford,  Pergamon  Press. 
Pp.  305-314. 

Norris,  K.  S.,  W.  E.  Evans,  and  R.  N.  Turner.  1967.  Echolocation  in  an 
Atlantic  bottlenose  porpoise  during  discrimination.  //;  R.-G.  Busnel 
(ed.),  Les  Systemes  Sonars  Animaux,  Biologic  et  Bionique,  Jouy-en- 
Josas,  France.   Pp.  409-437. 


1971  PORPOISE    SOUNDS  7 

NoRRis,  K.  S..  J.  H.  Prescott,  P.  V.  Asa-Dorian,  and  P.  Perkins.  1961. 
An  experimental  demonstration  of  echo-location  behavior  in  the  por- 
poise, Tursiops  truncatus  (Montagu).  Biological  Bull..  120  (2): 
163-176. 

SCHEVILL,  W.  E.,  AND  W.  A.  Watkins.  1966.  Sound  structure  and  direc- 
tionality in  Orciniis  (killer  whale).    Zoologica  (N.  Y.),  51  (2):  71-76. 

ScHEViLL,  W.  E.,  W.  A.  Watkins,  and  C.  Ray.  1969.  Click  structure  in  the 
porpoise    Phococna    phocncna.   Jour.    Mammalogy.    50    (4):    721-728. 

Watkins,  W.  A.  1963.  Portable  underwater  recording  system.  Undersea 
Technology,  4  (9):  23-24. 

Watkins,  W.  A.  1967.  The  harmonic  interval:  fact  or  artifact  in  spectral 
analysis  of  pulse  trains.  In  W.  N.  Tavolga  (ed.).  Marine  Bio- Acoustics, 
vol.  2.    Oxford.  Pergamon  Press.    Pp.   15-42. 


BREVIORA 


No.   366 


B 


/  msec/div. 

Figure  1.  Oscillographic  pictures  of  (A)  the  broadband  click,  (B)  the 
narrowband  click,  and  (C)  the  pulse  modulation  of  the  buzz.  Ambient 
noise  is  superimposed  on  these  sound  traces. 


1971 


PORPOISE    SOUNDS 


8000- 


Hz 


4000- 


I 
0 


'1 


05 


Seconds 


Figure  2.  Spectrographic  analysis  shows  a  burst  of  broadband  clicks 
followed  by  narrowband  clicks.  Although  the  latter  become  much  greater 
in  amplitude  as  the  animal  conies  closer,  the  frequency  spectrum  remains 
relatively  restricted.  The  bandwidth  of  the  analyzing  filter  is  300  Hz.  This 
figure  is  the  result  of  a  repetitive  analysis,  with  a  small  horizontal  displace- 
ment of  the  paper  between  analyses  to  widen  artificially  the  traces  of  these 
short-duration  sounds  for  better  photographic  reproduction. 


Narrowband  click 


Broadband  click 


Bandwidth 

Principal  frequency 

Duration 

Repetition  rate 

Intensity  (re  1  dyne/cm2) 


2  kHz 

1  kHz  or  less 

1.5  to  3  msec 

5  to  25 /sec 

—  20  db  at  principal 
frequency 


10  or  12  kHz 

from  less  than  1  to  5  kHz 

0.8  to  1  msec 

20  to  80/sec 

— 20db  spread  over 
bandwidth 


Table  of  characteristics  of  the  two  types  of  click 
heard  from  Lagenorhynchiis  australis. 


10 


BREVIORA 


No.  366 


7000- 


5000- 


Hz 


2000- 


Seconds 


tw 


i  \ 


^ai 


1.5 


Figure  3.  Two  simultaneous  buzzes  have  empiiasis  in  the  4-  to  5-kHz 
region  as  well  as  a  strong  fundamental  at  about  300  Hz.  The  analyzing 
filter  bandwidth  is  300  Hz.    Compare  Fig.  4. 


1000- 


Hz 


500- 


■       '         '  Seconds 

Figure  4.  The  fundamental  frequencies  of  the  same  two  buzzes  shown 
in  Fig.  3  show  variation  in  the  region  of  300  Hz.  The  continuous  low  fre- 
quency band  is  ship's  propulsion  noise  from  the  HERO  about  5  or  6  miles 
away.  The  analyzing  filter  bandwidth  is  45  Hz. 


BREVIORA 

Mniseeim   of   Cojniiparative   Zoology 

Cambridge,  Mass.  15  January,  1971  Number  367 

MICROMISCHODUS  SUGILLATUS,  A  NEW  HEMIODONTID 

CHARACIN   FISH    FROM    BRAZIL,    AND   ITS   RELATIONSHIP 

TO  THE  CHILODONTIDAE 

Tyson  R.  Roberts 


Abstract.  A  new  genus  and  species  of  Hemiodontidae,  designated  as 
a  new  subfamily,  Micromischodontinae,  is  described  from  the  lower  Rio 
Negro  and  Middle  Amazon  of  Brazil.  Its  osteology  is  described  and 
figured.  It  appears  to  be  the  hemiodontid  genus  most  closely  related  to 
Chilodontidae.  The  relationship  between  the  functional  and  replacement 
teeth  of  the  pharyngeals  suggests  the  probable  manner  in  which  the  peculiar 
pharyngeal  teeth  characteristic  of  Chilodontidae  and  Anostomidae  evolved. 
A  brief  definition  is  given  of  the  family  Chilodontidae. 

ACKNOWLEDGEMENTS 

Dr.  Stanley  H.  Weitzman,  Division  of  Fishes,  U.S.  National 
Museum,  suspected  hemiodontids  and  chilodontids  might  be  re- 
lated and  mentioned  this  to  me  two  or  three  years  ago.  He  is  now 
working  on  the  relationships  of  these  families  and  has  graciously 
let  me  examine  unpublished  illustrations  of  chilodontid  osteology. 
I  am  indebted  to  Sr.  Heraldo  Britski,  curator  of  the  fish  collections 
of  the  Museu  de  Zoologia,  Universidade  de  Sao  Paulo,  and  leader 
of  the  Expediyao  Permanente  da  Amazonia  when  the  new  fish  was 
collected,  for  permitting  me  to  prepare  its  description.  Professor 
George  S.  Myers,  Division  of  Systematic  Biology,  Stanford  Uni- 
versity.  Dr.  Weitzman  and  Sr.  Britski  reviewed  the  manuscript. 


2  BREVIORA  No.    367 

INTRODUCTION 

The  hemiodontid  herein  described,  collected  by  the  Expedi^ao 
Permanente  da  Amazonia'  in  1967,  represents  a  new  subfamily. 
While  lacking  certain  morphological  peculiarities  of  the  highly 
specialized  Chilodontidae,  it  nevertheless  appears  to  be  more 
closely  related  to  them  than  is  any  other  hemiodontid.  In  the 
light  of  its  discovery,  there  can  be  little  doubt  that  Chilodontidae 
and  Hemiodontidae  are  indeed  closely  related.  Although  the 
pharyngeal  teeth  of  this  new  form  are  single  cusped,  the  relation- 
ship between  functional  and  replacement  teeth  on  the  pharyngeals 
suggests  the  primitive  condition  from  which  the  peculiar  multi- 
cuspid pharyngeal  teeth  characteristic  of  Chilodontidae  and 
Anostomidae  presumably  evolved.  Its  highly  distinctive  trophic 
structures  indicate  an  unusual  mode  of  feeding,  perhaps  similar  to 
that  of  Bivibranchia,  considered  to  have  the  most  specialized 
trophic  structures  of  all  characoids.  Nevertheless,  it  represents  a 
hne  distant  from  Bivibranchia  (and  the  related  but  less  specialized 
Argonectes) . 

Hemiodontidae  are  marvelously  streamlined,  swift-swimming 
fishes  mostly  six  inches  to  a  foot  long.  They  form  small  groups  in 
open  water  in  big  rivers  and  lagos.  Hemiodus  are  known  in  Brazil 
as  "voadores"  because  of  their  ability  to  jump.  A  group  of 
voadores  leaping  away  from  predaceous  fishes  or  over  a  seine  net 
to  safety  is  an  impressive  sight.  Spawning  presumably  takes  place 
in  open  water  and  the  young  probably  grow  up  in  aggregations 
staying  near  the  bottom  in  fairly  shallow  open  water.  It  appears 
to  be  unrecorded  whether  hemiodontids  form  huge  schools  or 
undertake  major  spawning  migrations. 

Hemiodontids  hitherto  known  readily  fall  into  two  subfamilies, 
Hemiodontinae  and  Bivibranchiinae,  adults  of  which  have  multi- 
cuspid teeth  in  the  upper  jaw  and  no  teeth  in  the  lower  jaw.  The 
minute,  unicuspid  teeth  and  other  features  of  the  new  fish  differ  so 
greatly  from  previously  known  forms  that  it  represents  a  new  sub- 
family. 


1  The  Expedicao  Permanente  da  Amazonia,  under  the  direction  of  Dr. 
P.  E.  Vanzolini,  is  a  cooperative  effort  among  the  Museu  de  Zoologia, 
Universidade  de  Sao  Paulo  (MZUSP);  Instituto  Nacional  de  Pesquisas  da 
Amazonia  (INPA)  in  Manaus;  and  Museu  Goeldi  in  Belem.  It  is  financed 
by  the  Fundagao  de  Amparo  a  Pesquisa  of  the  state  of  Sao  Paulo.  Much 
attention  has  been  devoted  to  fishes  since  fieldwork  began  in  1967.  The 
fish  collections  are  housed  at  MZUSP. 


1971  BRAZILIAN    CHARACIN    FISH  3 

MICROMISCHODONTINAE,   new  subfamily 

Highly  streamlined,  fusiform  fishes  typically  hemiodontid  in 
habitus  and  osteology.  Teeth  pedicellate,  with  a  single  strongly 
recurved  cusp;  tooth  crowns  black  or  brownish  black,  stalks  deep 
yellow  or  yellowish  brown.  Each  dentary  and  lower  pharyngeal 
with  two,  nearly  coextensive  rows  of  50-60  teeth.  Teeth  on  upper 
pharyngeal  arranged  in  numerous,  extremly  regular  rows  (as  in 
Anostomidae).  Upper  jaw  with  a  broad  frenum,  nonprotractile; 
roof  of  mouth  with  fine,  linear  ridges,  without  valvelike  structures. 
Gill  rakers  elongate  and  numerous,  with  six  to  eight  papillae  on 
either  side  of  each  gill  raker,  forming  a  dense  carpetlike  hning  to 
gill  chambers.  Lower  pharyngeals  exceptionally  long  and  slender, 
tooth-bearing  for  virtually  their  entire  length.  Upper  limb  of 
second  gill  arch  with  a  fleshy  membrane  forming  a  sort  of  pocket 
anterior  to  upper  pharyngeals.  Posterior  face  of  fourth  gill  arch 
with  ordinary  gill  filaments;  face  of  fifth  gill  arch  smooth;  no  dorsal 
diverticulum  between  fourth  and  fifth  arches.  Stomach  reversed, 
that  is,  with  cardiac  portion  (entrance  of  esophagus)  posterior 
and  pyloric  portion  anterior  in  position;  pyloric  caeca  about  thirty, 
not  well  differentiated;  length  of  intestine  in  preserved  specimens 
about  equal  to  standard  length,  forming  a  single  loop  upon  leaving 
stomach,  then  passing  straight  to  vent.  Posterior  chamber  of  swim 
bladder  about  one-half  of  standard  length  or  six  times  length  of 
anterior  chamber,  terminating  in  a  fine  taper  which  extends  to 
above  base  of  last  anal  fin  ray.  Adipose  eye-fid  thick  and  very 
strong,  extending  from  immediately  behind  nostrils  well  onto  gill 
cover,  and  with  a  narrow  vertical  sfit  over  the  pupil  (Fig.  1). 

Cranial  fontanels  as  in  chilodontids  and  other  hemiodontids, 
anterior  fontanel  linear  and  narrow,  posterior  fontanel  slightly 
wider  (Fig.  2).  Size,  shape,  and  position  of  jaw  bones  as  in 
Hemiodus;  a  peculiar  fenestra  in  tooth-bearing  portion  of  dentary 
(a  similarly  located  fenestra  present  in  Hemiodus,  absent  in  fore- 
shortened dentary  of  chilodontids).  Anterior  end  of  ethmoid  with 
small  lateral  knobs.  Circumorbital  series  with  simple  antorbital, 
supraorbital,  and  full  complement  of  six  infraorbitals;  first  infra- 
orbital smaller  than  those  succeeding  it  (enlarged  in  Chilodon- 
tidae),  j^econd  through  fourth  infraorbitals  each  slightly  larger 
than  the  preceding  one.  Branchiostegal  rays  five  (five  in  Hemiodus 
and  Argonectes,  four  in  Chilodus  and  Caenotropus);  proximal  end 


4  BREVIORA  No.    367 

of  fourth  branchiostegal  ray  greatly  expanded;  hyoid  bar  general- 
ized (apparently  highly  specialized  in  Chilodontidae).  Gill  mem- 
branes free  from  isthmus,  united  to  each  other  at  a  point  below 
middle  of  eye  (broadly  united  to  isthmus  in  chilodontids);  isthmus 
scaled  anterior  to  cleithral  symphysis  (scaleless  in  chilodontids). 
Three  postcleithra;  third  (lowermost)  postcleithrum  with  a  lamel- 
lar, posteriorly  directed  extension  (as  in  Hemiodus).  Weberian 
apparatus  and  caudal  skeleton  without  unusual  modifications. 
Forty  vertebrae,  including  Weberian  apparatus. 

IVIICROMISCHODUS,   new  genus 

Nomendatiiral  type-species:  M.  sugillatus,  new  species 

Body  fusiform  and  highly  streamlined.  Secondary  sexual  di- 
morphism unknown  (specimens  at  hand  collected  in  November 
and  December,  with  unripe  gonads).  Cranial  roof  smooth.  Sides 
of  head  largely  covered  by  adipose  eye-lids.  Nares  nontubular, 
close-set  and  separated  only  by  a  flap  flush  with  surface  of  head. 
Tip  of  snout  extends  slightly  beyond  included  lower  jaw.  With 
mouth  fully  opened,  gape  almost  vertical  and  about  as  large  as 
eye  diameter.  With  mouth  closed,  dorsoposterior  edge  of  maxillary 
slips  under  first  infraorbital  bone;  maxillary  not  extending  as  far 
back  as  anterior  margin  of  eye,  but  only  to  below  posterior  nostril. 
Toothless  portion  of  lower  jaw  (posterior  to  rictal  membrane) 
about  four  or  five  times  longer  than  tooth-bearing  portion.  Articu- 
lation of  lower  jaw  below  middle  of  eye;  rictal  membrane  below 
nostril,  distinctly  in  front  of  anterior  orbital  rim.  Lateral  line 
complete,  slightly  decurved  anteriorly,  then  running  just  below 
lateral  midline  of  body  to  last  scale  row  on  caudal  base. 

Origin  of  dorsal  fin  midway  between  snout  tip  and  base  of 
caudal  fin.  Anal  fin  small.  Caudal  fin  deeply  forked.  Dorsal,  anal, 
and  median  caudal  fin  rays  Vv'ith  well-developed,  overlapping,  mem- 
branous lappets  or  alae  (Fig.  1 ).  Similar  structures  occur  in  many 
fast-swimming  lower  teleosts,  including  various  other  characoids, 
some  cyprinoids  and  clupeoids,  and  Chanos. 

Known  by  a  single  species  from  the  Middle  Amazon  and  lower 
Rio  Negro  in  Brazil. 

Derivation  of  name.  Micromischodus  is  from  the  Greek  micro, 
small,  little;  mischos,  stalk,  petiole,  peduncle;  and  odous  (odon), 
odontos,  masc,  tooth. 


1971  BRAZILIAN    CHARACIN    FISH  5 

M.   SUGILLATUS,   new  species 
Figure   1 

Note.  Standard  lengths  are  used  throughout  this  paper.  Un- 
less stated  otherwise,  proportional  measurements  are  expressed 
as  times  in  standard  length.  Counts  and  measurements  are  given 
for  the  holotype  first,  followed  in  parentheses  by  the  ranges  for 
the  paratypes. 

Holotype.  MZUSP  6773,  152.0  mm,  Igarape  Tarumazinho, 
15  km  NW  of  Manaus,  on  the  left  bank  of  the  Rio  Negro, 
Estado  do  Amazonas,  17-18  November  1967. 

Paratypes.  MZUSP  8870,  six  specimens  125.0-144.6  mm, 
same  data  as  holotype;  MZUSP  6691,  four  specimens  107.3-137.1 
mm,  Rio  Negro,  arredores  de  Manaus,  Estado  do  Amazonas, 
15-23  November  1967;  MCZ  46718,  two  specimens  118.4  and 
137.1  mm,  Rio  Canuma,  Canuma  (near  Maues),  Estado  do 
Amazonas,  28-29  November  1967;  MCZ  46719,  seven  specimens 
79.5-108.9  mm,  Igarape  do  Rio  Jamari,  Terra  Santa,  Estado  do 
Para,  14  December  1967. 

Proportional  measurements.  Greatest  body  depth  (at  origin  of 
dorsal  fin)  4.1  (4.0-4.5).  Greatest  body  width  (below  dorsal 
fin)  5.7  (5.6-6.6).  Least  depth  of  caudal  peduncle  11.4  (11.3- 
12.4).  Distance  from  snout-tip  to  dorsal  origin  2.01  (1.94-2.08). 
Length  of  caudal  peduncle  7.45  (6.4-7.8).  Head  3.4  (3.1-3.4). 
Eye  3.9  (3.4—4.1)  in  head.  Bony  interorbital  space  3.8  (3.5-4.1) 
in  head.  Snout  3.5  (3.4-3.8)  in  head.  Width  of  mouth  (measured 
to  outer  sides  of  maxillaries)  4.1    (4.1-4.7). 

Fins.  Fins,  excepting  caudal,  scaleless.  Dorsal  fin  rays  11 
(11  in  all  paratypes  except  one  with  10),  first  two  rays  simple, 
last  ray  divided  to  its  base.  Proximal  two-thirds  to  three-quarters 
of  each  ray  with  well-developed  membranous  lappets  or  alae, 
largely  overlapping  when  fin  is  depressed.  Dorsal  fin  margin 
falcate.  Height  of  dorsal  fin  4.7  (4.3-4.8).  Base  of  dorsal  fin  9.2 
(8.1-10.3).  Anal  fin  small,  about  one-third  as  large  as  dorsal  fin, 
with  similar  membranous  lappets.  Anal  rays  10  (10),  first  two 
rays  simple,  last  ray  divided  to  its  base.  Height  of  anal  fin  8.2 
(7.4-8.3).  Anal  fin  margin  falcate.  Base  of  anal  fin  12.4  (11.8- 
13.4).  Caudal  fin  deeply  forked.  Lower  caudal  lobe  slightly 
larger  than  upper  caudal  lobe,  with  its  upper  margin  shghtly  con- 
vex (Fig.  1).  The  lower  caudal  lobe  is  similarly  modified  in  other 


BREVIORA 


No.  367 


00 

B 
4) 


c 
a 


B 
B 

q 


CO 

3 


u 
a 

■4-* 

45 


en 

a 


60 

s 

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en 

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o 

tn 

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o 


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oo 


1971  BRAZILIAN    CHARACIN    FISH  7 

fast-swimming  characoids,  for  example  in  Hydrocynus  goliath 
(Boulenger,  1899,  pi.  11).  Principal  caudal  rays  10  -f-  9.  Median 
four  to  six  rays  with  well-developed  lappets.  Procurrent  rays 
moderately  numerous  (9  +  7  in  125-mm  specimen),  unspecial- 
ized.  Adipose  fin  small,  its  base  over  posterior  portion  of  anal 
fin  base.  Pectoral  and  pelvic  fins  with  two  or  three  peculiarly 
thickened  and  elongated  scales  forming  a  sheath  for  edge  of  outer- 
most rays.  Pectoral  fin  rays  21  (18-22).  Length  of  pectoral  fin 
6.3  (5.3-6.5).  Pelvic  fin  rays  11  (11),  outermost  ray  only  un- 
branched.    Length  of  pelvic  fin  7.0  (6.1-7.2). 

Scales.  Scales  cycloid,  or  with  laciniate  (but  not  ctenoid) 
borders.  Body  completely  scaled,  57  (56-64)  scales  in  a  lateral 
series;  about  21  (16-22)  predorsal  scales  (irregularly  aligned); 
11  (11  or  12)  scales  between  lateral  line  and  dorsal  origin;  4  (4) 
scales  between  lateral  line  and  pelvic  insertion;  20  (17-22)  scales 
between  last  dorsal  ray  and  adipose  fin;  15  (14-16)  scales  along 
midline  between  symphysis  of  cleithra  and  pelvic  base;  and  16 
(16-18)  scales  around  caudal  peduncle.  Prepelvic  scales  below 
lateral  line  gradually  increasing  in  size  ventralwards;  scales  on 
abdomen  about  two  or  three  times  larger  in  diameter  than  scales 
above  lateral  line.  Caudal  fin  beyond  hypural  fan  with  two  or 
three  rows  of  scales. 

Coloration  in  alcohol.  After  two  years  in  preservative  (fixed  in 
formalin  while  alive  and  transferred  to  ethyl  alcohol  within  a  few 
months)  the  specimens  are  straw  colored,  darkest  above.  The 
most  notable  feature  is  the  solid  black  or  blue-black  color  on  the 
membranes  between  the  distal  halves  of  all  of  the  dorsal  fin  rays 
(but  not  on  the  rays  themselves),  (The  hemiodontid  Argonectes 
scapularis  and  chilodontid  Tylobronchiis  maculosus  have  similarly 
marked  dorsal  fins. )  Pectoral,  pelvic,  anal,  and  adipose  fins  color- 
less; caudal  fin  dusky,  lower  lobe  of  caudal  becoming  darker  (but 
not  as  dark  as  dorsal  fin)  near  its  tip.  A  faint  longitudinal  stripe 
running  length  of  the  body  but  stopping  at  shoulder,  not  running 
through  eyes  or  onto  caudal  fin.  Above  lateral  line  fine  melano- 
phores  lie  beneath  the  scales  and  in  concentrations  paralleling 
exposed  scale  margins.  Below  lateral  line  melanophores  almost 
entirely  absent  in  some  specimens;  in  other  specimens  melano- 
phores are  virtually  absent  beneath  the  scales  but  are  present 
along  the  scale  margins.  The  reticulated  pattern  of  vertically 
oriented  spots  thus  produced  is  similar  to  the  pattern  present  in 


8  BREVIORA  No.    367 

all  Chilodontidae,  except  that  since  the  scales  are  much  smaller, 
the  spots  are  small  and  not  as  dark.  In  all  specimens  body  dis- 
tinctly lighter  below  lateral  line  than  above.  Gill  cover  marked 
by  an  indistinct  dark  oval  patch  caused  by  a  concentration  of 
melanophores  in  the  membrane  lining  inside  of  gill  cover,  which 
shows  through  the  opercular  bones. 

The  trivial  name  sugillatus  (Latin:  sugillo,  -atus,  beaten  black 
and  blue;  sugiUatum,  black  and  blue  spot,  bruise)  refers  to  the 
coloration  on  the  dorsal  fin  and  opercles. 

Ecological  notes.  According  to  Sr.  Britski,  specimens  of  M. 
sugillatus  were  collected  by  seining  along  shore  in  lakes  or  places 
with  slow-flowing,  black  or  crystalline  water.  A  very  large  number 
of  species,  predominantly  characins,  was  obtained  at  these  locali- 
ties. The  stomach  contents  of  specimens  from  the  Igarape  do 
Rio  Jamari  include  an  assortment  of  bottom  material,  including 
many  of  what  appear  to  be  droppings  of  small  fishes.  Very  small 
insects  are  well  represented,  including  larval  Diptera  and,  most 
abundant,  a  corixid  (identified  by  Dr.  John  Lawrence)  about  L5 
mm  long.  These  are  about  the  largest  organisms  in  the  stomach 
contents. 

OSTEOLOGY 
Figures  2—15 

Illustrations  of  the  osteology  of  M.  sugillatus  are  based  on  a 
125.0-mm  paratype  from  MZUSP  8870.  Supplemental  observa- 
tions were  made  on  a  102.2-mm  paratype  from  MCZ  46719.  The 
nomenclature  of  bones  follows  Weitzman  (1962)  except  that 
"vomer"  and  "intercalar"  are  used  in  place  of  "prevomer"  and 
"opisthotic." 

Cranium  (Figs.  2-4).  Roofing  bones  of  skull  smooth  and  flat- 
tened. Cranial  fontanels  narrow,  complete.  Anterior  fontanel 
linear  and  about  half  as  wide  as  posterior  fontanel  for  almost  its 
entire  length,  but  widening  immediately  in  front  of  epiphyseal  bar. 
Ethmoid  narrow,  with  two  lateral  knobs  anteriorly  articulating  with 
either  premaxillary,  ventro-lateral  laminar  projections  immediately 
posterior  to  these  knobs,  and  a  median  cleft  in  its  posterior  half 
(Fig.  2).  Supraoccipital  crest  flat,  not  extending  as  far  as  end  of 
cranium.  Posttemporal  fossae  well  developed.  Dilator  groove  well 
developed,  frontal  participating  in  its  formation;  dorsal  Umit  of 


1971 


BRAZILIAN    CHARACIN    FISH 


antorbjtal 
nasa 


vomer 
ethmoid 


parietal 


epiphyseal  bar 
lateral  ethmoid 
frontal 


sphenotic 


epiotic 


exoccipital 


supraoccipital 


premaxillary 


infraorbital  6 


Dterotic 


Figure  2.     Cranium   of  Micromischodiis  siigillatiis    (dorsal   view), 
osteological  figures  based  on  125-mm  specimen  from  MZUSP  8870. 


All 


dilator  groove  marked  by  a  concavity  in  dorsolateral  margin  of 
frontal  bone;  sphenotic  spine  lamellar,  rounded  at  tip. 

Ethmoid  separated  from  vomer  by  a  cartilaginous  septum  (in- 
dicated by  heavy  stippling  in  Figure  3).  Vomer  with  peculiar 
anterior  knoblike  processes  on  either  side.  Lateral  ethmoid  rela- 
tively large,  with  elongate,  strutlike  process  articulating  with  knob- 
hke  process  of  vomer  (Figs.  3  and  4)  and  a  small  median  projec- 
tion firmly  articulated  to  antero-ventral  comer  of  rhinosphenoid. 
Rhinosphenoid  large,  sharing  strongly  interdigitating  sutures  with 
antero-ventral  projection  of  orbitosphenoid  (Fig.  3).  Cartilaginous 
septum  between  dorsal  edge  of  rhinosphenoid  and  roof  of  cranium 
and  another  between  ventral  margin  of  rhinosphenoid  and  para- 
sphenoid  (cartilage  indicated  by  heavy  stippling  in  Figure  3). 
Rhinosphenoid  and  orbitosphenoid  not  directly  contacting  para- 
sphenoid.  Parasphenoid  deeply  cleft  posteriorly,  the  thin  divisions 
thus  formed  cleft  at  their  tips  (Fig.  4;  compare  with  Weitzman, 
1962,  fig.  4  of  Brycon  on  p.  60;  and  Roberts,  1969,  fig.  20  of 
Acestrorhynchus  on  p.  463).  Intercalar  well  developed.  Pterotic 
with  strong  posteriorly  directed  spine. 

Jaws  and  jaw  suspension  (Figs.  2,  5-7).  The  size  and  shape 
of  the  jaw  bones  and  their  relationships  to  each  other  are  similar 


10 


BREVIORA 


No.  367 


lateral  ethmoid  ^"^""^^l      ^Phenotic       pterotjc       parietal      supraocclpital 


ethmoid 


vomer 


rhinosphenoid 

orbitosphenoid 

pterosphenold  parasphenoid  Prootic      '"<ercalar       "basioccipital 

Figure  3.     Cranium  of  Microinischodus  sugillatiis   (lateral  view). 


to  those  in  Hemiodus.  PremaxiUary  with  a  slender,  medially 
directed  symphyseal  process,  round  in  cross  section  and  blunt  at 
the  tip,  which  approximates  but  does  not  articulate  or  contact  its 
opposite  fellow.  Lateral  surface  of  premaxillary  with  a  shelflike 
projection  posterior  to  which  is  a  groovelike  depression  into  which 
snugly  fits  anterodorsal  corner  of  maxillary.    Dorsal  portion  of 


parasphenoid 

pterosphenold 
mesopterygoid 
palatine     gctopterygoid 


hyomandibular 


epiotic 
basioccipital 


ethmoid 
vomer 


exoccipital 


lateral  ethmoid 


frontal 
orbitosphenoid 


intercalar 
pterotic 


sp  hen  otic 


prootic 


Figure  4.     Cranium   of  Miciomischodus  sugillatiis   (ventral   view). 


1971 


BRAZILIAN    CHARACIN    FISH 


11 


premaxillary  and  maxillary  firmly  embedded  in  a  tough  connective 
tissue  that  binds  them  to  tip  of  ethmoid  although  they  do  not  con- 
tact it.  Maxillary  with  dorsoposterior  corner  expanded  and  con- 
nected by  a  broad,  strong  ligament  to  palatine  (Fig.  2).  Maxillary 
bearing  a  short  segment  of  cephalic  sensory  canal  (Fig.  5). 

Dentary  with  a  slender,  median  symphyseal  process,  round  in 
cross  section,  blunt  at  the  tip  which  approximates  and  is  strongly 
joined  by  ligaments  to  its  opposite  fellow.  Tooth-bearing  portion 
of  dentary  elevated;  rictal  membrane  attaches  maxillary  to  lateral 
surface  of  elevated  portion  of  dentary.  Portion  of  dentary  pos- 
terior to  gape  gradually  diminishing  in  width,  about  twice  as  long 
as  portion  anterior  to  rictus;  articulation  with  quadrate  beneath 

infraorbitals 

supraorbital 


antorbital 

premaxillary 


ope  re  I e 
subopercle 


maxillary 


interopercle 


preopercle 


quadrate 


angular 


articular 


dentary 


Figure  5.     Jaws  and  facial  bones  of  Micromischodiis  siigiUatiis  (lateral 
view). 


middle  of  eye.  Elevated  portion  of  dentary  with  a  peculiar  fenestra 
below  part  of  the  tooth  rows  (Figs.  5-7);  a  fenestra  identical  in 
shape  and  position  occurs  in  the  toothless  dentary  of  Hemiodus 
but  is  lacking  in  chilodontids. 

Premaxillary  with  about  14  minute  moveable  teeth.  Maxillary 
toothless.  Dentary  with  two  coextensive  rows  of  minute  moveable 
teeth.  The  125-mm  specimen  has  about  54  teeth  in  outer  row 
and  about  60  (slightly  smaller)  teeth  in  inner  row,  uppermost  ten 


12 


BREVIORA 


No.  367 


of  which  are  nonpedicellate;  replacement  teeth  much  in  evidence 
(Fig.  7). 

The  palatine  arch  presents  no  unusual  features.  Metapterygoid- 
quadrate  foramen  well  developed.  Hyomandibular  well  separated 
from  mesopterygoid. 

Facial  bones  (Figs.  5-6).  Facial  bones  present  no  unusual 
features.  Circumorbital  series  complete.  Nasal  bone  tubular, 
laminar  projections  minute.  Antorbital  slender,  struthke.  Infra- 
orbitals six;  infraorbitals  2-4  gradually  increasing  in  size  over  ones 
preceding  them.  Infraortibal  1  not  enlarged.  Infraorbitals  3  and 
4  with  tubes  from  postorbital  branch  of  cephalic  sensory  canal 
system  leading  to  their  posterior  margin  (Fig.  5). 

Posterior  bony  margin  of  gill  cover  formed  largely  by  sub- 
opercle;  subopercle  with  well-developed,  dorsally-projecting  spine 
at  anteroventral  end.  Preopercle  with  a  slender  tubular  extension 
dorsally.   Suprapreopercle  absent. 

Visceral  arches  (Figs.  8-10).  Hyoid  arch  without  unusual  fea- 
tures. Branchiostegal  rays  five  (as  in  Hemiodus,  Argonectes), 
first  four  articulating  with  ceratohyal,  fifth  with  epihyal.  Proxunal 
end  of  fourth  where  it  connects  with  ceratohyal  greatly  expanded 
(see  Fig.  9). 


premaxillary 
maxillary 

palatine 


dentary 
coronomeckelian  bone 


opercle 


subopercle 


articular 


Interopercle 


preopercle 


Figure  6.     Jaws,  jaw  suspension,  and  opercular  bones  of  Micromischodus 
siigillatus  (internal  view). 


1971 


BRAZILIAN    CHARACIN    FISH 


13 


Figure  7.     Tooth-bearing     portion     of     dentary     of     Micromiscliodiis 
sugillattis  (internal  view). 


14 


BREVIORA 


No.  367 


ventral  liypohyal 
dorsal  hypohyal 


branch lostegal  rays 


Figure  8.     Hyoid    arch,    branchiostegal    rays,    and    urohyal    of    Micro- 
mischodits  siigillatiis  (dorsal  view). 


Pharyngeal  teeth  (Figs.  9  and  10).  Lower  phaiyngeals  pecu- 
liarly elongate  and  bearing  two  rows  of  teeth  for  virtually  their 
entire  length.  The  recurved  crowns  of  the  teeth  in  anterior  row  on 
lower  pharyngeal  project  forward;  replacement  teeth  lie  anteriorly 
to  their  bases  (Fig.  lOA).  On  the  trailing  edge  of  the  lower 
pharyngeals  is  a  row  of  smaller  teeth  with  the  recurved  crowns 
projecting  backwards;  replacement  teeth  lie  posterior  to  their 
bases  (Fig.  lOB).  In  125-mm  specimen  about  64  teeth  in  anterior 
row  and  60  in  posterior  row. 

At  first  glance  the  anterior  and  posterior  rows  of  lower  pharyn- 
geal teeth  each  appear  to  constitute  two  rows.    This  is  because 


1971 


BRAZILIAN    CHARACIN    FISH 


15 


basihyal 
basibranchials 


hypobranchials 


ceratobranchials 


epibranchials 

suspensory  pharyngeals 


upper  pharyngeals 


lower  pharyngeal 


Figure  9.  Gill  arches  of  Micromischodus  sitgillatiis  (dorsal  view).  Left 
side  in  normal  position,  right  side  with  uppermost  elements  pinned  out  and 
to  the  side. 


not  all  of  the  teeth  have  assumed  the  "definitive"  functional  posi- 
tion; teeth  just  coming  into  position  are  out  of  line  with  the  rest. 
Since  none  of  the  teeth  are  ankylosed  to  the  bone,  the  borderline 
between  teeth  in  functional  position  and  replacement  teeth  is 
indistinct.  Evidently  some  of  the  replacement  teeth  are  "func- 
tional" before  they  are  in  the  definitive  functional  position,  and 
even  before  the  functional  teeth  they  are  about  to  replace  have 
fallen  out.  Tooth  replacement  is  much  in  evidence,  and  probably 
occurs  in  waves  proceeding  the  length  of  the  lower  pharyngeals. 
In  some  places  a  functional  tooth  may  have  two  replacement  teeth 
at  its  base   (see  Fig.   lOB).    These  observed  characteristics  are 


16 


BREVIORA 


No.  367 


highly  suggestive  of  the  sort  of  situation  from  which  the  pedicellate 
multicuspid  pharyngeal  teeth  of  Chilodontidae  and  Anostomidae 
presumably  evolved.  If  this  view  is  correct,  then  successive  cusps 
fused  below  the  main  cusp  to  the  stalklike  base  are  phylogenetic- 
ally  equivalent  to  successive  generations  of  replacement  teeth. 


Figure   10.     Lower  pharyngeal  teeth  of  Micromischodiis  sugillatiis  (pos- 
terior view).     A,  anterior  row;  B,  posterior  row. 


The  upper  pharyngeals  bear  numerous  regularly  arranged  rows 
of  teeth  in  which  the  crowns  project  backwards  (in  opposition  to 
crowns  of  teeth  in  anterior  row  of  lower  pharyngeal  which  point 
forwards).  The  third  suspensory  pharyngeal  bears  a  small  patch 
of  similar  teeth.    Gill  rakers  edentulous. 

The  pharyngeal  teeth,  although  morphologically  similar  to  those 
in  the  jaws,  are  more  solidly  implanted  and  much  larger  (except 
for  the  teeth  in  the  posterior  row  on  lower  pharyngeal);  still,  they 
are  considerably  smaller  than  the  greatly  enlarged  and  very  solidly 
implanted  pharyngeal  teeth  of  Chilodontidae  and  Anostomidae. 
In  the  125-mm  specimen  the  teeth  in  the  upper  jaw  are  about  0.2 
mm  long;  the  teeth  in  the  outer  row  of  the  lower  jaw  are  0.4  mm 
long;  the  teeth  on  the  upper  pharyngeal  and  in  the  anterior  row  on 


1971 


BRAZILIAN    CHARACIN    FISH 


17 


the  lower  phaiyngeal  are  1.0  mm  long;  and  the  teeth  in  the  pos- 
terior row  on  the  lower  pharyngeal  are  0.4  mm  long.  The  highly 
regular  arrangement  of  tooth  rows  on  the  upper  pharyngeal  is 
suggestive  of  the  regular  rows  on  the  upper  pharyngeals  of  An- 
ostomidae.  The  arrangement  of  teeth  in  the  lower  pharyngeals  is 
unique.  In  most  characoids,  including  Hemiodus,  the  teeth  are 
in  several  irregular  rows  on  an  expanded  portion  of  the  lower 
pharyngeal  near  the  midline;  the  distal  half  of  the  lower  pharyngeal 
is  usually  toothless. 

Weberian  apparatus  (Figs.  11  and  12).  Weberian  apparatus 
showing  no  unusual  features,  similar  to  that  of  typical  Characidae. 
Neural  arch  pedicle  of  third  vertebra  with  a  dorsally  directed  pro- 
cess tightly  bound  into  a  groovehke  fossa  in  base  of  neural  arch 
complex.  Base  of  neural  arch  complex  extends  posteriorly  so  that 
its  posteroventral  surface  almost  contacts  entire  anterior  face  of 
neural  spine  of  fourth  vertebra.  Rib  of  fifth  vertebra  with  a 
medially  directed  process  ligamentously  attached  to  os  suspen- 
sorium.  Transverse  process  of  third  vertebra,  which  cradles  inter- 
calarium,  well  developed.  Lateral  process  of  os  suspensorium  very 


neural  complex 
claustrum 


neural  arch   of   third  vertebra 

transverse  process  of  third  vertebra 


supraneural 


neural  arch  and  spine 
of  fourth  vertebra 


scaphium 


intercalarium 


pleural  rib 


lateral  process  of  second/ 

vertebra  tripus' 


OS  suspensorium 


Figure   11.     Weberian   apparatus   of  Micromischodus  sugillatus   (lateral 
view). 


18 


BREVIORA 


No.  367 


neural  complex 


scaphium 


lateral  process  of  centrum  2 


tripus 


rib  of  fifth  vertebra 


OS  suspensorium 
centrum  4 

centrum  5 


Figure   12.     Weberian  apparatus  of  Micromischodus  sugillatiis   (ventral 
view). 


large,  overlying  transformator  process  of  tripus.  Neural  arch  of 
third  vertebra  extending  far  anteriorly  over  second  centrum  (Fig. 
11).   Lateral  process  of  centrum  2  very  large. 

Pectoral  girdle  (Fig.  13).  Pectoral  girdle  without  unusual 
specializations.  Three  postcleithra.  Most  distinctive  feature  is 
lamellar  projection  from  proximal  part  of  third  postcleithra  (simi- 
lar process  present  in  Hemiodus);  in  other  characoids  third  post- 
cleithrum  slender  for  entire  length. 

Pelvic  girdle  (Fig.  14).  Ischiac  process  well  developed;  four 
radials;  pelvic  splint  present;  rays  invariably  11. 

Caudal  skeleton  (Fig.  15).  Caudal  skeleton  generahzed.  Hy- 
purals  5  and  6  fused,  rest  separate.  Two  uroneurals.  Three 
epurals.  Principal  caudal  rays  invariably  10  +  9.  Nine  upper 
and  seven  lower  procurrent  rays  in  125-mm  specimen. 


' 


197 


BRAZILIAN    CHARACIN    FISH 


19 


posttemporal 


supracleithrum 


postcleithra 


extrascapular 


coracoid 


Figure   13.     Pectoral  girdle  of  Micromischodus  sugillatus  (internal  view). 
Inset:   external  view  of  extrascapular  and  posttemporal. 


20 


BREVIORA 


No.  367 


radials 


ischiac  process 


Figure  14.  Pelvic  girdle  of  Micromischodus  sugillatus  (ventral  view). 
Enlarged  view  on  right  side  with  radials  exposed  by  removal  of  outer  half 
of  each  lepidotrich. 


1971 


BRAZILIAN    CHARACIN    FISH 


21 


upper  procurrent  rays 


epurals 


uroneural  2 
hypural  I 
hypural  2 


uroneural  I 
neural  spines 


haemal  spines 


upper  principal  rays 


hypural  centrum 

hypural  7 

lower  principal  rays 
lower  procurrent  rays' 
Figure   15.     Caudal  skeleton  of  Micromischodus  sugillatiis  (lateral  view). 


22  BREVIORA  No.    367 

DEFINITION    OF   THE    FAMILY   CHILODONTIDAE 

A  definition  of  the  family  Chilodontidae  is  given  here  primarly 
for  comparison  with  Micromischodontinae.  This  definition  is  not 
the  result  of  thorough  researches  of  all  taxa  involved;  it  is  an- 
ticipated that  studies  in  progress  by  Weitzman  will  gready  extend 
knowledge  of  the  group.  Trophic  structures  were  emphasized  in 
defining  Micromischodontinae,  as  they  will  also  be  in  the  following 
definition.  Modification  of  trophic  structures  has  been  the  main 
theme  in  the  great  adaptive  radiation  of  characoids.  Trenchant 
differences  in  feeding  habits  and  trophic  structures  characterize 
most  genera  and  higher  taxa,  and  it  is  natural  to  emphasize  these 
differences  in  definitions.  Some  important  modifications  which  do 
not  directly  involve  trophic  structures  are  nevertheless  strongly 
linked  to  modes  of  feeding,  viz.,  swimming  position  in  Chilo- 
dontidae and  Anostomidae.  Parenthetically,  any  attempt  to  work 
out  a  phyletic  classification  of  the  higher  characoid  taxa  must 
necessarily  give  major  consideration  to  the  evolution  of  their 
trophic  structures. 

Chilodontidae.  Characoid  fishes  reaching  about  150  mm  in 
standard  length  which  spend  much  of  the  time  in  an  oblique  head- 
down  swimming  position.  In  many  regards — including  position 
of  fins,  approximate  number  of  fin  rays,  and  general  cranial  osteol- 
ogy— they  are  like  Hemiodontidae.  They  differ  from  the  Hemi- 
odontidae  in  having  the  skull,  including  the  lower  jaw,  and  the 
whole  body  relatively  short,  and  in  their  trophic  modifications. 
Number  of  scales  considerably  less  than  in  Hemiodontidae  (about 
25-30  vs.  50-125).  Pectoral  fin  with  13-16  rays  (18-23  in 
Hemiodontidae).  Vertebrae  including  Weberian  apparatus  33  in 
Chilodus,  35  in  Tylobronchus  (Eigenmann,  1912:  271-273). 

Lower  jaw  behind  rictal  membrane  greatly  foreshortened;  first 
infraorbital  enlarged;  jaw  teeth  and  pharyngeal  teeth  reduced  in 
number.  Premaxillary  with  a  single  row  of  conical  {Caenotropus, 
Chilodus)  or  bicuspid  {Tylobronchus),  stalked  teeth;  lower  jaw 
with  a  single  row  of  conical,  stalked  teeth  {Chilodus,  Tylo- 
bronchus) or  no  teeth  in  large  adults  {Caenotropus).  Teeth  em- 
bedded in  lips  and  freely  moveable,  not  ankylosed  to  jaw  bone. 
Upper  and  lower  pharyngeals  with  enlarged  teeth  with  two,  three, 
or  more  cusps  ossified  to  a  stout,  stalklike  base.  In  Chilodus, 
lower  pharyngeal  teeth  confined  to  a  small,  round  patch  in  the 


1971  BRAZILIAN    CHARACIN    FISH  23 

center  of  a  large,  bowllike  depression  formed  by  concave  dorsal 
surfaces  of  the  greatly  expanded  (and  highly  peculiar)  lower 
pharyngeal  bones.  Posterior  face  of  fourth  arch  and  exposed  face 
of  fifth  arch  bearing  complementary  rosettes  of  what  appear  to  be 
modified  gill  filaments  covered  with  tiny  papillae  and  with  tough 
booklets  at  their  distal  ends,  evidently  adapted  to  food  selection 
(see  Gery,  1964,  fig.  2  on  p.  63).  Gill  rakers  reduced  in  number; 
bony  lamellae  of  gill  rakers  reduced  or  absent  in  Chilodiis  (in- 
variably well  developed  in  Hemiodontidae).  Gill  membranes 
tightly  bound  to  posteriormost  part  of  isthmus,  i.e.,  immediately 
in  front  of  base  of  pectoral  girdle  (free  in  Hemiodontidae).  Hyoid 
bar  highly  modified.  Branchiostegal  rays  four  (verified  in  Caeno- 
tropiis  and  Chilodus).  Isthmus  scaleless.  Caudal  fin  less  forked 
and  anal  fin  larger  than  in  Hemiodontidae.  Membranous  lappets 
on  dorsal,  anal,  and  caudal  fins  reduced.  Adipose  eyelid  reduced. 
Distal  half  of  dorsal  fin  wholly  or  partly  covered  with  a  black  or 
bluish  black  color,  which  partly  breaks  up  into  spots  in  Chilodus; 
sides  of  body  with  a  punctuate  color  pattern,  spots  borne  on  in- 
dividual scales,  and  usually  with  a  dark,  longitudinal  stripe  on 
the  midline  extending  through  the  eye  onto  the  middle  of  the  caudal 
fin. 

1  have  pointed  out  (Roberts,  1969:  424,  442)  that  Chilo- 
dontidae  and  Anostomidae  have  similar  multicuspid  pharyngeal 
teeth,  and  suggested  that  perhaps  the  Chilodontidae  should  be 
regarded  as  a  subfamily  of  Anostomidae.  In  the  light  of  the  present 
study,  I  still  feel  that  the  two  groups  are  closely  related,  but  am 
inclined  to  regard  Chilodontidae  as  of  family  rank.  The  chilo- 
dontids  are  set  oflf  from  Anostomidae  by  the  specialized  structure 
of  their  fourth  and  fifth  gill  arches  and  form  a  small  group  of 
clearly  related  forms.  And  while  it  seems  clear  that  the  chilo- 
dontids  are  related  to  the  Anostomidae,  the  anostomid  genus 
closest  to  them  cannot  be  singled  out.  Furthermore,  the  chilo- 
dontids  show  equally  clearly  indications  of  relationship  with 
Hemiodontidae — a  relationship  closer  than  I  previously  had 
thought  likely.  Thus  the  reasonable  solution  for  now,  and  one 
which  may  prove  of  lasting  value,  is  recognition  of  three  families, 
Hemiodontidae,  Chilodontidae,  and  Anostomidae.  It  will  be  noted 
that  the  Anostomidae  form  a  "well-knit"  group  of  some  ten  or 
eleven  genera. 


24  BREVIORA  No.   367 

COMMENTS    ON    HEMIODONTINAE 
AND    BIVIBRANCHIINAE 

The  Hemiodontinae  comprises  Hemiodus  (but  see  Gery,  1963), 
with  numerous  species  differing  sharply  in  color  patterns  and  scale 
counts  (see  Bohkle,  1955)  and  two  or  three  closely  related  genera 
of  doubtful  distinctness  and  confusing  nomenclatural  status  (see 
Gery,  1961;  1963).  The  Bivibranchiinae  comprises  three  quite 
distinct  genera,  each  with  but  one  or  two  species,  Argonectes 
(Bohlke  and  Myers,  1956),  Atomaster  (Eigenmann  and  Myers, 
1927)  and  Bivibranchia.  Briefly,  the  Bivibranchiinae  have  a  highly 
protractile  upper  jaw  with  tricuspid  teeth,  and  highly  specialized 
trophic  structures  in  the  roof  of  the  mouth  and  in  the  pharynx. 
The  nature  of  their  pharyngeal  teeth  has  yet  to  be  elucidated.  Of 
the  three  genera,  Argonectes  is  least  specialized  and  approaches  in 
some  respects  the  Hemiodontinae,  which  have  relatively  nonpro- 
tractile  upper  jaws  with  multicuspid  teeth  of  eight  or  nine  cusps, 
and  relatively  generalized  oral  and  pharyngeal  passages. 

In  neither  of  the  two  subfamiUes  do  adults  have  teeth  in  the 
lower  jaw.  The  dentition  of  young  Hemiodus,  however,  is  very 
different  from  that  of  adults.  According  to  Gery  (1963:  604),  in 
alevins  of  Hemiodus  (tentatively  identified  as  H.  unimaculatus) 
up  to  17.3  mm  in  standard  length,  there  are  but  six  to  eight  teeth 
on  the  premaxillaries,  these  teeth  having  fewer  cusps  than  those 
in  adults,  and  the  dentary  bears  four  or  six  very  small  conical  teeth, 
visible  only  with  strong  magnification.  We  may  feel  fairly  secure 
in  supposing  (Roberts,  1967)  that  the  earliest  dentition  in 
Hemiodus  consists  of  small  conical  teeth  in  both  upper  and  lower 
jaws.  As  Hemiodus  grow,  presumably  the  upper  jaw  teeth  increase 
in  number  and  are  replaced  by  teeth  with  successively  more  cusps, 
whereas  the  conical  teeth  in  the  lower  jaw  are  replaced  relatively 
few  times,  if  at  all,  and  drop  out  altogether  at  a  fairly  early  stage. 

Menezes  and  Oliveira  e  Silva  (1949)  reported  that  stomach 
contents  of  Hemiodus  parnaguae  from  the  Rio  Parnaiba  in  Piaui, 
Brazil,  contain  mud,  algae,  and  remains  of  higher  plants.  No  in- 
formation is  available  on  food  habits  of  Bivibranchiinae.  I  suspect 
that  Bivibranchia  take  a  mouthful  of  sand,  sort  food  particles  out 
in  the  gill  chambers  and  then  spit  the  sand  out  of  the  mouth. 
Gery  (1969:  836)  stated  that  Bivibranchia  bury  themselves  in 
sand  "like  sand-eels"  but  gave  no  further  details.  Possibly  this 
observation  involves  a  feeding  activity. 


1971  BRAZILIAN    CHARACIN    FISH  25 

LITERATURE    CITED 

BoHLKE,  J.  E.  1955.  Studies  on  fishes  of  the  family  Characidae. — No. 
lU.  Notes  on  the  coloration  of  the  species  of  Hemiodiis,  Pterohemiodiis 
and  Aiiisitsia,  with  the  description  of  a  new  Hemiodiis  from  the  Rio 
Negro  at  the  Brazil-Colombia  border.  Acad.  Nat.  Sci.  Philadelphia, 
Notulae  Naturae,  No.  278:    1-15. 

,  AND  G.  S.  Myers.     1956.     Studies  on  fishes  of  the  family 

Characidae. — No.  11.  A  new  genus  and  species  of  hemiodontins  from 
the  Rio  Orinoco  in  Venezuela.  Acad.  Nat.  Sci.  Philadelphia,  Notulae 
Naturae,  No.  286:    1-6. 

BouLENGER,  G.  A.  1899.  Materiaux  pour  la  Faune  du  Congo.  Poissons 
nouveaux  du  Congo.  Ann.  Mus.  Congo  (Tervuren),  Zool.,  ser.  1, 
1   (pts.  1-6):    1-164. 

EiGENMANN,    C.    H.      1912.     The    fresh-water    fishes    of    British    Guiana. 

Mem.  Carnegie  Mus.,  5:  xxii  -\-  578  pp. 
,  AND  G.  S.  Myers.     1927.    A  new  genus  of  Brazilian  characin 

fishes  allied   to  Bivibranchia.    Proc.   Nat'l.   Acad.   Sci.    (Washington), 

3(8):   565-566. 

Gery,  J.  1961.  Pterohemiodiis  liielingi  sp.  nov..  un  curieux  poisson 
characoide  a  nageoire  dorsale  filamenteuse,  avec  une  cle  des  genres 
d'Hemiodontinae  (Ostariophysi-Erythrinidae).  Bonner  Zoologische 
Beitrage.   314(12):    332-342. 

. 1963.     Sur   la   nomenclature   et    la   systematique    du    genre 

Hemiodiis  Miiller  (Pisces,  Characoidei).  Bull.  Mus.  Nat'l.  Hist.  Nat., 
ser.  2,  35(6):  598-605. 

1964.     A    review    of   the    Chilodinae,    with    a    key    to    the 


species.     Tropical  Fish  Hobbyist,  May,  1964:  5-10,  63-67. 
1969.     The  fresh-water  fishes  of  South  America.  In  Fitlkau, 


E.  J.,  et  alia  (editors),  Biogeography  and  Ecology  in  South  America. 
Vol.  2,  pp.  828-848.    The  Hague,  Junk. 

Menezes,  R.  S.  and  S.  L.  Oliveira  e  Silva.  1949.  Alimentagao  de 
voador,  "Hemiodus  parnaguae"  Eigenmann  and  Henn,  da  bacia  do  Rio 
Parnaiba,  Piaui.     Rev.  Bras.  Biol.,  9(2):  241-245. 

Roberts,  T.  R.  1967.  Tooth  formation  and  replacement  in  characoid 
fishes.     Stanford  Ichth.  Bull.,  8(4):  251-259. 

1969.  Osteology  and  relationships  of  characoid  fishes,  par- 
ticularly the  genera  Hepsetiis,  Salminiis,  Hoplias,  Ctenoliiciiis,  and 
Acestrorhynchus.    Proc.  California  Acad.  Sci.,  ser  4,  36(15):  391-500. 

Weitzman,  S.  H.  1962.  The  osteology  of  Brycon  meeki,  a  generalized 
characid  fish,  with  an  osteological  definition  of  the  subfamily.  Stan- 
ford Ichth.   Bull.,  8(1):    1-77. 


BREVIORA 


Museium    of    Compsirative    Zoology 

Cambridge,  Mass.     29  January,  1971  Number  368 

STRUCTURAL  HABITATS  OF  WEST  INDIAN  ANOLIS 
LIZARDS  I.   LOWLAND  JAMAICA 

Thomas  W.  and  Amy  Schoener^ 


Abstract.  This  paper  reports  differences  in  structural  and  climatic 
habitat  among  the  commonest  Anolis  species  of  three  lowland  Jamaican 
localities.  Three  of  the  species  studied,  grahami,  opalinus,  and  valencienni, 
occurred  at  all  localities;  two  other  species,  sagrei  and  Uneatopiis,  occurred 
at  one  (Whitehouse)  and  two  (Port  Antonio,  Mona)  localities,  respec- 
tively, and  thus  were  complementary. 

With  a  few  exceptions,  the  ordering  of  species  by  height,  from  highest 
to  lowest,  was  valencienni,  grahami,  opalinus,  and  Uneatopiis  or  sagrei;  the 
ordering  by  diameter,  from  thickest  to  thinnest,  was  opalinus,  grahami, 
lineatopus  or  sagrei,  and  valencienni;  the  ordering  by  insolation,  from 
sunniest  to  shadiest,  was  sagrei,  grahami,  valencienni,  lineatopus,  and 
opalinus;  the  ordering  by  size,  from  largest  to  smallest,  was  valencienni, 
lineatopus,  grahami,  sagrei,  and  opalinus.  Within  species,  larger  individuals 
tended  to  occur  higher  and  on  thicker  perches,  smaller  individuals  lower 
and  on  thinner  perches. 

The  above  orderings  result  in  low  interspecific  spatial  overlap  of  similarly 
sized  individuals  in  two  ways.  First,  a  direct  relationship  between  body  size 
and  perch  diameter  within  species  and  an  inverse  one  between  species 
ensures  that  spatially  abutting  species  will  overlap  most  their  respective 
individuals  least  alike  in  size.  Second,  a  direct  relationship  within  species 
between  size  and  height  also,  except  for  valencienni  and  grahami,  results 
in  the  greatest  spatial  overlap  being  between  the  most  dissimilarly  sized 
individuals. 

Many  statistically  significant  associations  were  found  between  the  habitat 
and  climatic  variables;  the  most  common  was  a  tendency  for  thin  perches 
to  be  more  often  occupied  in  the  sun. 


1  Biological  Laboratories  and  Museum  of  Comparative  Zoology,  Harvard 
University,  Cambridge,  Mass.  02138. 


2  BREVIORA  No.    368 

This  is  the  first  of  a  series  of  papers  describing  in  a  standard 
way  the  structural  habitat  of  some  West  Indian  Anolis  Hzards.  Its 
primary  purpose  is  to  document  differences  between  the  size  and 
sex  classes  of  all  the  Anolis  species  found  within  a  particular, 
limited  study  area.  Between-site  comparisons  will  be  drawn  occa- 
sionally; however,  because  of  the  great  intersite  variation  in  vege- 
tation structure  and  its  effect  on  lizard  habitat  distributions,  that 
aspect  will  be  described  and  analyzed  in  detail  in  a  larger  work 
covering  much  of  the  western  Caribbean. 

The  "structural  habitat,"  a  term  first  invented  by  Rand  (1964) 
for  Anolis,  refers  to  the  spatial  niche  of  a  species  population  de- 
scribed in  terms  of  characteristics  of  the  vegetation  and  other 
structures  upon  which  these  arboreal  animals  carry  out  their  activi- 
ties. The  two  such  characteristics  that  Rand  originally  used  and 
that  have  subsequently  proven  most  useful  in  discriminating  the 
various  species  or  species-classes  are  perch  height  and  perch 
diameter  (Rand,  I.e.,  1967a;  Rand  and  Rand,  1966;  Schoener, 
1968;  Schoener  and  Gorman,  1968;  Laska,  1970),  and  these  will 
be  the  ones  used  below.  Other  possible  structural  characteristics 
are  perch  texture,  perch  color,  and  the  size  and  nature  of  the  plant 
or  other  object  to  which  the  perch  is  attached. 

Observations  that  combine  to  give  an  overall  picture  of  the 
spatial  dimensions  of  the  niche  must  be  summed  over  a  given 
time  period  and  over  a  particular  set  of  individuals.  The  method 
chosen  in  this  and  succeeding  studies  is  to  lump  together  "first 
sightings"  recorded  continuously  throughout  the  day  or  throughout 
the  period  of  maximum  activity  from  a  population  of  several  hun- 
dred animals  for  each  of  the  the  commonest  species.  Thus,  ideally, 
the  sites  of  the  major  activities — thermoregulation,  searching  for 
food,  capturing  and  eating  prey,  and  social  interaction — are 
weighted  when  observations  are  combined  according  to  that  frac- 
tion of  the  day  spent  by  the  average  individual  in  the  particular 
activity. 

There  are  several  hmitations  and  qualifications  of  the  structural- 
habitat  concept  which  must  be  mentioned  at  the  outset. 

First,  it  does  not  provide  a  true  picture  of  the  animals'  daily 
perch  distribution,  because  inconspicuous  animals  are  more  often 
missed.  This  means  that  the  most  visible  activities,  feeding  or  fight- 
ing, for  example,  are  disproportionately  weighted  in  the  totals.  In- 
conspicuousness  is  perhaps  less  of  a  problem  for  continuous 
observation  of  single  individuals  than  for  "first  sightings." 


1971  JAMAICAN    ANGLES  3 

Second,  weighting  activities  in  proportion  to  the  amount  of  time 
they  take  will  not  necessarily  produce  the  most  meaningful  measure 
of  a  species'  spatial  distribution,  either  for  testing  hypotheses  of 
optimal  individual  behavior  or  of  community  composition.  For 
example,  it  may  be  most  useful  to  know  the  places  where  prey  are 
captured  in  order  to  determine  how  similar  species  can  be  and  still 
coexist,  but  this  activity  consumes  a  very  small  amount  of  time,  and 
Andrews  (1971)  and  Trivers  (personal  communication)  have 
both  shown  that  distributions  of  feeding  sites  can  differ  markedly 
from  the  overall  structural  habitat.  However,  taxonomic  break- 
down of  the  prey  of  the  four  Bimini  Anolis  has  shown  that  the 
prey  is  qualitatively  what  would  be  predicted  from  the  overall 
structural  habitat  (Schoener,  1968). 

Third,  consideration  of  structural  habitat  alone  provides  an  in- 
complete picture  of  the  total  niche  of  a  species.  The  most  impor- 
tant other  kind  of  property  characterizing  the  space  in  which  an 
anole  lives  is  climatic;  some  measure  of  this  is  given  below  for 
certain  situations.  A  second  important  way  in  which  animals  of 
the  same  structural  habitat  may  differ  is  in  the  prey  selected  from 
the  habitat. 

Fourth,  structural  habitat  as  determined  by  first  sightings  is  a 
static  concept:  it  says  nothing  about  how  an  animal  gets  from  one 
part  of  its  home  range  to  another,  nor  indeed  about  how  perches 
of  various  heights  and  diameters  are  actually  connected  together 
in  the  habitat.  Knowledge  of  the  movements  of  animals  is  essen- 
tial for  certain  kinds  of  studies,  for  example,  those  on  foraging 
strategies,  and  may  provide  some  indication  of  the  type  of  prey 
captured.  This  limitation  for  Jamaican  Anolis  is  important:  Trivers 
(personal  communication)  has  shown  that  valencienni  differs 
strikingly  from  some  other  Jamaican  anoles  (e.g.,  lineatopus)  in 
its  active  but  cautious  manner  of  searching  for  prey.  The  limitation 
should  be  kept  in  mind  when  valencienni  is  compared  to  the  other 
species  below. 

Despite  these  disadvantages,  the  structural  habitat  has  proven  a 
useful  "summary  statistic"  in  describing  Anolis  communities.  It 
has  the  great  advantage  that  large  populations  of  animals  can  be 
sampled  quickly,  thus  permitting  several  such  populations  to  be 
studied  in  a  season.  More  balanced  and  detailed  intralocality 
studies  of  Anolis  populations  are  better  for  many  purposes  but 
are  impractical  for  the  study  of  the  geographic  variation  of  the 
niche.    Hopefully,  as  greater  numbers  of  these  detailed  studies 


4  BREVIORA  JNO.    368 

become  available,  it  will  be  possible  to  set  up  correspondences — 
e.g.,  animals  which  are  often  found  on  leaves  take  large  numbers 
of  aphids — between  the  many  properties  measured  in  the  detailed 
studies  and  the  few  properties  of  the  overall  structural  habitat. 
Then  some  supposition  can  be  made  concerning  the  geographic 
distribution  of  many  more  species  characteristics  than  those  ex- 
plicitly given  as  the  "structural  habitat." 

FORMAT 

The  format  for  reporting  the  results  in  this  and  succeedmg  papers 
will  begin  with  a  description  of  the  localities  studied,  including  a 
list  of  the  Anolis  lizards  seen.  This  will  be  followed  by  a  verbal 
summary  of  the  results  for  each  locality,  accompanied  by  tables 
depicting  the  structural  habitat  of  the  lizard  classes  considered,  as 
well  as  by  a  table  indicating  the  statistical  significance  of  differ- 
ences in  the  habitat  variables  between  all  possible  pairs  of  the 
lizard  classes.  Finally,  some  relation  will  be  made  of  the  results 
to  previous  studies  of  the  species  in  question  and  to  studies  of  the 
habitats  of  species  from  other  areas. 

METHODS 

Structural  habitats  were  estimated  by  the  "censusing"  method 
first  developed  by  Rand  (1964).  In  a  transect  through  the  study 
area,  each  new  lizard  seen,  unless  obviously  disturbed  by  the 
observers,  is  noted  as  to  its  perch  height,  diameter,  and  (some- 
times) insolation.  Rand  (1964,  1967a)  and  Schoener  (1968) 
have  pointed  out  the  possible  errors  in  this  technique,  including 
the  especially  serious  one  of  differential  visibility  of  various  por- 
tions of  the  habitat.  Thus  lizards,  sitting,  for  instance,  on  the  tops 
of  leaves  in  the  canopy,  are  often  likely  to  escape  detection.  How- 
ever, the  direction  of  difference  between  lizard  groups  within  a 
given  site  should  not  usually  be  affected  by  this  kind  of  error.  We 
did  most  of  the  observations  as  a  pair,  using  binoculars,  the  two  of 
us  crisscrossing  the  habitat  about  10  to  20  feet  apart;  this  technique 
probably  reduced  considerably  the  chance  of  missing  lizards.  Study 
areas  were  often  censused  several  times  per  day,  but  as  a  rule  no 
part  of  the  area  was  censused  at  intervals  closer  than  one  and  a 
half  hours;  observation  of  lizard  behavior  in  the  interval  indicates 
that  this  was  ample  time  for  the  animals  to  "recover"  from  dis- 
turbance. 


1971  JAMAICAN    ANGLES  5 

Data  were  cast  into  standard  tables  for  easy  intergroup  compari- 
son of  structural  habitat  (Tables  1-4).  For  each  lizard  class  for 
which  microclimatic  information  was  taken,  observations  of  cli- 
matic categories — sun,  shade,  and  clouds — were  lumped  into  a 
single  structural  habitat  table.  Additionally,  however,  the  percent 
occurrence  in  the  three  climatic  categories  were  Hsted  separately 
for  each  class  (Table  5). 

A  powerful  new  technique  of  multivariate  analysis  was  used  to 
compute  the  statistical  significance  of  habitat  differences  among 
the  various  groups  of  lizards.  The  technique  utilizes  the  iterative 
procedure  of  Deming  and  Stephan  (1940)  and  was  recently  ex- 
pounded by  Bishop  (1969).  It  is  designed  to  detect  associations 
between  variables — in  our  case  perch  diameter,  perch  height,  lizard 
class,  and  insolation — of  complex  contingency  tables;  thus  it  can 
handle  both  nominal  and  ordinal  variables.  Because  it  also  simul- 
taneously considers  associations  between  the  habitat  variables  per 
se,  this  technique  should  largely  eliminate  any  apparent  difference 
in  habitat  among  lizard  classes  caused  entirely  by  the  structure  of 
the  vegetation.  For  example,  were  relatively  high  perches  always 
also  relatively  thin  perches,  a  lizard  class  which  occupied  signifi- 
cantly higher  perches,  in  the  statistical  sense,  would  not  necessarily 
occupy  significantly  thinner  perches,  because  of  the  strong  height 
versus  diameter  interaction.  Details  of  the  application  of  the 
method  to  our  data  are  given  in  the  appendix  (see  also  Schoener, 
1970).  The  reader  not  famihar  with  these  techniques  should  first 
consult  the  paper  by  Fienberg  (1970),  which  is  an  exposition  of 
the  method  written  especially  for  ecologists. 

THE   SPECIES 

There  are  seven  species  of  Anolis  described  for  Jamaica  (Under- 
wood and  Williams,  1959). 

Two  of  the  species — sagrei  and  grahami — can  be  characterized 
as  inhabiting  strictly  lower  and  middle  elevations.  A.  grahami  is 
very  widespread,  occurring  abundantly  throughout  the  lowlands. 
Ty^icdX  grahami  (subspecies  grahami)  are  medium-sized  {'  snout- 
vent  length  (SVL)   =  65.5  mm;  9   SVL  =  44.0  mmy  green  to 


1  Means  are  of  the  largest  third  of  all  specimens  examined  (see  Schoener, 
1969). 


6  BREVIORA  No.    368 

green-blue  lizards  occurring  in  all  areas  but  the  northeast,  where 
they  are  replaced  by  grahami  aquarum,  a  somewhat  smaller 
(^  SVL  =  61.8  mm;  9  SVL  =  45.1  mm),  bright  emerald  green 
lizard.  A.  sagrei,  a  medium-small  (^  SVL  =  50.4  mm;  9  SVL  = 
40.9  mm)  brown  species,  is  restricted  in  habitat  on  Jamaica,  occur- 
ring only  over  the  western  portion  of  the  island  and  there  confined 
to  the  openest,  sunniest  areas.  It  is  often  associated  with  rocks. 
Apparently,  sagrei  has  invaded  Jamaica  from  Cuba  and  is  in  the 
process  of  spreading  eastward  (Underwood  and  Williams,  1959; 
Williams,  1970). 

Another  primarily  low  and  middle  elevation  species  is  lineatopus. 
This  medium-sized  (^  SVL  =  62.7  mm;  9  SVL  =  43.6  mm) 
lizard  is  perhaps  the  most  varied  in  its  coloration  and  pattern:  four 
subspecies  are  recognized,  some  of  which  are  found  in  dry  open 
areas  and  others  of  which  are  restricted  to  the  darkest  forest 
(Underwood  and  WilUams,  1959). 

Two  species  have  been  recorded  from  the  lowlands  to  c.  4500 
feet.  A.  opalinus,  slightly  smaller  than  sagrei  (^  SVL  =  49.5  mm; 
9  SVL  =  40.5  mm),  comes  in  varying  patterns  and  shades  of 
brown  and  grey.  There  is  scarcely  a  locality  in  Jamaica  that  does 
not  have  this  species,  though  in  the  lowlands  it  is  restricted  to  the 
shadiest  areas  and  in  the  uplands  is  found  in  very  open  situations 
(Underwood  and  WilUams,  1959;  Rand,  1967;  this  paper).  The 
grey-white,  medium-large  (^  SVL  =  79.4  mm;  SVL  =  68.5  mm) 9 
valencienni  seems  not  to  reach  the  density  that  the  aforementioned 
species  sometimes  do  but  is  found  throughout  Jamaica,  including 
some  areas  above  4000  feet.  It  appears  to  be  commoner  in  open 
than  in  heavily  shaded  situations,  but  by  no  means  is  absent  from 
the  latter  (see  below). 

The  above  five  species  are  the  ones  which  occurred  commonly  at 
one  or  more  of  the  three  localities  studied,  and  which  are  therefore 
included  in  the  comparisons  to  follow.  A  sixth  species,  the  "green 
lizard"  garmani,  was  seen  at  each  of  the  three  study  sites,  but  rarely. 
It  is  the  largest  of  the  Jamaican  anoles  (^  SVL  =  110.0  mm;  9 
SVL  =  82.5  mm)  and  occurs  throughout  the  island  at  all  eleva- 
tions (Underwood  and  Williams,  1959).  However,  it  is  most 
abundant  relative  to  other  Anolis  species  at  middle  elevations 
(e.g.,  Trivers,  MS,  and  below),  though  it  is  also  known  to  be 
common  at  certain  lowland  localities,  such  as  the  "ironshore"  vege- 
tation along  the  northwest  coast.   The  seventh  species,  reconditus, 


1971  JAMAICAN    ANGLES  7 

is  restricted  to  middle  and  upland  elevations  and  has  only  recently 
been  discovered  (Underwood  and  Williams,  1959;  Lazell,  1966). 

LOCALITIES 

Three  lowland  localities  were  selected  for  study,  representing  a 
wet,  a  rather  dry,  and  a  mesic  area. 

The  first,  about  ten  acres  in  extent,  was  located  east  of  the  town 
of  Port  Antonio,  on  Jamaica's  northeast  coast.  Specifically,  it  ex- 
tended over  the  northwestern  edge  of  a  point  of  land  supporting 
the  ruins  of  an  estate  locally  referred  to  as  the  "Folly."  The  vege- 
tation was  quite  secondary:  planted  trees  and  shrubs,  such  as  Ficus, 
limes,  palms,  and  mango  trees  intermingled  with  native  vegetation 
such  as  Tenninalia.  This  locality  had,  however,  become  consider- 
ably overgrown,  and  there  then  existed,  side-by-side,  an  area  of 
almost  continuous  canopy  and  oftentimes  sparse  understory  on  the 
one  hand,  and  an  area  of  widely  spaced  trees  and  shrubs  with 
much  low,  tangled  herbaceous  vegetation  on  the  other.  Both  areas 
were  studied  and  will  be  discussed  separately  as  "Port  Antonio 
Open"  and  "Port  Antonio  Closed." 

The  locality  was  worked  30  June-1 1  July  1967.  Despite  the  fact 
that  Jamaica  was  then  undergoing  one  of  its  most  intense  droughts, 
rain  fell  fairly  frequently  though  not  protractedly;  the  area  averages 
131  inches  of  rain  per  annum  (Handbook  of  Jamaica,  1966).  The 
anoline  species  grahami  aquarum,  lineatopus  lineatopus  (or  inter- 
mediates betwen  lineatopus  and  ahenobarbus)  and,  to  a  lesser 
degree,  opalimis  and  valencienni  were  abundant  in  the  open  area; 
the  species  opalimis  and  lineatopus,  and  to  a  much  lesser  degree 
valencienni,  were  common  in  the  closed  area. 

The  second  study  site,  about  four  acres  in  extent,  was  located  at 
Mona,  near  Kingston,  in  tall,  open  forest  near  the  base  of  Long 
Mountain.  It  apparently  was  marginal  to  Rand's  (1967)  "Mona 
bush"  study  area,  but  differed  in  its  much  greater  preponderance 
of  grahami.  Vegetation  in  this  area  consisted  of  large  trees  and 
smaller  woody  shrubs  of  typical  tropical  dry  forest  aspect:  thorns, 
flattened  canopies  and  small,  numerous  leaves.  The  understory,  in 
addition  to  the  shrubs,  was  mostly  grass  of  about  one  to  two  feet 
in  height,  but  certain  patches  were  practically  cleared  while  others 
had  a  more  varied  herbaceous  vegetation.  The  latter  appeared  seri- 
ously affected  by  the  drought.  The  site  in  general  falls  within 
Asprey  and  Robbins'  (1953)  "dry  limestone  scrub  forest." 


8  BREVIORA  No.    368 

The  area  was  studied  13-18  July  1967.  Rainfall  was  almost  non- 
existent during  this  period.  The  nearby  Hope  Gardens  record  51 
inches  of  rain  per  year  (Handbook  of  Jamaica,  1966),  though 
because  of  the  extreme  microgeographic  variation  in  climate  found 
on  the  Greater  Antilles,  this  figure  may  not  be  the  same  as  that 
for  the  study  site  itself.  The  anoline  species  grahami  grahami, 
lineatopus  lineatopus  and  opal'mus  abounded  in  the  area.  In  addi- 
tion, valencienni  was  not  uncommon. 

The  third  study  area  was  located  about  one  mile  west  of  White- 
house,  near  the  southwest  coast.  It  consisted  of  groups  of  trees 
and  shrubs  of  mesic  to  xeric  aspect,  which  remained  after  partial 
conversion  into  pastureland.  The  portion  of  this  area  closest  to  the 
coast  was  planted  in  limes  and  pimentos;  further  upland,  patches  of 
native  trees  merged  gradually  into  unbroken  forest.  In  places,  con- 
siderable grassy  and  rocky  areas  showed  effects  of  heavy  grazing. 
The  vegetation  is  labelled  by  Asprey  and  Robbins  (1953)  "culti- 
vated pasture  or  second  growth  scrub,"  bordered  by  remnants  of 
"dry  limestone  scrub  forest,"  or  by  forest  transitional  between  that 
and  "wet  limestone  forest."  The  total  area  considered  encompassed 
about  15  acres,  though  parts  of  it  were  not  included  in  the  censuses. 

The  area  was  studied  21-27  July  1967.  Weather  was  regular  and 
cychcal  during  that  time,  sunny  mornings  giving  way  to  overcast 
or  partly  cloudy  afternoons,  accompanied  sometimes  by  heavy 
downpours.  A  nearby  town  (Bluefields)  logs  91  inches  of  rain 
per  annum  (Handbook  of  Jamaica,  1966).  The  form  grahami 
grahami  occurred  throughout  the  study  area.  The  other  two  com- 
mon species,  sagrei  and  opalimis,  were  restricted  to  open  and  closed 
areas  respectively,  and  their  horizontal  ranges,  though  interdigitat- 
ing,  overlapped  Uttle  at  the  same  time  of  day.  A  fourth  species, 
valenciemii,  was  seen  rarely.  The  investigation  of  the  opalimis- 
grahami  area  has  been  partly  reported  in  a  different  context 
(Schoener,  1970)  but  will  be  reiterated  in  entirety  below  so  as 
to  standardize  its  results. 

RESULTS    FOR    LIZARD    STRUCTURAL   HABITATS 

In  the  following  discussion,  all  comparisons,  unless  stated  other- 
wise, are  statistically  significant  (Tables  6-9)  as  judged  by  the 
technique  described  in  the  appendix.  Statements  in  the  text  to 
follow,  such  as  lizards  of  species  A  "occurred  higher"  or  "were 


1971  JAMAICAN    ANGLES  9 

higher"  than  those  of  species  B,  should  be  interpreted  as  descrip- 
tive of  the  modal  individual  or  the  bulk  of  the  population  rather 
than  of  all  individuals  in  the  species'  population.  Large  lizards 
could  always  be  distinguished  as  adult  males  and  will  generally  be 
referred  to  hereafter  simply  as  "males."  Smaller  lizards  included 
mostly  adult  or  subadult  females  but  also  included  some  subadult 
males;  they  were  all  lumped  into  the  class  "female-sized  lizards" 
because  they  could  not  usually  be  distinguished  in  the  field.  When 
sufficiently  abundant,  the  smallest  lizards — "juveniles" — are  con- 
sidered separately. 

Mona  (Tables  1,  6).  At  Mona,  ten  classes  of  lizards  in  four  species 
were  considered. 

The  highest  lizard  species  observed  was  valencienni:  males  occurred 
higher  than  any  other  class,  and  female-sized  valencienni  were  higher  than 
all  but  grahami  males.  A.  grahami  was  the  next  highest  species:  its  males 
occurred  higher  than  all  classes  of  lineatopus  and  opalinns.  The  males  of 
opalinus  occurred  higher  than  female-sized  grahami  and  all  lineatopus. 
Female-sized  grahami  were  higher  than  all  lineatopus  and  female-sized 
opalinus.  Male  lineatopus  occurred  higher  than  female-sized  opalinus  and 
grahami  juveniles.  Female-sized  opalinus  occurred  higher  than  grahami 
juveniles  and  female-sized  or  juvenile  lineatopus.  Juveniles  of  grahami  were 
higher  than  female-sized  and  juvenile  lineatopus. 

A.  opalinus  as  a  species  was  on  perches  of  the  greatest  diameter;  males  of 
this  species  were  on  significantly  thicker  perches  than  all  classes  but  male 
grahami,  and  only  the  latter  occupied  thicker  perches  than  female-sized 
opalinus.  Male  grahami  were  also  on  thicker  diameters  than  any  other 
interspecific  class.  Female-sized  opalinus  and  male  lineatopus  had  about 
the  same  perch  diameters  but  were  on  thicker  perches  than  valencienni 
and  female-sized  or  juvenile  grahami  and  lineatopus.  Female-sized  grahami, 
valencienni,  and  lineatopus  all  occurred  on  thin  perches  of  nonsignificantly 
different  diameter.  Juveniles  of  lineatopus  and  grahami  occupied  the  small- 
est perches,  the  latter  the  smallest  of  all. 

Intraspecifically,  in  all  four  species  males  perched  higher  than  did  female- 
sized  individuals,  and  female-sized  individuals  in  grahami  and  lineatopus 
occurred  higher  than  did  juveniles.  In  all  but  valencienni,  males  frequented 
thicker  perches  than  did  female-sized  individuals,  and  in  grahami  and 
lineatopus,  female-sized  lizards  were  on  thicker  perches  than  juveniles. 

Although  climatic  observations  were  not  recorded  at  Mona,  our  impres- 
sion is  that  the  species  tended  to  separate  the  way  Rand  (1967a)  has  de- 
scribed for  a  nearby  area:  grahami  and  valencienni  were  in  the  openest, 
sunniest  situations;  lineatopus  was  intermediate;  and  opalinus  was  in  the 
shadiest  areas.  Relatively  shady  areas  at  Mona  are  associated  with  large- 
diametered   trees,    and    the   comparatively    small   opalinus   preferred   trees 


10  BREVioRA  No.  368 

whose  diameters  were  bigger  than  those  for  any  group  but  grahami  males. 

Port  Antonio  Open  Area  (Tables  2,  7).  The  classes  studied  in  the  open 
segment  of  the  Port  Antonio  site  were  the  same  as  those  observed  at  Mona. 

In  relative  height,  the  lizard  classes  were  arranged  in  nearly  identical 
fashion  to  those  at  Mona.  Male  valencienni  were  the  highest,  as  before, 
followed  by  grahami  males,  which  were  here  significantly  higher  than  female- 
sized  valencienni.  Probably  the  greater  number  of  low  thin-branched  shrubs 
in  relation  to  trees  in  the  open  area  at  Port  Antonio  is  responsible  for  this 
discrepancy  with  the  Mona  area.  Next  in  height  were  male  opaliniis,  higher 
than  female-sized  and  juvenile  grahami  as  well  as  all  classes  of  lineatopus. 
Female-sized  grahami  and  opalinus  were  distributed  over  similar  heights 
and  were  higher  than  any  class  of  lineatopus.  Males  of  lineatopus  were 
higher  than  juvenile  grahami,  but  the  latter  were  higher  than  female-sized 
or  juvenile  lineatopus. 

In  diameter,  there  was  a  major  reversal  from  the  pattern  at  Mona.  Adult 
male  valencienni,  the  largest  of  the  four  species,  occurred  on  diameters  not 
significantly  thinner  than  those  of  grahami  or  opalinus  males  and  signifi- 
cantly thicker  than  those  of  male  lineatopus.  Males  of  opalinus  at  Port 
Antonio  were  on  thicker  diameters  than  grahami  males,  and  the  latter 
showed  no  significant  difference  from  female-sized  opalinus.  Female-sized 
opalinus  were  on  thicker  perches  than  female-sized  or  juvenile  grahami, 
lineatopus,  or  valencienni.  Males  of  lineatopus  occurred  on  larger-diam- 
etered  perches  than  did  female-sized  and  juvenile  grahami  or  female-sized 
valencienni.  Female-sized  grahami  occupied  thicker  perches  than  did  female- 
sized  valencienni  or  female-sized  and  juvenile  lineatopus.  Female-sized 
valencienni  occurred  on  thicker  perches  than  did  female-sized  lineatopus  or 
juveniles  of  grahami  and  lineatopus.  Finally,  female-sized  lineatopus  were 
on  thicker  perches  than  grahami  juveniles. 

Within  the  same  species,  males  of  grahami,  opalinus,  and  lineatopus  were 
found  higher  than  smaller-sized  individuals.  In  addition,  female-sized  anoles 
were  higher  than  juveniles  in  grahami  and  lineatopus.  For  each  species, 
classes  whose  individuals  were  of  the  largest  size  were  found  on  thicker 
perches  than  all  classes  of  smaller  individuals. 

Once  again,  opalinus  and  grahami  segregated  by  shade  and  sun,  respec- 
tively. And  again,  opalinus,  a  small  species,  occurred  on  bigger  trunks  and 
branches  than  did  the  larger  species  grahami  or  lineatopus.  A.  opalinus  was 
also  found  close  to  the  ground  in  shrubby,  more  tightly  packed  vegetation, 
where  it  was  able  to  perch  in  the  shade.  In  such  areas,  which  were  scat- 
tered in  patches  throughout  the  study  site,  grahami  ranged  higher,  being 
found  on  leaves  and  more  exposed  branches.  As  at  Mona,  male  lineatopus, 
similar  in  size  to  male  grahami,  were  more  often  found  on  thinner  perches. 

Unlike  the  Mona  situation  where  leaves  were  mostly  small,  the  Port 
Antonio  site  contained  many  broad-leaved  herbaceous  plants.  In  such  vege- 
tation, particularly  on  leaves,  it  was  common  to  see  female  and  juvenile 


1971  JAMAICAN    ANGLES  U 

grahomi  (Table  2).  It  is  possible  that  aquarum,  which  is  that  form  of 
grahaini  inhabiting  the  wettest  lowland  areas  (including  Port  Antonio),  is 
both  smaller  and  of  a  brighter,  more  leafy  green  color  because  of  its  oppor- 
tunity for  occupying  the  more  luxuriant  green  vegetation  resulting  from  the 
heavy  rainfall. 

Port  Antonio  Closed  Area  (Tables  3,  8).  In  this  more  shaded  site,  so  few 
valencienni  were  seen  that  they  are  all  lumped  into  one  category.  Repre- 
sentatives of  grahami  were  also  very  uncommon  and  are  therefore  not 
included.  In  addition,  because  of  the  much  greater  abundance  of  opalinus, 
female-sized  individuals  are  treated  separately  from  juveniles  in  that  species. 

In  height,  differences  between  all  possible  pairs  of  lizard  classes  were 
significant.  The  order  of  groups,  from  highest  to  lowest,  was  valencienni, 
opalinus  males,  lineatopiis  males,  female-sized  opalinus,  opalinus  juveniles, 
female-sized  lineatopus,  and  lineatopus  juveniles. 

In  diameter,  opalinus  males  were  on  thicker  perches  than  any  other  group. 
Female-sized  opalinus,  male  lineatopus,  and  valencienni  occurred  on  perches 
not  significantly  different  in  diameters,  and  all  were  on  thicker  perches  than 
female-sized  lineatopus  or  juveniles  of  opalinus  and  lineatopus.  Female- 
sized  lineatopus  occurred  on  thicker  perches  than  did  juveniles  of  opalinus. 

Intraspecific  relations  paralleled  those  for  the  other  two  areas:  in  opalinus 
and  lineatopus,  the  larger  the  size  of  the  lizard,  the  higher  it  occurred,  and 
the  thicker  were  its  perches. 

Whitehouse  (Tables  4,  9).  The  study  site  near  Whitehouse  is  identical  in 
species  composition  to  those  near  Mona  and  Port  Antonio  except  that  sagrei 
replaces  lineatopus.  The  only  form  of  lineatopus  in  the  vicinity  of  the  site 
is  neckeri,  an  animal  which  seeks  darker  forest  than  opalinus.  As  stated 
above,  climatic  observations  were  recorded  at  Whitehouse  in  addition  to 
those  on  structural  habitat.  Although  reported  in  part  elsewhere  (Schoener, 
1970),  data  treatment  here  differs  in  two  major  respects:  the  category 
"clouds"  was  added  to  those  of  "sun"  and  "shade"  for  the  climatic  variable, 
and  "time"  is  not  considered  as  an  additional  variable. 

In  this  area  again,  grahami  males  and  valencienni  (all  classes  combined) 
were  found  at  the  greatest  heights.  They  were  followed  by  female-sized 
grahami,  which  occurred  higher  than  any  class  of  sagrei  or  opalinus. 
Juvenile  grahami  were  found  higher  than  sagrei  and  male  opalinus.  Both 
classes  of  opalinus  perched  at  greater  heights  than  did  any  class  of  sagrei. 

Male  grahami,  male  opalinus,  and  female-sized  opalinus  did  not  show 
significant  differences  in  perch  diameter,  though  the  first  were  on  the  thickest 
perches.  Male  grahami  were  found  on  thicker  diameters  than  male  sagrei, 
but  the  latter  did  not  differ  significantly  from  either  class  of  opalinus.  Male 
sagrei  occurred  on  thicker  perches  than  did  female-sized  grahami,  juvenile 
grahami  and  valencienni.  Female-sized  sagrei,  juvenile  sagrei  and  valen- 
cienni all  had  greater-diametered  perches  than  did  juvenile  grahami.  In 
addition,  sagrei  juveniles  perched  at  greater  diameters  than  did  the  com- 
bined valencienni. 


12  BREVIORA  No.    368 

Within  the  same  species,  adult  males  of  grahami,  sagrei,  and  opoliniis 
perched  higher  than  female-sized  individuals.  The  latter  in  sagrei  perched 
higher  than  juveniles,  but  in  grahami  the  two  classes  were  similar  in  height. 

Once  again,  males  of  the  three  commonest  species  occurred  on  thicker 
perches  than  did  smaller  individuals,  but  the  results  were  not  significant  for 
opalinus.  Juveniles  in  grahami  and  sagrei  were  found  on  thinner  perches 
than  the  other  intraspecific  classes. 

Although  there  was  an  overall  tendency  for  sagrei  and  valencienni  to  be 
found  most  often  in  the  sun  and  opalinus  most  often  in  the  shade  or  on 
cloudy  days,  this  pattern  varied  by  species  class  (Table  5).  Males  of 
opalinus  were  most  consistently  found  in  the  shade:  they  were  seen  signi- 
ficantly more  often  during  cloudy  days  or  occurred  more  often  on  shady 
perches  than  male  and  juvenile  sagrei,  male  and  female-sized  grahami,  and 
valencienni.  Juveniles  of  sagrei,  in  contrast,  were  very  frequently  seen  in 
the  sun:  all  classes  of  grahami  and  male  opalinus  were  seen  significantly 
more  often  in  the  shade  or  during  cloudy  weather  than  were  juvenile  sagrei. 
Only  two  other  intraspecific  comparisons  were  significant:  female-sized 
grahami  were  most  often  seen  in  the  sun  or  during  cloudy  days  than  male 
sagrei,  and  valencienni  were  most  often  seen  in  the  sun  or  on  cloudy  days 
than  male  grahami.  Thus  there  was  no  invariant  tendency  for  that  class 
recorded  most  often  in  the  shade  to  be  also  the  one  recorded  most  often 
during  cloudy  weather. 

Only  a  few  intraspecific  differences  were  significant:  male  opalinus  were 
recorded  more  frequently  in  the  shade  or  on  cloudy  days  than  smaller 
opalinus;  female-sized  grahami  were  more  frequently  seen  in  the  sun  or  on 
cloudy  days  than  male  grahami,  and  female-sized  sagrei  were  more  fre- 
quently seen  in  the  shade  or  during  cloudy  weather  than  juvenile  sagrei. 
Thus  there  was  some  inclination  for  the  smaller-sized  lizards  within  a  species 
to  be  on  sunnier  perches. 

DIFFERENCES    BETWEEN    HABITAT   VARIABLES 

The  statistical  treatment  of  the  structural-habitat  data  also  de- 
tects significant  interactions  between  the  two  perch  variables,  height 
and  diameter,  and  when  available,  the  climatic  variable.  Thus  it 
answers  the  following  kind  of  question:  is  there  a  significant  asso- 
ciation between  thin  perches  and  high  perches  for  all  perches 
combined  of  the  two  lizard  classes  being  compared? 

At  Mona,  for  most  comparisons  among  lizard  classes,  small 
perches  occurred  at  greater  heights  than  did  large  perches  (Table 
6).  However,  in  the  three  of  nine  cases  in  which  a  significant 
height-diameter  interaction  was  found  (male  grahami  with  female- 
sized  grahami,  male  valenciemii,  or  female-sized  valenciemu) ,  the 


1971  JAMAICAN    ANGLES  13 

reverse  was  true.  In  the  Port  Antonio  open  area,  on  the  other 
hand,  where  trees  were  more  widely  scattered  and  there  was  much 
low  second  growth,  all  significant  associations  were  of  small- 
diametered  perches  with  low  heights.  Whitehouse  resembled  the 
Mona  area  more  than  Port  Antonio  in  its  relation  of  perch  height 
to  perch  diameter;  low  perches  tended  to  be  of  larger  diameter. 
This  interaction  again  reflects  the  vegetation  structure:  at  White- 
house,  there  were  few  tall  trees  and  little  herbaceous  understory — 
most  large  perches  were  therefore  low,  including  the  fenceposts 
especially  preferred  by  sagrei.  The  only  statistically  significant  ex- 
ceptions to  this  pattern  were  for  sagrei  juveniles,  the  most  terrestrial 
class  of  lizards  on  the  site. 

At  Whitehouse,  it  was  also  possible  to  look  for  associations 
between  the  climatic  categories  and  those  of  perch  height  and 
diameter  (Table  9). 

There  were  few  significant  interactions  between  perch  height  and 
insolation,  probably  because,  in  the  patchy  vegetation  of  the  study 
site,  the  sun  penetrated  for  the  most  part  to  vegetation  of  all 
heights.  For  intraspecific  sagrei  comparisons,  higher  perches 
tended  to  be  relatively  shady  and  lower  perches  relatively  sunny. 
Individuals  of  sagrei  were  found  more  often  than  those  of  other 
species  in  areas  away  from  the  shade  provided  by  large  trees  and 
shrubs:  in  such  areas,  most  perches  are  both  low  and  sunny.  Lower 
perches  in  sun  than  during  cloudy  weather  were  found  for  the  com- 
bined data  of  juvenile  grahami  and  male  sagrei.  In  contrast,  the 
lowest  perches  were  found  in  the  shade  or  sun  and  the  highest  on 
cloudy  days  for  female-sized  sagrei  lumped  with  grahami  males. 
Why  these  were  the  only  interspecific  comparisons  showing  a  sig- 
nificant height-insolation  interaction  is  not  apparent. 

There  were  many  more  significant  associations  between  perch 
diameter  and  insolation.  All  but  one  were  of  two  sorts:  the  thinnest 
perches  were  occupied  in  the  sun  and  the  thickest  in  either  shade  or 
on  cloudy  days.  (The  exception  was  for  female-sized  and  juvenile 
grahami:  thinnest  perches  were  shadiest,  and  thickest  perches  were 
utilized  during  cloudy  weather.)  In  a  previous  study  which  also 
separated  observations  by  time  of  day,  a  three-way  interaction  be- 
tween diameter,  insolation,  and  time  was  detected  at  Whitehouse 
(Schoener,  1970).  Exterior  perches  tend  to  be  thinner  in  all  habi- 
tats, but  in  patchy  ones  such  as  that  at  Whitehouse,  tend  to  be 
sunnier  as  well — thus  the  association  may  simply  reflect  the  phys- 
iognomy of  the  vegetation.   However,  Jenssen  (1970)  found  that 


14  BREVIORA  No.    368 

individuals  of  Anolis  nebiilosus  climb  into  vegetation  during  mid- 
day and  has  attributed  this  behavior  to  a  warming  of  the  substrate. 
Perhaps  a  similar  thermoregulatory  function  can  explain  the  lizards' 
avoidance  of  sunny,  large  surfaces  during  most  of  the  day  at 
Whitehouse. 

In  several  of  the  comparisons  for  each  locality,  the  statistical 
procedure  indicated  that  there  might  be  significant  three-way  inter- 
actions between  the  variables  (see  appendix).  Several  are  of  inter- 
est. Two  were  interactions  between  perch  diameter,  insolation  and 
lizard  class.  These  were  cases  in  which  a  low  class,  one  of  sagrei, 
was  paired  with  a  higher  class,  one  of  either  grahami  or  valencienni. 
In  sagrei,  thick  perches  are  more  likely  to  be  used  in  the  shade  on 
sunny  days,  whereas  in  the  more  arboreal  forms,  thick  perches  arc 
more  likely  to  be  used  on  cloudy  days.  Another  three-way  inter- 
action showed  that  sagrei  males  tended  to  seek  out  shady  perches 
that  were  most  often  relatively  high,  whereas  female-sized  sagrei 
found  their  shady  perches  relatively  lower.  Both  these  results 
probably  reflect  differences  in  regard  to  relative  availability  of  sun- 
less perches  between  the  habitats  of  the  classes  being  compared. 

As  inspection  of  Tables  6-9  shows,  there  is  a  considerable  num- 
ber of  significant  interactions  involving  cHmatic  and/or  habitat 
variables  alone;  therefore  the  extended  statistical  treatment  given 
the  data  of  this  paper  is  well  justified.  Most  of  these  interactions 
reflect  differences  in  the  vegetational  structure  and  its  exposure  to 
the  sun.  As  mentioned,  a  few  may  indicate  thermoregulatory  be- 
havior on  the  part  of  the  hzards.  However,  the  use  of  the  climatic 
categories — sun,  shade,  and  clouds — can  only  give  a  crude  first 
approximation  of  the  climatic  preferences  of  these  animals.  Finer 
resolution  would  be  gained  were  temperature,  humidity,  wind 
speed,  and  other  variables  measured  at  each  perch. 

DISCUSSION    OF    LIZARD    STRUCTURAL    HABITATS    AND 
RELATION    TO    PREVIOUS   STUDIES 

The  climatic  and  structural  habitats  of  the  lowland  species  can 
be  summarized  as  follows. 

1.  Climatic.  As  first  pointed  out  by  Rand  (1967a)  for  Kings- 
ton populations,  in  all  localities  grahami  inhabited  relatively  open, 
sunny  places  and  opalimis  relatively  closed,  shaded  places.  At 
Mona  and  Port  Antonio,  Uneatopus  was  intermediate  in  this  regard. 
However,  sagrei,  its  structural  habitat  counterpart  at  Whitehouse, 
occurred  in  sunnier,  more  exposed  places  than  did  grahami.  In  that 


1971  JAMAICAN    ANGLES  15 

locality,  opaliniis  occurred  on  lower  perches  than  elsewhere  and 
thus  occupied  in  part  perches  where  Uiieatopus  would  have  been 
expected  were  it  present. 

2.  Structural.  In  all  four  study  areas,  valencienni  as  a  species 
was  seen  higher  than  its  congeners  (Figs.  1-4).  Wherever  found, 
grahami  was  next  in  height,  followed  usually  quite  closely  by  opa- 
linus.  However,  at  Port  Antonio  female-sized  lizards  of  grahami 
aquarum  were  lower  than  either  class  of  opalinus,  reflecting  their 
abundance  in  herbaceous  vegetation  at  that  site.  Lineatopus  and 
sagrei  both  occurred  lowest  in  their  respective  sites  though  sagrei 
appeared  relatively  more  terrestrial.  The  ranking  of  species  by 
height  at  Mona  was  the  same  as  that  found  by  Rand  in  several 
localities  near  Kingston.  As  can  be  seen  from  the  figures,  no  par- 
ticular between-species  relationship  of  species-size  to  height  was 
evident.  However,  within  species,  smaller  lizards  always  tended  to 
occur  lower  than  did  larger  ones. 

The  ordering  of  species  with  respect  to  perch  diameter  is  slightly 
less  consistent  from  locality  to  locality.  At  Mona,  both  male  and 
female-sized  lizards  taken  separately  showed  a  perfect  inverse  rela- 
tion of  body  size  and  perch  diameter:  the  largest  species,  valen- 
cienni, occurred  on  the  thinnest  perches,  followed  by  lineatopus, 
then  grahami,  and  finally,  the  smallest  species,  opalinus  (Fig.  1, 
Table  1) .  At  Port  Antonio  Open,  the  situation  was  the  same  ex- 
cept that  male  valencienni  occurred  on  thicker  perches  than  all  but 
male  opalinus,  and  female-sized  lineatopus  occurred  on  thinner 
perches  than  female-sized  valencienni  (Fig.  2,  Table  2).  At  Port 
Antonio  Closed,  where  only  two  species  were  considered  in  detail, 
opalinus  again  took  thicker  perches  than  did  lineatopus  for  both 
sexes  (Fig.  3,  Table  3).  At  Whitehouse,  the  ordering  was  essen- 
tially the  same  as  at  Mona,  except  that  sagrei  replaces  lineatopus 
(Fig.  4,  Table  4).  However,  sagrei  is  smaller  than  grahami,  so 
there  is  not  a  perfect  inverse  relation  of  species-size  and  diameter 
at  Whitehouse.  Taken  as  a  whole,  the  data  are  in  almost  total 
opposition  to  what  would  be  expected  if  perch  diameters  were 
selected  by  species  on  the  basis  of  body  weight.^  The  inverse  rela- 
tion is  made  all  the  more  interesting  by  the  fact  that  within  each 


1  It  should  be  pointed  out,  however,  that  garmani,  the  largest  species  on 
Jamaica,  was  very  rare  and  was  therefore  not  considered  in  the  study  sites. 
What  few  data  exist  on  the  perch  diameter  of  this  species  (Rand,  1967a, 
our  unpublished  data)  indicate  that  garmani  do  not  inhabit  thinner  perches 
than  valencienni  but  rather  are  often  found  on  large  trees  and  therefore 
often  perch  on  large  branches. 


16  BREVIORA  No.    368 

species,  all  significant  associations  are  of  larger  individuals  with 
larger  perches  and  vice-versa.  Clearly  some  explanation  other  than 
a  purely  supportative  one  must  be  sought  for  species-specific  differ- 
ences in  perch  diameter. 

A  possible  explanation  is  the  following.  Given  that,  within 
species,  larger  individuals  are  found  on  larger  perches,  an  inverse 
relation  between  perch  diameter  and  species  size  would  be  expected 
if  species  evolved  so  that  that  class  of  a  given  species  overlapping 
in  space  the  most  with  a  class  of  another  species  was  the  one  which 
differed  the  most  in  size  from  the  latter  class.  In  other  words,  a 
direct  relationship  between  size  and  perch  diameter  within  species 
and  an  inverse  one  between  species  is  one  way  of  ensuring  that 
interspecific  spatial  overlap  is  between  dissimilarly  sized  individuals. 
In  fact,  given  the  direct,  within-species  relationship,  none  of  the 
24  possible  permutations  of  the  species  ordered  by  diameter  results 
in  less  total  difference  in  the  sizes  of  the  most  closely  overlapping 
interspecific  pairs,  though  a  few  alternatives  are  about  as  good  as 
the  one  discussed.  Because  anoline  lizards  of  different  sizes  take 
differently  sized  foods  (Rand,  1967a;  Schoener,  1967,  1968; 
Schoener  and  Gorman,  1968),  such  staggering  of  sizes  in  space 
should  alleviate  resource  competition  (Rand,  1967b;  Schoener, 
1968). 

Reversal  of  both  the  within-  and  between-species  relationships  is, 
of  course,  an  alternative  way  of  juxtaposing  dissimilarly  sized 
classes  from  different  species.  Why  then  does  this  second  arrange- 
ment not  occur  instead?  An  answer  can  perhaps  be  found  if  we 
examine  the  probable  course  of  faunal  increase  on  Jamaica.  It  is 
highly  unlikely  that  the  four  species  evolved  simultaneously  and 
sympatrically.  Therefore,  while  in  isolation  from  other  anoles,  the 
first  species  to  have  evolved  probably  showed  a  direct  within-species 
relationship  between  body  size  and  perch  diameter:  not  only  is  a 
direct  relationship  adaptive  over  the  large  range  in  body  sizes 
spanned  by  the  different  age  classes,  but  dominant  individuals 
in  Anolis  are  usually  largest  (Rand,  1967b;  Trivers,  in  prep.; 
Schoener,  in  prep.)  and  would  therefore  appropriate  the  most  suit- 
able perches.  Furthermore,  all  solitary  species  studied  in  hetero- 
geneous vegetation  showed  such  a  direct  relationship  (Rand  and 
Rand,  1966;  Schoener,  1967;  Schoener  and  Schoener,  in  prep.). 
Upon  coming  together,  in  order  to  achieve  the  second  arrangement, 
the  species  would  have  to  change  their  species-specific  size  and/or 


1971  JAMAICAN    ANGLES  17 

perch  diameters  as  well  as  the  within-species  relationship  between 
size  and  perch  diameter.  Rather  than  that,  it  seems  more  feasible 
for  species  to  shift  their  size  and/or  perch  diameters  in  such  a  way 
as  to  preserve  the  intraspecific  relationship  and  still  avoid  overlap 
of  similarly  sized  individuals,  i.e.,  in  accordance  with  the  existing 
arrangement.  The  positioning  of  a  relatively  large  species  on 
perches  of  relatively  small  diameter  could  then  be  facilitated  by 
morphological  changes  in  body  proportions,  such  as  those  in  rela- 
tive leg  length.  Indeed,  some  proportional  differences  do  seem  to 
exist  in  the  Jamaican  species:  valencienni,  the  largest  species  con- 
sidered, has  relatively  short  limbs,  particularly  in  femur.  Similar 
changes  in  proportions  would  likely  be  more  difficult  to  build  into 
the  ontogeny  of  single  species,  as  would  be  necessary  were  the 
second  arrangement  adhered  to. 

Though  there  is  no  between-species  relationship  of  perch  height 
and  size,  the  within-species  tendency  for  smaller  individuals  to  be 
found  relatively  low  also  results  in  minimal  interspecific  spatial 
overlap  of  similarly  sized  individuals,  except  for  the  valencienni- 
grahami  combination,  in  which  female-sized  valencienni  are  about 
the  same  size  as  male  grahami.  However,  those  classes  occur  on 
quite  different  perch  diameters  (Figs.  1-2,  Tables  1-4),  and  Trivers 
(personal  communication)  has  evidence  for  major  differences  in 
searching  for  prey  and,  possibly,  prey  taxa  between  the  two  species. 
Rand  (1967a)  noted  a  tendency  for  opalinus  and  lineatopus  to 
juxtapose  dissimilar  sizes  according  to  height,  in  localities  around 
Kingston,  but  he  found  the  opposite  for  grahami  and  lineatopus. 
A  further  difference  between  Rand's  and  our  study  is  that  his  data 
for  small-sized  grahami  are  bimodally  clustered  by  height,  one 
mode  being  below  six  feet  and  the  other  above  ten  feet.  A  likely 
reason  for  the  discrepancy  is  difference  in  the  structure  of  the  avail- 
able vegetation  of  the  respective  sites.  Rand  observed  most  of  his 
grahami  on  the  campus  of  the  University  of  the  West  Indies  where 
there  is  little  high,  shrubby  understory  surrounding  the  large  trees. 
Thus  the  distribution  of  female-sized  grahami  may  have  paralleled 
differences  in  vegetational  layers.  The  three  localities  we  looked 
at  were  all  more  overgrown  and  vegetationally  more  heterogeneous. 
We  also  found  a  greater  difference  in  perch  height  between  male 
and  female-sized  grahami  in  all  localities  than  did  Rand.  Possibly 
at  Mona  there  were  many  more  females  on  high  branches  than  we 
were  able  to  detect,  but  this  is  unlikely  to  be  much  of  a  factor  at 


18  BREVIORA  No.    368 

either  Port  Antonio  or  Whitehouse,  where  the  canopy  is  lower  and 
more  broicen.  Again,  the  lack  of  a  viney,  bushy  understory  in  the 
"park-like"  vegetation  where  Rand  studied  most  of  his  grahami  is 
probably  responsible  for  the  difference.  A  third  possible  reason  for 
the  difference  is  simply  some  effect  associated  with  the  smaller 
sample  size  Rand  used,  either  one  purely  of  sampling  error,  or  one 
related  to  a  smaller  range  of  times  of  day  or  weather  conditions 
than  covered  in  our  study. 

ACKNOWLEDGMENTS 

We  thank  T.  A.  Jenssen,  A.  S.  Rand,  R.  L.  Trivers,  and  E.  E. 
Williams  for  critical  comments  on  the  manuscript  and  S.  D.  Fien- 
berg  for  statistical  advice.  We  also  thank  C.  B.  Lewis  and  T.  Farr  of 
the  Jamaica  Institute  and  I.  Goodbody  of  the  University  of  the  West 
Indies  for  assistance  in  the  field.  Research  was  supported  by  NSF 
grants  GB  3167  to  the  Committee  on  Evolutionary  Biology,  Har- 
vard University,  and  NSF  grants  GB  6944  and  B  01 9801 X  to  E.  E. 
Williams. 

APPENDIX    I 

Statistical  Appendix 

Data  of  the  sort  presented  above  are  ideally  treated  in  the  form 
of  a  multiway  contingency  table,  because  variables  are  both  ordinal 
(perch  height  and  diameter)  and  nominal  (lizard  group,  climatic 
category).  In  the  case  of  nominal  variables,  there  is  no  problem 
in  selecting  categories  (referred  to  as  "levels"):  there  are  two 
lizard  groups  and  three  climatic  categories  (see  above).  However, 
for  ordinal  variables,  a  continuous  set  of  quantitative  data  must  be 
broken  at  one  or  more  places  in  order  to  form  categories.  Because 
of  the  multiphcative  increase  in  the  total  number  of  cells  in  a  con- 
tingency table  with  increasing  number  of  categories  for  a  single 
variable,  two  categories  each  were  chosen  for  perch  height  and 
perch  diameter.  That  is  to  say,  all  observations  less  than  or  equal 
to  some  number  were  cast  into  one  category,  and  all  those  greater 
than  that  number  were  cast  into  the  other.  The  point  at  which  the 
data  were  broken  was  chosen  by  computing  that  number  which 
gave  the  maximum  difference  in  cumulative  frequency  between  the 
two  distributions  of  observations  belonging  to  the  hzard  groups 
being  compared.    Hence  this  procedure  was  designed  to  detect 


1971  JAMAICAN    ANGLES  19 

maximum  differences  in  height  and  diameter  taken  separately  be- 
tween the  lizard  classes,  although  because  of  interactions  between 
variables,  it  will  not  necessarily  produce  a  maximum  difference  in 
a  combined  model.  The  critical  values  were,  of  course,  usually 
much  removed  from  those  required  to  give  maximum  interaction 
between  the  environmental  variables  themselves  (e.g.,  perch  height 
and  insolation).  The  critical  value  so  determined  for  height  or 
diameter  was  generally  different  in  different  comparisons,  and 
ranged  from  one-fourth  inch  to  four  inches  for  diameter  and 
eleven  inches  to  ten  feet  for  height.  An  alternative  procedure 
would  have  been  to  choose  the  same  intervals  for  all  comparisons, 
but  given  the  great  variation  in  lizard  habitat  preference,  would 
have  obscured  most  differences.  What  we  have  in  effect  done  is  to 
redefine  "high"  and  "thick"  for  each  comparison.  There  are  sta- 
tistical objections  to  this  procedure,  but  at  present  appropriate 
alternative  methods  of  grouping  data  are  not  available  (Fienberg, 
1970).  The  points  at  which  the  data  were  broken  are  fisted  here 
(Table  10)  for  two  reasons:  1)  Other  researchers  may  wish  to 
define  "high"  and  "thick"  differently  and  therefore  can  better 
compare  their  method  with  the  one  used  here;  and  2)  It  is  of 
biological  interest  when  comparing  habitat  distributions  to  know 
where  the  point  of  maximum  difference  fies,  especially  in  case 
the  observations  were  repeated  later  in  the  same  or  similar  areas. 

Once  categories  were  chosen,  the  procedures  diverged  for  three 
and  four  variable  situations. 

In  the  four-way  case,  a  contingency  model  was  first  set  up  which 
contained  all  possible  two-factor  or  pairwise  interactions  between 
the  four  variables;  in  this  case  there  were  (  ^  )  =  6  such  inter- 
actions. Then  an  iterative  procedure  described"  elsewhere  (Bishop, 
1969;  Mosteller,  1968;  Fienberg,  1970;  Schoener,  1970)  was  used 
to  fit  the  data  to  the  model,  that  is,  to  compute  expected  values  for 
each  ceU  of  the  contingency  table.  Two  measures  of  goodness  of 
fit,  the  standard  chi-square  and  the  log-likelihood  chi-square  (Kull- 
back,  1959)  were  computed  and  degrees  of  freedom  determined  as 
described  by  Ku  and  Kullback  (1968)  and  Fienberg  (1970).  It 
was  then  noted  whether  the  model  gave  a  fit  satisfactory  at  the  5 
per  cent  level.  In  most  cases  the  two  statistics  were  very  similar, 
but  where  they  allowed  a  different  conclusion  to  be  drawn  about 
significance,  the  log-likelihood  ratio  chi-square  was  followed. 

Next,  each  two-way  interaction  was  individually  dropped,  giving 
six  new  models.  For  each  of  these,  the  difference  between  the  new 


20  BREVIORA  No.    368 

model  and  the  original  model  was  evaluated  for  statistical  signifi- 
cance by  testing  the  difference  in  their  log-likelihood  ratio  chi- 
squares,  according  to  the  partitioning  technique  expounded  in 
Kullback  (1959),  Ku  and  KuUback  (1968),  and  Fienberg  ( 1970). 
If  all  new  models  were  significantly  diiferent  from  the  old  model 
at  the  5  per  cent  level  the  process  was  terminated.  Otherwise,  that 
new  model  was  then  chosen  (and  thereby  the  corresponding  inter- 
action removed)  whose  log-likelihood  ratio  chi-square  was  most 
similar  to  that  of  the  original  model.  The  procedure  was  then  re- 
peated, five  new  models  each  containing  four  two-way  interactions 
being  tested  against  the  model  containing  five  two-way  interactions. 
Interactions  were  thus  removed,  one  at  a  time,  until  all  models 
with  a  smaller  number  of  interactions  were  judged  significantly 
different  from  the  next  most  inclusive  model,  or  until  no  interaction 
remained. 

Because  of  space  limitations,  detailed  results  could  not  be  re- 
ported as  they  were  in  a  previous  paper  (Schoener,  1 970) .  Instead, 
the  results  are  summarized  in  Table  10.  The  six  tiers  of  the  table 
correspond  to  the  six  possible  two-way  interactions.  For  each  lizard 
combination,  these  are  given  a  number  from  zero  to  four.  A  "1" 
denotes  that  the  interaction  remained  significant  in  the  above  sense 
every  time  it  was  tested  in  the  removal  procedure.  A  "2"  denotes 
that  the  interaction  was  significant  at  least  at  the  termination  of  the 
procedure.  A  "3"  means  that  the  interaction  was  significant  when 
removed  from  the  most  inclusive  model  (with  six  interactions)  but 
not  at  termination.  A  "4"  indicates  that  the  interaction  was  sig- 
nificant sometime  during  the  procedure  but  not  at  the  beginning  or 
end.  A  "0"  indicates  that  the  interaction  was  never  significant. 
Interestingly,  in  Table  1 0  most  interactions  could  be  labelled  either 
"0"  or  "1",  and  in  the  simpler  three-variable  case,  all  interactions 
could  be  so  labelled  (Tables  7-9).  In  the  discussion  of  the  text, 
any  interaction  labelled  1-4  is  considered  significantly  non-zero, 
but  the  tables  should  be  checked  for  fine  distinctions. 

In  the  case  of  three-variable  tables  (perch  height,  perch  diameter, 
and  lizard  group),  there  are  (  ^  )  =3  two-way  interactions.  The 
reduction  procedure  for  these  was  similar  to  that  described  for  four- 
way  tables,  but  of  course  is  much  shorter:  only  three  new  models 
need  be  tested  against  the  most  inclusive  model  on  the  first  round 
instead  of  six. 

Rarely,  a  set  of  models  was  encountered  which  never  gave  a 


1971  JAMAICAN    ANGLES  21 

chi-square  value  denoting  a  satisfactory  fit  of  the  model  at  the  5 
per  cent  level,  regardless  of  what  interactions  were  removed.  These 
are  labelled  in  the  tables.  In  such  cases,  differences  between  models 
were  still  computed  in  the  usual  way  and  the  results  listed  in  the 
tables.  In  addition,  however,  a  search  was  programmed  for  signi- 
ficant three-way  interactions,  in  order  to  see  if  an  improved  fit 
could  be  obtained.  In  the  case  of  four  variables,  there  are  (  3  )  = 
4  three-way  interactions.  The  procedure  was  to  test  each  of  four 
models  corresponding  to  the  addition  of  a  different  three-way  inter- 
action to  the  model  with  all  two-way  interactions.  For  the  White- 
house  data,  there  was  no  tendency  for  any  particular  three-way 
interaction  to  predominate:  each  produced  the  best  fit  at  least  once. 
Some  of  these  are  discussed  in  the  text.  In  no  case  was  it  necessary 
to  consider  more  than  one  three-way  interaction  in  order  to  pro- 
duce a  satisfactory  fit.  Once  such  a  fit  was  obtained,  the  three 
two-way  interactions  able  to  be  removed  were  deleted  one  at  a 
time  as  before,  and  differences  in  chi-square  with  more  inclusive 
models  were  tested.  In  most  cases,  the  two-way  interactions  that 
could  be  removed  without  producing  a  significant  difference  be- 
tween models  were  the  same  as  some  of  those  removed  in  the 
analysis  of  two-way  interaction  models  only. 

In  the  case  of  a  model  with  three  variables,  there  is  but  a  single 
three-way  interaction.  Fitting  this  interaction  would  be  a  trivial 
exercise  resulting  in  a  perfect  fit  (within  the  hmits  of  computational 
accuracy);  therefore,  three-way  interactions  could  only  be  con- 
sidered for  tables  with  four  variables. 

In  several  cases  it  happened  that  margins  (the  total  number  of 
observations  in  a  particular  category  of  a  variable  or  combination 
of  such  categories)  were  zero.  For  these  cases,  two  procedures 
were  tried.  The  first  was  to  correct  for  the  additional  degrees  of 
freedom  lost  in  such  a  table  according  to  the  method  of  Bishop 
(unpublished  thesis;  Fienberg,  personal  communication).  Once  this 
was  done,  the  removal  procedure  could  be  carried  out  as  befora. 
In  no  case  in  the  present  study  was  the  recalculated  number  of 
degrees  of  freedom  zero  or  negative,  though  if  there  are  too  many 
zeros  this  will  happen.  A  second  way  to  handle  zero  margins  is  to 
adjust  the  table  slightly  by  shifting  one  (if  possible)  or  more  ob- 
servations so  that  margins  are  no  longer  zero.  This  is  best  done 
conservatively,  that  is,  so  as  to  reduce  the  likelihood  of  achieving 
a  significant  difference  to  the  variables  of  interest,  in  our  case  those 


22  BREVIORA  No.    368 

in  structural  habitat.  For  such  tables,  where  there  was  a  choice 
from  several  cells  for  selecting  the  observation  to  be  moved,  the 
cell  with  the  most  observations  was  chosen.  While  far  less  prefer- 
able than  the  first  method,  table  adjustment  had  to  be  carried  out 
for  the  three-variable  case,  because  the  initial  2X2X2  model 
tested  has,  assuming  no  zero  margins,  but  one  degree  of  freedom; 
thus  no  further  deletion  is  possible.  Unless  otherwise  specified, 
values  in  the  tables  of  significance  for  four-way  comparisons  are 
computed  by  the  first  method,  though  in  only  about  15  per  cent  of 
tables  with  zero  margins  so  far  examined  did  conclusions  from  the 
two  methods  differ  at  all. 

APPENDIX   II 

Remarks  on  Other  Localities 

Jamaica,  like  the  other  Greater  Antilles,  is  large  and  topographi- 
cally diverse,  yet  it  contains  only  seven  species  as  compared  to 
Puerto  Rico's  ten,  Hispaniola's  24  and  Cuba's  24.  Jamaica's  less 
diverse  fauna  is  in  part  apparently  associated  with  a  great  variation 
from  locality  to  locality  within  Jamaica  in  regard  to  what  species 
are  found  in  certain  segments  of  the  vegetation.  Brief  visits  which 
we  made  to  other  Jamaican  localities  give  an  inkling  of  this  vari- 
ability. Already  shown  is  that  in  western  Jamaica  sagrei  replaces 
Uneatopus  as  the  open-area  trunk-ground  Hzard.  In  darker,  mesic 
forests  west  of  the  Whitehouse  locality  (such  as  that  near  Ferris 
Cross),  the  trunk-ground  species  is  Uneatopus  necked,  an  olive 
green-brown  form  somewhat  smaller  than  the  nominate  subspecies. 
A.  opalimis  is  also  common  in  such  forests,  but  inhabits  less  shady 
places  and  is  more  likely  to  be  encountered  marginally.  A .  grahami 
seems  entirely  absent  from  these  dark  forests,  but  garmani  is  pres- 
ent. More  xeric  forests  two  to  five  miles  east  of  the  Whitehouse 
study  area  contained  no  trunk-ground  species  per  se.  Instead, 
opalinus  occurred  often  on  low  perches  (though  no  measurements 
were  made),  and  garmani  seemed  commoner  than  at  any  of  our 
study  areas. 

Yet  other  species  combinations  are  possible.  In  natural  beach 
vegetation  near  Rose  Hall  on  the  northwest  coast,  we  saw  grahami 
and  sagrei  commonly.  Where  this  vegetation  met  the  xeric  "iron- 
shore"  limestone  formation,  these  species  were  replaced  by  Uneato- 
pus merope,  a  rubiginous  form  well  camouflaged  on  the  rust-colored 
limestone,  and  garmani.  In  certain  moist  mid-elevation  sites  such  as 


1971  JAMAICAN    ANGLES  23 

can  be  found  about  Mandeville,  garmani  was  the  common  arboreal 
species,  and  opalinus  occurred  in  quite  open,  sunny  places,  includ- 
ing low  woodpiles  and  fenceposts.  In  these  localities  we  found 
grahami  to  be  practically  absent,  while  lineatopus  neckeri  was  com- 
mon in  the  blackest  part  of  the  forest.  E.  E.  Williams  and  T.  A. 
Jenssen  (personal  communication)  have  also  observed  opalinus  in 
exposed  situations  at  Mandeville;  Williams,  however,  ionnd  grahami 
moderately  common  in  certain  of  these  situations.  In  montane 
forest  (c.  4000  feet),  such  as  that  surrounding  Green  Hills,  we 
frequently  observed  opalinus  in  extremely  exposed  places,  including 
along  roadsides  as  at  least  temporarily  a  terrestrial  lizard.  Other 
lizards  in  the  area  were  valencienni  in  open  situations  and  garmani 
in  somewhat  more  enclosed  places;  we  also  saw  several  reconditus 
in  relatively  dark  woodland. 

LITERATURE    CITED 

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ogy, in  press. 

AsPREY,  G.  F.,  AND  R.  C.  RoBBiNs.  1953.  The  vegetation  of  Jamaica.  Ecol. 
Monogr..  23:  359-412. 

Bishop,  Y.  M.  M.  1969.  Full  contingency  tables,  logits,  and  split  con- 
tingency tables.    Biometrics,  25:  383-400. 

Deming,  W.  E.,  and  F.  F.  Stephan.  1940.  On  a  least  squares  adjustment 
of  a  sampled  frequency  table  when  the  expected  marginal  totals  are 
known.    Ann.  Math.  Stat.,  11:  427-444. 

FiENBERG,  S.  E.  1970.  The  analysis  of  multidimensional  contingency  tables. 
Ecology,  51:  419-433. 

Jenssen,  T.  a.  1970.  The  ethoecology  of  Anolis  nebulosits  (Sauria,  Iguani- 
dae).   J.  Herpetology,  4:  1-38. 

Ku,  H.  H.,  AND  S.  KuLLBACK.  1968.  Interactions  in  multidimensional  con- 
tingency tables:  an  information  theoretic  approach.  J.  Res.  Natl.  Bur. 
Standards— Math.  Sci.,  728:   159-199. 

KuLLBACK,  S.  1959.  Information  Theory  and  Statistics.  New  York,  Dover 
Publications.   399  pp. 

Laska,  a.  L.  1970.  The  structural  niche  of  Anolis  scriptiis  on  Inagua. 
Breviora,  349:    1-6. 

Lazell,  J.  D.  1966.  Studies  on  Anolis  reconditus  Underwood  and  Wil- 
liams.  Bull,  Inst.  Jamaica  Science,  Ser.  18:  5-15. 

Mosteller,  F.  1968.  Association  and  estimation  in  contingency  tables. 
J.  Amer.  Stat.  Assoc,  63:  1-28. 


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Rand,  A.  S.    1964.   Ecological  distribution  in  anoline  lizards  of  Puerto  Rico. 

Ecology,  45:  745-752. 
.     1967a.     The    ecological    distribution   of   the   anoline   lizards 

around  Kingston,  Jamaica.   Breviora,  272:   1-18. 
.    1967b.   Ecology  and  social  organization  in  the  iguanid  lizard 


Anolis  lineatopus.   Proc.  U.S.  Natl.  Mus.,  122:  1-79. 

Rand,  A.  S.,  and  P.  J.  Rand.  1966.  Field  notes  on  Anolis  lineatus  in 
Curasao.    Stud.  Fauna  Curasao,  24:   112-117. 

SCHOENER,  T.  W.  1967.  The  ecological  significance  of  sexual  dimorphism 
in  size  in  the  lizard  Anolis  conspersus.   Science,  155:  474-477. 

.    1968.    The  Anolis  lizards  of  Bimini:  resource  partitioning  in 

a  complex  fauna.   Ecology,  49:  704-726. 

.    1969.  Size  patterns  in  West  Indian  Anolis  lizards.   I.  Size  and 


species  diversity.   Syst.  Zool.,  18:  386-401. 
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habitats.  Ecology,  51:  408-418. 

Schoener,  T.  W.,  and  G.  C.  Gorman.  1968.  Some  niche  differences  among 
three  species  of  Lesser  Antillean  anoles.   Ecology,  49:  819-830. 

Underwood,  G..  and  E.  E.  Williams.  1959.  The  anoline  lizards  of  Jamaica. 
Bull.  Inst.  Jamaica,  Science  Ser.,  9:   1-48. 

Williams,  E.  E.  1970.  The  ecology  of  colonization  as  seen  in  the  zoo- 
geography of  anoline  lizards  on  small  islands.  Quart.  Rev.  Biol.,  44: 
345-389. 


1971 


JAMAICAN    ANGLES 


25 


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Figure  1.  Mona.  Species-classes  are  ranked  by  perch  height  and  perch 
diameter;  distances  between  species-classes  are  not  representative  of  the 
magnitude  of  difference.  Circles  have  diameters  in  proportion  to  the  length 
of  the  individuals  in  the  designated  class.  Clear  circles  are  of  classes  found 
mostly  in  open,  sunny  areas;  shaded  circles  are  of  classes  in  mostly  closed, 
shady  situations;  intermediate  classes  are  represented  by  half-shaded  circles. 
V  =  valencienni,  G  =  grahami,  O  =  opalinus,  L  =  lineatopus. 


26 


BREVIORA 


No.   368 


HIGH 


^^P 


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H 
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Figure  2.     Port  Antonio  Open.   Symbols  as  in  Fig.  1. 


1971 


JAMAICAN    ANGLES 


27 


HIGH 


T 

H 

I 

C 

K 


^^   ] 


o 


T 
H 
I 
N 


® 


LOW 

Figure  3.     Port  Antonio  Closed.   Symbols  as  in  Fig.  1. 


28 


BREVIORA 

HIGH 


No.  368 


H 


K 


^^^B 


i 


T 
H 
I 
N 


LOW 
Figure  4.     Whitehouse.    Symbols  as  in  Fig.  1.    S  =  sagrei. 


97; 


JAMAICAN    ANGLES 


29 


Table  1.   Mona. 
Percent  observations  in  various  structural  habitat  categories. 
H  =  >20';  G  =  ground;  R  =  rocks;  N  =  sample  size. 


Diameter 
Ht.^~~--^in.) 
(feet) 


>5    5-2  1/2   2  1/4-7/8   7/8-1/8   leaves   Total 


N  =  385 

10.5-20 
5-10 
3-4  3/4 
<3 

Total 

N  =  246 

10.5-20 
5-10 
3-4  3/4 
<3 

Total 

N  =  31 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 

N  =  214 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 


male  grahami 

H 

=  2.3 

G 

=  0 

R  =  0 

3.6     8.1 

6.6 

3.8 

0 

3.6    13.8 

21.4 

9.5 

0.3 

3.6     5.5 

4.6 

3.5 

0 

3.6     2.6 

3.3 

2.5 

0 

12.4    30.0 


35.9 


19.3 


0.3 


female- 

-sized 

grab 

ami 

H 

=  0    G  = 

=  0.3 

R 

0.7 

2.7 

2.9 

2.6 

0 

0.3 

3.4 

14.9 

28.2 

1.0 

0.3 

2.7 

6.0 

11.5 

0 

2.7 

4.1 

7.2 

8.4 

0 

22.1 
48.9 
16.2 
10.7 

=  0 

8.9 
47.9 
20.5 
22.4 


4.1 


13.0 


30.9 


50.6 


1.0 


juvenile  £r 

ah 

ami 

H  = 

0 

G  =  0 

R  =  3.2 

0      0 

0 

0 

0 

0      0 

0 

25.8 

0 

0      0 

4.8 

37.1 

3.2 

0      0 

6.5 

19.4 

0 

0 
25.8 
45.1 
25.9 


0 

0 

11.3 

male 

opalinus 

H  =  0 

1.9 

4.2 

2.3 

4.2 

21.0 

21.3 

2.3 

7.0 

6.3 

1.9 

5.6 

3.3 

10.3 

37.8 

33.2 

82.3 

;  =  0 

1.4 

12.4 

3.5 

0.5 

17.8 


3.2 
R  =  0 
0 

0.5 
0 
0 
0.5 


9.8 

59.4 
19.1 
11.3 


30 


BREVIORA 


No.  368 


Table   1.       (cont'd) 


-~-~...,^^  Diameter 
Ht>-~~^in.) 
(feet)^---^ 

>5 

5-2  1/2 

2  1/4-7/8 

7/8-1/8 

leaves 

Total 

N  =  235 

female-sized 

opalinus   H 

=  0 

G 

=  0.9 

^  =  0 

10.5-20 

0.4 

2.1 

1.3 

0.9 

0 

4,7 

5-10 

2.6 

10.2 

18.1 

14.3 

0 

45.2 

3-4  3/4 

1.7 

4.7 

10.9 

7.5 

0 

24.8 

<3 

3.4 

8.1 

8.3 

4.9 

0 

24.7 

Total 

8.1 

25.1 

38.6 

27.6 

0 

N  =  15 

juvenile  opalinus   H  =  0 

G  = 

0 

R  =  0 

10.5-20 

0 

0 

0 

0 

0 

0 

5-10 

0 

0 

0 

22.2 

0 

22.2 

3-4  3/4 

0 

0 

0 

11.1 

0 

11.1 

<3 

0 

11.1 

22.2 

33.3 

0 

66.6 

Total 

0 

11.1 

22.2 

66.6 

0 

N  -  838 

male 

lineatop 

us    H  =  0.2 

G  = 

0. 

8    R  =  ( 

) 

10.5-20 

0.4 

1.1 

1.8 

0.1 

0 

3.4 

5-10 

2.6 

13.4 

22.6 

13.0 

0 

51.6 

3-4  3/4 

2.1 

7.2 

14.1 

9.5 

0.1 

33.0 

<3 

1.7 

2.5 

3.6 

3.0 

0 

10.8 

Total 

6.8 

24.2 

42.1 

25.6 

0.1 

K  =  436 

femal 

e-sized 

lineatopus 

H  =  0 

G  =  4.4 

R  =  0 

10.5-20 

0 

0 

0 

0 

0 

0 

5-10 

0.5 

1.4 

6.0 

3.9 

0.2 

12.0 

3-4  3/4 

0.5 

4.6 

8.4 

18.9 

0 

32.4 

<3 

1.4 

8.3 

16.3 

24.8 

0.7 

51.5 

Total 

2.4 

14.3 

30.7 

47.6 

0.9 

1971 


JAMAICAN    ANGLES 


31 


Table  1.   (cont'd) 


Diameter 
Ht.  -^in.) 
(feet) 

N  =  24 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 

N  =  15 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 
K  =  16 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 

N  =  3 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 


>5    5-2  1/2   2  1/4-7/8   7/8-1/8   leaves   Total 


juvenile  lineatopus   H=0   G=12.5   R=0 


0  0 

0  0 

0  4.2 

0  8.3 


0 
0 
0 
2.1 


0 
0 

8.8 
56.3 


0      12.5 

male  valencienni 
0      6.7 
0      6.7 
0      0 
0      0 


2.1 


64.6 


H  =  6.7   G  =  0 
6.7       13.3 
6.7       33.3 
0        13.3 
0         6.7 


66.6 


6.3 


25.1 


12.6 


juvenile  valencienni 
0      0         0 
0      0         0 
0      0         0 
0      0         0 


50.1 

=  0    G 

33.3 

0 

0 

66.7 

100.0 


0 
0 
0 
8.3 


0 

0 

12.5 

75.0 


8.3 


26.7 

46.7 

13.3 

6.7 


female- 

-sized 

val 

encienni 

H  =  6 

3 

G  =  0 

0 

6.3 

6.3 

12.5 

0 

0 

12.5 

6.3 

6.3 

0 

6.3 

6.3 

0 

12.5 

0 

0 

0 

0 

18.8 

0 

25.1 
25.1 
25.1 
18.8 

0 
33.3 

0 

0 
66.7 


32 


BREVIORA 


No.  368 


Table  2.   Port  Antonio  Open. 
Percent  observations  in  various  structural  habitat  categories. 
H  =  >20';  G  =  ground;  R  =  rocks;  N  =  sample  size. 
Diameter 


Ht>^~..,,.^(in.) 

(feet)^^^-,^ 

>5 

5-2  1/2 

2  1/4-7/8 

7/8-1/8 

leaves 

Total 

N  =  146 

male 

grahami 

H  =  4.1 

G 

=  1.4 

R  =  0 

10.5-20 

2.7 

6.9 

2.7 

0 

0 

12.3 

5-10 

5.5 

7.5 

12.3 

11.0 

0 

36.3 

3-4  3/4 

5.5 

3.4 

1.7 

9.9 

0.7 

21.2 

<3 

4.8 

2.1 

6.8 

8.9 

2.1 

24.6 

Total 

18.5 

19.9 

23.6 

29.8 

2.7 

N  =  163 

female-sized  < 

grahami 

H 

=  0.6 

G  =  2.5 

R  =  0 

10.5-20 

0.6 

0.6 

0.6 

0 

0 

1.8 

5-10 

1.2 

2.5 

7.7 

5.2 

0 

16.6 

3-4  3/4 

1.2 

0 

2.8 

10.7 

1.8 

16.6 

<3 

3.7 

2.5 

4.6 

34.7 

16.6 

62.0 

Total 

6.8 

5.5 

15.6 

50.6 

18.4 

N  =  75 

juvenile  grab 

ami    H  = 

0 

G  =  0 

R  =  0 

10.5-20 

0 

0 

0 

0 

0 

0 

5-10 

0 

0 

0 

0 

0 

0 

3-4  3/4 

0 

0 

0 

10.7 

0 

10.7 

<3 

0 

0 

1.3 

57.3 

30.7 

89.4 

Total 

0 

0 

1.3 

68.0 

30.7 

N  =  17S 

male 

opalinus 

H  =  1.1 

G  =  0 

R  =  0 

10.5-20 

0.6 

1.7 

10.8 

1.7 

0 

14.8 

5-10 

5.7 

15.9 

12,8 

4.3 

0 

38.6 

3-4  3/4 

6,3 

11.4 

5.4 

6.0 

0 

29.0 

<3 

4.6 

7.4 

0.6 

3.4 

0.6 

16.5 

Total 

17,1 

36.4 

29.6 

15.3 

0.6 

1971 


JAMAICAN    ANGLES 


33 


Table    2.       (cont'd) . 


-...,,^^  Diameter 

HtT~~-^-^4in . ) 

(feet)  ^^-^-^^ 

>5 

5-2  1/2   2 

1/4-7/8 

7/8-1/8 

leaves 

Total 

N  =  136 

female 

-sized  opa 

linus   H 

=  0    G  = 

=  0   R  = 

0 

10.5-20 

0 

1.5 

0 

0 

0 

1.5 

5-10 

3.7 

5.2 

14.3 

4.8 

0.7 

28.7 

3-4  3/4 

3.7 

2.9 

5.5 

7.0 

0.7 

19.9 

<3 

2.9 

6.6 

11.0 

27.9 

1.5 

50.0 

Total 

10.3 

16.2 

30.9 

39.7 

3.0 

N  =  21 

juveni 

le  opalinus   H  =  0 

G  =  0 

R  =  0 

10.5-20 

0 

0 

0 

0 

0 

0 

5-10 

0 

0 

4.8 

4.8 

0 

9.5 

3-4  3/4 

0 

0 

0 

14.3 

0 

14.3 

<3 

0 

0 

9.5 

66.7 

0 

76.2 

Total 

0 

0 

14.3 

85.7 

0 

N  =  183 

male  1 

ineatopus 

H  =  0 

G  =  3.3 

R  =  0 

10.5-20 

0 

0 

0 

0 

0 

0 

5-10 

0 

1.1 

1.6 

3.8 

0 

6.6 

3-4  3/4 

2.2 

6.6 

5.2 

13.4 

0.6 

27.9 

<3 

3.8 

7.7 

12.0 

37.7 

1.1 

62.3 

Total 

6.0 

15.3 

18.9 

54.9 

1.6 

N  =  110 

female 

-sized  lineatopus 

H  =  0 

G  =  11.8 

R  =  0 

10.5-20 

0 

0 

0 

0 

0 

0 

5-10 

0 

0 

0 

0 

0 

0 

3-4  3/4 

0 

0 

0.5 

5.0 

0.9 

6.4 

<3 

0 

0.9 

9.1 

63.6 

8.2 

81.8 

Total 

0 

C.9 

9.5 

68.6 

9.1 

34 


BREVIORA 


No.  368 


Table    2.       (cont'd) 


Htr-~-~-^n.) 
(feet)  ^~~--.>.^ 

>5 

5-2  1/2   2 

1/4-7/8 

7/8-1/8 

leaves 

Total 

N  =  23 

juveni 

le  lineatopus 

H 

=  0   G  = 

26.1 

R 

=  0 

10.5-20 

0 

0 

0 

0 

0 

0 

5-10 

0 

0 

0 

0 

0 

0 

3-4  3/4 

0 

0 

0 

0 

0 

0 

<3 

0 

0 

0 

56.5 

17.4 

73.9 

Total 

0 

0 

0 

56.5 

17.4 

N  =  25 

male  valencienni 

H  = 

4. 

0    G  =  0 

R  = 

0 

10.5-20 

8.0 

12.0 

16.0 

0 

0 

36.0 

5-10 

8.0 

12.0 

12.0 

8.0 

0 

40.0 

3-4  3/4 

4.0 

4.0 

0 

0 

0 

8.0 

<3 

0 

0 

4.0 

8.0 

0 

12.0 

Total 

20.0 

28.0 

32.0 

16.0 

0 

N  =  36 

female 

-sized  valencienni 

H  =  2.8 

G  = 

0 

R  =  C 

10.5-20 

2.8 

0 

0 

0 

0 

2.8 

5-10 

2.8 

2.8 

8.3 

19.5 

0 

33.4 

3-4  3/4 

2.8 

8.3 

0 

11.1 

2.8 

25.0 

<3 

2.8 

0 

0 

33.3 

0 

— 

36.1 

Total 

11.1 

11.1 

8.3 

63.9 

2.8 

N  =  3 

juveni 

le  valencienni 

H 

=  0    G  = 

0    R 

= 

0 

10.5-20 

0 

0 

0 

0 

0 

0 

5-10 

0 

0 

0 

33.3 

0 

33.3 

3-4  3/4 

0 

0 

0 

0 

0 

0 

<3 

0 

0 

0 

66.7 

0 

— 

66.7 

Total 

0 

0 

0 

100.0 

0 

1971 


JAMAICAN    ANGLES 


35 


Table  3.   Port  Antonio  Closed. 
Percent  observations  in  various  structural  ha±>itat  categories. 
H  =  >20';  G  =  ground;  R  =  rocks;  N  =  sample  size. 
Diameter 


N  =  185 

male 

opalinus 

H  =  1.6 

G  =  0. 

5 

R  =  0 

10.5-20 

6.5 

1.6 

1.6 

2.2 

0 

11.9 

5-10 

7.0 

9.7 

22.2 

9.7 

0 

48.6 

3-4  3/4 

5.9 

1.6 

8.6 

2.7 

1.1 

19.9 

<3 

1.6 

2.7 

9.2 

3.2 

0.5 

17.2 

Total 

21.1 

15.7 

41.6 

17.8 

1.6 

N  =  206 

fema] 

.e-sized 

opalinus 

H  =  1.0 

G  = 

2.4 

R  =  0 

10.5-20 

0.5 

0.5 

0.7 

1.2 

0 

2.9 

5-10 

8.3 

3.4 

9.5 

15.8 

0 

37.0 

3-4  3/4 

5.3 

1.5 

5.8 

6.8 

0.5 

19.9 

<3 

6.3 

3.9 

9.5 

15.8 

1.5 

37.0 

Total 

20.4 

9.2 

25.5 

39.6 

1.9 

N  =  79 

juvenile  opal 

inus    H  = 

0    G  = 

0 

R  =  0 

10.5-20 

0 

0 

0 

0 

0 

0 

5-10 

0 

1.3 

1.3 

19.0 

0 

21.5 

3-4  3/4 

0 

0 

0 

17.7 

0 

17.7 

<3 

0 

0 

9.5 

50.0 

1.3 

60.8 

Total 

0 

1.3 

10.8 

86.7 

1.3 

N  =  122 

male 

lineatopus   H  =  0 

G  =  0 

R 

=  0 

10.5-20 

0 

0 

0 

0 

0 

0 

5-10 

4.1 

3.3 

15.6 

14.8 

0 

37.7 

3-4  3/4 

5.7 

3.3 

10.2 

18.4 

0.8 

38.5 

<3 

4.1 

3.3 

9.0 

7.4 

0 

23.8 

Total 


13.9 


9.9 


34.8 


40.6 


0.8 


36 


BREVIORA 


No.  368 


Table    3 .       (concl'd) . 


"--■-^^Diameter 
(feet)  ^^^^ 

>5 

5-2  1/2 

2  1/4-7/8 

7/8-1/8 

lee 

ives 
3.6 

Total 

N  =  112 

female 

-sized  lineatopus 

H  =  0" 

G  = 

R  =  0 

10.5-20 

0 

0 

0 

0 

0 

0 

5-10 

0 

0.9 

0.9 

8.9 

0 

10.7 

3-4  3/4 

0 

0.9 

4.9 

21.0 

0. 

9 

27.7 

<3 

2.7 

1.8 

16.5 

30.8 

6. 

3 

58.0 

Total 

2.7 

3.6 

22,3 

60.7 

7 

2 

N  =  32 

juveni 

le  lineatopus 

H  = 

0    G  = 

3.1 

R 

=  0 

10.5-20 

0 

0 

0 

0 

0 

0 

5-10 

0 

0 

0 

6.3 

0 

6.3 

3-4  3/4 

0 

0 

0 

6.3 

0 

6.3 

<3 

0 

3.1 

9.4 

53.1 

18 

8 

84.4 

Total 

0 

3.1 

9.4 

65.7 

18 

8 

N  =  13 

valencienni 

H  =  0 

G  = 

0    R  = 

0 

10.5-20 

7.7 

7.7 

15.4 

7.7 

0 

38.5 

5-10 

0 

0 

15.4 

15.4 

0 

30.8 

3-4  3/4 

15.4 

7.7 

0 

7.7 

0 

30.8 

<3 

0 

0 

0 

0 

0 

0 

Total 

23.1 

15.4 

30.8 

30.8 

0 

197; 


JAMAICAN    ANGLES 


37 


Table  4.   whitehouse. 
Percent  observations  in  various  structural  habitat  categories. 
H  =   20';  G  ■=  ground;  R  =  rocks;  N  =  sample  size. 
Diameter 

>5    5-2  1/2   2  1/4-7/8   7/8-1/8   leaves   Total 


Ht.^'^-.^dn.) 
(feet) 


N  =  219 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 

N  =  284 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 

N  =  54 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 

N  =  88 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 


male 

g 

rahami 

H 

=  1.4 

G 

=  0.5 

R  =  0 

1.8 

1.8 

2.3 

1.4 

0 

2.7 

9.6 

21.5 

9.1 

2.3 

0.5 

7.3 

10.1 

4.1 

0.5 

1.8 

10.1 

7.1 

4.3 

0 

6.8    28.8 


41.0 


18.9 


2.8 


fema] 

.e- 

-sized 

2£ 

ahami 

H 

=  0 

G  =  2.5 

R 

0 

0 

0.4 

0 

7 

0 

0.7 

2.8 

14.1 

21 

8 

4.6 

1.8 

1.8 

5.8 

7 

9 

2.5 

1.4 

9.9 

12.3 

7 

7 

1.1 

7.3 
45.2 
22.5 
28.3 

=  0.4 

1.1 
44.0 
19.8 
32.4 


2.9    14.5 


32.6 


38.1 


8.2 


juvenile  gr 

ahami 

H  = 

0 

G  =  0 

R  =  0 

0       0 

0 

0 

0 

0      0 

3.7 

38.9 

0 

0       1.9 

1.9 

31.5 

0 

0       0 

6.5 

13.9 

1.9 

0 
42.6 
35.3 
22.3 


1.9 


12.1 


J4.3 


1.9 


male 

opalinus 

H  = 

0 

G  = 

=  0 

R 

=  0 

0 

0 

0 

0 

0 

1.1 

6.8 

18 

2 

4.6 

0 

2.3 

13.6 

15 

9 

1.1 

0 

1.1 

20.5 

9 

1 

4.6 

1. 

1 

0 
30.7 
32.9 
36.4 


4.5    40.9 


43.2 


10.3 


1.1 


38 


BREVIORA 


No.  368 


Table    4.       (cont'd) . 


^"^^Diameter 

Ht7""^^^in.) 

(feet)^<v^ 

>5 

5-2  1/2 

2  1/4-7/8 

7/8-1/8 

leaves 

Total 

N  =  72 

female 

-sized 

opalinus   H 

=  0 

G 

=  2.8 

R  =  0 

10.5-20 

0 

0 

0 

0 

0 

0 

5-10 

0 

5.6 

7.0 

1.4 

0 

14.0 

3-4  3/4 

2.8 

4.2 

16.7 

1.4 

0 

25.1 

<3 

2.8 

31.9 

19.5 

4.2 

0 

58.4 

Total 

5.6 

41.7 

43.2 

7.0 

0 

N  =  10 

juveni 

le  opal 

inus    H  =  0 

G  = 

0 

R  =  0 

10.5-20 

0 

0 

0 

0 

0 

0 

5-10 

0 

0 

10.0 

20.0 

0 

30.0 

3-4  3/4 

0 

10.0 

10.0 

20.0 

0 

40.0 

<3 

0 

10.0 

10.0 

10.0 

0 

30.0 

Total 

0 

20.0 

30.0 

50. D 

0 

N  =  263 

male  sagrei 

H  =  0    G  = 

6.5 

R 

=  2.7 

10.5-20 

0 

0 

0 

0 

0 

0 

5-10 

0 

0.8 

1.5 

0 

0 

2.3 

3-4  3/4 

0 

6.5 

8.4 

2.3 

0 

17.2 

<3 

2.3 

30.0 

27.8 

11.4 

0 

71.5 

Total 

2.3 

37.3 

37.7 

13.7 

0 

N  =  393 

female 

-sized  sagrei   H  = 

0    G 

= 

13.2    R 

=  4.8 

10.5-20 

0 

0 

0 

0 

0 

0 

5-10 

0 

0 

0.8 

0.3 

0 

1.1 

3-4  3/4 

0 

1.6 

1.3 

0.3 

0 

3.2 

<3 

2.5 

31.8 

22.5 

21.0 

0 

77.8 

Total 

2.5 

33.4 

24.6 

21.6 

0 

1971 


JAMAICAN    ANGLES 


39 


Table    4.        (concl'd) . 


Diameter 
(feet) 


N   =    251 
10.5-20 
5-10 
3-4    3/4 
<3 

Total 

N    =    7 
10.5-20 
5-10 
3-4    3/4 
<3 

Total 

N   =    8 
10.5-20 
5-10 
3-4    3/4 
<3 

Total 

N   =    7 
10.5-20 
5-10 
3-4    3/4 
<3 

Total 


>5         5-2    1/2      2    1/4-7/8      7/8-1/8      leaves      Total 


juveni 

le  sag 

rei 

H 

= 

0 

G  =  31 

9 

R 

=  4 

0 

0 

0 

0 

0 

0 

0 

0 

8 

1.6 

0 

0 

0.8 

0 

4 

2.0 

0 

2.0 

17.8 

12 

6 

25.6 

0. 

4 

29.2 


14.3     0         42.9       42.9 
female-sized  valencienni   H  =  0 


0  0 

0  0 

0  0 

0  0 


0 
0 

37.5 
0 


0 

25.0 

0 
37.5 


37.5 


62.5 


0.4 


G  =  0 
0 
0 
0 
0 


0 


0 
0 

2.4 
3.2 

58.4 


ma] 

Le 

va 

lencienni 

H  = 

0 

G  =  0 

R  = 

0 

0 

0 

0 

0 

0 

14 

3 

0 

28.6 

42.9 

0 

0 

0 

14.3 

0 

0 

0 

0 

0 

0 

0 

juvenile  valencienni 

H 

=  0 

G  = 

=  0 

R  = 

0      0 

0 

0 

0 

0      0 

42.9 

14 

3 

0 

0      0 

0 

28 

6 

0 

0      0 

14.3 

0 

0 

0 

85.8 
14.3 
0 

R  =  0 

0 
25.0 
37.5 
37.5 

0 

0 
57.2 
28.6 
14.3 


57.2 


42.9 


40 


BREVIORA 


No.  368 


Table  5.   Percent  observations  for  Whitehouse 
species  in  climatic  categories. 


Sun 

Shade 

Clouds 

male  sagrei 

17.4 

74.4 

8.3 

female-sized  sagrei 

15.9 

73.8 

10.2 

juvenile  sagrei 

33.8 

58.8 

7.4 

male  grahami 

12.4 

74.6 

12.9 

female-sized  grahami 

20.5 

61.4 

18.1 

iuvenile  grahami 

15.7 

66.7 

17.6 

male  opalinus 

3.5 

72.1 

24.4 

small  opalinus 

14.5 

66.3 

19.3 

valencienni 

36.4 

50.0 

13.6 

1971 


JAMAICAN    ANGLES 


41 


TUUaTOUa-[BA 
P3ZTS 

-aXBuraj 


p  TuuaxouaxBA 


10 

c 

0 
(0 
•H 

snuTxedo 
XX^uis 

10 

a 
% 

p  snuTxedo 
3XT"9AnC 

<d 

c 

0 

sndo:^B9UTX 

U 
0 

IM 
0) 

u 

c 

(0 
•H 

c 

•H 

sndo:iB3UTX 

pazTS 

-aXBuraj 

sndorjESUTX 
aXT"9^r\C 

(0 

rH 
(0 
O 

TiueqeaB 

•H 

10 
•H 
■P 

m 
■p 

TuiBqejb 

pSZTS 

-axeuraj 

so 

0) 
rH 

Si 


P     Tureqejb 


* 


N 

•H 

W 

I 


E 
(0  j:: 


>n    D> 


« 

O  rH 


c 
> 

3 


w 
a 
ftj 

o 
•p 

ID 

c 

•H 


73 

Q) 

N  « 

•H  3 

to  a 

I  o 

o  -P 

(0  0) 

8  -H 


to 

3 

a 
o 
-p 

ro- 
Qi 

c 


to 

3 

•0 

C 

T3 

'O 

•rl 

■H 

OJ  -rl 

rH 

c 

N    C 

(T5 

c 

•H    C 

0) 

tn 

a 

Q) 

CO  a; 

rH 

3 

0 

•H 

1     -H 

H 

C 

U 

d)   o 

C 

•iH 

r-\ 

c 

rH    c 

<u 

•-\ 

f-\ 

(U 

<C    Q) 

> 

ID 

a 

iH 

e    rH 

3 

(i 

R 

ID 

(U  m 

r-i 

O 

w 

> 

<*A  > 

42 


BREVIORA 


TuuaTouaxEA 

pazTS 

-aXBuiaj 


p    TuuaxouaxBA 


snuT-[Bdo   xiBuis 


p     snuTxedo 


__9Xtus»AnC 
sndoieauTx 


c 
o 
u 


« 

fH 
Si 

« 


sndot^BauTx 
pazTS 

-aXBuiaj 

p     sndo^eauTx 


aXTU3i^£i£ 
Tureqeab 


TureqBab 

pazTS 

-aXBUiaj 


p     TureqBjB 


N 


CO 


N 


N  2 


N 


M 


M 


N 


m 


03 


CQ 

iH  O 


m 


o       o 


<        CQ 


N  tq  O  O  O 


O  rH  O  O 


O  O  O  O 


03 


CQ 

O  r-l 

< 
O  t-i 


T3 
01 
N 
•H 
(0 

O  E 

iH    (3 

10  x: 
u 


tT>l       M-i    OT        CP 


4> 
f-l 
•H 

c 
> 

3 


(0 

3 

a 
o 
■p 

IT] 
OJ 

c: 


0) 

N  to 

•H  3 

(0  a 

I  o 

OJ  4-1 

iH  (0 

n)  0) 

e  c 


3 

a  (u 

O  -H 
4J  -H 


to 

3 

c 

•H 

o 


(0 

a 
o 


No. 

368 

-3      i« 

C3 

>    f 

u 

Si^ 

«  G 

rt   2 

—     c 

^  "*-■ 

o 

^   o 

_    c: 

a  o 

o  •— 

■«-»  ■*-• 

o 

C3 

=«     ^ 

-y)    a< 

u    h 

.S:    1) 

o 

D.  •- 

'■^     u. 

DQ 

II     ^ 

iH 

*•       ^ 

u 

•  '  x: 

22    o 

a   u 

■ga 

O 

1^ 

o  -c 

_ 

U 

CQ 

?i  ^ 

rH 

i«    2 

^_^ 

(U 

CQ 

II    B 

^^ 

a 

i-l 

N  ^ 

,  r.    ^^ 

5^  "rt 

^ 

5  S 

« 

— c       CO 

rH 

^     II 

m 

^  CQ 

^^ 

cS     ., 

5 

c/l 

rH 

cant 
rche 

tC     <U 

■S   o- 

00       l;^ 

"   o 

t-  "* 

V      4-> 

>     CO 

w 

C       1/5     -   . 

^-     o    ^ 

o   E   g 

(0 

e 

en 


T3 

H 

flj  -H 

c: 

N    C 

c 

•rH     C 

<u 

U)    0) 

H 

1    -ri 

0 

0)    U 

c 

,-i   c 

0) 

(0    <D 

rH 

6  ^ 

rO 

a  10 

> 

U-l  > 

c  .ii 


II   -   "^ 


on 


CO     CO 

B  -^ 


<?' 


1971 


JAMAICAN    ANGLES 


43 


(0 

C 

o 

u 

-H 

u 

ca 
cu 
e 
o 
o 

c 

a. 
o 

o 

•H 

c 
o 

c 

< 

V4 

0 

0- 

u 
o 

0) 

o 
c 
ta 
u 


■H 

c 


(0 


4J 
(0 


TuuaxouaxBA 

TIBUIS 

p 

TuuaTouaxEA 

snuxxedo   tlBuis 

p    snuTxedo 

_axju3An£ 
SHdoicauTX 


sndo^eauTx 

pazTs 

-aXBUiag 


p    sndo:;EauTx 


aXJuaAnC 
TureqEj5 


TuieqeaB 

pazTS 

-aXBiuaj 


«       «       *  *  «  « 


«  *  *  *  *  *  « 


*  *  * 


*  *  *  *  « 


*  * 

rH  O  1-1 


* 


*  * 


O  r^ 


*****  « 

"-H^nH  ,-1  .HiHOO  f-H 


T3 

c 

(U 

M 

T3 

0) 

> 

<U 

•O 

«0 

N 

3 

<n 

N  in 

W 

•H 

•r-i 

3 

•H  p 

3 

W 

a 

u  a 

a 

Q) 

W 

•H 

1     -H 

•H 

0 

1    o 

n 

rH 

1 

b 

i)    S 

E 

■p 

Q)  +J 

4J 

•H 

C 

fl 

iH    (3 

<d 

(0 

^  (tj 

10 

C 

•H 

x: 

«  £ 

x; 

(U 

CO    0) 

(U 

(11 

t-i 

(0 

e  (0 

10 

c 

e  c 

c 

> 

m 

M 

S  V4 

M 

•H 

QJ  -H 

•H 

-1 

0 

Oi| 

i*-i  cH 

cH 

rH 

in  rH 

iH 

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o 

10 

E 


•H 

•H 

c 

c 

c 

c 

<u 

0 

H 

•H 

u 

o 

c 

rH    C 

(U 

rH    <U 

'-^ 

(0   rH 

10 

e  10 

> 

w   > 

44 


BREVIORA 


No.  368 


TuuaxouaxEA 

XI  GUIS 


p   TUuaxouaxBA 

snuTXBdo  XTSUJS 

p  snuTx^do 

aXTuaAnC 
sndo:;BauTx 


sndo:;BauTx 

pazTS 

-aXBuiaj 


p    sndot^Bauxx 


u 
a 
o 
u 


H 

n) 


aX_£uaAnC 
TuiBqeaB 


TuiBqBJb 

pazTS 

-aXBuiaj 


p       TUIBqBjB 


Si 

IT) 


0) 

N 
•H 

M 

I    • 

0) 
.-H 

e 

0) 


to 


N 


N  ^3 


en 


5 

O  r-K 


<  <  < 

O  rH  .H  iH 


•H 

c 
> 

3 


re 
u 


3 

a 
o 
+j 

(1) 

c 

•rH 


T3 

01 

N    W 
•H    3 

m  D- 
I  O 
Q)  +J 

rH     (TJ 

53  -H 

>4-l  rH 


ta 

3 

c 
o 
■p 

o 
c 

•H 


e 


> 

Ui 

u 

5     !3 


5 

.HO  rH 


O         O  O 


<    5 

O  rH  rH  O  O 


H 

•rt 

C 

C 

C 

c 

0) 

(U 

H 

■H 

O 

o 

c 

.H    C 

0) 

rH    01 

rH 

(0   r^ 

«J 

E  "0 

> 

w   > 

o  .^ 

*"  -o 
*-    c 

a. 

c/) 


(U 


a, 


0$ 


in 


rt 


^    s 


t/1 


c 
o 


> 

#. - 


.  'r: 

5  ^ 

u  Si 

■?  n. 

•-  ^ 

="  o 

—  w 

0)  ■4-J 

o  E 

E  5 
•5 

II  - 


C/5 

Z 


c^ 


1971 


JAMAICAN    ANGLES 


45 


(A 

C 

o 

w 

■H 

u 
m 
o. 

B 
O 

o 

■a 

01 
Ui 

o 
o 

o 

•H 

c 
o 

4-1 

c 
< 

4-1 

0 
(X 

o 

dJ 
u 
c 

u 


c 


o 

•H 
4J 

w 

•H 
4-1 
(0 

4J 


Eh 


TuuaTouaxBA 


^sXj[uaAn£ 
sndoieauTx 


sndo:;BauTX 

pazTS 

-aXBuiaj 


p    sndo^BauTX 


ajTuaAnC 


snuTx^do 


snufxedo 

pazTs 

-axBuiaj 


p    snuTXBdo 


* 


* 


-a 

•0 

T3 

0) 

01 

N 

to 

N    (0 

W 

•H 

3 

•H   3 

3 

(0  tn 

(A 

0) 

a 

w  a 

D. 

0) 

1     3 

3 

rH 

0 

1     0 

O 

•-t 

o  c 

C 

■H 

+j 

OJ  -P 

4J 

•H 

rH   -H 

•H 

c 

(C 

rH     (0 

fl 

C 

(0  i-H 

iH 

OJ 

OJ 

(0    <D 

0) 

Q) 

g    ro 

10 

> 

c 

e  c 

c 

> 

<u  a 

a 

3 

•H 

0)  -H 

•H 

3 

K-l    0 

0 

•r-\ 

r-H 

1^   rH 

rH 

•r-i 

■r4 
C 
C 

0) 
•H 
0 

c 

rH 

> 


46 


BREVIORA 


No.  368 


juuaTouaxBA 


sridoieauf  X 


sndo:^BauTX 

pazTs 

-a-[Bura3 


p    snSo^BaTrfx 


aiTuaAnC 
^  * pj- 

snuTXBclo 


snuTXBdo 

pazTs 

-axBuiaj 


p     snujx'sdo 


t) 


o 
c 
o 
o 


eo 

V 

<-* 
Xi 
10 


N 


t3 


pa 


m  u 

(0 

>   9> 

3 

4J 

C 

CuO) 

•H 

B§ 

r-l 

M-H 

a 

tr-d 

01 

1? 

« 

•0 

S 

0) 

N 

(0 

N  n 

10 

•H 

3 

•H  3 

3 

0)    (0 

(0 

a> 

& 

(0  a 

a 

<u 

1     3 

3 

i-{ 

0 

1    o 

0 

.H 

(U   C 

c 

•H 

4J 

(U  .P 

+) 

■H 

^  -H 

•H 

c 

nj 

r-4    (0 

nj 

C 

<0  rH 

rH 

(U 

<u 

(0   0) 

0) 

0) 

B  (0 

« 

> 

c 

a)  -H 

C 

> 

a  a 

a 

3 

•H 

•H 

3 

tt-i  o 

0 

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f-l 

<W  rH 

rH 

•n 

u 

60 


a 


(U 

'k' 

u 

g 

.2 

•5 

;3 

«3 

a 

in 

II 

PQ 

■  #k 

<u 

3 

CO 

> 

Ui 

lU 

eo 

u« 

i2 

c« 

<a 

x; 

s 

o. 

x 

o 

'•5 

•4—' 

n 

■*-» 

a 

CO 

a 

o. 

«5 

c4 

JJ 

'o 

CQ 

<u 

o 

4-* 

•*..* 

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* 

in" 
C 

03 

00 

^ 

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u 

3 

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(M 

VI 

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II 

rt 

N 

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t8 

& 

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■*-• 

a 

1971 


JAMAICAN    ANGLES 


47 


w 

c 
0 

(A 
■H 
U 
TO 

a 
g 
o 
u 

<u 
in 

3 
0 

X 

<u 

4-1 
•H 


V4 

0 


O 

c 

ID 
U 


•H 

c 


(0 

(J 


4J 

CO 


(0 


w 


TUU3TOUS-[BA 
XIBUIS 

p    snuixBdo 


sjTuaAnC 
TuiBqejb 


Tureqeab 

P3ZTS 

-sXBurag 


aXJU3AnC 
xajbBS 


xaaBes 
pazTS 

-aXBUiaj 


p    T3j5es 


+ 
« 


+      + 
«       • 


+ 


«       « 

O  (N  .H 


« 


+ 

«  « 


*  « 

iH  O  O  iH 


« 
(N 


«  «  « 


•H 

T3 

C 

(U 

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N 

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3 

•H 
(0 

tn 


01 

1 

(1)  -H 
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m 
in  tn 


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10 

en 


•a 

(U 
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I    -H 
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IT3  X 

E   (0 
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6 
en 


48 


BREVIORA 


No.  368 


TUUaTOUa-[BA 

snuTxedo 

XIEUIS 

p     snuTXBdo 


ajjuaAnC 
TureqeaB 


TuiiqBxB 
pszTS-ajBuraj 


p     Ttiiei{9j5 


aXJuaAn£ 


jaabBS 

pazTS 

-aXBuiaj 

p      TaoEBs 


c 

•  0 

01  -H 

>-y 

IS 

P.M 

9  0 

0   W 

n  c 

/      • 

Oi-H 

/      M 

/ 

>    ^1 

/ 

(U 

/ 

+J  +J 

/ 

4=    <U 

/ 

.?§ 

J 

(U-H 

/ 

45-0 

u      ^ 
«         — ' 


M        U 


i-l  (N 


u 

O        H 


(0 


<u 

N 
•H 

M 

1 

0)  -H 
.H    QJ 

m  M 

a  m 

M-l    w 


(N 


♦ 


u      u 


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«        « 


o       o 


•H 
C 

(U 
> 

3 


rH  O 


U 


U 
O  O  rH 


O  O 


03 


03 


c 

TJ 

(U 

OJ 

> 

N 

3 

I    -H 

(U  E 

r-l     (3 

TO 

u 


cr      i*-i  t7H      Cr> 


03        CQ 


n      n     03      n 

r-l  iH  iH  r-i 


o       o       o       o 


5  5 

t-i       o       o       m       o 


o       o       o       o 


<  03 

O  HO  iHOOOO 


10 

E 


I 


1971 


JAMAICAN    ANGLES 


49 


JUU3JOUaXBA 


snuTxedo  XT'^uis 


p    snuTXBdo 


9X_TuaAn£ 
TureqBjB 


"fureqioB 

pazTS 

-aXBuraj 

p     TureiiBa6 


aXJu3An£ 
TaaBes 


T) 


P3ZTS 

-aXBuraj 
p    xaxEiis 


o      o      o  o      o      o      o 


o       o       o  o       o       o 


o       o       o 

o 


3    3 

CM       ro       o 


o       o       o 


3    3 

rH  n  O  O  O 


S       S       1^       h3       to 


rH  O  rH  O  iH  O  O 

S3  £         S         3  3 

rHiHO  rHr-lrHOiH 


(0 


•a 

N 

•H 
(0 
I 
0)  -H 

10  n 


•H 

c 
> 

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(0 


0) 
N 
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tn 

I    -H 
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ro  X 
(0 


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BREVIORA 


Mitasemiinii   of   Comparative    Zoology 

Cambridge,  Mass.     29  January,  1971  Number  369 

LITHOPHAGA  ARISTATA  IN  THE  SHELL-PLATES  OF 
CHITONS  (MOLLUSCA) 

Robert   C.   Bullock 

and 
Kenneth   J.   Boss 


Abstract.  The  occurrence  of  the  mytilid  bivalve  Lithophaga  aristata  as 
a  borer  into  the  shell-plates  of  polyplacophorans  is  unreported.  Our  investi- 
gation revealed  this  lithophage  in  the  Panamic  Chiton  stokesii  and,  less 
commonly,  in  the  West  Indian  C.  tiiheniihitiis.  A  review  of  other  organ- 
isms known  to  associate  with  chitons  is  provided,  although  none  is  appar- 
ently deleterious  to  the  host-species  as  in  the  case  of  Lithophaga.  Damage 
to  the  chiton  by  L.  aristata  appears  to  consist  predominantly  of  the  weaken- 
ing of  the  shell-plates  and  not  the  destruction  of  the  aesthetes  of  the 
nervous  system. 

INTRODUCTION 

Although  several  symbiotic  organisms  are  known  to  live  in 
association  with  chitons,  the  boring  of  the  mytilid  bivalve  Litho- 
phaga into  the  shell-plates  of  polyplacophorans  appears  to  be 
unreported  in  the  literature.  During  a  dissection  of  a  specimen  of 
Chiton  stokesii  Broderip,  1832,  several  Lithophaga  {Myojorceps) 
aristata  (Dillwyn,  1817)  were  discovered  in  the  shell-plates.  A 
survey  was  undertaken  to  assess  the  occurrence,  and  to  determine 
the  nature,  of  the  infestation  of  Lithophaga  in  C.  stokesii  and 
other  species  of  chitons  from  various  localities.  In  addition,  the 
known  symbionts  of  chitons  were  reviewed.  The  results,  presented 
in  this  paper,  indicate  that  the  presence  of  Lithophaga  in  the  shell- 
plates  of  chitons  is  unusual  and  represents  the  most  detrimental 
polyplacophoran  symbiont  known.  We  have  observed  L.  aristata 
boring  in  the  shell-plates  of  the  Panamic  Chiton  stokesii  and  the 
Caribbean  Chiton  tuberculatiis  Linnaeus,  1758. 


BREVIORA  No.    369 


ACKNOWLEDGMENTS 


The  manuscript  has  been  critically  read  by  our  colleagues  in 
the  Museum  of  Comparative  Zoology,  Messrs.  R.  I.  Johnson  and 
M.  K.  Jacobson,  and  Dr.  Peter  W.  Glynn  of  the  Smithsonian 
Tropical  Research  Institute.  The  X-ray  apparatus  was  made  avail- 
able by  the  Museum  of  Comparative  Zoology  through  a  Milton 
Fund  grant  to  Drs.  R.  D.  Turner  and  S.  J.  Gould.  Funds  enabhng 
the  senior  author  to  collect  Panamanian  Polyplacophora  were 
provided  by  a  National  Science  Foundation  grant,  GB  8620,  issued 
to  the  Committee  on  Evolutionary  Biology,  Dr.  R.  Rollins  prin- 
cipal investigator. 

METHODS   AND    MATERIALS 

Numerous  specimens  of  Chiton  stokesii,  collected  at  various 
localities  in  the  Gulf  of  Panama  by  the  senior  author  during  July 
and  August  1969,  were  examined  by  radiographic  techniques  for 
the  presence  of  Lithophaga.  A  survey  was  made  of  the  large  col- 
lection of  Polyplacophora  in  the  Museum  of  Comparative  Zoology, 
Harvard  University,  in  an  effort  to  locate  other  species  host- 
ing Lithophaga,  and  X-rays  of  suspected  host-individuals  were 
made.  All  radiographs  were  checked  for  the  number  of  lithophages 
present,  their  spatial  distribution,  and  orientation.  Borers  were 
extracted  at  random  to  check  their  identity  and  all  proved  to  be 
L.  aristata. 

POLYPLACOPHORAN    SYMBIONTS 

Few  records  are  to  be  found  in  the  literature  concerning  sym- 
bionts  of  polyplacophorans,  but  organisms  representing  several 
phyla  are  associated  with  chitons.  Cryptochiton  stelleri  (Midden- 
dorff,  1846)  is  known  to  harbor  two  commensals:  a  crustacean, 
Opisthopus  transversus  (Rathbun,  1893)  and  an  annelid,  Arctonoe 
vittata  (Grube,  1855)  (MacGinitie  and  MacGinitie,  1968;  Web- 
ster, 1968). 

Glynn  (1968)  and  Menzies  and  Glynn  (1968)  summarized 
present  knowledge  of  the  symbionts  of  the  mantle  cavity  on  the 
West  Indian  chitonids,  Acanthopleura  granulata  (Gmelin,  1791) 
and  Chiton  tuberculatus  Linnaeus,  1758.  Included  were:  the 
isopods,  Dynamenella  perforata  (Moore,  1901)  with  A.  granulata 
and  C.    tuberculatus;   Exosphaeroma   alba    Menzies   and   Glynn, 


1971  LITHOPHAGA    IN    CHITONS  3 

1968,  Exosphaeroma  cremilatum  (Richardson,  1902),  Dynamen- 
opsis  dianae  Menzies,  1962  with  C  tuberciilatus;  Exosphaeroma 
alba  var.  chromata  Menzies  and  Glynn,  1968  with  C.  mannoratus 
Gmelin,  1791;  and  the  foraniiniferan,  AcerviiUna  inhaerens 
Schulze,  1854  and  the  amphipod,  Parhyale  hawaiensis  (Dana, 
1853)  both  with  C.  tuberciilatus;  the  harpacticoids,  Harpacticus 
sp.  and  Heterolaophonte  sp.  with  A.  ^ranulata  and  C  tuberciilatus; 
and  the  coUembolan,  Actaletes  ueptiini  Giard,  1889  with  A. 
gramilata. 

The  mite  Halixodes  chitonis  (Brucker,  1897)  has  been  found 
attached  to  the  gills  of  the  Neozelanic  Cryptoconchus  porosus 
(Burrow,  1815)  (Brucker,  1897;  Brucker  and  Trouessart,  1900). 
Helfman  (1968)  observed  the  ctenostomatous  ectoproct  Farella 
elongata  (van  Beneden,  1845)  in  the  ventral  girdle  tissue  border- 
ing the  pallia!  groove.  Arey  and  Crozier  (1919)  reported  the 
following  symbionts  on  the  shell-plates  of  C.  tuberciilatus:  the 
barnacle,  Tetraclita;  the  polychaetes,  Spirorbis  and  Serpula;  and 
algae,  including  the  "Enteromorphas."  They  mentioned  that  the 
algae  afforded  protection  for  various  young  moUusks,  nematodes, 
archiannelids,  and  protozoans.  None  of  these  symbionts  has  been 
shown  to  be  harmful  to  the  host. 

After  conducting  extensive  studies  on  Chiton  tuberciilatus ,  Arey 
and  Crozier  (1919:  171-172)  remarked:  "The  general  impres- 
sion derived  from  the  consideration  of  destructive  agents  in  relation 
to  Chiton  is  that  these  mollusks  are  very  efficiently  protected.  The 
length  of  life  which  they  seem  to  attain,  the  variety  of  habitats 
which  they  frequent,  and  the  character  of  their  sensory  responses, 
which  determine  certain  features  of  their  life  in  their  habitats, 
afford  important  evidence  to  this  effect." 

While  the  above  statement  is  generally  true  for  C.  tuberciilatus, 
the  Panamic  C.  stokesii  appears  far  more  vulnerable  to  attack  by 
destructive  agents  than  C.  tuberciilatus.  We  observed  large  indi- 
viduals of  C.  stokesii  from  different  localities  that  were  not  only 
greatly  eroded,  but  heavily  fouled  with  calcareous  algae,  bryozoans, 
and  polychaete  tubes.  Most  of  the  latter  were  heavily  infested  with 
Lithophaga  aristata,  some  of  which  had  grown  large  enough  to  fall 
out  of  their  burrows,  leaving  greatly  weakened  shell-plates.  The 
cases  of  C.  tuberciilatus  from  Trinidad  (MCZ  31955)  and  Isla 
Margarita  (MCZ  273763),  in  which  we  found  examples  harboring 
L.  aristata,  appear  to  be  rare.  Our  examination  of  numerous  other 


4  BREVIORA  No.    369 

samples  of  C.  tuberculatus  produced  no  additional  Lithophaga. 
It  is  probable  that  differences  in  shell-structure  account  for  the 
greater  penetrability  and  susceptibility  for  fouling  and  boring  in 
C  stokesii. 

RESULTS   AND    DISCUSSION 

The  mytilid  bivalve  Lithophaga  {Myojorceps)  aristata  (Dillwyn, 
1817)  (Figs.  7  and  8)  bores  into  calcareous  substrates,  including 
the  shells  of  large  bivalves  (e.g.,  Spondyhis,  Chama,  Ostrea)  and 
gastropods  (e.g.,  Haliotis,  Patella,  Strombus,  and  Pleuroploca) . 
The  species  occurs  in  warm  temperate  to  tropical  waters  in  the 
eastern  Pacific,  western  Atlantic,  and  eastern  Atlantic  regions  and 
is  usually  found  in  shallow  water,  although  Soot-Ryen  (1955) 
reported  a  living  specimen  taken  from  165  fathoms  (Turner  and 
Boss,  1962). 

In  both  C.  stokesii  and  C.  tuberculatus,  Lithophaga  aristata 
was  present  only  in  large  specimens.  This  relationship  coincides 
with  the  findings  of  Arey  and  Crozier  (1919)  and  Crozier  and 
Arey  (1920)  who  observed  the  presence  of  barnacles,  polychaetes, 
and  algae  only  on  larger  C.  tuberculatus.  The  erosion  of  the  shell- 
plates,  which  is  brought  about  by  physical  agents  of  the  environ- 
ment and  by  organisms  which  live  on  the  chiton's  shell,  appears 
to  be  a  prerequisite  for  the  boring  of  Lithophaga.  During  settle- 
ment the  pediveligers  of  L.  aristata  evidently  reject  the  uneroded 
areas  of  the  polyplacophoran  shell  and  metamorphosis  occurs  on 
the  eroded  substrate.  We  noted  that  most  lithophages  began 
boring  at  the  posterior  edge  of  the  intermediate  valves,  which  was 
normally  eroded  in  large  individuals.  Large  C.  stokesii  showing 
little  or  no  erosion  had  few,  if  any,  L.  aristata;  the  valves  of  those 
chitons  that  were  considerably  eroded  revealed  Lithophaga  boring 
in  them  at  various  places,  not  just  at  the  posterior  edge.  Chiton 
viridis  Spengler,  1797,  a  Caribbean  species  that  normally  lives 
below  the  low-water  mark,  is  rarely  eroded  and  no  Lithophaga  were 
found  in  the  shell-plates  of  this  species. 

After  initial  penetration  of  the  shell,  most  L.  aristata  bored  hori- 
zontally. In  several  instances  we  observed  the  burrows  of  Litho- 
phaga extending  into  a  second  valve.  In  one  example  from  Culebra 
Island,  Canal  Zone,  which  harbored  over  40  L.  aristata  (Fig.  1 ), 


1971  LITHOPHAGA    IN    CHITONS  5 

two  individual  lithophages  had  bored  vertically  from  one  valve  to 
the  next,  penetrating  the  intervening  musculature  (Fig.  4).  One 
such  burrow  passed  from  valve  III  into  the  insertion  plate  of  valve 
IV  (Fig.  1).  All  cases  of  vertical  burrows  apparently  occurred  in 
overcrowded  conditions. 

Most  burrows  of  intermediate  valves  were  roughly  parallel  with 
the  antero-posterior  axis  of  the  chiton  with  the  siphons  of  the 
Litlu)pluii>a  pointed  posteriorly,  although  they  deviated  somewhat 
by  orienting  themselves  along  an  axis  extending  from  the  zone  of 
erosion  toward  the  nearest  growth  zone.  The  reason  for  this  is 
obvious.  Should  a  lithophage  burrow  perpendicularly  to  the  antero- 
posterior axis  and  only  in  the  region  of  the  mucro,  it  would  risk 
having  its  surrounding  substrate  eroded  away.  By  burrowing  from 
the  zone  of  erosion  toward  a  growth  zone,  the  lithophage  is  assured 
of  an  increasing  substrate  in  which  to  bore.  This  explanation  clar- 
ifies the  otherwise  haphazard  orientation  of  the  burrows  in  the 
posterior  valve,  where  the  oldest  shell  material  is  near  the  center, 
not  at  the  posterior  edge  (Fig.  2). 

As  the  lithophage  increases  in  size,  it  faces  problems  caused 
by  the  restricted  space  in  which  it  can  grow.  Although  some 
Lithophaga  enlarge  their  burrows  dorsally,  most  penetrate  ventrally 
and  eventually  reach  the  mantle  of  the  chiton.  When  the  latter 
situation  occurs,  the  chiton  secretes  a  thin  calcareous  shield  in  an 
effort  to  contain  the  intrusion  of  the  lithophage.  Sometimes  more 
than  half  of  the  ventral  portion  of  the  lithophage  is  situated  below 
the  ventral  shell-plate  surface.  In  spite  of  the  efforts  of  the  Lith- 
ophaga to  increase  in  size  and  the  chiton's  effort  to  contain  it,  the 
lithophage  soon  reaches  a  point  where  further  growth  is  impossible. 
Whether  this  represents  a  truly  stenomorphic  condition  or  not  is 
uncertain,  because  we  do  not  know  if  the  L.  aristata  we  observed 
ever  reached  sexual  maturity.  Lithophaga  aristata  is  known  to 
attain  a  length  of  52  mm  (Turner  and  Boss,  1962);  the  largest 
specimen  extracted  from  a  C.  stokesii  was  9.0  mm,  while  the  aver- 
age length  was  about  7.0  mm. 

There  is  evidence  that  at  least  a  few  L.  aristata  outgrow  their 
restricted  polyplacophoran  substrate  (Fig.  6).  Some  of  the  largest 
burrows  that  we  examined  were  exposed  along  their  entire  dorsal 
surface,  indicating  that  the  lithophages  may  have  fallen  from  their 


6  BREVIORA  No.    369 

burrows.    It  is  probable  that  specimens  that  outgrow  the  chiton 
perish  in  the  external  environment.^ 

The  effect  of  numerous  Lithophaga  in  the  shell-plates  must  be 
detrimental  to  Polyplacophora.  In  addition  to  damaging  the  spe- 
cialized portion  of  the  nervous  system  that  makes  up  the  aesthetes 
in  the  tegmentum,  Lithophaga  weakens  the  valves  and,  at  times, 
probably  affects  the  maneuverability  of  the  chiton.  The  seriousness 
of  damage  to  a  large  amount  of  the  tegmental  nervous  tissue  is 
open  to  question  and  may  depend  upon  the  species  involved.  Aes- 
thetes are  photosensitive,  being  activated  both  by  light  of  constant 
intensity  and  by  a  decrease  of  light  intensity  (Arey  and  Crozier, 
1919).  Studies  on  the  growth  and  behaviour  of  Chiton  tubercu- 
latus  indicated  that  normal  erosion  of  shell-plates  and  concomitant 
loss  of  tegmental  aesthete  photosensitivity  produced  at  least  a 
partial  inversion  in  its  phototropic  response.  While  young  C.  tiiber- 
ciilatiis  are  photonegative,  older  individuals  may  be  irresponsive  or 
photopositive  (Arey  and  Crozier,  1919;  Crozier  and  Arey,  1920), 
although  Glynn  (personal  communication)  found  older  C.  tubercu- 
latus  from  Puerto  Rico  also  to  be  photonegative.  It  appears,  then, 
that  Lithophaga  mainly  affects  the  durability  of  the  shell,  rendering 
the  chiton  more  susceptible  to  predation. 

REFERENCES    CITED 

Arey,  L.  B.,  and  W.  J.  Crozier.     1919.    The  sensory  responses  of  Chiton. 

J.  Exper.  Zoo!.,  29:   157-260. 
Brucker,  a.     1897.     Sur  un  noiivel  Acarien  marin.    C.  R.  See.  Biol.,    49: 

632-633. 
Brucker.  A.,  and  E.  Trouessart.     1900.     Seconde  note  sur  un  Acarien 

marin   (Halacaride),  parasite  de  VAcanthocliiton  porosiis.    C.  R.  Soc. 

Biol..  52:    107    109. 
Crozier.  W.  J.,  and  L.  B.  Arey.     1920.    On  the  ethology  of  Cliiton  tiiber- 

ctilatiis.    Proc.  Natl.  Acad.  Sci..  5:  496-498. 


1  Although  Hodgkin  (1962)  maintained  L.  pitimiila  kelseyi  Hertlein  and 
Strong,  1946  outside  their  burrows  for  over  one  year  under  laboratory  con- 
ditions. Otter  (1937)  was  unsuccessful  in  his  attempts  to  rear  L.  cumingi- 
ana  (Reeve,  1857)  and  L.  teres  (Philippi.  1846)  that  had  been  removed 
from  their  burrows.  It  is  doubtful  if  Lilliophaga  could  survive  out  of  its 
burrow  under  exposed  conditions. 


1971  LITHOPHAGA    IN    CHITONS  7 

Glynn,  P.  W.     1968.     Ecological  studies  on  the  associations  of  chitons  in 

Puerto  Rico,  with  special  reference  to  sphaeromid  isopods.    Bull.  Mar. 

Sci.,  18:  572-626. 
Helfman,  E.  S.     1968.    A  ctenostomatous  ectoproct  epizoic  on  the  chiton 

Ischnochiton  mertensii.   Veliger,  10:  290-291. 
Hodgkin,    N.   M.      1962.      Limestone    boring   by    the   mytilid   Lithophaga. 

Veliger,  4:    123-129,  3  pis. 
MacGinitie,  G.  E.,  and  N.  MacGinitie.     1968.     Notes  on  Cryptochiton 

stelleri  (Middendorff,  1846).   Veliger,  11:  59-61,  pi.  6. 

Menzies,  R.  J.,  AND  P.  W.  Glynn.  1968.  The  common  marine  isopod 
Crustacea  of  Puerto  Rico.  A  handbook  for  marine  biologists.  Studies 
Fauna  Curasao,  27:   1-133. 

Otter,  G.  W.     1937.     Rock-destroying  organisms  in  relation  to  coral  reefs. 

British    Mus.    (Nat.    Hist.)    Great    Barrier    Expedition    1928-29,    Sci. 

Repts.,  1:  323-352,  6  pis. 
Soot-Ryen,   T.      1955.  A   report  on  the  family   Mytilidae   (Pelecypoda). 

Allan  Hancock  Pacific  Expeditions.  20:   1-154,  10  pis. 
Turner,    R.   D.,   and  K.  J.   Boss.      1962.     The  genus   Lithophaga   in  the 

western  Atlantic.    Johnsonia,  4:  81-116,  pis.  57-75. 

Webster,  S.  K.  1968.  An  investigation  of  the  commensals  of  Crypto- 
chiton stelleri  (Middendorff,  1846)  in  the  Monterey  Peninsula  area, 
California.    Veliger.    11:    121-125. 


BREVIORA 


No.   369 


1971  LITHOPHAGA    IN    CHITONS 


Figure  1.  Radiograph  of  disarticulated  shell-plates  from  a  specimen 
of  Chiton  stokesii  from  Culebra  Island.  Panama  Bay,  Canal  Zone 
(MCZ  277122),  showing  a  high  degree  of  infestation  by  Lithopliaga  aris- 
tata   (0.84    x  ). 

Figure  2.     Enlargement  of  posterior  valve  of  Fig.   1    (3.2    X  ). 

Figure  3.  Typical  siphonal  opening  of  L.  aristata  burrow  in  an  uneroded 
portion  of  a  C.  stokesii  shell-plate  (12    X  )• 

Figure  4.  Intervening  shell-plate  musculature  located  between  valves  IV 
and  V  in  Fig.  1,  showing  damage  resulting  from  penetration  of  Lithophaga 
(9.2   X). 

Figure  5.  Example  of  L.  aristata  (MCZ  277123)  in  shell-plate  cross 
section  of  C.  stokesii  from  Punta  Mala,  Panama  (3.9   x  )• 


10 


BREVIORA 


No.   369 


Figure  6.    Exposed  burrow  of  Lithophaga  aristata  in  Chiton  stokesii  from 
Panama  City,  Panama  (MCZ  78821)   (4.2   x  ). 

Figures   7-8.     L.   aristata   extracted   from    burrow   illustrated   in   Fig.    5 
(MCZ  277123)    (6.5    x  ). 


BREVIORA 

Miaseuni   of   Comparative   Zoology 

Cambridge,  Mass.  31  March,  1971       Number  370 

ECOLOGICAL  OBSERVATIONS  ON  A  LITTLE  KNOWN 
SOUTH  AMERICAN  ANOLE:  TROPIDODACTYLUS  ONCA 

James   P.  Collins^ 

Abstract.  The  little  known  anole  Tropidodactylus  onca  on  the  island 
of  Margarita  is  typically  restricted  to  belts  of  low  xerophytic  vegetation 
adjacent  to  the  open  sandy  area  of  natural  beaches.  Most  animals  are 
found  on  the  ground  or  in  low  bushes  and  occur  up  to  a  height  of  30.0 
cm.  They  are  poor  climbers  and  will  occasionally  escape  into  holes  made 
by  ghost  crabs. 

INTRODUCTION 

A  brief  visit  (from  July  8  to  July  21,  1968)  to  the  Fundacion 
La  Salle  on  Margarita  Island,  Venezuela,  afforded  me  an  oppor- 
timity  to  collect  and  observe  a  little  known  anole,  Tropidodactylus 
onca.  Margarita  is  a  continental  island  approximately  twenty-one 
miles  off  the  district  of  Sucre  on  the  northern  coast  of  Venezuela. 
It  is  approximately  two  hundred  air  miles  northeast  of  Caracas. 

Tropidodactylus  onca  is  a  speciaUzed  derivative  of  Anolis  but 
with  keeled  scales  underneath  the  digits  instead  of  the  expanded 
digital  pads  with  adhesive  lamellae  so  characteristic  of  the  latter 
primarily  arboreal  genus.  The  difference  in  morphology  should 
be  reflected  in  ecology,  but  there  have  been  no  detailed  reports 
on  the  habits,  habitat,  or  even  color  in  Ufe  of  T.  onca.  This 
paper  attempts  to  remedy  this  gap  in  information. 

Description  and  color  in  life.  Tropidodactylus  onca  is  a  rela- 
tively large  anole.  The  largest  of  the  specimens  collected  is  75 
mm  snout- vent  length.  The  tail  is  round  with  no  dorsal  crest 
and  is  approximately  equal  to  the  snout-vent  length  of  the  animal. 

The  most  distinctive  specialization  of  the  anoles  in  general, 
the  dewlap,  is  extremely  well  developed  in  this  genus.  It  has  a 
bright  yellow  ground  color  in  which  individual  red  scales  are 
embedded. 

1  Museum  of  Zoology,  University  of  Michigan,  Ann  Arbor.  Mich. 


BREVIORA 


No.  370 


The  dorsal  color  of  the  lizard  varies  from  a  very  light  ashy- 
gray  to  a  dark  gray-brown  with  a  disruptive  pattern  of  black 
and  white  longitudinal  markings.  These  vary  from  barely  visible 
to  very  prominent.  The  ventral  surface  of  the  lizard  is  white. 
The  species  is  not  sexually  dichromatic  and  is  very  difficult  to 
sex  externally.  The  cryptic  coloration  of  the  species  is  perfect. 
In  the  field  the  animals  are  indistinguishable  from  their  sur- 
roundings. In  fact,  an  animal  can  usually  be  located  only  when 
the  collector  inadvertently  frightens  it  into  movement. 

Habits  and  habitat.  Tropidodactylus  onca  is  a  beach  anole. 
Its  distribution  is  typically  restricted  to  the  belt  of  low  xerophy- 
tic  vegetation  adjacent  to  the  open  sandy  area  of  a  natural  beach. 
The  exact  width  of  this  belt  and  its  continuity  varies  according 
to  the  geological  and  ecological  factors  of  the  particular  locality. 
The  animal  was  never  observed  in  the  open  sandy  areas  devoid 
of  vegetation,  and  penetrates  only  slightly  into  the  more  land- 
ward areas  where  the  vegetation  is  higher  than  0.75  to  1.00  m. 


20 

"T" 


10 


64" 


50 


10 


50'- 


40 


LOS   FRAILES 

El  Aguo 
Punta   Montadaro 


Playa   Guacuco 


ISLA    CUBAGUA 


ISLA    COCHE 


PENINSULA     DE  ARAYA 


(0' 


SO 


Figure   1.     Margarita  Island.     Localities  at  which  Tropidodactylus  onca 
was  observed  or  collected  are  shown  as  solid  circles. 


1971  TROPIDODACTYLUS   ONCA  3 

All  the  specimens,  with  the  exception  of  one  taken  at  a  height 
of  1.25  m,  were  collected  on  the  ground  or  up  to  30.0  cm  high 
on  low  bushes,  vines,  etc. 

Observation  and  collecting  was  restricted  to  six  localities  (Fig. 
1),  all  on  the  eastern  half  of  the  island.  Roze  (1964),  however, 
has  reported  the  lizard  from  the  western  half  (Macanao).  Of  the 
six  localities  in  which  the  species  was  observed,  five  are  on  the 
coast.  The  exception,  El  Aguila,  is  a  town  approximately  2.5 
km  from  Punta  de  Piedras.  Possible  reasons  for  the  animal's 
appearance  here  will  be  discussed  later.  Outside  of  this  single 
exception,  no  specimens  were  ever  observed  in  noncoastal  por- 
tions of  the  island  and  all  were  collected  at  sea  level. 

The  vegetation  of  the  zone  in  which  Tropidodactylus  is  found 
consists  of  only  low  ground  growth.  The  sand-shrub  communities 
of  the  five  coastal  localities  in  which  Tropidodactylus  is  found 
each  contain  at  least  two  and  as  many  as  four  of  the  following 
species  of  plant:  Sesuvium  portidacastrum,  Philoxerus  vermicu- 
laris,  Bat  is  maritima,  Sporobolus  (virginicus?),  Ipomoea  (pescap- 
rae?),  and  Mallotonia  gnaphalodes.  Howard  (1950)  lists  these 
six  species  as  pan-Caribbean  in  distribution.  These  are  found  in 
association  with  less  abundant  and  restricted  species,  the  exact 
taxa  varying  from  locality  to  locality.  The  landward  edge  of  this 
coastal  community  typically  contains  representatives  of  the  genera 
Opuntia,  Melocactus,  Lemairocereus,  Philoxocereus,  and  Proso- 
phis.    Tropidodactylus  penetrates  slightly  into  this  zone. 

The  majority  of  the  animals  collected  were  taken  in  large 
patches  of  Ipomoea  found  at  two  of  the  localities  investigated  (El 
Agua  and  Playa  Guacuco).  The  reptile  was  found  both  on  the 
plants  and  in  the  open  space  between  them.  If  the  patch  was 
dense  enough,  the  animals  were  typically  found  with  their  head 
on  top  of  the  leaves  and  their  trunk  and  tail  among  the  tangled 
vines.  Some  were  also  found  on  an  occasional  outcropping  of 
rock  or  log.  When  frightened,  the  animal  would  either  duck  into 
the  mat  of  vegetation  (if  dense  enough)  or  scamper  across  the 
open  sand  until  it  reached  a  vine  or  series  of  vines  which  it  would 
then  proceed  to  run  clumsily  over.  Being  nonwoody,  the  plants 
do  not  give  much  support  and  the  animal  could  easily  be  taken. 
In  the  area  just  north  of  Punta  Montadero  where  Mallotonia,  a 
woody-stem  plant,  is  dominant,  the  animal's  behavior  was  very 
different.  Here,  when  first  sighted,  the  lizard  was  always  on  the 


BREVIORA 


No.  370 


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1971  TROPIDODACTYLUS   ONCA  5 

ground.  When  pursued,  the  majority  of  animals  observed  would 
merely  run  among  the  ground  cover.  A  few  specimens,  however, 
were  observed  to  climb  the  Mallotonia,  some  to  a  height  of  30.0 
cm.  Their  climbing  was  clumsy  and  ineffective.  The  toe  structure 
of  this  genus  is  not  well  adapted  for  tree  climbing.  Unlike  most 
anoles,  T.  onca  is  not  arboreal. 

Another  means  of  retreat  should  also  be  pointed  out.  At  times, 
a  specimen,  being  pursued,  would  run  into  a  large  hole  in  the 
sand  opening  into  a  tunnel.  Ruthven  (1922)  also  reports  this 
species  as  escaping  into  holes.  It  should  be  noted,  however,  that 
these  holes  are  resting  places  made  by  ghost  crabs  (Ocypode)  and 
are  not  dug  by  Tropidodactylus.  It  should  also  be  noted  that  this 
was  a  rather  infrequent  means  of  escape,  used  by  the  lizard  only 
when  almost  completely  exhausted. 

At  each  of  the  six  localities,  T.  onca  is  found  sympatric  with 
Cnemidophorus  lemniscatus  lemniscatus.  In  those  localities  (El 
Agua  and  Punta  los  Cocos)  where  the  landward  border  of  the 
coastal  area  is  occupied  by  a  semi-desertic  community,  the  terri- 
tory of  Tropidodactylus  partially  overlaps  that  of  Tropidurus  tor- 
quatus  hispidus.  The  Tropidodactylus  penetrate  this  zone  for  only 
a  very  small  distance.  In  some  areas,  two  other  organisms  also 
found  sympatric  with  Tropidodactylus  are  the  gecko  Gonatodes 
vitatus  vitatus  and  the  microteiid  Gymnopthalmus  laevicauda. 

Roze  (1964)  has  the  following  note  concerning  the  diet  of 
Tropidodactylus:  "The  stomach  contents  examined  in  various 
specimens  of  this  species  revealed  the  remains  of  grasshoppers 
(Grillidae),  Coleoptera,  spiders,  and  various  species  of  Diptera,  as 
well  as  the  remains  of  other  unidentifiable  arthropods."  Tropido- 
dactylus then,  hke  most  anoles,  is  insectivorous.  Similarly,  like 
most  anoles,  the  animal  is  diurnal  in  its  activity.  All  but  one  of 
the  twenty-five  specimens  were  captured  during  the  day.  The 
single  exception  was  collected  alongside  the  road  near  the  town 
El  Aguila  approximately  2.5  km  from  Punta  de  Piedras.  It  was 
on  a  branch  of  a  low  bush,  Jatropha  gossypiifolia,  in  the  cleared 
margin  alongside  the  road.  The  animal  was  in  typical  anole 
sleeping  posture,  snout  toward  the  main  stem,  but  with  its  eyes 
open.  Just  prior  to  being  seized,  the  animal  moved  its  head  but 
did  not  attempt  to  flee.  This  single  exception  to  the  otherwise 
complete  coastal  distribution  of  the  animals  on  the  island  most 
probably  migrated  to  this  inland  area  along  the  corridor  of  low 
vegetation  bordering  either  side  of  the  roadway.  This  habitat  is 
ecologically  similar  to  that  of  the  coastal  zone. 


6  BREVIORA  No.    370 

ACKNOWLEDGMENTS 

I  am  grateful  to  Dr.  Janis  Roze  and  Dr.  Ernest  E.  Williams  for 
critically  reading  the  manuscript  and  for  their  valuable  sugges- 
tions. This  study  was  carried  out  at  the  Fundacion  La  Salle,  Mar- 
garita Island,  Venezuela;  I  thank  Hermano  Gines  for  making  the 
facilities  there  available  to  me.  Field  expenses  were  partially  met 
by  NSF-GY-4183,  administered  by  Manhattan  College,  and  NSF- 
GB-6944  to  Ernest  E.  Williams. 

REFERENCES 

Howard,  R.  A.  1950.  Vegetation  of  the  Bimini  island  group.  Ecol.  Mono. 
20:   317-349. 

Roze,  J.  A.  1964.  La  herpetologia  de  la  Isia  de  Margarita,  Venezuela. 
Mem.  Soc.  Cien.  Nat.  La  Salle,  24  (69):  209-241. 

RuTHVEN,  A.  G.  1922.  The  amphibians  and  reptiles  of  the  Sierra  Nevada 
de  Santa  Marta,  Colombia.  Miscellaneous  PubUcation  No.  8,  Museum 
of  Zoology,  University  of  Michigan. 


BREVIORA 

Miaseiuioi   of   Comparative   Zoology 

Cambridge,  Mass.  31  March,  1971  Number  371 


A  NEW  SPECIES  OF  BROMELIAD-INHABITING  GALLIWASP 
(SAURIA:  ANGUIDAE)  FROM  JAMAICA 

Albert  Schwartz^ 

Abstract.  A  new  species  of  anguid  lizard,  Diploglossus  fowleri,  is 
described  from  two  specimens  collected  from  bromeliads  at  the  northern 
edge  of  Jamaica's  Cockpit  Country.  The  affinities  of  the  new  species  are 
with  D.  hewardi  and  D.  diiqiiesneyi;  both  D.  fowleri  and  D.  duquesneyi 
appear  to  be  geographic  or  ecological  isolates  of  the  widespread  D.  hewardi. 

The  Antillean  islands  of  Jamaica  and  Hispaniola  have  excep- 
tionally large  numbers  of  species  of  the  anguid  lizard  genus 
Diploglossus  Wiegmann.  The  latter  island  has  six  extant  species, 
whereas  Jamaica  likewise  had  six  species  of  which  one  {occiduus 
Shaw)  is  presently  considered  extinct.  Cousens  (1956)  summar- 
ized the  then-known  Jamaican  galliwasps  and  regarded  cnisculus 
Carman,  harbour i  Grant,  hewardi  Gray,  and  duquesneyi  Grant 
as  valid  species.  Since  that  time,  D.  microblepharis  Underwood 
has  been  named  from  a  single  specimen  from  the  northeastern 
Jamaican  coast.  Cousens  (1956),  followmg  Grant  (1940b),  sep- 
arated the  four  forms  then  recognized  into  two  major  groups: 
one  group  {crusculus,  barbouri)  with  short  legs  and  the  other 
{hewardi,  duquesneyi)  with  long  legs.  Schwartz  (1970),  in  dis- 
cussing D.  occiduus,  suggested  that  the  species  crusculus-hewardi- 
barbouri-occiduus  might  represent  a  phylogenetic  series,  despite 
the  interposition  in  this  sequence  of  both  long-  and  short-limbed 
species.  D.  microblepharis  stands  alone;  its  relationships  are  with 
the  Puerto  Rican  D.  pleei  Dumeril  and  Bibron  and  the  Cuban  D. 
delasagra  Cocteau. 

In  the  summer  of  1961,  while  cutting  bromeliads  in  the  decid- 
uous forest  at  the  northern  edge  of  Jamaica's  Cockpit  Country, 

1  Miami-Dade  Junior  College,  Miami,  Florida  33167 


2  BREVIORA  No.    371 

the  extensive  karst  region  in  northwestern  Jamaica,  we  secured  a 
single  immature  galUwasp.  Despite  the  peculiar  habitat  (no  Antil- 
lean  Diploglossus  had  ever  been  recorded  from  bromehads)  the 
Hzard  bore  resemblances  to  D.  hewardi,  and  it  was  so  considered 
in  the  field.  Not  until  1969,  when  the  paper  dealing  with  D. 
occiduus  (Schwartz,  1970)  was  in  preparation,  was  the  lizard 
re-examined  in  a  routine  study  of  D.  hewardi  for  comparative 
purposes.  At  that  time,  the  difference  in  scutellation  between  D. 
hewardi  and  the  1961  juvenile  specimen  quickly  became  appar- 
ent. Further  examination  of  the  specimen  indicated  that,  although 
it  resembled  D.  hewardi  in  general  (being  a  long-limbed  form), 
it  differed  chromatically  and  in  pattern  from  that  species.  But, 
since  it  was  immature,  no  further  course  of  action  was  planned. 

It  was  thus  with  great  pleasure  that  I  accepted  the  invitation 
of  Dr.  Thomas  H.  Patton  of  the  Florida  State  Museum  to  visit 
Jamaica  and  stay  at  Worthy  Park  Estate  during  August  1970. 
Although  it  was  hardly  likely  that,  even  with  persistent  bromeliad 
cutting,  we  would  encounter  another  specimen  of  the  arboreal 
galliwasp,  plans  were  made  to  revisit  the  site  of  capture  of  the 
first  individual  (Windsor,  Trelawny  Parish).  Thanks  to  the  efforts 
of  my  assistants  and  native  help,  we  were  successful  in  securing 
another  and  adult  specimen  of  the  same  form.  Study  of  both  indi- 
viduals convinces  me  that  they  represent  a  new  species,  related  to 
D.  hewardi,  which  has  apparently  taken  to  a  bromeliad-inhabiting 
niche  —  a  niche  that  is  virtually  unoccupied  by  Antillean  reptiles. 

In  the  summer  of  1961,  I  had  the  capable  assistance  of  Ronald 
F.  Klinikowski  and  David  C.  Leber.  Our  activities  were  facilitated 
by  C.  Bernard  Lewis  of  the  Institute  of  Jamaica.  The  1970  trip 
was  made  both  pleasant  and  profitable  by  the  presence  of  Dale  E. 
Becker,  Michael  T.  Felix,  and  Danny  C.  Fowler,  whose  energy 
expenditures  in  bromeliad  cutting  were  noteworthy.  In  addition, 
I  have  examined  specimens  collected  by  Richard  Thomas  in  1967, 
and  by  Robert  Brenner  and  Paul  Moravec  in  the  same  year.  All 
specimens  are  in  the  Albert  Schwartz  Field  Series  (ASFS)  with 
the  exception  of  the  holotype  of  the  new  taxon  and  two  speci- 
mens of  D.  duqiiesneyi,  which  are  in  the  Museum  of  Comparative 
Zoology  (MCZ)  at  Harvard  University.  All  measurements  are  in 
millimeters  and  color  designations  are  from  Maerz  and  Paul 
(1950).  I  am  especially  grateful  to  Dr.  Patton  for  making  the 
Worthy  Park  facilities  available  to  us,  and  to  Dr.  Ernest  E.  Wil- 
liams for  the  loan  of  the  holotype  of  D.  duquesneyi. 


1971  BROMELIAD    GALLIWASP  3 

In  honor  of  Danny  C.  Fowler,  whose  endeavors  on  my  behalf 
can  only  be  recognized  in  a  token  fashion  by  associating  his  name 
patronymically  with  the  species,  I  propose  that  this  bromeliad- 
inhabiting  galliwasp  be  called 

Diploglossus  fowleri,  new  species 

Holotype.  MCZ  125601,  a  female,  from  Windsor,  elevation 
about  500  feet  (153  meters),  Trelawny  Parish,  Jamaica,  taken 
15  August  1970  by  Danny  C.  Fowler.  Original  number  ASFS 
V19902. 

Paratype.  ASFS  14421,  same  data  as  holotype,  12  July  1961, 
D.  C.  Leber. 

Diagnosis.  An  apparently  moderately  sized  (only  known  adult 
105  mm  snout-vent  length),  long-limbed,  bromeliad-dwelling  gal- 
liwasp distinguished  from  all  other  Jamaican  species  by  a  com- 
bination of:  1)  low  number  (101-103)  of  ventral  scales  between 
mental  and  vent,  2)  low  number  (41-43)  of  scales  around  body 
at  midbody,  3)  angular  subocular  scale  modally  between  supra- 
labials  6  and  7,  4)  enlarged  postmental  scale  contacting  5  infra- 
labial  scales,  5)  fourth  toe  lamellae  18-21,  6)  ratio  of  head 
width  to  head  length  high  (80.0),  7)  auricular  opening  small, 
8)  dorsal  trunk  and  dorsal  caudal  scales  keeled  and  striate,  9) 
ventral  scales  smooth,  10)  dorsal  pattern  of  tans  and  browns 
arranged  in  a  distinct  chevronate  pattern,  and  11)  with  dark 
markings  on  the  head  shields. 

Distribution.    Known  only  from  the  type  locality. 

Description  of  holotype.  An  (apparently)  adult  female  with  a 
snout- vent  length  of  105  mm  and  tail  (almost  entirely  regener- 
ated) 75  mm;  ventral  scales  between  mental  and  vent  103,  41 
scales  around  body  at  midbody;  fourth  toe  lamellae  21,  angular 
subocular  between  supralabials  6  and  7  on  one  side,  between  7 
and  8  on  the  other;  head  length  18.5,  head  width  14.8;  ratio  of 
head  width  to  head  length  80.0;  median  enlarged  postmental 
(=  first  unpaired  chin  shield)  small  and  contacting  5  infralabials. 
In  life,  dorsal  pattern  consisting  of  a  series  of  about  16  or  17 
wood  brown  chevrons,  their  apices  pointing  posteriorly,  from  the 
neck  to  the  sacrum,  on  a  tan  ground;  sides  with  somewhat  lighter 
brown  continuations  of  these  chevrons  both  on  the  neck  and 
between  the  limbs,  the  lateral  continuations  forming  a  series  of 
more  or  less  vertical  brown  bars  which  extend  ventrad  to  about 
the  level  of  the  limb  insertions;  a  few  scattered  paler  tan  dots  or 


4  BREVIORA  No.    371 

flecks  in  two  vague  lateral  horizontal  rows,  associated  with  the 
lateral  brown  vertical  bars;  head  tan,  with  more  or  less  symmet- 
rical wood  brown  markings  (a  pair  on  the  snout,  an  unpaired 
median  blotch  in  the  preorbital  region,  a  median  unpaired  blotch 
on  the  posterior  portion  of  the  frontal,  and  the  interparietal- 
parietal  region  with  the  scales  dark  edged);  a  black  preorbital  line 
on  the  lores;  temples  longitudinally  streaked  with  very  dark  wood 
brown;  a  series  of  three  brown  lines  on  the  supralabials,  one  below 
the  eye,  the  two  others  extending  vertically  across  the  supralabials 
in  the  loreal  region,  all  continuous  ventrally  across  the  infralabials; 
a  series  of  three  very  dark  brown  to  black  nuchal  blotches,  the 
posteriormost  the  largest  and  located  above  the  insertion  of  the 
forelimb;  Umbs  mottled  brown  and  black  dorsally,  the  forelimbs 
additionally  with  some  intermixed  tan  areas  and  consequently 
appearing  more  mottled  or  marbled  than  the  hindlimbs;  underside 
pale  orange,  with  discrete  brown  longitudinal  streaks  (four  scales 
in  length)  or  flecks  on  throat,  and  deep  orange  streaks  on  venter; 
underside  of  limbs  and  tail  (unregenerated  portion)  pale  orange; 
iris  brown  with  orange  pupillary  ring. 

Variation.  The  paratype  is  a  juvenile  lizard  with  a  snout- vent 
length  of  66  mm.  Scale  counts  are:  101  scales  between  mental 
and  vent,  43  scales  at  midbody,  angular  subocular  between  supra- 
labials 6  and  7  on  one  side,  between  8  and  9  on  the  other,  fourth 
toe  lameUae  18;  head  length  12.7,  head  width  9.3  (ratio  73.2). 
In  hfe,  the  paratype  was  tan  (PI.  14G6)  dorsally  with  about  18 
dorsal  chevrons  between  the  neck  and  the  sacrum;  the  sides  were 
paler  tan  (PL  13D3).  The  snout  was  olive,  with  the  jowls  and 
the  base  of  the  tail  slightly  reddish.  The  Hmbs  were  tan,  spotted 
with  dark  brown  to  black.  The  venter  was  translucent  gray, 
marbled  with  brown  on  the  throat,  and  marked  with  reddish  on 
the  trunk  and  underside  of  the  hindlimbs  and  tail.  The  facial 
markings,  described  for  the  holotype,  were  equally  as  prominent 
in  the  juvenile  paratype.  The  dorsal  chevronate  pattern  was  dark 
brown  to  black,  and  on  the  sides  the  chevrons  were  continuous 
with  weakly  defined  lateral  vertical  brown  bars,  each  of  which 
was  followed  by  a  creamy  bar.  Three  nuchal-supra-axillary 
blotches  were  black,  and  the  frontal  head  shield  had  a  dark  ante- 
rior margin  with  some  additional  dark  sulTusions  on  the  dorsal 
surface  of  the  head.  The  postmental  scale  in  the  paratype  is  very 
small,  but  it  contacts  7  infralabials;  the  contact  on  the  right  side 


1971  BROMELIAD    GALLIWASP  5 

between   the  postmental  and   the  third  infralabiai  is  slight,   but 
the  contact  on  the  left  side  is  slightly  more  broad. 

Comparisons.  D.  fowleri  needs  comparison  only  with  the  three 
long-limbed  Jamaican  species  (occiduus,  hewardi,  duquesneyi) . 
The  new  species  differs  from  the  short-limbed  cnisculus  and 
barboiiri  in  having  much  larger  Umbs  and  from  microblepharis 
in  having  the  frontal  longer  than  broad  (in  microblepharis,  the 
frontal  is  broader  than  long).  Counts  of  ventral  scales  (101-103) 
in  fowleri  overlap  (of  the  other  species)  only  the  counts  of  crus- 
culus  (97-122,  data  from  Grant,  1940b);  all  other  Jamaican 
species  combined  have  ventral  counts  ranging  from  107  to  150, 
with  the  low  count  of  107  in  the  giant  occiduus,  the  high  count 
of  150  in  barbouri.  In  midbody  scales,  fowleri  (41-43)  overlaps 
only  cruscuhis  (36-49)  and  microblepharis  (43).  Combined 
midbody  counts  for  all  other  Jamaican  species  (with  the  excep- 
tion of  cruscuhis  and  microblepharis)  vary  between  47  {bar- 
bouri) and  59  {hewardi).  In  having  the  angular  subocular 
between  supralabials  6  and  7,  fowleri  resembles  barbouri  and 
cruscuhis  but  differs  from  hewardi  and  duquesneyi  (7  and  8), 
microblepharis  (5  and  6),  and  occiduus  (8  and  9). 

In  fowleri,  the  dorsal  scales  are  striate  and  keeled;  this  condition 
occurs  in  all  other  Jamaican  galliwasps  with  the  exception  of 
occiduus  (dorsals  striate  but  not  keeled).  In  having  smooth 
ventrals,  fowleri  resembles  barbouri,  hewardi,  occiduus,  and 
microblepharis.  The  ventral  scales  are  striate  in  crusciilus  and 
duquesneyi.  Note,  however,  that  hewardi  may  have  weakly  striate 
ventrals,  and  duquesneyi  may  have  smooth  ventrals.  Finally,  the 
striate  and  keeled  dorsal  caudal  scales  of  fowleri  are  Hke  those  of 
cruscuhis  and  duquesneyi;  all  other  Jamaican  species  have  smooth 
{hewardi,  occiduus)  or  keeled  {microblepharis)  superior  caudals. 
From  the  above  summary,  it  is  obvious  that  fowleri  combines 
features  of  scuteUation  of  several  Jamaican  species  in  new  and 
different  ways,  and  that  the  new  species  differs  in  combination  of 
these  characteristics  from  all  other  Jamaican  species. 

Presumably,  as  will  be  noted  below,  D.  fowleri  is  a  local  deriva- 
tive of  the  widespread  D.  hewardi.  The  fact  that  the  juvenile 
fowleri  was,  in  the  field,  considered  as  hewardi  suggests  the  simi- 
larities between  the  two  species.  However,  in  addition  to  the 
structural  differences  noted  in  the  above  paragraph,  the  two  spe- 
cies differ  strikingly  in  coloration  in  life  and  perhaps  less  so  in 


6  BREVIORA  No.    371 

dorsal  pattern.  More  importantly,  the  size  of  the  auricular  open- 
ing in  fowleri  is  much  the  smaller;  comparison  of  the  opening  in 
the  fowleri  holotype  and  a  similarly  sized  hewardi  (ASFS  14892; 
female  with  snout- vent  length  of  109  mm)  reveals,  even  upon 
casual  inspection,  that  the  auricular  opening  of  fowleri  is  slightly 
more  than  half  the  size  of  that  of  the  hewardi.  In  addition,  the 
two  species  differ  in  that  fowleri  has  larger  ventral  scales  (101- 
103  between  mental  and  vent  in  fowleri,  113-135  in  hewardi), 
and  fewer  scales  at  midbody  (41-43  versus  49-59  in  hewardi). 
The  enlarged  postmental  contacts  7  infralabials  in  all  hewardi  ex- 
amined, whereas  at  least  in  the  fowleri  holotype  this  scale  con- 
tacts only  5  infralabials  (weak  contact  with  7  infralabials  in  the 
paratype).  In  fowleri,  the  angular  subocular  modally  hes  between 
supralabials  7  and  8,  whereas  in  hewardi  it  lies  between  suprala- 
bials  6  and  7.  D.  fowleri  exceeds  D.  hewardi  in  number  of  fourth 
toe  lamellae  (15-19  in  22  hewardi,  18  and  21  in  two  fowleri). 
Finally,  the  head  width/head  length  ratio  in  adult  female  hewardi 
varies  between  70.7  and  74.1,  whereas  in  the  fowleri  holotype, 
this  ratio  is  80.0.  There  are  no  comparably  sized  juvenile  hewardi 
for  comparison  of  this  ratio  in  the  paratype  of  fowleri,  but  the 
ratio  (73.2)  in  this  specimen  lies  near  the  upper  extreme  of  ratios 
in  hewardi  with  shorter  snout-vent  lengths  (45-52  mm;  ratios 
66.4  to  73.8). 

The  dorsal  coloration  of  hewardi  has  been  repeatedly  recorded 
as  greenish  brown  to  greenish  tan,  but  some  individuals  have  the 
dorsum  very  dark  brown  (almost  black)  to  metallic  tan.  The 
head  regularly  is  unmarked  dorsally,  and  vertical  subocular  and 
loreal  lines  are  absent.  The  dorsal  pattern  consists  of  a  trans- 
verse series  of  confused  bars  or  bar  fragments;  these  pattern  ele- 
ments are  usually  so  broken  that  no  meaningful  count  can  be 
taken.  There  is  a  strong  tendency  for  the  hewardi  dorsal  pattern 
elements  to  consist  of  bars,  rather  than  chevrons  as  in  fowleri. 
Perhaps  the  most  distinctive  pattern  feature  of  hewardi,  in  con- 
trast to  fowleri,  is  that  of  the  throat.  In  hewardi,  the  throat  has 
a  broad  dark  reticulum,  the  pattern  extending  as  far  posterior 
as  the  forelimb  insertions.  This  pattern  is  expressed  even  in  the 
smallest  juveniles  and  becomes  more  intense  with  increasing  size. 
No  hewardi  has  the  discrete  brown  throat  lines  and  flecks  of 
fowleri.  In  addition,  the  ground  color  of  the  throat  in  hewardi 
is  often  blue  to  purplish,  not  pale  orange  as  in  fowleri.  The  deep 
orange  belly  markings   of  fowleri  are   absent  in  hewardi;  some 


1971  BROMELIAD    GALLIWASP  7 

hewardi  have  belly  markings  that  are  not  discrete  as  in  fowled 
and  are  gray  in  life. 

Comparisons  in  detail  with  D.  occiduus  are  hardly  necessary. 
In  addition  to  the  scutellogical  differences  noted  above,  the  huge 
size  of  occiduus  (to  305  mm  snout-vent  length)  and  its  presumed 
terrestrial  habits,  coupled  with  its  general  bulk,  immediately  dis- 
tinguish it  from  fowled. 

The  only  other  long-limbed  Jamaican  galliwasp  is  D.  duques- 
neyi.  Scutellogical  differences  have  already  been  noted  between 
this  species  and  fowled.  I  have  examined  the  holotype  (MCZ 
45194)  and  one  other  specimen  (MCZ  45181)  of  duquesneyi. 
The  species  was  casually  defined  by  Grant  (1940a:  6)  on  the 
basis  of  one  juvenile  specimen,  and  Cousens  (1956)  gave  addi- 
tional pigmental  and  pattern  differences  between  two  specimens 
of  duquesneyi,  and  hewardi.  I  have  examined  the  two  extant 
duquesneyi  and  both  are  damaged  about  the  body  so  that  accurate 
scale  counts  are  difficult.  Ventral  scales  between  the  mental  and 
vent  are  about  116  and  122,  midbody  scales  are  about  48  and 
49,  and  fourth  toe  lamellae  are  19  and  23.  The  angular  subocular 
lies  between  supralabials  7  and  8  on  both  sides  of  both  specimens. 
D.  hewardi  and  D.  duquesneyi  are  comparable  in  dorsal  pattern: 
the  transverse  markings  in  both  are  distinctly  straighter  and  more 
barlike  than  the  chevronate  pattern  in  fowleri.  In  addition,  com- 
parison of  equally  sized  hewardi  and  duquesneyi  shows  that  du- 
quesneyi (like  fowleri)  has  a  larger  auricular  opening  than 
hewardi. 

D.  fowleri  differs  from  D.  duquesneyi  in  that  the  former  has 
fewer  ventrals  between  mental  and  vent  (101-103  versus  116- 
122),  fewer  midbody  scales  (41-43  versus  48-49),  the  angular 
subocular  between  supralabials  6  and  7  rather  than  between  7 
and  8,  and  smooth  rather  than  striate  ventrals  (although  the  holo- 
type of  duquesneyi  has  smooth  ventrals).  Two  pattern  elements 
differentiate  duquesneyi  from  fowleri:  the  former  has  the  tail  (at 
least  in  juveniles)  banded  alternately  black  and  sky  blue  (Grant, 
1940b:  106),  a  feature  unknown  in  any  other  Antillean  galliwasp, 
and  duquesneyi  has  an  immaculate  throat  and  venter  (color  un- 
known), a  feature  that  separates  duquesneyi  from  both  fowleri 
and  hewardi.  D.  duquesneyi  also  lacks  the  prominent  facial  mark- 
ings of  D.  fowleri.  Finally,  the  head  width/head  length  ratio  (X 
100)  in  duquesneyi  is  much  less  than  this  ratio  in  both  fowleri 


8  BREVIORA  No.    371 

and  hewardi.  In  an  apparently  subadult  female  duquesneyi  with 
a  snout-vent  length  of  96,  the  HW/HL  ratio  is  69.8,  below  that 
of  similarly  sized  female  hewardi  (ratios  70.7-13.1)  and  much 
below  that  of  the  slightly  larger  female  holotype  of  jowleri  (80.0). 
The  HW/HL  ratio  in  the  juvenile  holotype  of  duquesneyi  (snout- 
vent  length  about  65)  is  66.4,  whereas  this  ratio  in  the  jowleri 
paratype  (snout-vent  length  66)  is  73.2;  the  HW/HL  ratio  in 
the  duquesneyi  holotype  falls  at  the  lower  extreme  of  this  ratio 
in  smaller  hewardi  (ratio  66.2  to  67.3  in  hewardi  juveniles  with 
snout-vent  lengths  of  49  to  52). 

Interestingly,  Richard  Thomas  noted  that  a  D.  hewardi  from 
Darliston,  Westmoreland  Parish,  in  western  Jamaica,  (and  far 
removed  from  the  known  range  of  D.  duquesneyi,  which  has  been 
taken  only  on  Portland  Point,  Clarendon  Parish,  in  south-central 
Jamaica)  with  a  snout-vent  length  of  48  mm,  had  pale  blue  distal 
tail  bands  alternating  with  brown  bands.  There  seems  little  doubt 
that  hewardi,  duquesneyi,  and  jowleri  are  closely  related,  and 
that  duquesneyi  and  presumably  jowleri  are  peripheral  geographic 
satellite  species  derived  from  parent  hewardi  in  special  situations. 

Remarks.  The  two  specimens  of  D.  jowleri  were  collected 
under  the  following  circumstances.  Both  specimens  were  taken 
from  bromeliads  along  the  edge  of  the  steep  trail  from  Windsor 
Great  House  to  Windsor  Cave  and  thence  up  the  escarpment  of 
the  Cockpit  Country.  In  the  case  of  the  holotype,  a  Jamaican  had 
been  hired  to  cut  arboreal  bromeliads  and  had  climbed  a  tall 
tree  of  moderate  girth  (0.5  meters)  just  below  the  path  in  decidu- 
ous forest.  He  had  cut  all  but  the  last  one  or  two  bromeliads  when 
the  galliwasp  rapidly  descended  the  trunk  of  the  tree  and  paused 
in  confusion  on  a  leaf  about  six  feet  above  the  ground.  There  is 
no  doubt  that  the  animal  had  been  disturbed  from  its  diurnal 
retreat  by  the  chopping  of  adjacent  bromeliads  and  had  decided 
to  abandon  its  place  of  retirement.  The  small  paratype  was  taken 
from  the  moist  center  of  a  bromehad  that  had  been  growing  2.5 
meters  above  the  ground.  When  the  bromeliad  was  cut  and  thrown 
onto  the  narrow  path,  the  lizard  was  found  inside  the  whorls  of 
leaves.  In  both  cases,  the  adjacent  area  was  well  forested.  The 
elevation  along  the  path  is  about  500  feet  (153  meters). 

The  Jamaican  Cockpit  Country  is  a  karst  region  in  north- 
western Jamaica.  Its  extent  is  about  20  miles  (32  kilometers) 
east-west  and  about  10  miles  (16  kilometers)  north-south;  the 
region  centers  in  Trelawny  Parish  but  extends  for  short  distances 


1971  BROMELIAD    GALLIWASP  9 

into  St.  James  Parish  on  the  west  and  St.  Elizabeth  and  Man- 
chester parishes  to  the  south.  No  roads  penetrate  it,  but  a  series 
of  peripheral  roads  allows  some  ingress  into  the  region.  An  excep- 
tion is  a  relatively  newly  constructed  road  north  of  Quick  Step 
on  the  southern  border  of  the  Cockpit,  where  penetration  of  about 
five  miles  (8  kilometers)  is  possible  into  virtually  virgin  territory. 

In  search  of  Sphaerodactylus  and  hylid  and  leptodactylid  frogs, 
we  cut  both  terrestrial  and  arboreal  bromeliads  in  several  regions 
associated  with  the  Cockpit  periphery  and  elsewhere:  between 
Spring  Vale  and  Mulgrave  (St.  James  and  St.  Elizabeth  parishes), 
between  Stonehenge  and  Burnt  Hill  (Trelawny  Parish);  south 
of  Moneague  on  Mt.  Diablo  and  west  of  Lluidas  Vale  (St.  Cath- 
erine Parish),  in  the  Dolphin  Head  region  between  Askenish  and 
Town  Head  (Hanover  and  Westmoreland  parishes),  between 
Plum  Park  and  Garlands  (St.  James  Parish),  and  between  Raheen 
and  north  of  Quick  Step  (Trelawny  Parish).  In  no  case  did  we 
secure  D.  fowleri,  although  a  single  D.  cnisculus  was  secured  from 
a  terrestrial  bromehad  north  of  Cave  in  Westmoreland  Parish. 
The  possibiUty  remains  that  D.  fowleri  is  not  an  obligate  inhab- 
itant of  bromeliads,  and  that  it  is  a  terrestrial  galliwasp  that,  in 
the  pitted,  pocked,  and  rock-strewn  Cockpit  Country,  finds  diur- 
nal sanctuary  in  terrestrial  situations  from  which  it  would  be  a 
lucky  collector  indeed  who  would  secure  it.  On  the  other  hand, 
there  is  no  evidence  to  controvert  the  apparent  fact  that  D.  fowled 
is  indeed  a  bromeliad  dweller  and  that  it  occurs  in  no  other  situ- 
ation. If  such  is  the  case,  it  must  be  either  extremely  uncommon, 
remarkably  elusive,  or  ecologically  or  altitudinally  restricted  in 
some  presently  unknown  fashion.  Along  these  lines,  see  Under- 
wood's (1959:  1)  comments  on  his  inability  to  secure  a  second 
specimen  of  D.  microblepharis.  The  fact  that  the  area  where  the 
microblepJiaris  was  secured  backs  upon  limestone  hills  suggests, 
as  Underwood  stated,  that  it  may  have  wandered  from  its  usual 
habitat  into  a  situation  where  it  was  fortuitously  secured  with 
relative  ease. 

Diploglossiis  fowleri  is  not  known  to  be  sympatric  with  any 
other  species  of  galhwasp.  However,  D.  hewardi  has  been  taken 
1.5  miles  NW  of  Windsor,  and  D.  cruscidiis  has  been  secured  3.0 
miles  N W  of  Windsor  —  both  in  terrestrial  situations.  In  addi- 
tion, D.  barbouri  has  been  collected  along  the  eastern  margin  of 
the  Cockpit  Country  between  Stonehenge  and  Burnt  Hill.    The 


10  BREVIORA  No.    371 

lack  of  precisely  sympatric  records  between  fowleri  and  any  of 
these  three  species  is  not  surprising,  since,  as  pointed  out  above, 
collecting  galliwasps  within  the  Cockpit  Country  itself  is  a  difficult 
and  well-nigh  impossible  task  except  in  especially  favorable  local- 
ities. If  fowleri  is  truly  bromeliadophilous,  then  it  may  in  places 
be  syntopic  with  D.  crusculus,  but  such  syntopy  remains  to  be 
encountered. 

As  presently  understood,  then,  D.  fowleri  is  a  bromehad- 
inhabiting  galliwasp  that  is  presumably  limited  to  the  Cockpit 
Country  area  and  possibly  to  lower  elevations  in  that  region.  It 
is  rather  surprising  that  the  bromeliad  niche  has  been  so  neglected 
by  Antillean  reptiles,  in  contrast  to  Antillean  amphibians.  Cer- 
tainly Jamaica  has  the  highest  share  of  bromeUadicoles,  both 
amphibians  and  reptiles;  in  addition  to  D.  fowleri,  Hyla  brunnea, 
H.  wilderi,  H.  marianae,  and  Eleutherodactylus  jamaicensis  are 
obligate  bromeliad  dwellers,  and  several  other  frogs  {E.  grabhami, 
E.  cundalli,  E.  pantoni)  are  encountered  with  regularity  in  terres- 
trial bromeliads.  Among  reptiles,  Sphaerodactylus  oxyrhinus 
appears  to  be  confined  to  this  situation,  and  a  new  species  of 
Sphaerodactylus,  to  be  described  by  Richard  Thomas,  likewise  is 
thus  limited  in  habitat.  S.  argiis,  D.  crusculus,  and  Tropidophis 
haetianus  are  encountered  in  bromefiads  upon  occasion.  This  list 
of  both  obligate  and  facultative  bromeliadicoles  far  exceeds  that 
from  any  other  Antillean  island.  On  the  other  hand,  no  one  has 
systematically  cut  arboreal  and  terrestrial  bromefiads  elsewhere 
than  on  Jamaica.  It  seems  likely  that  this  is  a  niche  that  will 
well  repay  investigation  on  other  Antillean  islands. 

LITERATURE    CITED 

CousENs,  Peggy  N.     1956.    Notes  on   the  Jamaican  and  Cayman  Island 

lizards  of  the  genus  Celestiis.   Breviora,  No.  56:   1-6. 
Grant,  Chapman.    1940a.  Notes  on  the  reptiles  and  amphibians  of  Jamaica, 

with  diagnoses  of  new  species  and  subspecies.  Jamaica  To-day.   London 

and  Aylesbury,  Hazell,  Watson,  and  Viney,  Ltd.   Chapter  15:   151-157. 
1940b.    II.    The  Reptiles.    In  Lynn,  W.  G.,  and  C.   Grant, 

The  herpetology  of  Jamaica.   Bull.  Inst.  Jamaica,  Sci.  Ser.,  1:  1-148. 
Maerz,  a.,  and  M.  Rea  Paul.    1950.   A  Dictionary  of  Color.    New  York, 

McGraw-Hill  Book  Co.,  pp.  i-vii,  1-23,  137-208,  56  pis. 
Schwartz,  Albert.    1970.    A  new  species  of  large  Diploglossus  (Sauria: 

Anguidae)    from   Hispaniola.    Proc.   Biol.   Soc.    Washington,    82(60): 

777-788. 
Underwood,  Garth.   1959.  A  new  Jamaican  galliwasp  (Sauria,  Anguidae). 

Breviora,  No.  102:  1-13. 


BREVIORA 

Mmsemim   of   Contiparative    Zoology 

Cambridge,  Mass.  31  March,  1971  Number  372 


THE  PALEONTOLOGY  AND  EVOLUTION  OF  CERION  II: 

AGE  AND  FAUNA  OF  INDIAN  SHELL  MIDDENS 

ON  CURACAO  AND  ARUBA 

Stephen   Jay   Gould 

Abstract.  Cerion  iiva  has  been  found  in  great  abundance  in  three  Meso- 
Indian  (preceramic)  shell  middens  on  Curasao.  Shells  from  all  three  sites 
yield  radiocarbon  ages  of  about  4000  years  B.P.  Different  groups  of  Meso- 
Indians  from  Venezuela  reached  Curasao  and  the  nearby  island  of  Cubagua 
at  about  the  same  time.  A  Neo-Indian  (ceramic)  midden  on  Aruba  is  ap- 
proximately 1500  radiocarbon  years  old.  Lists  of  the  molluscan  fauna  from 
all  sites  contain  only  intertidal  and  shallow  water  species.  Collecting  areas 
can  be  specified  by  noting  differences  among  sites  in  the  presence  of  species 
from  various  environments  (rocky  intertidal,  mangrove,  shallow  grassy  and 
shallow  rocky). 

In  the  shell  middens,  Cerion  presents  two  outstanding  features:  1)  almost 
all  shells  have  had  the  apical  whorls  removed  artificially  and,  2)  shells  are 
larger  than  any  living  today.  The  apical  whorls  were  removed  by  striking; 
flint  tools  found  at  the  sites  accomplish  this  task  easily.  This  was  done  to 
release  the  internal  vacuum  and  allow  the  animal  to  be  sucked  out  through 
the  normal  aperture.  Larger  shells  might  indicate,  since  modern  Cerion  is 
so  phenotypically  variable,  that  the  climate  of  Curasao  4000  years  ago  was 
more  moist  (and  therefore  more  hospitable)  than  today.  But  there  is  no 
independent  evidence  for  more  rainfall  at  that  time.  If  the  effect  is  mainly 
genetic,  these  shells  might  come  from  relict  populations,  adapted  to  the 
pluvials  of  the  previous  glaciation.  Cerion  iiva  has  been  found  in  a  shell 
midden  in  Venezuela;  this  establishes  the  reciprocity  of  trade  between  main- 
land and  offshore  islands. 

INTRODUCTION 

Only  a  few  mollusks  have  won  entry  into  the  Papiamento  lan- 
guage of  the  Dutch  Leeward  Islands.  These  are  mostly  edible 
species  —  kiwci  (Cittarium  pica),  karko  (Strombus  gigas),  and 
tcipa  koncha  ("cover  shell"  —  a  general  name  for  chitons).    Yet 


2  BREVIORA  No.    372 

Cerion  uva,  the  ubiquitous  pulmonale  of  these  islands,  stands  out 
for  the  plethora  of  names  attached  to  it,  names  that  distinguish 
small  from  large  and  beach  from  bush.  Nevertheless,  Cerion  plays 
almost  no  role  in  the  economy  of  these  islands  today  —  though 
one  of  its  names,  kokoUshi  kalakuna  (turkey  shell),  reflects  the 
fact  that  it  is  sometimes  fed  to  turkeys  as  a  source  of  lime.  It 
is  never  eaten,  save  as  an  aphrodisiac  by  some  older  residents 
who  believe  that  sea  shells  preserve  sexual  potency  (and  do  not 
realize  that  this  halophilic  pulmonale,  which  lives  just  landward 
of  Tectariits  muricatus,  does  not  come  from  the  sea).  But  to 
another  people,  the  original  Indian  inhabitants  of  Curasao,  Cerion 
uva  was  a  major  source  of  food,  for  the  oldest  middens  of  the 
island  are  crammed  with  their  shells. 

Of  the  many  sheU  sites  that  have  been  studied  (Van  Heekeren, 
1960:  103-109,  for  review  of  archaeological  work  and  Van  Heek- 
eren, 1963),  Cerion  is  known  only  from  the  older,  preceramic 
middens  of  Curasao.  Whenever  it  occurs,  it  presents  two  peculi- 
arities: sheUs  are  far  larger  than  the  largest  living  C.  uva,  and 
most  all  have  had  the  apical  whorls  removed  artificially. 

Thanks  to  the  kindness  of  Father  Paul  Brenneker  and  Mr. 
Elis  JuUana,  local  collectors,  folklorists,  and  historians  (and  my 
informants  for  the  opening  paragraph),  and  Dr.  F.  Creutzberg, 
Director  of  the  Biological  Station  at  Piscadera  Baai,  Curasao, 
I  had  the  opportunity  to  study  the  sheU  sites  during  the  summer 
of  1968.  In  this  paper,  I  shall  review  the  archaeological  setting  of 
these  islands,  report  on  radiocarbon  dating  of  the  shell  sites,  tabu- 
late the  fauna  of  each  and  present  environmental  interpretations, 
and  discuss  the  occurrences  of  Cerion  with  special  reference  to 
the  peculiarities  mentioned  above. 

CARIBBEAN  PREHISTORY  AND  DESCRIPTION  OF  SITES 

The  Dutch  Leeward  Islands  are  tied,  geographically,  to  Vene- 
zuela. Aruba,  only  27  km  from  the  mainland,  lies  on  the  coastal 
shelf,  in  easily  navigable  waters.  Curacao  and  Bonaire  are  more 
distant  (64  and  87  km  respectively),  and  the  passage  is  deeper 
(up  to  1500  m)  and  more  treacherous  (Van  Heekeren,  1960: 
103).  The  early  colonization  of  these  islands  must  be  discussed 
in  the  context  of  Venezuelan  archaeology  (Cruxent  and  Rouse, 
1958-59,  1969;  Rouse  and  Cruxent,  1963;  Rouse,  1960, 
1964,    1966). 


1971  CERION   FROM   INDIAN   SHELL-HEAPS  3 

The  Pre-Columbian  inhabitants  of  Venezuela  and  the  Carib- 
bean are  designated  Paleo-,  Meso-,  or  Neo-Indians  on  the  basis 
of  technology  and  inferred  economy.  Although  the  three  stages 
do  express  a  chronological  progression,  none  of  their  artifacts 
function  as  "index  fossils"  in  establishing  contemporaneity 
throughout  the  Caribbean,  for  the  traits  of  a  new  stage  are 
attained  at  different  times  by  different  peoples.  There  were,  for 
example,  still  some  preceramic  Meso-Indians  on  Haiti  and  Western 
Cuba  when  Columbus  arrived  (Rouse,  1966). 

The  original  inhabitants  of  the  New  World  were  Paleo-Indians, 
"hunters  of  mammoths  and  other  large  land  mammals"  (Rouse, 
1966:  125).  Their  stone  tools  have  been  found  in  Venezuela  and 
designated  as  markers  of  the  Joboid  Series.  They  date,  approxi- 
mately, from  17,000-7,000  B.P.  The  oldest  radiocarbon  date 
for  Joboid  charcoal  is  16,870  years  B.P.  (Rouse  and  Cruxent, 
1963).  In  earlier  works,  Cruxent  and  Rouse  held  that  Paleo- 
Indians  were  not  sea-farers,  but  Paleo-Indian  sites  have  recently 
been  found  at  Mordan  in  the  Dominican  Republic  and  dated  to 
at  least  4560  radiocarbon  years  B.P.  They  beheve,  moreover, 
that  the  Mordan  site  is  predated  by  another  at  Casimira  that  may 
be  as  much  as  7,000  years  old  (Cruxent  and  Rouse,  1969). 
Although  the  mainland  source  of  these  first  Hispaniolans  is  not 
known,  these  finds  indicate  that  some  Paleo-Indians  crossed  con- 
siderable stretches  of  ocean,  probably  on  rafts  and  by  accident 
(Cruxent  and  Rouse,  1969). 

Much  scholarly  agitation  of  late  has  been  directed  to  the  issue 
of  whether  or  not  Paleo-Indians  were  responsible  for  the  extermi- 
nation of  large  land  mammals  (Martin  and  Wright,  1967).  In 
any  event,  their  demise  drew  our  pre-agricultural  people  to  the 
sea  and  inaugurated  MesoTndian  culture,  characterized  by  "rela- 
tively few  stone  tools.  Projectile  points  are  made  of  bone  rather 
than  stone  and  shell  artifacts  are  common,  reflecting  the  mari- 
time orientation"  (Rouse,  1966:  126).  Meso-Indian  artifacts  in 
Caribbean  Venezuela  belong  to  the  Manicuaroid  Series  and  date, 
approximately,  from  7,000  to  3,000  years  B.P.  The  oldest  radio- 
carbon date  for  mainland  Venezuelan  Meso-Indians  is  5750  B.P. 
(Rouse  and  Cruxent,  1963).  There  is  an  extensive  Meso-Indian 
site  on  Cubagua,  another  of  Venezuela's  offshore  islands.  Char- 
coal from  the  base  of  this  deposit  dates  at  4275  radiocarbon 
years  B.P. 


4  BREVIORA  No.    372 

The  subsequent  Neo-Indian  culture  is  "marked  by  pottery 
making  and  fully  developed  agriculture"  (Rouse,  1966:  126). 
The  invention  of  pottery  was  the  crucial  archaeological  event  that 
inaugurated  the  Neo-Indian  period;  therefore  MesoTndian  and 
earlier  sites  are  often  designated  simply  as  "preceramic."  Agri- 
culture, with  manioc  as  a  staple  crop,  and  pottery  were  developed 
in  the  Orinoco  Valley  during  the  2nd  millennium  B.C.  During 
the  1st  millennium  B.C.,  some  Neo-Indians  moved  out  to  the 
coast  and  became  sea-farers.  Displacing  Meso-Indians  as  they 
went,  they  migrated  to  the  coastal  islands,  up  the  Lesser  Antilles 
and  reached  the  Greater  Antilles  ca.  250  A.D.  and  the  Bahamas 
ca.  1000  A.D.  This  displacement  was  still  occurring  when  Colum- 
bus reached  the  New  World  (Cruxent  and  Rouse,  1969). 

The  Cerion  sites  of  Curasao  are  all  Meso-Indian  in  nature.  I 
studied  the  following  three  sites: 

1.  Rooi  Rincon  —  North  coast,  west  of  Hato  Airfield;  in  soil 
at  the  base  of  a  small  cave  in  a  raised  Pleistocene  reef  that  also 
houses  the  larger  cavern  of  Hato  and  several  others;  approximately 
40  m  above  present  sea  level  and  1  km  from  the  coast.  This  well- 
known  site  was  excavated  by  Cruxent  in  1965  (Tamers,  1967) 
and  by  Van  Heekeren  in  1960  (Van  Heekeren,  1963).  Crudely 
chipped  stone  tools  and  flint  flakes  are  common  but,  after  dig- 
ging for  14  days.  Van  Heekeren  found  only  one  other  artifact,  a 
shell  disc  bead  (Van  Heekeren,  1963:  5).  The  naturally  broken 
columellar  tips  of  Strombus  gigas  are  similar  in  form  to  some  of 
the  fashioned  shell  gouges  common  in  the  Manicuaroid  deposits 
of  Cubagua  (Cruxent  and  Rouse,  1958-59);  they  may  have  been 
used  for  digging  meat  out  of  sheUs.  Many  other  natural  objects 
could  have  been  used  as  tools.  Particularly  suspect  are  the 
smoothly  eroded  and  fairly  pointed  branches  of  the  stag  horn 
coral,  Acropora  cervicornis,  that  are  fairly  common  at  this  site 
and  at  Kintjan  (site  2).  These,  obviously,  have  no  nutritional 
value  and  must  have  been  carried  to  the  site  for  some  other  pur- 
pose. Other  objects,  land  crab  claws  for  example,  might  have 
been  used  for  digging  meat  from  shells  after  their  own  contents 
had  been  consumed.  I  found  a  few  bits  of  charcoal:  some  of 
the  shells  are  strongly  scorched.  Cruxent  says  of  this  deposit: 
"A  Meso-Indian  complex  of  collectors  with  industry  of  stone 
chips.  Classified  as  a  marginal  development  of  El  Jobo.  No 
archaeologic  station  of  this  type  presently  known  in  Venezuela" 
{in  Tamers.  1967:  244). 


971 


CERION    FROM    INDIAN    SHELL-HEAPS 


2.  Kintjiin  —  Near  south  coast,  east  ^  Willemstad.  The  area, 
a  hillslope,  is  being  cleared  for  construction  and  shells  are  loose 
at  the  surface;  their  presence  in  a  small  area  indicates  original 
concentration  in  a  coherent  deposit.  Flint  chips  and  crude  stone 
tools  are,  as  at  Rooi  Rincon,  common  at  this  site. 

3.  Tafelberg  —  Near  south  coast,  just  east  of  the  Tafelberg 
Santa  Barbara.  Only  a  few  shells  could  be  collected  from  the 
recently  blasted  rubble  of  these  phosphate  workings.  Mr.  Harry 
Evers,  engineer  at  the  Tafelberg  phosphate  workings,  informs  me 
that,  prior  to  the  blasting,  the  shell  heap  was  a  coherent  deposit 
with  two  layers,  marine  shells  at  the  base  and  decapitated  Cerion 
at  the  top.    I  found  no  artifacts  at  this  much  disturbed  site. 

Dr.  P.  Wagenaar  Hummelinck,  pre-eminent  natural  historian  of 
these  islands,  has  told  me  (personal  communication,  1970)  of 
one  additional  Cerion  locality  at  Hato  Cave;  I  have  not  seen  this 
site.  He  also  states  that  he  knows  of  no  other  Cerion  site  on  any 
of  the  three  islands. 

For  comparison,  I  add  to  the  Cerion  sites  of  Curacao  one 
later,  Neo-Indian  deposit  from  Aruba: 


t:.t  V- 


^pt>^^ 


Figure   1.    Artifacts  from  Ceru  Canashito,  Aruba. 

la)    left:  rock  drawing,  presumably  depicting  a  pregnant  woman, 
lb)    right:   shell  disc  made  from  Melongena  melongena.    Actual 
height:  43  mm. 


6  BREVIORA  No.    372 

4.  Ceru  Canashito  —  North  slope  of  this  Hmestone  terrace. 
I  chose  this  among  the  many  Neo-Indian  sites  of  Aruba  for  two 
of  its  outstanding  features.  Good  skeletal  material  has  been  col- 
lected from  the  caves  near  its  summit  (Tacoma,  1959),  and  these 
caves  contain  some  of  the  best  of  the  celebrated  and  mysterious 
rock  paintings  of  these  islands  (Hummelinck,  1953,  1957).  One 
of  these,  probably  depicting  a  pregnant  woman,  is  reproduced  as 
Figure  la.  (There  is,  of  course,  no  reason  to  assume  that  the 
rock  drawings  are  contemporaneous  with  the  shells;  Van  Heek- 
eren  (1960),  in  fact,  suspects  that  they  were  fashioned  by  Meso- 
Indians  and  venerated  by  later  inhabitants.)  Shells  occur  at  all 
levels  of  the  slope,  but  are  concentrated  by  gravity  at  the  base 
in  an  inhomogeneous  deposit.  Sherds  of  a  coarse,  unornamented, 
grit-tempered  pottery  are  common.  Shell  artifacts  include  the 
columellar  points  of  Strombus  gigas  and  the  unperforated  shell 
disc,  made  from  the  outer  whorl  of  Melongena  melongena,  shown 
in  Figure  lb.  Such  unperforated  shell  discs  are  common  on  the 
islands;  their  function  is  unknown  (Van  Heekeren,  1960:    112). 

AGE    OF   THE   SHELL   MIDDENS 

Tamers  (1967)  reported  the  first  radiocarbon  dates  from 
archaeological  sites  in  the  Dutch  Leeward  Islands;  all  samples 
were  charcoal  and  all  were  supplied  by  Cruxent.  Included  are 
five  dates  for  the  Rooi  Rincon  shell  midden,  two  from  a  pit  previ- 
ously excavated  by  Van  Heekeren  and  three  from  two  new  pits. 
The  dates  range  from  3900  ±  50  to  4490  ±  60  with  a  mean  of 
4194  radiocarbon  years  (see  Stuiver  and  Suess,  1966  on  the 
relationship  between  radiocarbon  and  calendar  years).  These 
are  the  only  dates  previously  calculated  for  preceramic  sites  on 
these  islands. 

Radiocarbon  ages  were  determined  for  1 1  shell  samples  by 
Geochron  Laboratories,  Inc.,  Cambridge,  Massachusetts  (Chama 
macerophylla  and  Cittarium  pica  from  each  of  the  five  sites  and 
Anadara  notob'iUs  from  Ceru  Canashito) .  "The  shells  were  cleaned 
of  foreign  material  and  were  thoroughly  leached  with  dilute  HCl 
in  an  ultrasonic  cleaner  to  remove  the  surficial  layer  of  carbonate 
and  expose  fresh  material.  The  cleaned  shells  were  then  hydro- 
lyzed  to  recover  CO.,  for  the  analysis"  (personal  communication 
from  H.  W.  Krueger  of  Geochron).  Dates  are  based  on  a  half- 
life  of  5570  years  and  referenced  to  1950  A.D. 


1971  CERION    FROM    INDIAN    SHELL-HEAPS  7 

Dates  based  on  shells  are  not  as  reliable  as  those  determined 
for  pure  carbon  (charcoal),  for  CaCO,,  is  often  altered  by  per- 
colating, acidic  groundwaters.  I  was  anxious  to  determine  the 
correspondence  between  shell  and  charcoal  dates  for  Rooi  Rincon; 
I  found  no  charcoal  at  any  of  the  other  sites.  All  dates  are  shown 
in  Table  1. 

The  correspondence  at  Rooi  Rincon  is  satisfactory,  and  all  pre- 
ceramic  sites  of  Curacao  are  about  4000  radiocarbon  years  old. 
This  date  is  particularly  interesting  since  it  corresponds  so  well 
with  the  base  of  the  great  Meso-Indian  site  at  Punta  Gorda, 
Cubagua  Island  (p.  21).  The  artifacts  of  this  Cubagua  complex 
of  the  Manicuaroid  series  differ  greatly  from  those  of  Rooi  Rin- 
con (Cruxent  and  Rouse,  1958-59)  and  we  must  assume  that 
different  groups  of  Meso-Indians  from  Venezuela  colonized  the 
coastal  islands  at  about  the  same  time. 

The  great  spread  of  dates  for  the  Neo-Indian  site  of  Ceru  Cana- 
shito  can  be  explained  in  two  ways.  It  is  a  very  inhomogeneous 
deposit  of  shells  artificially  concentrated  at  the  base  of  a  slope 
and  may  represent  a  long  span  of  habitation.  Alternately,  the  Cit- 
tarium  date  could  be  spuriously  young.  Cittarium  has  been  and 
remains  a  staple  food  of  the  islands.  The  kiwa  is  sold  at  all  native 
market  places;  shells  are  carried  and  discarded  all  over  the  island. 
If  this  date  has  been  falsified  by  the  inclusion  of  a  fairly  modem 
shell,  then  the  Canashito  midden  may  represent  a  more  coherent 
deposit,  about  1500  radiocarbon  years  old. 

FAUNA   OF  THE   SHELL   MIDDENS 

In  presenting  these  faunal  lists,  I  have  excluded  the  micro- 
molluscs  that  could  have  played  no  role  in  the  economy  of  the 
Indians  (though  Tnmcatella  and  other  rissoids  are  reasonably 
common  as  accidental  transports).  In  each  site,  there  are  a  few 
species  that  clearly  dominate;  these  are  merely  listed  as  common. 
Numbers  of  specimens  are  given  for  other  species.  I  have  used 
Warmke  and  Abbott  (1961)  and  Coomans  (1958)  as  guides  to 
identification;  order  of  listing  and  family  allocations  follow  the 
former  source. 

1.    Rooi  Rincon 
AMPHINEURA 

A  cant  ho  pleura  graniilata  —  common 


8  BREVIORA  No.    372 

GASTROPODA   PROSOBRANCHIA 
Trochidae 

Cittarium  pica  —  common 

TURBINIDAE 

Astraea  tecta  —  1 
Astraea  tuber —  1 
Neritidae 

Merita  peloronta  —  11 
Nerita  versicolor  —  6 
Nerita  tesselata  —  4 

LiTTORINIDAE 

N odilittorina  tuberculata  —  4 

Echinus  nodulosus  —  1 

Tectarius  muricatus  —  1 0 
Vermetidae 

Petaloconchus  mcgintyi  —  3 
Strombidae 

Strombus  gigas  —  4  apices  and  3  columellas 

MURICIDAE 

Murex  brevifrons  —  8 
Magilidae 

Coralliophila  abbreviata  —  2 

Coralliophila  caribbea  —  I 
Fasciolariidae 

Leucozonia  nassa  —  1 
Xancidae 

Vasum  capitellum  —  1 

GASTROPODA  PULMONATA 
Cerionidae 

Cerion  uva  —  common;  18  of  129  specimens  have  in- 
tact apices 

BIVALVIA 
Arcidae 

Area  zebra — 12  valves 

Area  imbricata  —  4 

Anadara  notabilis  —  4 
Mytilidae 

Brachidontes  exustus  —  2 
Pteriidae 

Pinctada  radiata  —  1 3 


1971  cerion  from  indian  shell-heaps  9 

Pectinidae 

Pecten  ziczac  —  2 

LiMIDAE 

Lima  scabra —  10 

OSTREIDAE 

Ostrea  jrons  —  1 2 
Crassostrea  rhizophorae  —  9    . 
Chamidae 

Chama  macerophylla  —  common 
Pseudochama  radians  —  2 

Nonmolluscan  remains:  a  few  branches  of  stag-horn  coral 
{Acropora  cervicornis) ,  land  crab  claws  (common),  a  few  barna- 
cles, fish  bones  and  a  small  fragment  of  an  echinoderm  test. 

Not  all  these  animals  were  eaten.  Many,  especially  among  the 
snails,  are  small  and  rare  at  the  site  (turbinids,  magilids,  fasci- 
olariids,  and  xancids);  others  (Petaloconchus  and  barnacles) 
cement  to  other  shells  and  surely  won  a  free  ride  on  their  edible 
hosts  (probably  Chama). 

The  main  food  sources  were  the  land  snail  Cerion,  land  crabs, 
intertidal  chitons,  the  intertidal  and  just  subtidal  snail  Cittarium 
and  the  shallow  water  clam,  Chama;  all  are  very  abundant  and 
easily  gathered.  Less  common  but  still  important  as  food  sources 
are  the  conch  Strombus  gigas,  Nerita  peloronta,  and  Murex  brev- 
ifrons  among  the  snails  (the  last  two  artificially  broken  in  char- 
acteristic ways  —  Figs.  2  and  3 )  and  arcids,  oysters,  and  limids 
among  the  clams. 

The  shells  provide  an  excellent  picture  of  the  environment  from 
which  they  were  gathered.  All  the  major  intertidal  rock-clingers 
are  represented  (all  three  common  West  Indian  Nerita,  chitons, 
and  the  famous  homeomorphic  series  Nodilittorina-Echinus- 
Tectarius).  These  species  inhabit  rocky  shores  in  areas  of  active 
surf.  All  other  species  can  be  found  in  less  than  10  feet  of  water 
on  a  varied  bottom  containing  reefy  and  rocky  areas  (Chama, 
Area,  Lima)  and  stretches  of  sand  and  grass  (Anadara,  Strom- 
bus).  There  may  have  been  a  lagoon  with  mangroves  nearby, 
for  many  important  elements  of  the  mangrove-root  community 
are  present  (Murex  brevijrons,  Ostrea  jrons,  Crassostrea  rhizo- 
phorae, and  Brachidontes  exustus). 

Van  Heekeren  (1963)  stated,  correctly  no  doubt,  that  the 
shells  were  collected  on  the  nearby  north  coast  (Fig.  4b).    Since 


10 


BREVIORA 


No.  372 


Figure  2.  Miire.x  brevifroiis  shells  from  Kintjan  (left)  and  Rooi  Rincon 
(right).  Note  characteristic  breakage  pattern  in  both.  This  can  be  achieved 
by  placing  the  shell  face  down  upon  its  aperture  and  striking  the  apex. 
Actual  height  of  Kintjan  specimen:  54  mm. 


Figure  3.  Neritids  from  Rooi  Rincon  broken  in  characteristic  fashion. 
Left:  apertural  portion  from  rear;  Right:  apertural  portion  from  front. 
Such  a  break  is  made  by  placing  the  shell  face  down  upon  its  aperture  and 
striking  the  body  whorl  with  a  blunt  object.  This  is  also  the  natural  break- 
age pattern  in  most  cases.    Right-hand  fragment  is  18  mm  high. 


1971  CERION    FROM    INDIAN    SHELL-HEAPS  11 

the  unremitting  trade  winds  blow  against  this  coast  (producing 
a  strong  surf  most  unconducive  to  shell  gathering),  Van  Heekeren 
suggested  that  sea  level  at  this  earlier  time  was  6-7  m  higher 
than  today.  This  would  submerge  the  extensive  raised  reef  that 
forms  the  lower  terrace  all  around  Curacao  and  produce  a  broad 
area  of  calmer,  shallow  water.  (And  from  the  supposed  extent 
of  this  change  in  level,  he  postulated  a  great  age  for  the  deposit 
and  classified  it,  tentatively,  as  Paleo-Indian.)  This  hypothesis 
of  a  major  shift  in  sea  level  is  unnecessary  for  two  reasons:  1) 
With  an  age  of  4000  radiocarbon  years,  any  eustatic  fall  in 
level  is  ruled  out;  if  anything,  mean  sea  level  then  was  a  bit 
lower  than  today  (Redfield,  1967;  Milhman  and  Emery,  1968). 
This  leaves  tectonic  uplift.  Curacao  has,  indeed,  been  uplifted 
during  the  Pleistocene  (the  oldest  terrace,  atop  the  Tafelberg, 
lies  at  140-200  m,  but  7  m  in  4000  years  is  not  likely).  2)  The 
trade  winds  do  produce  a  strong  surf  along  the  north  coast.  But 
Rooi  Rincon  lies  on  that  part  of  the  coast  that  runs  due  east- 
west;  here  the  winds  run  along  the  coast  and  the  waters  are  fairly 
calm.  Modern  Cerion  populations  illustrate  the  climatic  results 
of  changes  in  coastal  direction.  Cerion  lives  atop  the  first  terrace 
all  along  the  coast.  In  areas  continually  buflfetted  by  the  strong 
dry  wind,  they  aestivate  for  much  of  their  lives  and  remain  small 
as  adults;  they  grow  bigger  in  calmer  areas.  A  graph  of  Cerion 
size  vs.  distance  from  Westpunt  (Fig.  4a)  is  a  good  map  of  coastal 
direction  (Fig.  4b).  Cerion  is  small  where  the  coast  runs  north- 
south  and  large  where  it  runs  east-west.  They  reach  their  greatest 
size  at  Rooi  Rincon.  Thus,  Rooi  Rincon  lies  in  the  only  area  of 
Curasao  that  provides  good  conditions  for  shell  gathering  on  the 
north  coast. 

2.    Kintjan 

GASTROPODA   PROSOBRANCHIA 
Trochidae 

Cittarium  pica  —  common 
Strom  BiDAE 

Strombus  gigas  —  common 
Cymatiidae 

Charonia  variegata  —  1 

MURICIDAE 

Murex   brevijrons — 3    (broken   as   at   Rooi   Rincon, 

Fig.   2) 


12 


BREVIORA 


No.   372 


Melongenidae 

Melongena  melongena  —  2 

GASTROPODA   PULMONATA 
Cerionidae 

Cerion  uva  —  common,  7  of  347  specimens  have  in- 
tact apices 

BIVALVIA 

Arcidae 

Area  imbricata — 13 
Barbatia  cancellaria  —  3 


Anadara  notabilis - 
Pteriidae 

Pinctada  radiata  — - 
Pectinidae 

Pecten  ziczac  —  7 
Limidae 

Lima  scabra  —  6 


common 


Figure  4.    Correlation  of  coastal  direction  and  shell  size. 

4a)  left:  map  of  Cura^,ao.  1.  Rooi  Rincon  at  point  where  coast 
runs  east-west.  2.  Kintjan.  3.  Tafeiberg.  4.  Schottegat  (where  shells  at 
Kintjan  were  collected). 


1971 


CERION    FROM    INDIAN    SHELL-HEAPS 


13 


OSTREIDAE 

Ostrea  frons  —  7 
Crassostrea  rhizophorae  —  6 
Chamidae 

Chama  macerophylla  —  common 

NonmoUuscan  remains:  branches  of  stag-horn  coral  (Acropora 
cervicornis),  barnacles,  and  fish  bones. 

The  shallow  water  fauna  of  Kintjan  is  very  similar  to  that  of 
Rooi  Rincon,  both  in  species  composition  and  order  of  dominance 
{Chama  and  Cittarium  followed  by  S trombus,  arcids,  oysters,  and 
limids).  Since  shells  are  not  so  common  at  Kintjan,  several  spe- 
cies, rare  and  unimportant  at  Rooi  Rincon,  are  not  found  here. 


10  20  30 

Distance  from  Westpunt  (miles) 

4b)  right:  Mean  shell  heights  (20  adults  per  sample)  for  local 
populations  living  in  similar  microhabitats  directly  on  the  first  terrace  along 
the  east  coast  of  Curasao.  Shells  are  largest  where  trade  winds  do  not  hit 
coast  directly. 


14  BREVIORA  No.    372 

I  found  no  land  crabs  at  Kintjan,  but  Cerion  uva  is  even  more 
common  here  than  at  Rooi  Rincon.  There  is,  however,  one  out- 
standing difference  between  the  two  sites:  there  are  no  intertidal 
rock-dwellers  at  Kintjan  (neritids,  littorinids,  or  chitons),  while 
all  the  common  forms  are  found  at  Rooi  Rincon.  This  difference 
permits  us  to  specify  the  collecting  area  for  Kintjan  shells. 

The  entire  periphery  of  Curasao  is  framed  by  an  uplifted  Pleis- 
tocene reef;  intertidal  forms  are  common  all  around  the  coast. 
But  the  central  areas  are  underlain  by  volcanic  rocks  that  erode 
more  easily  than  the  coastal  limestone.  During  the  last  glacial 
period,  when  sea  levels  were  lower,  extensive  drainage  systems 
were  developed  on  the  volcanic  terrain;  these  breached  the  harder 
limestone  rim  in  only  a  few  places.  These  valley  systems  were 
drowned  when  sea  level  rose  and  produced  the  outstanding  pro- 
tected harbors  that  characterize  all  three  islands:  narrow  inlets 
with  expansive  inland  waters.  Willemstad,  the  capital  of  Curacao, 
is  built  on  both  sides  of  the  largest  harbor,  the  Schottegat.  The 
inland  shores  of  the  Schottegat  are  volcanic;  in  the  absence  of 
strong  surf  and  a  rocky  coast,  the  rock-dwelling  intertidal  forms 
do  not  inhabit  these  shores.  I  conclude  that  the  Kintjan  shells 
were  collected  in  the  Schottegat  (Fig.  4b);  the  extensive,  calm, 
shallow  waters  provided  an  excellent  site  for  gathering. 

3.    Tafelberg 

GASTROPODA  PROSOBRANCHIA 
Trochidae 

Cittarinm  pica  —  several  fragments 

LiTTORINIDAE 

Tectarius  muricatus 

GASTROPODA  PULMONATA 
Cerionidae 

Cerion  uva  —  common,  5  of  1 1 1  have  intact  apices 

BIVALVIA 
Arcidae 

Area  imbricata — 1 
Chamidae 

Chama  maeerophylla  —  common 
The  site  has  been  thoroughly  disturbed  by  blasting. 


1971  CERION    FROM    INDIAN    SHELL-HEAPS  15 

4.    Ceru  Canashito 
AMPHINEURA 

Acanthopleiira  granulata  —  4  plates 

GASTROPODA 
Trochidae 

Cittarium  pica  —  8 
Turbinidae 

Astraea  tecta — 1 
Neritidae 

Nerita  tessellata  —  3 
Littorinidae 

Tectarius  miiricatiis  —  5 

MODULIDAE 

Modulus  modulus  —  1 
Cerithiidae 

Cerithium  algicola  —  1 

Cerithium  Utteratum  —  1 
Strombidae 

Strombus  gigas  —  common 
Muricidae 

Murex  pomum  — 7 

Murex  brevijrons  —  1 

Thais  deltoidea  —  1 
Melongenidae 

Melongena  melongena  —  common 
Xancidae 

Vasum  muricatum  —  common 

BIVALVIA 
Arcidae 

A  nadara  notabilis  —  common 
Pteriidae 

Pinctada  radiata  —  1 

LUCINIDAE 

Codakia  orbicularis  —  common 
Chamidae 

Cliama  macerophylla  —  common 
Pseudochama  radians  —  1 


16  BREVIORA  No.    372 

Intertidal  rock-dwellers  are  found  here,  but  the  series  is  not 
nearly  so  complete  as  at  Rooi  Rincon  (only  one  Nerita,  Tectarius, 
but  neither  Echinus  nor  Nodilittorina).  Among  shallow  water 
forms,  there  are  two  major  differences  between  Canashito  and 
both  Rooi  Rincon  and  Kintjan.  The  Curasao  sites  contained  a 
suite  of  mangrove-dwellers  that  are  completely  absent  here  (Cana- 
shito yielded  one  Murex  brevijrons,  a  common  mangrove  form, 
but  Murex  pomum,  an  open  water  species  absent  from  both  Cura- 
sao sites,  is  the  common  Murex  here).  In  addition,  Canashito 
contains  a  suite  of  shells  {Modulus,  the  two  Cerithium  species 
and,  especially,  the  common  Codakia  orbicularis)  that  inhabit 
grass  and  algal  beds;  none  of  these  occur  in  the  Curasao  deposits. 
The  shells  were  probably  collected  in  calm  waters  off  the  leeward 
south  coast,  near  the  site  of  the  present  airport. 

CERION   UVA    IN  THE  PRECERAMIC    MIDDENS 
OF   CURACAO 

In  all  three  preceramic  middens  of  Curagao,  the  most  common 
moUuscan  shell  is  that  of  the  land  snail  Cerion  uva.  These  shells 
present  two  outstanding  features:  more  than  80  percent  in  each 
locality  have  lost  their  apical  whorls  and  shells  are  larger  and 
more  variable  than  modern  specimens. 

1.  Removal  of  the  apical  whorls.  By  reason  and  experiment, 
one  of  a  list  of  possible  proposals  can  be  identified  as  the  cause 
of  removal.  I  list  the  suggestions  made  to  me  by  many  friends 
and  colleagues. 

A)  Natural  removal 

B)  Artificial  removal 

i)    by  biting 
ii)     by  rubbing 

iii)    by  crushing  (striking  with  the  shell  held  up- 
right) 
iv)     by  slicing   (striking  with  the  shell  placed  on 
its  side). 
Although  the  apical  whorls  form  the  weakest  part  of  the  shell, 
I  do  not  believe  that  they  could  have  been  lost  naturally  by  so 
many  specimens.    I  have  extensive  collections  of  much  older  fos- 
sils from  fissure-fills  on  Aruba.    These  tumbled,  often  down  sev- 
eral meters,  into  the  fissures,  suffered  strong  compaction,  under- 
went tectonic  uplift  and  still  retain,  in  almost  all  cases,  the  apical 


971 


CERION    FROM    INDIAN    SHELL-HEAPS 


17 


whorls.  I  have  never  seen  a  natural  accumulation,  cither  recent 
or  fossil,  in  which  many  specimens  are  missing  their  apical  whorls. 

After  suffering  one  dental  misfortune,  I  am  quite  sure  that  the 
tops  cannot  be  bitten  off.  Apices  can  be  removed  by  rubbing 
either  against  limestone  or  volcanic  rock,  but  the  process  is 
much  too  laborious  and  time-consuming.  I  am  convinced  that 
the  tops  were  removed  by  striking.  They  were  not  crushed  by 
striking  the  top  of  the  shell  while  holding  the  bottom  against  a 
substrate  (and  keeping  the  shell  vertical),  for  this  process  invari- 
ably breaks  the  lower  lip  of  the  aperture  before  crushing  the  top. 
If,  however,  the  shell  is  placed  on  its  side,  horizontally  against 
the  substrate,  the  top  can  easily  be  removed  by  striking  with  a 
sharp  instrument.  In  fact,  the  flint  chips  and  stone  tools  of  Rooi 
Rincon  and  Kintjan,  are  excellent  devices  for  this  purpose.  With 
a  bit  of  practice,  the  apices  can  be  removed  with  a  single  blow. 

This  leaves  open  the  question  of  why  the  apices  were  removed. 
1  can  imagine  three  interpretations: 

A)  Removal  is  unrelated  to  eating;  the  shells  were  used  for 
an  ornamental  or  other  purpose. 

B)  When  the  top  is  removed,  the  animal  can  be  sucked  out 
through  the  apical  hole  thus  produced. 

C)  Removal  of  the  top  aids,  somehow,  in  sucking  the  animal 
out  through  its  normal  aperture. 

I  cannot  imagine  what  nongastronomical  purpose  so  many 
thousand  decapitated  shells  could  have  served.  Moreover,  the 
following  demonstration  that  decapitation  is  an  aid  to  removal 
of  the  animal  argues  strongly  against  A. 


Figure  5.  X-ray  photographs  of  decapitated  Ccrion  uva  from  Kintjan 
(left  2  specimens)  and  Rooi  Rincon  (right  2).  Since  internal  whorl  parti- 
tions are  intact,  animal  was  not  removed  through  apical  hole.  Specimen  on 
left  is  32.8  mm  high. 


18  BREVIORA  No.    372 

If  the  animal  were  sucked  out  through  the  top,  some  of  the 
internal  whorl  partitions  would  have  to  be  broken,  for  the  large 
foot  could  not  fit  in  the  small  whorls  left  near  the  top  of  the  shell. 
X-ray  photographs  of  decapitated  shells  (Fig.  5)  show  clearly 
that  the  whorl  partitions  are  never  disturbed.  The  animal  could 
not  have  been  extracted  through  the  apical  hole. 

If  you  take  an  intact  shell  with  its  animal  inside  and  suck  as 
hard  as  possible  at  the  aperture,  the  animal  cannot  be  extracted. 
But,  when  the  apex  is  removed,  a  single  hard  suck  upon  the  aper- 
ture will  extract  either  the  large  foot  of  the  animal  or  the  entire 
body  itself.  Removal  of  the  top  breaks  the  vacuum  inside  the  shell 
and  facilitates  the  extraction  of  its  contents.  The  entire  process 
is  really  quite  efficient:  one  strike,  one  suck,  and  the  animal  is 
removed.  Several  can  be  eaten  in  a  minute  (though  I  recommend 
Cerion  only  to  the  starving). 

Somehow,  I  find  it  satisfying  to  think  that  the  Meso-Indians  of 
Curacao  discovered  an  important  physical  principle  for  such  a 
practical  procedure.  This  idea,  so  obvious  to  all  of  us  who  were 
raised  in  the  pre  pop-top  age  of  the  beer  can  industry,  is  by  no 
means  a  self-evident  principle. 

2.  Variation  and  jorm  of  Cerion  uva.  Any  sample  from  a  shell 
midden  is,  of  course,  strongly  biased  from  a  biometrical  point  of 
view.  The  probable  bias,  in  these  cases,  is  twofold:  the  selection 
of  large  individuals  (for  Cerion  is  not  a  large  snail  and  much 
work  must  be  expended  for  little  nutrition),  and  the  amalgama- 
tion of  shells  from  several  local  populations. 

Much  has  been  made  in  the  literature  of  the  extreme  intraspe- 
cific  variability  of  land  snail  shells.  This  indeed  is  true,  but  it  is 
usually  of  a  particular  kind  (and  this  is  rarely  emphasized).  The 
variation  is  interpopulational,  i.e.,  the  shells  of  any  local  popu- 
lation are  not  unusually  variable,  but  differences  among  the  means 
of  local  populations  are  often  extreme.  Thus,  it  is  likely  that  our 
two  biases  will  afi'ect  the  mean  of  a  midden  sample  in  opposite 
ways:  the  selection  of  large  shells  will  augment  the  mean,  but 
the  amalgamation  of  large  individuals  from  several  local  popula- 
tions will  produce  a  midden  mean  smaller  than  the  true  mean  of 
a  local  population  with  large  shells. 

The  rise  in  variability  from  amalgamation  of  local  populations 
can  be  gauged  by  comparing  coefficients  of  variation  (C.V.) 
(Simpson,  Roe,  and  Lewontin,  1960:  89-95)  of  midden  samples 


1971 


CERION  FROM   INDIAN   SHELL-HEAPS 


19 


and  modern  local  populations  for  the  same  character.  Table  2 
presents  C.V/s  for  shell  height  of  the  three  midden  samples  and 
a  mean  value  for  69  modern  local  populations  (Gould,  unpub- 
lished data  for  monograph  in  preparation;  N  =  20  for  all  samples, 
midden  and  modern;  values  for  midden  shells  are  estimates  for 
actual  height  with  decapitated  apical  whorls  restored;  all  shells 
are  adults  with  completed  growth ) .  All  midden  means  are  above 
the  modern  grand  mean.  Rooi  Rincon  and  Tafelberg  are  within 
the  span  of  modern  C.V.'s  (4.03  to  10.18),  but,  at  15.45,  shells 
from  Kintjan  are  far  more  variable  than  those  of  any  modern 
local  population. 

The  striking  feature  of  midden  samples  is  the  large  size  of  some 
of  their  shells.  Fortunately,  Cerion  iiva  is  among  the  world's  best 
known  land  snails  from  a  biometrical  point  of  view.  Three  major 
studies  have  been  done  in  this  century:  by  Baker  in  the  earlv 
1920's  (Baker,  1924),  by  Hummelinck  in  the  late  1930's  (Hum'- 
mehnck,  1940)  and  by  myself  during  the  past  two  years.  Table 
2  compares  the  heights  of  shells  in  midden  and  modern  samples. 
Each  modern  study  has  uncovered  a  local  population  with  greater 
mean  height  than  the  smallest  midden  sample,  and  one  of  Hum- 
melinck's  local  populations  exceeds  the  largest  midden  sample  in 
mean  height.   Still,  of  course,  the  midden  means  are  all  well  above 


T^'*' 


Figure  6.  Comparison  of  largest  shell  heap  (left,  from  Kintjan,  34.3  mm 
high)  Cerion  and  largest  modern  shell.  Difference  is  much  more  striking  in 
actual  shells  in  which  areal  artifact  of  two  dimensional  representation  is 
lost  and  judgment  of  size  is  made  more  properly  by  volume. 


20  BREVIORA  No.    372 

the  grand  mean  of  means  for  each  modern  study.  However,  as 
mentioned  previously,  the  midden  means  are  almost  surely  lower 
than  the  true  means  of  local  populations  with  large  shells  living  at 
that  time.  A  more  appropriate  comparison  might  be  made  using 
maximal  size. 

Among  almost  12,000  modern  snails  from  248  local  popula- 
tions over  50  years,  no  snail  greater  than  30  mm  in  height  has 
ever  been  found.  (In  only  one  of  Hummelinck's  local  populations 
did  any  individuals  exceed  29  mm;  neither  Baker  nor  Gould  found 
any  taller  than  28.5  mm.)  Yet  snails  exceeding  30  mm  in  height 
are  very  common  in  two  of  the  three  midden  samples  and,  at  34.3 
mm,  the  largest  snail  from  Kintjan  dwarfs  my  modern  "giant" 
(Fig.  6). 

Two  separate  factors  can  make  a  snail  tall,  and  both  operated 
to  produce  the  large  midden  shells.  First,  a  snail  can  increase  in 
height  simply  by  adding  more  whorls.  Each  of  the  decapitated 
shells  of  Figure  5  shows  1 1  whorls  below  the  break;  the  complete 
shell  would  have  had  one  or  two  more  postprotoconch  whorls. 
Modern  shells  with  more  than  IOV2  postprotoconch  whorls  are  a 
great  rarity  (Baker  and  Hummelinck  included  protoconch  whorls 
in  their  count,  hence  their  larger  figures).  Secondly,  a  tall  snail 
may  have  as  many  whorls  as  a  smaller  one,  but  simply  have  larger 
whorls.  Protoconch  size  is  a  good  measure  of  general  whorl  size 
(Gould,  1969).  Only  Rooi  Rincon  has  enough  complete  shells 
to  permit  the  calculation  of  mean  protoconch  width.  At  1.67  mm, 
mean  protoconch  width  for  Rooi  Rincon  is  at  the  top  of  the  range 
of  modem  mean  widths  (1.41-1.69  mm  for  69  samples,  N  ^  20 
for  each  sample ) .  The  midden  shells  grew  more  whorls  than  any 
modern  sample  and  had  larger  whorls  than  most. 

Why  were  the  midden  snails  larger  than  modern  snails?  All 
three  modern  studies  have  demonstrated  the  extreme  phenotypic 
plasticity  of  Cerion  iiva.  Shell  size  of  adults  is  a  direct  function  of 
microenvironment;  snails  are  large  when  habitats  are  moist,  calm, 
and  well  vegetated.  Curasao  today  is  an  arid  island.  It  receives 
only  17-22  inches  of  rain  per  year,  most  in  brief  downpours.  It 
is  hard  to  imagine  a  less  hospitable  area  in  the  West  Indies  for 
pre-agricultural  Meso-lndians.  I  do  not  know  what  they  could 
have  found,  in  this  cactus-covered  land,  to  supplement  a  diet  of 
sea  food.  It  is  therefore  tempting  to  think  that  the  large  midden 
shells  indicate  a  wetter  climate  that  might  have  supplied  to  Meso- 
lndians  some  of  the  tropical  fruits  that  adorn  most  West  Indian 


1971  CERION   FROM    INDIAN   SHELL-HEAPS  21 

islands.  Unfortunately,  there  is  no  other  evidence  for  greater  rain- 
fall 4000  years  ago.  If  Curasao  were  much  larger  or  higher  than 
it  is  today,  continental  effects  might  lead  to  increased  rainfall. 
But  the  eustatic  rise  of  sea  level  has  not  been  more  than  10  feet 
during  the  past  4000  years  (Redfield,  1967;  Milliman  and  Emery, 
1968)  and  the  direction  of  tectonic  movement  has  been  upward 
(Weyl,  1966).  Rouse  and  Cruxent  (1936:  38)  believe  that  tem- 
peratures and  rainfall  have  not  varied  appreciably  during  the  past 
5000  years  in  Venezuela  and  surrounding  areas. 

If  large  size  is  not  an  immediate  phenotypic  response  to  local 
conditions  more  favorable  than  today's,  then  I  suspect  that  the 
midden  snails  were  programmed  to  be  large,  i.e.,  that  the  effect 
is  mainly  genetic.  In  this  case  they  probably  represent  the  relict 
populations  of  snails  that  had  been  genetically  adapted  to  more 
favorable  conditions  during  pluvial  cycles  of  the  previous  glacial 
period.  In  any  event,  they  served  the  Meso-Indians  well;  it  would 
be  hard  to  make  a  meal  of  modern  Cerion. 

There  is  an  interesting  postscript  to  the  relationship  of  Cerion 
with  Meso-Indians.  There  is  considerable  evidence  for  trade 
between  the  mainland  and  coastal  islands,  but  it  is  all  unidirec- 
tional. Rouse  and  Cruxent  (1963:  45)  found  trade  pottery  from 
Venezuela  in  the  Punta  Gorda  complex  of  the  Manicuaroid  Series 
on  Cubagua.  Du  Ry  (1960:  85)  discovered  that  the  oldest  pot- 
tery of  Aruba  is  finer  in  texture  than  later  examples.  He  assumes 
that  this  first  pottery  was  imported  from  northeastern  Venezuela 
and  that  the  later  work  is  indigenous.  In  a  nearly-forgotten  work, 
Berry  (1934)  found  Cerion  iiva  in  an  Indian  shell  heap  near  Lake 
Valencia,  Venezuela.  Berry  was  not  convinced  that  these  shells 
were  imported  from  the  Dutch  Leeward  Islands.  But  his  argu- 
ment that  Cerion  might  have  once  inhabited  the  shores  of  Lake 
Valencia  can  be  discounted  because  this  halophile  would  not  sur- 
vive so  far  inland.  I  also  doubt  that  Cerion  inhabited  the  coast  of 
Venezuela,  for  it  has  never  been  recorded  from  shell  heaps  there. 
Since  there  is  no  evidence  that  Cerion  uva  ever  lived  elsewhere 
than  the  Dutch  West  Indies,  I  conclude  that  the  Valencia  speci- 
mens establish  the  reciprocity  of  transport  between  Venezuela 
and  the  islands. 


22  BREVIORA  No.    372 

ACKNOWLEDGEMENTS 

I  thank  Father  Paul  Brenneker  and  Mr.  Ehs  Juhana,  local  folk- 
lorists  and  archaeologists,  who  collected  with  me  at  Rooi  Rincon; 
Dr.  F.  Creutzberg,  Director  of  CARMABI,  who  showed  me  the 
Kintjan  site,  and  Mr.  Harry  Evers,  who  allowed  me  to  collect  at 
the  Tafelberg  midden.  This  work  was  supported,  in  part,  by 
N.S.F.  Grant  No.  GB-12553. 


1971  CERION    FROM    INDIAN    SHELL-HEAPS  23 


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LITERATURE   CITED 

Baker,  H.  B.  1924.  Land  and  freshwater  molluscs  of  the  Dutch  Leeward 
Islands.    Occas.  Pap.  Mus.  Zool.  Univ.  Mich.,  No.  152.    158  pp. 

Berry,  C.  T.  1934.  Pleistocene  remains  found  near  Lake  Tacarigua,  Vene- 
zuela.  J.  Washington  Acad.  Sci.,  24:  387-395. 

CoOMANS,  H.  E.  1958.  A  survey  of  the  littoral  Gastropoda  of  the  Nether- 
lands Antilles  and  other  Caribbean  Islands.  Stud.  Fauna  Curasao, 
8:  42-111. 

Cruxent,  J.  M.,  AND  L  Rouse.  1958-59.  An  Archaeological  Chronology  of 
Venezuela.  Social  Sci.  Monogr.  VI,  vols.  I,  277  pp.  and  11,  223  pp. 
Pan  American  Union,  Washington,  D.C. 

1969.    Early  man  in  the  West  Indies.  Sci.  Am.  421:  42-52. 

Du  Ry,  C.  J.  1960.  Notes  on  the  pottery  of  Aruba,  Curasao,  and  Bonaire. 
Stud.  Archaeol.  Netherlands  Antilles,  I:  81-102. 

Gould,  S.  J.  1969.  An  evolutionary  microcosm:  Pleistocene  and  Recent 
history  of  the  land  snail  P.  (Poecilozonites)  in  Bermuda.  Bull.  Mus. 
Comp.  Zool.,  138:  407-532. 

Heekeren,  H.  R.,  VAN.  1960.  A  survey  of  the  non-ceramic  artifacts  of 
Aruba,  Curacao,  and  Bonaire.  Stud.  Archaeol.  Netherland  Antilles,  II: 
103-120. 

1963.  Prehistorical  research  on  the  islands  of  Curagao,  Aruba, 

and  Bonaire  m  I960.    Stud.  Archaeol.  Netherlands  Antilles,  III:    1-24. 

Hummelinck,   p.  W.   1940.  Mollusks  of  the   genera    Cerion   and   Tiidoni. 

Stud.  Fauna  Curasao,  Aruba,  Bonaire,  and  the  Venezuelan  Islands,  2: 

43-82. 
1953.     Rotstekeningen    van    Curasao,    Aruba    en    Bonaire. 

(Linear  rock  designs  of  Curasao.  Aruba,  and  Bonaire).    West-Indische 

Gids,  34:  173-209. 
1957.   Rotstekeningen  van  Cursn^diO,  Aruba  en  Bonaire.   West- 


Indische  Gids,  37:  93-126. 

Martin,  P.  S.,  and  H.  E.  Wright,  Jr.  (eds.).    1967.   Pleistocene  Extinctions: 
the  Search  for  a  Cause.   New  Haven,  Yale  Univ.  Press.    453  pp. 

Milliman,  J.  D.,  and  K.  O.  Emery.    1968.  Sea  levels  during  the  past  35,000 
years.  Science,  162:  1121-1123. 

Redfield.  a.  C.    1967.    Postglacial  change  in  sea  level  in  the  western  North 
Atlantic  Ocean.  Science,  157:  687-691. 

Rouse,  I.    1960.    The  entry  of  man  into  the  West  Indies.    Yale  Univ.  Publ. 

Anthrop.,  No.  61.   26  pp. 

1964.   Prehistory  of  the  West  Indies.    Science,  144:  499-513. 

1966.   Paleo-  and  Meso-Indians  of  the  Caribbean  area.   Qua- 

ternaria,  8:  125-132. 


26  BREVIORA  No.    372 

Rouse,   I.,   and  J.   M.   Cruxent.     1963.    Venezuelan    Archaeology.     New 

Haven,  Yale  Univ.  Press.    179  pp. 
Simpson,  G.  G.,  A.  Roe,  and  R.  C.  Lewontin.   1960.  Quantitative  Zoology. 

New  York,  Harcourt,  Brace  and  Co.   440  pp. 
Stuiver,  M.,  and  H.  E.  Suess.    1966.    On  the  relationship  between  radio- 
carbon dates  and  true  sample  ages.  Radiocarbon  8:  534-540. 
Tacoma,  J.    1959.  Indian  skeletal  remains  from  Aruba.  Stud.  Phys.  Anthrop. 

Netherlands  Antilles,  II:  95-112. 
Tamers,  M.  A.    1967.    Instituto  Venezolano  de  Investigaciones  Cientificas. 

Natural  radiocarbon  measurements  111.    Radiocarbon,  9:  237-245. 
Warmke,  G.  L.,  and  R.  T.  Abbott.    1961.   Caribbean  Seashells.  Livingston 

Co.    346  pp. 
Weyl,    R.     1966.     Geologic   der   Antillen.     Berlin,    Gebriider   Borntraeger. 

410  pp. 


BREVIORA 

Mnasemim    of   Comiparative    Zoology 

Cambridge,  Mass.  31  March,   1971  Number   373 


THE  CHANARES  (ARGENTINA)  TRIASSIC 
REPTILE  FAUNA. 

VIII.  A   FRAGMENTARY  SKULL  OF  A   LARGE  THECODONT, 
LUPEROSUCHUS  FR ACTUS 

Alfred  Sherwood  Romer 

Abstract.  Incomplete  remains  of  a  large  skull,  not  improbably  repre- 
S2nting  a  raiiisuchid  thecodont  from  the  early  Middle  Triassic  of  Argentina, 
are  described  as  Luperosiichiis  fractns,  gen.  et  sp.  nov.  Large  dermal  scutes, 
found  isolated,  may  pertain  to  this  form. 

INTRODUCTION 

A  moderate  number  of  specimens  assignable  to  the  reptilian 
order  Thecodontia  are  present  in  our  Chaiiares  collections.  Apart 
from  materials  that  are  difficult  of  interpretation  or  assignment, 
there  are  definitely  present:  (  1  )  a  small  and  primitive  member 
of  the  Ornithosuchidae;  (2,  3)  two  long-snouted  forms,  with  gen- 
eral proportions  resembling  crocodilians,  but  without  any  positive 
indications  of  affinities  with  that  group;  (4)  a  small  form  with  a 
very  lightly  built  skull,  of  which  the  limbs  are  unknown;  (5,  6) 
two  forms  known  from  very  slender  hind  limbs  of  unusual  con- 
struction; and  (7)  a  large  animal,  probably  a  rauisuchid.  repre- 
sented only  by  a  partial  skull.  In  addition  there  are  various 
isolated  materials,  pseudosuchian  in  nature.  In  the  present  short 
paper  1  shall  describe  only  the  last  specimen  listed,  leaving  the 
others  for  later  description. 

Since  our  collections  were  made,  Sr.  Bonaparte  of  Tucuman 
has  made  several  visits  to  the  Chaiiares  region,  and  found,  inter 
alia,  a  fair  amount  of  thecodont  material.  He  invited  me  to  make 
use  of  this  in  my  work  on  thecodonts,  and  in  June  1970  I  spent 
a  week  in  Tucuman  studying  this  material.  I  found  no  identifiable 
forms  not  already  present   in  the  Harvard-La  Plata  collections, 


BREVIORA 


No.   373 


but  in  a  number  of  regards  his  materials  supplemented  ours  and 
substantiated  our  conclusions.  I  am  deeply  grateful  to  Sr.  Bona- 
parte and  the  authorities  of  the  Instituto  Lillo  for  placing  this 
material  at  my  disposal. 


LuPEROsucHUS  FRACTUS  gen.  et  sp.  nov. 

Combined  generic  and  specific  diagnosis.  A  large  thecodont, 
with  an  estimated  skull  length  of  about  60  cm,  probably  pertain- 
able  to  the  family  Rauisuchidae.  A  shtlike  opening  apparently 
present  posterior  to  the  nares  between  premaxilla  and  maxilla; 
antorbital  opening  large;  apparently  no  parietal  foramen;  lateral 
temporal  opening  with  vertical  posterior  border;  archosaur  type 
of  otic  notch  partially  developed. 

Holotype  of  the  species.  La  Plata  Museum  1964-X1-14-9,  an 
incomplete  skull,  consisting  of  most  of  the  dermal  roof  and  part 
of  the  left  side  of  the  "face"  collected  from  the  Chanares  Forma- 
tion in  La  Rioja  Province,  Argentina,  north  of  the  north  fork  of 
the  Chanares  River,  about  5  km  NE  of  the  point  where  this  river 
emerges  into  the  Piano  de  Talampaya. 

The  generic  and  specific  names  refer  to  the  fragmentary  and 
perplexing  nature  of  the  type  material. 

I  am  indebted  to  National  Science  Foundation  Grant  GB-2454 
for  aid  in  the  collecting  of  the  material  and  to  further  grants  for 
its  preparation  and  for  publication  costs. 


Figure  1.     Side  view  of  the  fragmentary  type  skull  of  Liiperosiicluis  frac- 
tus.  as  preserved.  X    1/6. 


197 


LUPEROSUCHUS   SKULL 


Description.  This  form  is  represented  by  a  single  fragmentary 
specimen  that  includes  most  of  the  dorsal  surface  of  a  skull  and 
part  of  the  dermal  bones  of  the  left  side  of  the  skull  (Figs.  1,2). 
The  condition  of  the  material  is  none  too  good,  and  sutures  are 
generally  difficult  to  determine.  The  specimen  was  found  close 
beside  the  skeleton  of  a  dicynodont.  Near  it  were  found  a  con- 
siderable number  of  weathered  scraps  of  bone;  whether  they 
belong  to  the  specimen  here  described  or  to  the  dicynodont 
is  uncertain. 

The  animal  was  a  large  one;  the  portions  of  the  skull  preserved 
measure  54.5  cm  in  length  and  if  the  missing  anterior  and  posterior 
regions  be  restored,  the  length  in  life  would  have  been  about  60 
cm.  In  general,  the  reptiles  present  in  the  Chanares  Formation 
are  of  modest  size;  apart  from  this  Liiperosuchus  specimen,  the 
dicynodonts  are  the  only  large  animals  known. 

As  mentioned,  most  of  the  skull  roof  is  preserved;  the  cranium 
was  obviously  long  and  slender,  as  in  many  early  archosaurs. 
Posteriorly,  the  parietals  are  incomplete,  and  their  posterior  exten- 
sions, which  presumably  formed  the  median  boundaries  of  the 
superior  temporal  fenestrae,  are  missing.  There  was  no  parietal 
foramen  in  the  portion  of  the  bone  preserved  (although  it  may 
possibly  have  been  present  in  the  missing  posterior  portion).  A 
median  longitudinal  suture  can  be  made  out  for  almost  the  entire 
length  of  the  roof  as  preserved.  Other  sutures  are  obscured  by 
poor  preservation  and  bone  fusion  in  this  seemingly  mature  skull. 


Figure  2.  Dorsal  view  of  the  skull,  restored.  Parts  present  in  stipple. 
Abbreviations:  /.  frontal;  /.  jugal;  /.  lacrimal;  m,  maxilla;  /;.  nasal;  p,  pari- 
etal; pj,  postfrontal;  pm.  premaxilla;  po,  postorbital;  prj.  prefrontal;  qj. 
quadratojugal;  sq,  squamosal.   X    1/6. 


4  BREVIORA  No.    373 

I   have  restored  the  probable  sutural   pattern,  but  it  should  be 
emphasized  that  uncertainties  exist. 

The  area  of  the  posterior  part  of  the  frontals  and  the  median 
portion  of  the  parietals  is  depressed,  and  bounded  on  either  side 
by  prominent  ridges  running  back  along  the  lateral  margins  of 
the  frontals  and  continuing  backward  along  the  parietals.  Postor- 
bitals  are  present  along  the  back  portion  of  the  supraorbital  rims 
and  extend  backward  and  medially  to  meet  the  parietals  along 
the  anterior  border  of  the  superior  temporal  fenestrae.  As  far  as 
can  be  determined,  there  were  large  postfrontals,  forming  part 
of  the  upper  margins  of  the  orbits  and  extending  back  between 
frontals  and  postorbitals  to  gain  contact  with  the  parietals.  The 
frontals  are  broad  posteriorly;  anteriorly  they  become  reduced  in 
width  between  the  prefrontals.  It  is  possible  that  the  frontals 
entered  the  orbital  margins  briefly,  but  imperfections  of  the  speci- 
men render  this  uncertain,  and  they  may  have  been  excluded  by 
a  narrow  contact  between  postfrontals  and  prefrontals.  The  latter 
elements  appear  to  be  relatively  narrow,  projecting  somewhat 
outward  over  the  anterodorsal  corner  of  the  orbits  and  extending 
a  modest  distance  forward  on  either  side  on  the  dorsal  surface. 
Anteriorly,  about  opposite  the  front  margin  of  the  antorbital  vacu- 
ity, the  nasals,  as  seen  in  side  view,  rise  upward  markedly  above 
the  general  line  of  the  skull  roof  on  their  forward  course.  I  was 
at  first  inclined  to  believe  this  appearance  was  due  to  post-mortem 
distortion;  however,  inspection  indicates  that  this  "roman  nosed" 
elTect  is  a  real  structural  feature;  the  conjoined  nasals  form  a 
sharp  ridge  below  which  the  two  bones  are  apposed  for  some  dis- 
tance and  then  slant  outward  toward  either  side  ventrally.  It 
seems  obvious  that  the  nasals  are  incomplete  anteriorly.  Ventrally 
the  point  of  separation  of  the  nasal  from  the  posterior  extension 
of  the  premaxilla  below  it  indicates  the  probable  position  of  the 
posterior  angle  of  the  naris.  Most  of  the  premaxilla  is  missing. 
A  small  fragment  of  bone  attached  to  the  anterior  end  of  the 
maxilla  presumably  represents  the  most  posteroventral  position 
of  the  bone.  More  dorsally  a  band  of  bone  with  well-defined 
margins  extends  dorsoposteriorly  between  maxilla  and  nasal,  indi- 
cating a  posterior  extension  of  the  premaxilla  that  excludes  the 
maxilla  from  the  narial  margin,  as  in  certain  other  thecodonts 
(and  ornithischians).  The  whole  aspect  of  the  anterior  portion 
of  the  skull,  as  far  as  preserved,  strongly  suggests  the  presence 


1971  LUPEROSUCHUS   SKULL  5 

of  an  expanded  narial  area,  and  in  Figure  3  I  have  restored  the 
narial  region  on  this  supposition. 

A  large  portion  of  the  maxilla  is  present.  A  ventroanterior  area, 
much  thickened,  represents  the  ventral  margin  adjacent  to  the 
premaxilla.  This  region  is  excavated  internally  and,  although 
preservation  is  imperfect,  represents  the  area  of  insertion  of  a 
series  of  large,  probably  subthecodont,  anterior  maxillary  teeth. 
Above  this  region  the  anterior  margin  of  the  maxilla  slants  upward 
and  backward  parallel  to  the  posterodorsal  extension  of  the  pre- 
maxilla. In  the  specimen  as  preserved  the  two  bones  are  separated 
here  by  a  long  if  narrow  slit.  For  much  of  this  distance  the  facing 
margins  of  both  bones  are  broadened  so  that  they  can  readily  be 
apposed  to  one  another;  hence,  when  I  first  attempted  a  restora- 
tion of  the  skull,  I  placed  these  margins  in  firm  apposition.  But 
in  contrast  to  the  close  union  of  all  other  portions  of  the  skull, 
in  the  specimen  as  preserved,  there  was  here  a  very  distinct  separa- 
tion, suggesting  that  a  slitlike  opening  was  present  in  life.  Dr. 
W.  D.  Sill,  who  is  currently  studying  Saurosuchiis,  a  seemingly 
related  form  from  the  Ischigualasto  Formation,  informs  me  that 
such  an  opening  was  definitely  present  in  that  genus,  and  I  have 
therefore  indicated  such  an  opening  in  the  restoration  in  Figure 
3.  I  have  no  worthwhile  suggestion  as  to  the  possible  function 
of  this  slit. 

Back  of  the  nasal  region,  dorsal  and  lateral  surfaces  are  sharply 
separated  for  most  of  the  skull  length  and,  even  allowing  for 
possible  crushing,  it  seems  certain  that  the  side  walls  descended 
nearly  vertically  from  the  lateral  dorsal  ridges.  A  short  length 
of  maxilla  is  preserved  ventrally;  above,  there  is  a  broad  plate  of 
bone  apparently  formed  by  the  maxilla,  extending  back  above  the 
antorbital  fenestra.  The  margins  of  this  fenestra  are,  for  the 
most  part,  clearly  outlined;  it  was  an  opening  of  considerable  size. 
In  many  advanced  thecodonts  the  fenestra  is  centrally  situated  in 
a  depressed  area  of  the  cheek;  in  this  specimen  the  anterior  rim 
of  this  depression  is  clearly  incised  in  the  maxilla.  The  suture 
between  prefrontal  and  lacrimal  is  not  clear,  but  the  latter  bone 
apparently  includes  the  posterior  part  of  the  upper  margin  of  the 
antorbital  fenestra  as  well  as  the  preserved  portion  of  a  stout  bar 
of  bone  that  separates  orbit  and  antorbital  fenestra.  Behind  the 
orbit,  the  bar  of  bone  between  orbit  and  lateral  temporal  fenestra 
is  completely  preserved,  and  there  are  indications  of  a  suture  well 


BREVIORA 


No.  373 


down  this  bar,  between  postorbital  and  jugal.  A  fraction  of  the 
latter  bone  is  present,  defining  the  lower  margin  of  the  orbit,  a 
section  of  the  cheek  rim,  and  a  small  area  of  the  anteroventral 
margin  of  the  lateral  temporal  fenestra.  Above  this  fenestra  a 
stout  bar  of  bone  is  present,  presumably  formed  anteriorly  by 
the  postorbital,  posteriorly  by  the  squamosal  (the  suture  between 
the  two  is  not  clear).  An  incomplete  flange  of  the  latter  bone 
extends  directly  downward  as  part  of  the  posterior  border  of  the 
lateral  fenestra.  The  squamosal  extended  backward  beyond  the 
level  of  this  descending  flange,  although  this  extension  is  broken 
off  in  the  specimen.  The  vertical  descent  of  the  squamosal  flange 
indicates  that  the  posterior  border  of  the  fenestra  had  not  acquired 
the  V-shaped  contour  seen  in  various  more  advanced  thecodonts; 
on  the  other  hand,  the  posterior  prong  of  the  squamosal  suggests 
the  initiation  of  a  typical  archosaur  type  of  otic  notch. 

In  Figure  3  I  have  freely  restored  the  skull  in  side  view  to  give 
a  suggestion  of  its  probable  appearance  in  life.  Despite  the  incom- 
plete nature  of  the  evidence  I  do  not  think  that  there  can  be  too 
great  a  departure  from  life  conditions  in  most  regards.  Most 
doubtful,  because  of  lack  of  material,  is  the  suspensorial  region. 

Systematic  position.  As  to  relationships  of  Luperosuchiis,  an 
early  Middle  Triassic  form,  one  tends  to  think  first  of  the  larger 
erythrosuchid  members  of  the  Proterosuchia  —  a  group  most 
recently  discussed  by  Reig  (1970),  and  by  Charig  and  Reig 
(1970).  Primitive,  for  example,  is  the  apparent  presence  of  a 
large  postfrontal.    Liiperosuchus,  however,  is  more  advanced  than 


Figure  3.     Side  view   of  the  skull,  restored.     Abbreviations  as  in    Fig. 
2.     X    1/6. 


1971 


LUPEROSUCHUS  SKULL 


proterosuchians  in  various  regards,  such  as  the  large  size  and 
incised  nature  of  the  antorbital  fenestra,  probable  absence  of  a 
parietal  foramen,  and  the  apparent  beginning  of  the  pseudosuchian 
development  of  an  otic  notch.  More  reasonable  is  assignment  to 
the  Rauisuchidae  (or  Prestosuchidae),  a  family  of  large  but  rela- 
tively primitive  Middle  Triassic  thecodonts,  first  seriously  studied 
by  Reig  (1961).  Included  here  may  be  such  forms  as  Ticinosii- 
chiis  from  the  European  Anisian  (Krebs,  1965),  Fenhosuchus 
and,  doubtfully,  Shansisiichus  from  China  (Young,  1964),  Stcigo- 
nosuchus  (Huene,  1938),  and  Mandasuchus  from  the  Manda 
beds  of  East  Africa.  The  presence  of  rauisuchids  in  the  Middle 
Triassic  of  South  America  is  well  attested  by  the  presence  of 
Rauisiichiis  and  Prestosuclms  from  the  Santa  Maria  of  Brasil  and 
Saiirosuchus  of  the  Middle  Triassic  Ischigualasto  Formation  of 
Argentina. 

The  material  of  Liiperosuchus  is  too  fragmentary  to  warrant 
any  extended  discussion  of  rauisuchid  relationships.  Are  they,  as 
Reig  believes  (1970,  fig.  10),  a  side  branch  from  a  somewhat 
advanced  pseudosuchian  stock,  or  could  they  have  progressed  in 
parallel  fashion  from  the  proterosuchian  base  of  the  Thecodontia? 
Are  they  a  sterile  group,  without  descendants,  or  could  they  be 
related  to  the  ancestry  of  certain  of  the  later  saurischians,  the 
Prosauropoda  (Palaeopoda)  or,  more  especially,  ancestral  Sauro- 
poda?  It  is  possible  that  Dr.  SilFs  current  studies  of  Saurosuchus 
will  shed  light  on  rauisuchid  relationships. 

Dermal  scutes.  In  two  instances  we  found  in  the  Chanares 
region  large  scutes  not  definitely  associated  with  other  identifiable 
skeletal  remains  (Fig.  4).  They  are  too  large  to  be  attributed  to 
any  of  the  other  (and  much  smaller)   thecodonts  present  in  our 


1  2  CM 

J I 


Figure  4.     Two  dermal  scutes,  possibly  referable  to  Luperosuchus. 


8  BREVIORA  No.    373 

collections  (and  they  are  not,  of  course,  attributable  to  the  synap- 
sids,  which  make  up  the  remainder  of  the  materials  collected). 
Of  known  forms  from  the  Chanares,  Luperosuchus  is  the  only 
one  to  which  they  could  have  belonged  and,  since  comparable 
scutes  are  known  in  other  rauisuchids,  we  may  provisionally  assign 
them  to  the  present  genus.  None  of  the  scutes  is  perfectly  pre- 
served. One  type,  rectangular  in  shape,  has  a  thickened,  saw- 
toothed  border  along  one  edge,  indicative  of  an  interdigitating 
connection  with  another  element.  Such  scutes  are  presumably 
paramedian  paired  scutes,  found  in  various  other  thecodonts. 
Subcircular  scutes,  also  present,  may  be  more  lateral  elements  or 
median  caudal  ones. 

REFERENCES  CITED 

Charig,  a.  J.,  AND  O.  A.  Reig.     1970.     The  classification  of  the  Protero- 

siichia.    Biol.  Jour.  Linn.  Soc,  2(2):    125-171. 
HuENE,  F.  VON.     1938.     Ein  grosser  Stagonolepide  aus  der  jiingeren  Trias 

Ostafrikas.  Neues  Jahrb.  Min.  Geol.  Pa!.,  Beii.-Bd.,  80:  264-278. 

Krebs,  B.    1965.    Ticinosuchiis  ferox  nov.  gen.  nov.  sp.    Ein  neuer  Pseudo- 

suchier  aus  der  Trias  des  Monte  San  Giorgio.    Schweiz.  Palaont.  Ab- 

handl.,   81:    1-140. 
Reig,    O.    A.      1961.      Acerca    de    la    Posicion    Sistematica    de    la    Familia 

Rauisuchidae    y    del    Genero    Saiirosiichiis    (Reptilia,    Thecodontia). 

Publ.  Mus.  Munic.  Cienc.  Nat.  Tradic.  Mar  del  Plata,   1(3):   73-114. 
1970.     The  Proterosuchia  and  the  early  evolution   of  the 

archosaurs;  an  essay  about  the  origin  of  a  major  taxon.   Bull.   Mus. 

Comp.  Zool.,  139(5):  229-292. 
Young,  C.  C.     1964.    The  pseudosuchians  in  China.    Palaeont.  Sinica,  new 

sen  C,  No.  19:   107-205. 


BREVIORA 

Mmseiuijni   of   Comparative   Zoology 

Cambridge,  Mass.  15  June,  1971  Number  374 


THE   FISHES   OF  THE   MALAYSIAN   FAMILY 
PHALLOSTETHIDAE   (ATHERINIFORMES) 

Tyson  R.  Roberts^ 

Abstract.  The  tiny  fishes  of  the  family  Phallostethidae,  from  Malaya 
and  Thailand,  develop  a  large  penis  and  differ  radically  in  structure  of  the 
bilaterally  asymmetrical  priapium  from  the  somewhat  larger  fishes  of  the 
more  widely  distributed  Neostethidae,  the  only  other  family  in  the  sub- 
order Phallostethoidea.  A  morphological  characterization  of  the  Phallo- 
stethidae is  given  and  its  features  compared  to  those  of  Neostethidae. 
There  are  three  species:  Phallostethus  diinckeri  Regan  (1913),  known 
only  from  the  type  specimens  collected  in  the  mouth  of  the  Muar  River 
in  Johore,  Malaya;  Phenacostethus  smithi  Myers  (1928),  known  from  the 
types  and  many  other  specimens  collected  in  the  khlongs  of  Bangkok  and 
reported  in  this  paper  from  Chantaburi  Province  in  southeast  Thailand; 
and  Phenacostethus  posthon,  new  species,  from  the  Indian  Ocean  coast  of 
peninsular  Thailand.  Ph.  posthon  and  Ph.  smithi  differ  considerably  in 
morphology  of  the  priapium  and  penis.  Furthermore,  the  asymmetrical 
priapium  in  Ph.  posthon  is  invariably  sinistral.  In  all  other  phallostethoids, 
so  far  as  known,  it  may  be  either  sinistral  or  dextral;  in  Ph.  smithi  the  ratio 
of  sinistral  and  dextral  males  is  near  equality  (Hubbs  and  Hubbs,   1945). 

The  ecology  of  phallostethids  is  described  for  the  first  time,  excepting 
some  brief  remarks  by  H.  M.  Smith  (1927;  1945),  who  seems  to  have 
confused  Phenacostethus  in  the  field  with  neostethids  and  perhaps  with 
Oryzias.  An  hypothesis  is  offered  that  the  selective  advantage  of  internal 
fertilization  in  Phallostethoidea  (an  oviparous  group)  lies  in  permitting 
temporal  separation  of  mating  and  spawning  activities,  corresponding,  re- 
spectively, with  periods  of  low  water  and  high  water  in  habitats  subject 
to  strong  tidal  fluctuations.  Two  trends  in  the  reproductive  biology  of 
atheriniform  fishes  that  might  be  conducive  to  the  evolution  of  internal 
fertilization  are:  1)  towards  eggs  in  which  either  embryonic  development 
is  slowed  down  or  temporarily  arrested,  or  hatching  of  embryos  is  deferred; 
and  2)  away  from  expelling  all  ovulated  eggs  at  once  and  towards  expel- 
ling them  in  small  batches  or  even  singly. 


1  Museum   of   Comparative    Zoology,    Harvard   University,    Cambridge, 
Massachusetts  02138. 


2  BREVIORA  No.    374 

ACKNOWLEDGMENTS 

My  studies  in  Thailand  were  carried  out  under  the  sponsorship 
of  the  Thai  National  Research  Council.  The  College  of  Fisheries 
of  Kasetsart  University  acted  as  my  host,  providing  laboratory 
space,  library  facilities,  and  access  to  fish  collections,  including 
specimens  of  Phenacostethus  smithi  collected  by  H.  M.  Smith.  I 
wish  to  thank  the  following  people  for  their  substantial  aid,  par- 
ticularly in  the  aspects  of  my  fieldwork  concerning  phallostethoids: 
Dean  Jinda  Thiemeedh,  Mr.  Prajit  Wongrat,  and  Mrs.  Supap 
Monkolprasit  of  the  College  of  Fisheries;  Miss  Prachuab  Suk- 
charean  and  Mr.  Sopon  Chantarat  of  the  Marine  Fisheries  Station 
of  Songkhla;  and  Dr.  Vagn  Hansen,  Director  of  the  Phuket  Marine 
Biological  Center.  Mrs.  Monkolprasit  was  extremely  helpful,  par- 
ticularly in  arranging  my  trips.  Dean  Thiemeedh  kindly  en- 
couraged my  work  and  arranged  transportation  to  Chantaburi 
Province,  where,  with  Mr.  Wongrat's  help,  not  only  Ph.  smithi, 
but  also  large  series  of  the  neostethids  Neostethus  siamensis 
(hitherto  known  only  from  a  single  female)  and  Ceratostethus 
bicornis  (previously  unrecorded  from  Thailand)  were  obtained. 
Mr.  Wongrat  also  helped  find  Phenacostethus  near  Bangkok. 
Miss  Sukcharean  arranged  my  travels  from  Songkhla  to  Satul;  Mr. 
Chantarat  accompanied  me  on  this  trip  and  helped  collect  the 
first  specimens  of  Phenacostethus  posthon.  Dr.  Hansen  arranged 
my  fieldwork  in  Pungah. 

For  translations  of  the  papers  by  Aurich  and  Woltereck  I  am 
obliged  to  Miss  Deborah  White  and  Dr.  Elizabeth  Deichmann. 
Prof.  George  S.  Myers  read  the  paper  in  manuscript. 

INTRODUCTION 

This  account  of  the  family  Phallostethidae  is  the  first  paper 
dealing  with  the  fresh-  and  brackish-water  fishes  collected  by  me 
in  Thailand  from  April  15  to  July  14,  1970,  and  deposited  in  the 
fish  collection  of  the  Museum  of  Comparative  Zoology.  Collecting 
phallostethoid  fishes  was  one  of  the  main  objectives  of  my  field- 
work  in  Thailand.  In  addition  to  Phenacostethus  smithi  Myers 
(1928)  and  the  new  phallostethid  described  in  this  paper,  large 
series  of  the  neostethids  Neostethus  siamensis  Myers  (1937) 
and  Ceratostethus  bicornis  (Regan,  1916)  were  obtained.  These 
represent  the  first  specimens  of  Ceratostethus  recorded  from  Thai- 
land, and  the  only  specimens  of  Neostethus  siamensis  other  than 


1971  PHALLOSTETHIDAE  3 

the  female  holotype.  (/V.  siamensis  is  close  to,  and  perhaps  spe- 
cifically identical  with,  N.  lankesteri  Regan  (1916),  the  type 
locality  of  which  is  the  mouth  of  the  Muar  River,  Johore,  and 
Singapore.)  The  osteology  and  functional  anatomy  of  Cerato- 
stethus  will  be  considered  in  another  paper. 

The  Phallostethoidea  are  small,  highly  specialized  fresh-  or 
brackish-water  fishes  in  which  males  have  a  remarkable  sub- 
cephalic  copulatory  organ,  the  priapium.  The  skeleton  and  mus- 
culature of  this  complicated  bilaterally  asymmetrical  organ,  which 
functions  both  in  clasping  and  intromission,  are  derived  mainly 
from  the  pelvic  fins  and  girdle.  Minor  contributions  come  from 
the  first  pair  of  ribs  and  anteroventral  part  of  the  pectoral  girdle. 
In  females  the  pelvic  fins  are  absent  or  vestigial.  Aurich  (1937) 
divided  the  Phallostethoidea  into  two  "Familien,"  but  gave  these 
divisions  names  in  subfamily  form,  Phallostethinae  and  Neo- 
stethinae.  Berg  (1940:  465-466)  recognized  them  as  families, 
Phallostethidae  and  Neostethidae,  as  did  Rosen  (1964:  261) 
and  Greenwood  et  al.  (1966:  398).  Neostethidae,  comprising 
eight  genera  and  about  15  species,  have  been  recorded  from 
Thailand,  Malaya,  Sumatra,  Borneo,  and  the  Philippine  Islands. 
Six  of  the  genera  —  Gulaphallus  Herre  (1925),  Mirophallus 
Herre  (1926),  Plectrostethiis  Myers  (1935),  Solenophallus  Au- 
rich (1937),  Ctenophallus  Herre  (1939),  and  Manacopus  Herre 
(1940)  — are  known  only  from  the  Philippines. 

The  Phallostethidae,  even  more  specialized  (and  rarer  in  mu- 
seum collections)  than  Neostethidae,  comprise  three  species  from 
the  Malay  Peninsula  and  adjacent  parts  of  Thailand.  Phallostethus 
dunckeri  Regan  (1913),  the  first  phallostethoid  to  be  described, 
is  known  only  from  the  type  specimens  Duncker  collected  previous 
to  1904  at  the  mouth  of  the  Muar  River,  about  20  miles  south 
of  Malacca,  Johore  Province,  Malaya  (Duncker,  1904:  171). 
Phenacostethus  smithi,  hitherto  known  only  from  several  large 
series  collected  by  H.  M.  Smith  from  khlongs  in  Bangkok,  was 
obtained  by  me  at  Bangkhen  (a  suburb  of  Bangkok)  and  at 
Chantaburi,  near  the  southeast  corner  of  Thailand  (near  Cam- 
bodia). The  third  species,  described  in  this  paper,  is  from  the 
Indian  Ocean  coast  of  Thailand.  All  localities  where  phallostethids 
have  been  collected  are  shown  in  Figure  1.  The  present  paper 
presents  characterizations  of  the  family  Phallostethidae  and  of 
the  phallostethid  species,  a  description  of  the  new  species  just 
mentioned,  and  observations  on  the  ecology  of  Phallostethidae. 


BREVIORA 


No.  374 


ir 


10" 


5*- 


-  10" 


15* 


5* 


100* 


lOS* 


Figure  1.  All  localities  where  Phallostethidae  have  been  collected.  1. 
Mouth  of  Muar  River  at  Bandar  Maharani  (type  locality  of  Phallostethus 
dimckeri  Regan,  1913);  2.  Bangkok  (type  locality  of  Phenacostethiis  smithi 
Myers,  1928);  3.  Bangkhen,  a  suburb  of  Bangkok  (Ph.  smithi);  4.  Chanta- 
buri  City  {Ph.  smithi);  5.  Khlong  La  Ngoo,  48  km  NW  of  Satul  Town, 
6°  52'  30"  N,  99°  48'  10"  E  (type  locality  of  Phenacostethiis  posthon  n. 
sp.);  6.  Khlong  Kla  Sohm,  15  km  S  of  Pungah  Town,  on  Pakasem  Road 
from  Pungah  going  towards  Phuket  Island  (type  locality  of  Ph.  posthon 
n.  sp.) 


Definition  of  the  suborder  Phallostethoidea  and  discussion  of 
phyletic  trends  in  the  Phallostethoidea  will  be  presented  in  a 
forthcoming  paper  on  Ceratostethus. 

Ph.  smithi  provides  an  Asian  example  of  the  phenomenon  (of 
which  Africa  and  South  America  provide  numerous  examples) 


1971  PHALLOSTETHIDAE  5 

that  the  smallest  fishes  amidst  the  richest  tropical  freshwater 
faunas  are  representatives  not  of  the  dominant  fish  groups  present, 
but  of  groups  with  a  marginal  distribution  pattern.  The  ecology 
of  such  minute  fishes,  when  known,  usually  proves  to  be  highly 
specialized. 

Rosen  (1964)  united  the  exocoetoids,  scomberesocoids,  adri- 
anichthyoids,  cyprinodontoids,  atherinoids  and  phallostethoids  in 
a  new  order,  the  Atheriniformes.  Atherinoids  and  cyprinodont- 
oids were  widely  separated  in  earlier  classifications,  the  artificial- 
ity of  which  has  become  increasingly  apparent.  Such  similarities 
as  were  noted  between  atherinoids  and  cyprinodontoids  had 
usually  been  attributed  to  convergence.  Having  personally  investi- 
gated the  osteology  of  phallostethoids  (which  evidently  are  re- 
lated to  atherinoids),  atherinoids,  and  cyprinodontoids,  and 
reviewed  much  of  the  literature  on  osteology  and  reproductive 
biology  of  these  groups,  I  am  inclined  to  believe  that  they  may 
be  related.  Some  of  the  similarities  in  reproductive  biology  were 
first  brought  to  my  attention  in  a  talk  given  by  Neal  R.  Foster 
at  the  1968  meetings  of  the  American  Society  of  Ichthyologists 
and  Herpetologists. 

Note  on  the  figures.  Figures  2-5,  prepared  with  the  aid  of  a 
Wild  microscope  and  camera  lucida,  are  based  on  formalin  speci- 
mens. Formalin  specimens  of  Phallostethidae  are  more  nearly 
normal  in  appearance  than  alcoholic  specimens,  since  the  latter 
invariably  undergo  at  least  some  shrinkage.  In  specimens  that 
have  been  transferred  from  the  original  formalin  fixative  to  60 
per  cent  ethyl  alcohol  for  permanent  storage,  teeth  protrude  more 
from  the  gums,  scales  stand  out  more  clearly,  the  membranous 
dome  atop  the  head  has  disappeared,  and  the  caudal  peduncle  is 
decidedly  narrower. 

CHARACTERIZATION   OF  THE  FAMILY  PHALLOSTETHIDAE 

The  following  characterization  of  the  Phallostethidae  is  based 
on  my  observations  of  Ph.  sinithi  and  Ph.  posthon,  including  study 
of  alizarin  preparations,  and  on  accounts  of  Ph.  smithi  by  Myers 
(1928),  Bailey  (1936),  and  TeWinkel  (1939),  and  of  Phallo- 
stethus  dunckeri  by  Regan  (1913;  1916). 

1 .  Slender  elongate  phallostethoids,  very  delicate,  largely  trans- 
lucent, with  deciduous  scales;  externally  visible  concentrations  of 
melanophores  restricted  to  the  top  of  the  braincase,  middle  of  the 


6  BREVIORA  No.    374 

dorsum,  midlateral  intermuscular  septum,  priapium,  and  bases  and 
edges  of  fin  rays;  maximum  standard  length  about  23  or  24  mm. 

2.  Dorsum  of  head  with  a  translucent,  membranous  dome. 

3.  Mature  individuals  of  both  sexes  with  a  bright  orange-yellow 
bar  on  caudal  peduncle. 

4.  Branchiostegal  rays  4. 

5.  Main  "externalized"  clasping  bone  in  the  priapium  is  the 
toxactinium;  ctenactinium  reduced  or  absent. 

6.  A  greatly  enlarged,  oval,  concave  pad,  or  pulvinulus,  shghtly 
posterior  to  toxactinium. 

7.  Vas  deferens  terminating  in  a  large  penis  that  projects  con- 
siderably from  the  priapium. 

8.  Pelvic  spines  or  rays,  if  present,  greatly  reduced  and  modi- 
fied beyond  recognition. 

9.  Vas  deferens  highly  coiled,  forming  a  sort  of  epididymis. 

Comments  on  the  family  characters.  Neostethids,  while  small 
as  fishes  go,  are  all  or  almost  all  larger  when  adult  than  phallo- 
stethids.  Most,  if  not  all,  neostethids  are  hardier  fishes  than  phal- 
lostethids  and  have  relatively  adherent  scales.  While  they  also 
are  largely  translucent,  neostethids  usually  have  relatively  more 
melanophores  than  phallostethids.  The  epidermis  paralleling  the 
scale  margins  is  often  well  provided  with  melanophores  in  neo- 
stethids but  invariably  devoid  of  melanophores  in  phallostethids. 
Neostethids  (Ceratostethus  and  Neostethus),  even  at  comparable 
sizes,  lack  a  membranous  dome  on  the  dorsum  of  the  head,  or  if 
one  is  present,  it  is  not  notably  elevated.  According  to  TeWinkel 
(1939)  this  region  bears  sensory  canals  in  both  Phenacostethus 
and  Gulaphallus.  In  neostethids  large  sensory  pores  are  evident 
in  the  frontal  region,  whereas  the  membranous  dome  in  phal- 
lostethids is  apparently  entire. 

With  regard  to  characteristic  number  3  (bright  orange-yellow 
markings  at  the  base  of  the  caudal  fin  and  sometimes  at  the  origin 
of  the  anal  fin),  these  are  present  in  Uving  specimens  of  Ph.  smithi 
and  in  Ph.  posthon.  There  is  no  way  of  teUing  whether  such  spots 
are  also  present  in  Phallostethus.  The  orangish  yellow  coloration, 
contained  in  chromatophores  (approximately  50-75  chromato- 
phores  constituting  the  caudal  base  mark)  gradually  disappeared 
after  a  few  weeks  of  preservation  in  formalin.    Similar  markings 


1971  PHALLOSTETHIDAE  7 

were  definitely  absent  in  live  specimens  of  Neostethus  and  Cera- 
tostethus  observed  by  me,  nor  is  there  any  mention  of  such  marks 
in  the  literature  on  Neostethidae. 

Concerning  character  4,  Neostethidae  usually  have  5  branchio- 
stegal  rays.  The  number  of  branchiostegal  rays  in  Phallostethus 
is  unknown. 

Characters  5-9  concern  the  priapium,  which  differs  funda- 
mentally from  that  of  Neostethidae.  In  Neostethidae  the  main 
"externalized"  bony  clasping  element,  the  ctenactinium,  is  appar- 
ently a  modified  pelvic  fin  ray  or  spine.  The  mam  "externalized" 
bony  element  in  the  priapium  of  phallostethids,  the  toxactinium, 
is  not  homologous  with  the  ctenactinium.  My  observations  con- 
firm Bailey's  view  (Bailey,  1936:  463,  471)  that  it  is  homologous 
with  the  pulvinular  bone,  one  of  the  anteriormost  internal  bony 
elements  in  the  priapium  of  neostethids.  The  homologies  of  this 
element  are  unclear,  but  it  is  almost  certainly  not  a  modified  pel- 
vic ray  or  spine.  The  ctenactinia  of  phallostethids,  which  may  or 
may  not  be  homologous  with  the  elements  called  ctenactinia  in 
neostethids,  are  greatly  reduced  in  size.  The  ctenactinium  of  Phal- 
lostethus dimckeri,  while  relatively  short,  bears  several  "teeth" 
or  sharp  projections;  these  are  perhaps  comparable  to  the  single 
curved  hook  present  near  the  base  of  the  ctenactinium  in  Neo- 
stethus. The  pulvinulus  of  phallostethids  probably  functions  as  a 
pad  in  conjunction  with  the  toxactinium.  A  homologous  but  much 
smaller  pulvinulus  is  present  in  neostethids.  A  striking  character- 
istic of  the  phallostethid  priapium  is  the  development  of  a  large 
penis.  In  Phenacostethus  posthon  the  organ  is  entirely  smooth; 
in  Ph.  smithi  its  distal  half  bears  a  series  of  stiff  ruffled  pleats. 
The  development  of  a  large  penis  evidently  occurred  independently 
in  the  neostethid  Mirophallus  bikolanus  (Herre,  1926,  pi.  3,  fig. 
1 ) .  In  most  neostethids  a  compUcated  flap  covers  the  opening  of 
the  vas  deferens  (Aurich,  1937).  This  flap  is  absent  in  PhaUo- 
stethidae.  Various  bony  elements  in  the  priapium  of  phallostethids, 
including  a  peculiar  slender  element  lodged  in  the  concave  side 
of  the  penis  bone  in  Ph.  smithi,  may  be  homologous  with  pelvic 
rays,  but  the  priapium  of  phaUostethids  does  not  bear  any 
branched  elements  that  obviously  are  relatively  unmodified  pelvic 
rays.  Several  branched  pelvic  rays  of  relatively  normal  appear- 
ance occur  in  the  neostethids  Ceratostethus,  Neostethus,  Soleno- 
phallus,  and  Gulaphallus  (personal  observations;  Aurich  [1937], 
TeWinkel  [1939],  Woltereck  [1942  a,  b]). 


8  BREVIORA  No.    374 

The  priapium  of  Phallostethus  is  clearly  of  the  same  general 
type  as  that  of  Ph.  smithi  and  Ph.  posthon.  In  Phallostethus  the 
toxactinium  and  pulvinulus  are  very  similar  to  these  structures  in 
Phenacostethus.  It  is  likely  that  Phallostethus  develops  a  large 
penis.  The  penis  in  phallostethids,  like  the  ctenactinium  of  neo- 
stethids,  only  reaches  its  full  development  in  the  largest  males. 

Regan  (1916:  22)  hypothesized  that  in  Phallostethus  the  tox- 
actinium grips  the  female  under  the  chin  or  is  held  in  her  mouth, 
while  the  serrated  edge  of  the  ctenactinium  gives  a  firm  hold  on 
the  pectoral  region  in  front  of  and  on  the  far  side  of  the  genital 
orifice,  in  order  that  the  seminal  papilla  could  be  placed  against 
it  or  introduced  into  it.  In  Neostethus  he  hypothesized  that  the 
female  is  held  across  the  back  of  the  head  by  the  ctenactinium, 
the  anterior  descending  part  of  which  lies  on  the  side  of  the  female 
away  from  the  male.  Copulation  has  yet  to  be  observed  in  Neo- 
stethus or  in  any  phallostethids.  It  has  been  observed  only  in  the 
neostethid  Gulaphallus  mirabilis.  In  this  species  the  female  is 
held  across  the  back  of  the  head  by  the  ctenactinium;  the  "second 
ctenactinium"  of  Gulaphallus  mirabilis,  which  actually  is  an  exter- 
nalized pelvic  bone,  apparently  rests  or  presses  against  the  female's 
opercular  region  on  the  side  next  to  the  male  (Villadohd  and  Man- 
acop,  1934:  pi.  5,  fig.  2).  The  reduced  ctenactinium  of  Phallo- 
stethidae  could  hardly  function  in  the  same  manner  as  the  elongate 
ctenactinium  characteristic  of  all  neostethids.  It  may  be  that  the 
toxactinium  is  held,  not  under  the  female's  chin  or  in  her  mouth, 
but  atop  the  front  of  her  head. 

In  Phallostethus  (Regan,  1916:  19,  fig.  14)  the  vas  deferens 
is  highly  coiled  within  the  abdominal  cavity  to  form  a  sort  of 
epididymis.  TeWinkel  (1939)  reports  a  similar  coiling  of  the 
vas  deferens  in  Ph.  smithi.  In  Neostethus  lankesteri  (Regan, 
1916:  10,  fig.  6)  and  in  Gulaphallus  mirabilis  (Villadolid  and 
Manacop,  1934:  pi.  3,  fig.  4)  the  vas  deferens  is  unconvoluted 
from  its  origin  on  the  testis  to  where  it  enters  the  priapium,  then 
forms  an  expanded  loop  inside  the  priapium.  The  sperm  of  Neo- 
stethus lankesteri  (Regan,  1916:  13,  fig.  9)  are  concentrated  into 
"spermatophores,"  more  properly  called  spermozeugmata  (Niel- 
sen et  al.,  1968:  248).  Regan  (1916:  19)  stated  that  Phal- 
lostethus evidently  did  not  produce  "spermatophores"  like  those 
of  Neostethus.  In  mature  Neostethus  and  Ceratostethus  (per- 
sonal observation)   the  posteriormost  portion  of  the  priapium  is 


1971  PHALLOSTETHIDAE  9 

sometimes  greatly  swollen  with  closely  packed,  adherent  small 
vesicles  that  presumably  are  spermozeugmata.  The  priapium 
apparently  does  not  become  similarly  swollen  in  phallostethids. 
Insofar  as  can  be  determined  from  examination  of  the  bones 
only,  the  contributions  of  the  first  pair  of  ribs  and  of  the 
shoulder  girdle  to  the  priapium  is  the  same  in  Phallostethidae  and 
Neostethidae. 

THE   SPECIES   OF   PHALLOSTETHIDAE 
Phallostethus  dunckeri  Regan  1913 

Phallostethus  dunckeri  Regan,  1913:  550,  figs.  1-4  (original  description; 
types  from  mouth  of  Muar  River  at  Bandar  Maharani,  Johore,  Ma- 
laya; soft  anatomy).  —  Regan,  1916  (soft  anatomy,  histology,  oste- 
ology, comparison  with  Neostethiis). 

This  species  is  known  only  from  the  specimens  collected  by 
G.  Duncker  at  the  mouth  of  the  Muar  River  at  Bandar  Maharani, 
Johore,  Malaya.  The  following  statements  are  based  on  the  two 
accounts  of  this  species  by  Regan  (1913,  1916).  It  is  character- 
ized by  an  exceptionally  long  anal  fin,  with  26-28  elements 
(eight  to  ten  rays  more  than  are  found  in  phallostethoids  with 
the  next  highest  number  of  anal  fin  elements),  an  anal  base  about 
30  per  cent  of  the  standard  length  (compared  to  anal  base  20-25 
per  cent  of  standard  length  in  all  other  phallostethoids)  and  origin 
of  anal  considerably  nearer  to  snout  tip  than  to  end  of  hypural 
fan  (anal  origin  slightly  to  considerably  nearer  to  end  of  hypural 
fan  than  to  snout  tip  in  all  other  phallostethoids),  and  by  a  ser- 
rated ctenactinium  (Regan,  1916:  fig.  13).  Regan  did  not  have 
very  many  specimens  (some  were  used  for  histological  preparations 
or  cleared  in  oil  of  cloves  for  bone  study).  Dr.  P.  H.  Greenwood 
informs  me  that  the  British  Museum  (Natural  History)  has  four 
specimens  (types?)  of  Phallostethus  dunckeri  in  rather  poor  con- 
dition. Although  Regan's  specimens  of  Phallostethus  dunckeri 
(at  23-29  mm  in  total  length)  are  larger  than  Phenacostethus, 
and  the  males  figured  by  him  have  well-developed  priapia,  perhaps 
the  penis  is  not  fully  developed  in  them.  This  seems  likely,  be- 
cause in  both  species  of  Phenacostethus  the  largest  females  are 
only  about  one-half  to  one  milUmeter  longer  than  the  largest 
males,  whereas  Regan's  largest  female  of  Phallostethus  is  six  mil- 
limeters longer  than  his  largest  male.  In  Phenacostethus  the  penis 
is  fully  formed  only  in  the  largest  males. 


10  BREVIORA  No.    374 

The  second  dorsal  fin  of  P.  dimckeri  has  eight  to  ten  elements 
(a  number  found  in  some  Neostethidae);  the  highest  number  in 
Phenacostethus  is  seven.  It  is  unknown  whether  Phallostethus  has 
a  first  dorsal  fin.  Regan  did  not  mention  its  presence,  but  he  over- 
looked the  first  dorsal  in  his  material  of  Neostethus  lankesteri 
and  Ceratostethus  bicornis.  Phallostethus  probably  has  a  small 
spinous  first  dorsal  fin,  but  the  absence  of  one  would  not  be  unique 
among  Phallostethoidea:  the  first  dorsal  is  lacking  in  the  neosteth- 
ids  Mirophallus  bikolamis  Herre  (1926),  (Herre,  1942:  141; 
Myers,  1937:  142)  and Solenophallus  thessa  Aurich  (1937:  265). 

Phenacostethus  smithi  Myers   1928 
(Figures  2,  4,  6) 

Neostethus  lankesteri  (not  of  Regan)  Smith,  1927:  353-355  (misidenti- 
fication). 

Phenacostethus  smithi  Myers,  1928:  6,  figs.  1  and  2  (original  description; 
types  from  Bangkok;  holotype  in  American  Museum  of  Natural  His- 
tory). —  Bailey,  1936  (osteology).— TeWinkel,  1939  (soft  anat- 
omy).—Smith,  1945:  475  (Bangkok;  synonymizes  Ph.  thai  Fowler; 
ecology). 

Phenacostethus  thai  Fowler,  1937:  219;  figs.  189,  190  (original  description; 
Bangkok;  holotype  in  Philadelphia  Academy). 

Material  studied.  MCZ  47055,  13  specimens,  five  females 
13.7-14.8  mm  and  eight  males  13.6-14.9  mm  (three  with  toxac- 
tinium  arising  on  left  side,  five  on  right  side),  from  Khlong  Bang- 
khen  at  bridge  on  Nzarm  Wong  Wan  Road,  a  few  km  west  of 
Kasetsart  University,  Bangkhen,  Bangkok,  Thailand,  30  April 
1970;  MCZ  47299,  20  specimens,  three  females  13.4-15.6  mm 
and  17  males  12.7-14.9  mm  (12  with  toxactinium  arising  on  right 
side,  five  on  left  side),  from  Khlong  Kee  Nawn,  behind  Cathohc 
church  in  Chantaburi  City,  Chantaburi  Province,  Thailand,  5 
May  1970. 

Myers'  figure  1  of  Ph.  smithi  does  not  show  the  membranous 
dome  of  the  dorsum  of  the  head  (Fig.  2) ;  it  is  likely  to  be  shrunken 
in  alcoholic  specimens.  The  adult  male  in  Myers'  figures  1  and  2, 
at  13.5  mm  in  standard  length,  does  not  have  the  penis  as  fully 
developed  as  in  my  specimens  14.3  (Fig.  2),  14.1  (Fig.  4),  and 
14.5  (Fig.  6)  mm  in  standard  length.  In  these  specimens  the 
penis  is  much  larger,  and  its  distal  end  bears  a  series  of  a  half- 
dozen  or  more  crenulated  radial  folds  or  extensions  resembling  a 


1971 


PHALLOSTETHIDAE 


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12  BREVIORA  No.    374 

set  of  ruffled  lace  cuffs  (best  shown  in  Fig.  4).  These  folds  can 
be  seen  in  one  of  Bailey's  anatomical  figures  based  on  material 
of  Ph.  smithi  collected  by  Hugh  M.  Smith.  Direct  comparison  of 
Ph.  smithi  collected  by  Smith  in  Bangkok  (deposited  in  the  fish 
collection  of  the  College  of  Fisheries,  Kasetsart  University,  and 
in  the  MCZ  fish  collections)  with  my  material  from  Bangkhen  and 
Chantaburi  indicates  that  only  one  species  is  involved.  Live  speci- 
mens of  Ph.  smithi  of  both  sexes  from  Bangkhen  and  from  Chanta- 
buri had  a  bright  orange-yellow,  anteroventrally-posterodorsally 
oriented  bar  on  the  lower  half  of  the  caudal  peduncle.  This  bar 
disappeared  from  specimens  kept  a  few  weeks  in  formahn.  The 
color  was  due  to  about  50-75  chromatophores.  There  is  a  small, 
shiny  blue  spot  over  the  brain  (well  behind  the  eyes),  and  a  very 
small  silvery  spot  in  the  middle  of  the  eyes'  dorsal  surface. 

Alizarin  preparations  reveal  the  first  dorsal  fin  consists  of  a 
single  tiny  spine,  as  indicated  by  Myers.  Most  specimens  are  miss- 
ing many  scales.  Head  scaleless.  Abdominal  keel  scaleless  in 
both  sexes  (abdominal  keel  scaled  in  females  of  Ceratostethus 
bicornis).  Scales  on  body  cycloid,  number  of  scale  rows  corre- 
sponding closely  with  the  number  of  myotomes.  Teeth  in  both 
jaws  in  a  single  series;  medial  portion  of  premaxillary  with  about 
eight  sharp  conical  teeth,  lateral  (expanded)  margin  of  premaxil- 
lary with  about  seven  to  nine  slightly  larger  conical  teeth;  medial 
portion  of  dentary  with  about  a  dozen  conical  teeth  opposing  but 
much  smaller  than  those  on  medial  portion  of  premaxillary. 

For  counts  of  fin  elements  and  vertebrae  based  on  alizarin 
preparation  see  Table  1. 

Phenacostethus  posthon,  new  species 
(Figures  3,  5,  7) 

Holotype.  MCZ  47300,  a  16.7-mm  male  from  Khlong  Kla  Sohm 
about  15  km  southwest  of  Pungah  Town,  where  it  is  crossed  by 
a  bridge  on  the  Pakasem  Road  (between  Pungah  Town  and  Phu- 
ket), Pungah,  Thailand.    29  June  1970. 

Paratypes.  MCZ  47301,  58  specimens,  comprising  two  im- 
matures,  11.9  and  12.0  mm,  22  females,  12.3-17.7  mm,  and  34 
males  12.7-17.0  mm  (of  which  two  males,  15.5  and  16.5  mm,  are 
cleared  and  stained),  same  data  as  holotype;  MCZ  47302,  20 
specimens,  comprising  three  immatures  9.6-12.0  mm,  10  females 
12.7-18.0  mm,  and  7  males  12.9-16.7  mm,  from  Khlong  Langu 


1971  PHALLOSTETHIDAE  13 

at  Langu  Town,  48  km  northwest  of  Satul  Town (6°  52'  30"  N, 
99°  48^'  10^'  E).    23  June  1970. 

The  most  obvious  differences  between  this  species,  from  the 
Indian  Ocean  coast  of  Thailand  (Fig.  1),  and  Ph.  smithi  involve 
the  priapium  and  the  position  of  the  dorsal  fin.  Granted  that  both 
species  have  the  characteristic  priapial  elements  of  the  family 
Phallostethidae,  the  priapium  is,  in  fact,  so  different  in  the  two 
species  that  the  question  may  even  be  raised  as  to  whether  separate 
generic  status  is  indicated. 

Differences  in  the  priapium  of  the  two  species  involve  external 
morphology  of  the  penis,  skeleton  of  the  penis,  ctenactinium,  tox- 
actinium,  and  the  nature  of  the  laterality  of  the  priapium  itself. 
In  Ph.  smithi  1 )  the  distal  portion  of  the  penis  is  ruflfled  (see 
description  above);  2)  the  penial  skeleton  includes  a  large  papil- 
lary bone  with  a  slender  penial  bone  lodged  in  its  concave  surface 
(Fig.  6;  see  also  Bailey,  1936:  3  and  4);  3)  the  ctenactinium  is 
relatively  large  and  externally  evident;  4)  the  toxactinium  is  rela- 
tively slender  and  gently  curved;  and  5)  the  priapium  itself  may 
be  either  sinistral  or  dextral.  In  Ph.  posthon,  on  the  other  hand, 
1 )  the  penis  is  smooth;  2)  the  penial  skeleton  has  a  large  papillary 
bone  but  the  penial  bone  is  absent;  3)  the  ctenactinium,  if  it  is 
present  at  all,  is  reduced  and  hardly  detectable  externally;  4)  the 
toxactinium  is  stouter  and  distinctly  more  sharply  curved;  and  5) 
the  priapium  is  invariably  sinistral  (toxactinium  arising  on  left 
side)  in  the  material  examined. 

Ph.  posthon  and  Ph.  smithi  of  both  sexes  can  be  distinguished  at 
a  glance  by  the  position  of  the  first  dorsal  fin  relative  to  the  anal 
fin  base.  In  Ph.  posthon  the  first  dorsal  (which  has  a  single  spine 
as  in  Ph.  smithi)  originates  slightly  posterior  to  the  base  of  the 
last  ray  in  the  anal  fin;  in  Ph.  smithi  it  originates  over  the  middle 
of  the  anal  fin  base.  The  first  dorsal  fin  is  somewhat  closer  to 
the  second  dorsal  origin  in  Ph.  posthon  than  in  Ph.  smithi.  Ph. 
posthon  is  more  elongate  (depth  of  body  at  anal  fin  origin  about  7, 
vs.  6  in  Ph.  smithi)  and  evidently  a  larger  species.  The  average 
and  maximum  sizes  of  specimens  in  my  two  samples  of  Ph. 
posthon  are  definitely  larger  than  in  my  two  samples  of  Ph.  smithi 
(which  include  specimens  larger  than  those  previously  recorded). 
The  largest  male  and  female  specimens  of  Ph.  smithi  are,  respec- 
tively, 14.9  and  15.6  mm;  of  Ph.  posthon,  17.0  and  18.0  mm 
(standard  lengths).  The  largest  specimens  (both  sexes)  had  a 
bright  orange-yellow  bar  on  the  caudal  peduncle,  as  in  Ph.  smithi, 


14 


BREVIORA 


No.  374 


Figure   4.     Phenacostethus  smithi   Myers    (1928),   ventral  view   of  pri- 
apium,  14.1-mm  specimen,  MCZ  47055  (formalin). 


and  also  a  smaller  orange-yellow  bar  on  the  body  next  to  the  anal 
fin  origin. 

As  in  Ph.  smithi,  there  appears  to  be  a  one-to-one  correspon- 
dence between  the  scale  rows  and  the  myotomes.  The  thin  scales 
are  extremely  difficult  to  see  in  specimens  under  alcohol  or  water; 
and  most  specimens  are  missing  many  scales.  I  find  in  several 
specimens  eight  oblique  scale  rows  between  dorsal  midline  and 
anal  fin  origin,  and  six  oblique  scale  rows  between  dorsal  fin 
origin  and  anal  base.  Shape  of  jaw  bones  and  disposition  of  teeth 
as  in  Ph.  smithi. 

For  fin  and  vertebral  counts  based  on  alizarin  preparations  of 
Ph.  posthon  see  Table  1.  Ph.  posthon  seems  to  have,  on  the  aver- 
age, one  less  ray  in  the  dorsal  fin  (verified  by  counts  of  unstained 
specimens)  and  one  more  vertebra  than  Ph.  smithi. 

Right-  and  left-handedness  in  the  priapiiim  of  Phallostethidae. 


1971 


PHALLOSTETHIDAE 


15 


Figure  5.     Ph.  posthon  n.  sp.,  ventral  view  of  priapium  in  16.9-mm  para- 
type,  MCZ  47301  (formalin). 


That  the  priapium  of  Neostethus  lankesteri  may  be  either  right- 
or  left-handed  is  stated  by  Regan  (1916:  5).  Regan  did  not  spe- 
cifically state  that  the  priapium  of  Phallostethus  may  be  either 
way,  but  in  a  general  discussion  of  the  priapium  as  compared  to 
copulatory  organs  of  other  fishes,  he  refers  to  its  being  either 
dextral  or  sinistral  (Regan,  1916:  23).  Regan's  figures  of  Phal- 
lostethus depict  both  right-handed  and  left-handed  males.  It  is 
conceivable  that  one  or  more  of  them  might  be  reversed  images, 
the  images  being  reversed  either  by  the  illustrator  or  by  the  printer, 
so  the  figures  cannot  be  taken  as  definite  proof  that  P.  dimckeri 
may  be  either  left-handed  or  right-handed.  Concerning  Phena- 
costethus  smithi,  Hubbs  and  Hubbs  (1945:  294)  found  that  in 
334  males  (from  material  collected  by  H.  M.  Smith  at  Bangkok) 


16 


BREVIORA 


No.  374 


posttemporal 
c  lei  thrum 
coracoid 


supracleithrum 
scapula 


tozactiiiium 


antepleural 


papillary 


axial 


Figure  6.  Ph.  smithi  Myers  (1928),  skeleton  of  priapium  and  pectoral 
fin  in  14.5-nim  specimen,  MCZ  47301.  Terminology  of  priapial  elements 
according  to  Bailey  (1936). 


posttemporal 

cleithrum 
coracoid 


supracleithrum 

scapula 

radial 


toxactinium 

pulvinulus 

antepleural 


ribs 
anal 

basipenial 
prepapillary 
uncus 
anterior  infrasulcar' 


posterior  infrasulcar 
ctenactinium 


Figure  7.  Ph.  posthon  n.  sp.,  skeleton  of  priapium  and  pectoral  fin  in 
16.5-mm  paratype,  MCZ  14301.  Priapial  elements  of  uncertain  homology 
with  those  in  Ph.  smithi  are  unlabelled. 


1971  PHALLOSTETHIDAE  17 

the  aproctal  side  was  the  left  side  in  155  and  the  right  side  in 
179.  The  deviation  from  equality  is  statistically  insignificant.  In 
my  samples  from  Bangkhen  and  from  Chantaburi  (too  small  for 
statistical  analysis)  I  find  both  left-  and  right-handed  males.  In 
Phenacostethus  posthon  the  toxactinium  arises  on  the  left  side 
in  every  male  in  which  the  priapium  is  sufficiently  developed  to 
have  a  toxactinium  (27  specimens  from  Pungah  and  five  from 
Satul).  To  my  knowledge  this  is  the  only  phallostethoid  in  which 
the  sidedness  of  the  priapium  appears  to  be  fixed.  Females  of  Phal- 
lostethidae  are  bilaterally  symmetrical,  the  genital  openings  lying 
in  the  middle  of  the  throat. 

ECOLOGICAL   OBSERVATIONS 

The  only  ecological  information  Regan  had  about  Phallostethus 
dunckeri  was  that  it  came  from  brackish  water  from  the  Muar 
River  at  Bandar  Maharani.  Duncker  also  collected  Neostethus 
lankesteri  in  the  same  general  locahty. 

Smith  (1927;  1945:  476)  made  brief  ecological  observations 
on  Phenacostethus  smithi  but  in  restrospect  it  seems  that  he  some- 
times confused  this  little  fish  in  the  field  with  Neostethus  or  Cera- 
tostethus  and  perhaps  even  with  Oryzias.  I  did  not  observe  either 
phallostethids  or  neostethids  at  the  surface,  and  feel  that  they 
generally  keep  well  below  the  surface.  Smith's  remarks  (that 
Phenacostethus  "normally  remain  at  or  close  to  the  surface,  where 
they  would  be  difficult  to  see  were  it  not  for  a  glistening  yellow 
area  on  the  top  of  the  head'')  sound  more  like  Oryzias.  The  glisten- 
ing area  on  the  top  of  the  head  in  phallostethoids  is  relatively  small 
and  bluish,  compared  to  the  large  yellowish  glistening  area  in 
Oryzias,  which  is  comparable  to  the  striking  head  spots  in  rivuline 
cyprinodontids  of  the  genera  Epiplatys  and  Aplocheilus.  In  any 
event.  Smith  records  that  Ph.  smithi  abounds  in  freshwater  pools, 
ditches  and  smaller  canals  in  the  Bangkok  region,  Hving  in  water 
that  is  nearly  always  muddy  or  turbid,  and  that  the  species  is 
oviparous  (although  spawning  was  not  observed);  the  egg-bearing 
and  spawning  periods  are  protracted,  corresponding  with  the  rainy 
season,  and  may  extend  from  May  to  December.  Small  numbers 
were  maintained  in  aquaria  for  a  month  by  the  daily  introduction 
of  fresh  ditch  or  canal  water  to  provide  food  in  the  form  of  minute 
crustaceans,  protozoans,  worms,  etc.  Smith  found  the  larvae  of 
anopheline  mosquitoes  much  too  large  for  Ph.  smithi  to  ingest. 


18  BREVIORA  No.    374 

Undoubtedly  Ph.  smithi  once  lived  in  innumerable  khlongs  and 
ditches  in  Bangkok  which  are  today  so  polluted  that  they  are 
inhabited  only  by  the  hardiest  air-breathing  fishes  such  as  Anabas 
testudineiis.  In  Khlong  Bangkhen,  a  few  kilometers  from  Kasetsart 
University,  I  found  Ph.  smithi  in  association  with  a  variety  of 
primary  and  secondary  freshwater  fishes,  principal  among  which 
were  cyprinids  mainly  of  the  genus  Rasbora,  Dermogenys,  Xenen- 
todon,  Oryzias,  Gobiopterus  chuno  (a  small  translucent  goby), 
young  Fhita,  and  Chaudhuria.  The  Phenacostethus  were  mostly 
in  a  little  backwater,  close  to  the  main  current  in  the  khlong,  in 
very  turbid  water.  I  was  unable  to  taste  any  salt  in  the  water. 
At  Chantaburi  City,  Phenacostethus  was  collected  in  a  turbid 
ditch  or  small  khlong,  Khlong  Kee  Nawn,  behind  the  Catholic 
church.  There  were  a  number  of  houses  along  the  khlong  at  this 
point,  and  considerable  rubbish  had  been  thrown  into  it,  so  col- 
lecting efl'orts  were  confined  to  dip-netting  for  Phenacostethus. 
Dermogenys,  Brachygobius  and  Gobiopterus  were  collected  inci- 
dentally. About  two  kilometers  downstream,  where  the  khlong 
traversed  a  large  open  field,  we  found  minnows  such  as  Oxygaster, 
Esomus  and  Rasbora  (but  no  Phenacostethus)  which  indicates  the 
water  in  the  khlong  was  not  brackish. 

At  Satul  and  at  Pungah  Ph.  posthon  was  obtained  along  the 
margins  of  khlongs  or  tiny  branches  of  khlongs  in  which  the  water 
was  swiftly  flowing,  highly  turbid,  and  probably  completely  fresh. 
A  few  of  the  largest  females  (collected  June  1970)  were  replete 
with  ripe  ova.  Both  localities  were  at  places  fully  subject  to  tidal 
fluctuations,  but  far  upstream  from  branches  having  water  the 
least  bit  sahy  to  the  taste.  At  Khlong  Langu  in  Satul  Province 
the  water  level  was  undoubtedly  high  because  of  heavy  rains  for  the 
preceding  12  hours  or  more;  Phenacostethus  were  collected  in 
the  khlong  both  on  the  falling  tide  and  rising  tide.  No  primary 
freshwater  fishes  were  obtained.  Species  in  the  khlong  where 
Ph.  posthon  was  collected  included  Oryzias,  Dermogenys,  Chanda, 
Gobiopterus,  Butis,  and  Tetraodon.  In  Khlong  Kla  Sohm,  near 
Pungah,  Ph.  posthon  was  coUected  in  a  narrow  side  channel  more 
or  less  uniformly  3-4  feet  deep,  swiftly  flowing,  with  hard-packed 
mud  bottom,  well  shaded  by  Nipa  palm  and  mangrove.  Oryzias, 
Dermogenys,  Gobiopterus,  Periophthalmus,  Tetraodon,  and  young 
Scatophagus  were  the  only  other  fishes  collected  or  observed  in 
this  channel. 


1971  PHALLOSTETHIDAE  19 

In  contrast,  on  the  more  numerous  occasions  when  I  obtained 
either  Neostethus  or  Ceratostethus  in  Thailand,  the  water  was 
usually  brackish  or  even  very  salty  to  the  taste.  At  one  locality 
Neostethus  and  Ceratostethus  were  collected  together  in  large 
numbers  but  neither  were  collected  in  association  with  Phenaco- 
stethus.  I  did  not  find  Neostethus  or  Ceratostethus  in  association 
with  primary  freshwater  fishes  except  on  one  occasion  (afternoon, 
1 1  July  1970)  when  Ceratostethus  was  found  in  a  khlong  (strongly 
influenced  by  tides)  about  midway  between  Bangkok  and  Samutsa- 
korn,  in  association  with  Toxotes,  Dermogenys,  Rasbora  and  Eso- 
mus.  The  water  was  more  or  less  fresh  to  the  taste.  A  number 
of  dead  Esomus  were  carried  by  the  current  of  the  khlong,  and 
a  Rasbora  or  two  may  have  been  amongst  them.  I  thought  at 
the  time  that  mortality  of  these  minnows  was  perhaps  due  to  in- 
cursion of  salt  water.  The  dead  fish  were  carried  by  the  out- 
going tide. 

My  impression  is  that,  in  Thailand,  phallostethids  occur  in 
water  that  is  turbid  and  fresh;  and  neostethids  in  water  that  is 
turbid  and  brackish  or  even  quite  salty.  I  would  guess  that  at 
some  of  the  seven  locahties  where  I  collected  neostethids  the  water 
was  at  least  a  third  and  perhaps  one-half  or  more  as  salty  as 
sea  water. 

The  only  phallostethoid  in  which  mating  and  egg-laying  have 
been  observed  (but  not  in  sequence)  is  the  neostethid  GulaphaUus 
mh-abilis  Herre  (VilladoUd  and  Manacop,  1934).  It  seems  prob- 
able that  all  phallostethoids  are  oviparous.  No  females  carrying 
embryos  have  been  observed.  It  is  unclear  how  much  time  elapses 
between  copulation  and  egg-laying  in  G.  mirabilis,  or  whether 
several  egg-layings  follow  a  single  copulation.  Judging  from  the 
range  in  size  of  young  individuals  found  with  adults  in  my  collec- 
tions of  phallostethoids,  I  suspect  that  in  Thailand  species  some 
reproduction  goes  on  throughout  the  year.  It  seems  Hkely  that 
reproductive  peaks  occur  towards  the  latter  part  of  the  rainy  sea- 
son (November  and  December). 

The  distribution  of  phallostethoids  is  marginal  to  the  rich  East 
Indian  marine  and  freshwater  fish  faunas.  They  do  not  occur  in 
the  sea,  nor  do  they  penetrate  very  far  into  fresh  water  where 
there  is  a  continental  fauna  of  primary  freshwater  fishes.  The 
Phallostethidae  penetrate  further  into  waters  inhabited  by  primary 
freshwater  fishes  than  any  other  phallostethoids,  but  they  do  not 


20  BREVIORA  No.    374 

get  very  far  inland.  Usually  the  canals  or  creeks  they  inhabit  are 
strongly  influenced  by  tides,  and  thus  the  faunal  composition  (with 
regard  to  fishes  at  any  rate)  is  subject  to  considerable  temporal 
variation,  involving  retreat  of  primary  freshwater  fishes  and  inva- 
sion of  brackish-water  forms,  and  vice  versa.  In  places  where  the 
tidal  changes  are  greatest,  these  invasions  and  counterinvasions 
would  be  a  daily  event,  varying  of  course  with  the  extent  in  the 
tides.  In  other  places  they  might  occur  only  during  the  strongest 
tides.  Gulaphallus  on  the  island  of  Luzon  probably  pass  their  en- 
tire lives  in  fresh  water — where  no  primary  freshwater  fishes  occur. 

DISCUSSION 

Selective  advantage  of  internal  fertilization  in  phallostethoids. 
One  usually  associates  copulatory  organs  in  teleostean  fishes  with 
viviparity,  as  in  Poecihidae,  Embiotocidae,  and  Brotulidae.  It 
is  a  striking  fact,  however,  that  several  groups  of  oviparous  teleosts 
normally  have  internal  fertilization.  Among  these  are  some  Cot- 
tidae,  some  Scorpaenidae,  probably  some  Clinidae,  and  probably 
some  glandulocaudine  characids.  According  to  Nelson  (1964) 
the  evolution  of  internal  fertihzation  in  the  oviparous  glandulo- 
caudine characids  of  tropical  South  America  appears  to  be  a 
response  to  well-marked  wet  and  dry  seasons.  The  presumed 
advantage  of  a  temjxDral  separation  in  mating  and  spawning  is  as 
follows:  mating  occurs  during  the  dry  season,  when  populations 
are  crowded  together  in  small  pools,  food  is  scarce  and  conditions 
for  survival  are  generally  unfavorable;  spawning,  on  the  other 
hand,  occurs  during  the  height  of  the  rainy  season,  when  the  popu- 
lation is  maximally  dispersed  (so  much  so  that  males  and  females 
may  no  longer  be  together)  and  conditions  for  survival  of  the 
young  are  optimum  (abundance  of  food,  well-oxygenated  waters, 
access  to  areas  where  most  predators  are  too  large  to  enter). 
A  very  similar  set  of  conditions  may  apply  to  the  evolution  of 
internal  fertihzation  combmed  with  oviparity  in  phallostethoids, 
with  temporal  separation  of  mating  and  spawning  corresponding, 
respectively,  with  periods  of  low  water  and  high  water.  This 
hypothesis  should  be  extended  to  the  oviparous  atheriniform  fishes 
Horaichthys  setnai  Kulkarni  (1940)  and  Tomeurus  gracilis,  males 
of  which  have  independently  evolved  excessively  complicated 
copulatory  organs  through  modification  of  the  anal  fin.  Tomeurus 
occurs  in  brackish  water  along  the  northeastern  coast  of  South 


1971  PHALLOSTETHIDAE  21 

America,  including  the  mouth  of  the  Amazon  River,  Horaichthys 
in  brackish  water  along  the  Bombay  and  Kerala  coast  of  India. 
The  sperm  in  Tomeurus  are  transmitted  in  spermozeugmata  (Niel- 
sen, et  al.,  1968:  253),  as  in  the  viviparous  poecilioids  (the  nature 
of  the  phyletic  relationship  between  Tomeurus  and  poecilioids  is 
unclear;  they  probably  are  closely  related).  Horaichthys,  on  the 
other  hand,  is  among  the  very  few  teleosts  known  to  have  a  true 
spermatophore  (Kulkarni,  1940;  Nielsen,  et  al.,  1968).  (In  true 
spermatophores  the  sperm  are  enclosed  in  a  capsule.  A  spermo- 
zeugma  is  an  unencapsulated  group  of  sperm  held  together  by 
a  mucoid  substance.) 

Trends  in  the  reproductive  biology  of  atherinijorm  fishes  that 
might  be  conducive  to  the  evohition  of  internal  fertilization.  When 
oviparous  fishes  with  internal  fertilization  exhibit  a  marked  delay 
between  mating  and  spawning,  it  may  be  presumed  that  fertiliza- 
tion actually  occurs  just  before  spawning,  the  sperm  having  been 
stored.  Storage  of  sperm  and  delayed  fertiUzation  evidently  char- 
acterize at  least  some  viviparous  fishes,  such  as  those  poecihoids 
(including  forms  with  superfoetation  and  forms  without  it)  in 
which  females  are  capable  of  producing  up  to  four  or  five  suc- 
cessive broods  after  a  single  mating  session.  It  should  be  noted, 
however,  that  the  eggs  of  a  number  of  atheriniform  fishes  with 
external  fertilization  normally  exhibit  arrested  embryonic  develop- 
ment or  delayed  hatching.  A  lengthening  of  the  period  between 
fertilization  and  hatching,  particularly  if  it  could  be  subjected  to 
hormonal  control,  might  be  highly  preadaptive  to  the  evolution 
of  internal  fertilization  with  delayed  spawning.  While  there  is  no 
evidence  of  arrested  embryonic  development  or  delayed  hatching 
in  atheriniforms  with  internal  fertilization,  it  seems  worthwhile 
to  review  briefly  what  is  known  about  these  phenomena  in  forms 
with  external  fertilization. 

Wourms  (1967)  found  that  the  eggs  of  annual  cyprinodont 
fishes  of  the  subfamily  Rivulinae  (Cynolebias,  Pterolebias,  Racho- 
via,  Nothobranchius,  and  Austrofundulus)  are  subject  to  develop- 
mental arrest  at  one  or  more  stages.  In  Austrofundulus  myersi 
dispersion  of  amoeboid  blastomeres  occurs  early  in  development 
(stages  19-22)  so  that  there  is  no  embryo  or  aggregation  of  cells. 
This  is  followed  by  a  slow  reaggregation  of  cells  and  resumption 
of  development.  This  arrested  phase  (Diapause  I)  is  facultative, 
and  also  occurs  in  other  annuals.   Obligate  developmental  arrests 


22  BREVIORA  No.    374 

in  annuals  were  found  in  presomite  embryos  (stage  33,  Diapause 
II)  and  in  prehatching  embryos  (stage  44,  Diapause  III).  The 
duration  of  these  phases  is  rather  variable.  Wourms  suggested  that 
"the  net  effect  of  a  developmental  system  which  can  undergo  dia- 
pause of  variable  duration  at  several  stages  is  to  generate  a  wide 
distribution  of  eggs  in  any  single  developmental  stage,  and  to  make 
the  transition  from  stage  to  stage  a  variable  phenomenon.  The 
continued  survival  of  the  population  is  ensured  in  spite  of  climatic 
cycles  which  are  variable  in  periodicity  and  intensity"  (Wourms, 
1967:  341 1 ).  The  eggs  of  annual  cyprinodonts  have  exceptionally 
hard  chorionic  membranes.  Harrington  (1959)  reported  delayed 
hatching  in  stranded  eggs  of  marsh  killifish,  Fundiilus  confiuentus, 
a  member  of  the  cyprinodontid  subfamily  Fundulinae,  and  Jones 
(1944)  reported  delayed  hatching  in  Oryzias  melastigma,  a  mem- 
ber of  the  cyprinodontoid  family  Oryziatidae  (see  Rosen,  1964, 
for  a  characterization  of  this  family).  In  O.  melastigma  hatching 
normally  occurs  in  8-14  days,  yet  can  be  delayed  up  to  six  weeks; 
hatching  can  be  induced  by  adding  water  of  lower  salinity.  The 
only  noncyprinodontoid  fishes  in  which  delayed  hatching  has  been 
reported  as  a  normal  phenomenon  are  one  or  two  members  of  the 
atherinid  subfamily  Atherinopsinae,  including  the  grunion,  Leu- 
resthes  tenuis.  In  this  species,  "spawning  begins  just  after  turning 
of  tide  during  the  lower  (bright  moon)  series  of  high  tides,  but 
somewhat  later  than  turn  of  tide  during  the  higher  (dark  moon) 
series  of  high  tides.  Thus  the  eggs  are  always  deposited  near  the 
same  point  on  the  beach  profile  so  that  after  2  weeks  the  lower 
series  of  high  tides  washes  out  the  eggs  deposited  during  the 
higher  series,  and  vice  versa.  During  the  interim  of  low  tides,  the 
eggs  are  above  tide  level  in  moist  sand  4  inches  below  the  surface" 
(Harrington,  1959:  434-435,  after  Thompson  and  Thompson, 
1919;  Clark,  1925).  Grunion  eggs  presumably  have  a  highly 
protective  covering.  It  seems  likely  that  more  atheriniform  fishes 
will  be  found  with  either  delayed  embryonic  development  or  else 
deferred  hatching  (with  viability  of  embryos  sustained  far  beyond 
the  usual  incubation  periods).  The  outer  covering  of  the  egg  in 
many  atheriniform  fishes  is  highly  protective.  These  reproductive 
features  obviously  could  be  advantageous  to  fishes  such  as 
cyprinodontoids,  which  generally  exploit  niches  in  ephemeral 
waters   (Foster,   1967). 

Finally,  it  should  be  noted  that  Laale  and  McCallion  (1968) 
experimentally  induced  developmental  arrest  in  Brachydanio  rerio, 


1971  PHALLOSTETHIDAE  23 

a  cyprinid.  Exposure  to  extracts  from  Brachydanio,  frog,  or  chick 
embryos  caused  Brachydanio  embryos  at  stages  17-18  to  stop 
developing.  Returned  to  buffered  water,  the  embryos  resumed 
normal  development  and  hatched.  Laale  and  McCallion  suggested 
that  the  inhibitory  factor  might  be  a  nuclease. 

Foster  (1967)  suggested  that  in  cyprinodontoids  the  shift  from 
expelling  and  fertilizing  all  of  the  ovulated  eggs  in  one  continuous 
spawning  act  to  expelling  and  fertilizing  them  singly  or  in  small 
batches  greatly  increased  the  amount  of  courtship  behavior  per 
fertilized  egg  and  thereby  the  impact  of  sexual  selection.  The 
habit  of  expelling  a  few  eggs  at  a  time  is  also  found  among  ather- 
inoids  (see  Breder  and  Rosen,  1966)  and  is  apparently  char- 
acteristic of  phallostethoids  (Villadolid  and  Manacop,  1934,  for 
Gulaphallus  mirabilis;  Myers,  1935,  for  Plectrostethus  palawanen- 
sis) ,  Horaichthys  (Kulkarni,  1940),  and  Tomeurus  (Myers,  1947: 
8-11;  Breder  and  Rosen,  1966:  341-343).  Whereas  in  many 
atheriniforms  the  tendency  to  deposit  a  few  eggs  at  a  time  seems 
to  have  led  to  the  evolution  of  prolonged  courtship,  in  other  lines 
it  may  have  led  to  internal  fertilization.  Supposing  females  carry 
a  fair  number  of  eggs  but  lay  only  a  few  at  a  time,  males  that  can 
impregnate  the  female  and  fertilize  all  of  the  eggs  at  once  have 
an  obvious  selective  advantage  over  males  that  can  fertilize  only 
a  few  eggs  at  a  time.  Even  more  to  the  point,  there  may  be  little 
to  prevent  the  sperm  from  getting  into  the  oviduct  and  fertilizing 
eggs  retained  inside  the  female.  Thus,  while  fertilization  normally 
is  external  in  Oryzias,  instances  of  O.  latipes  females  with  inter- 
nally fertilized  eggs  (developing  embryos)  do  occur  (Amemiya  and 
Murayama,  1931).    Oryzias  evidently  is  ancestral  to  Horaichthys. 


24 


BREVIORA 


No.  374 


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1971  PHALLOSTETHIDAE  25 

LITERATURE    CITED 

Amemiya.  I.,  AND  S.  MuRAYAMA.  1931.  Some  remarks  on  the  existence  of 
developing  embryos  in  the  body  of  an  oviparous  cyprinodont,  Oryzias 
{Aplocheiliis)  latipes  (Temminck  et  Schlegel).  Proc.  Imp.  Acad.  Japan 
(Tokyo),  7(4):   176-178. 

AuRiCH,  H.      1937.     Die  Phallostethiden    (Unterordnung   Phallostethoidea 
Myers).    Intnatl.  Rev.  Ges.  Hydrobiol.  Hydrogr.,  34:  263-286. 

Bailey,  R.  J.  1936.  The  osteology  and  relationships  of  the  phallostethoid 
fishes.     J.  Morph.,  59(3):  453-483,  4  pis. 

Berg,  L.  S.  1940.  Classification  of  fishes,  both  recent  and  fossil.  Trav. 
Inst.  Zool.  Acad.  Sci.  URSS,  5:  87-517. 

Breder,  C.  M.,  and  D.  E.  Rosen,  1966.  Modes  of  Reproduction  in  Fishes. 
Garden  City,  New  York,  Nat.  Hist.  Press,    xv  +  941  pp. 

Duncker,  G.  1904.  Die  Fische  der  Malayischen  Halbinsel.  Mitt.  Naturh. 
Mus.  Hamburg,  21:    135-207. 

Foster,  N.  R.  1967.  Trends  in  the  evolution  of  reproductive  behavior 
in  killifishes.    Stud.  Trop.  Oceanogr.  (Miami),  5:  549-566. 

Fowler,  H.  W.  1937.  Zoological  results  of  the  third  de  Schauensee 
Siamese  Expedition.  Part  VIII,  —  Fishes  obtained  in  1936.  Prcc. 
Philadelphia  Acad.  Nat.   Sci.,   89:    125-308. 

Greenwood,  P.  H.,  D.  E.  Rosen,  S.  H.  Weitzman,  and  G.  S.  Myers. 
1966.  Phyletic  studies  of  teleostean  fishes,  with  a  provisional  classifi- 
cation  of  living   forms.     Bull.   Amer.    Mus.   Nat.   Hist.,    131,   art.    4: 

341-455. 

Harrington,  R.  W.,  Jr.  1959.  Delayed  hatching  in  stranded  eggs  of 
marsh  killifish,  Fimdulus  confliientiis.    Ecology,  40(3):   430-437. 

Herre,  a.  W.     1925.     Two  strange  new  fishes  from  Luzon.    Philippine  J. 

Sci.,  27:   507-513,  2  pis. 
1926.    Four  new  Philippine  fishes.   Philippine  J.  Sci.  31(4): 

533-543,  3  pis. 
1939.    The  senera  of  Phallostethidae.    Proc.  Biol.  Soc.  Wash- 


ington, 52:    139-144. 

1940.     Manacopus,  a  new  name  for  a  genus  of  Phallosteth- 


idae.    Copeia,  1940(2):    141. 

-.     1942.    New  and  little  known  phallostethids,  with  keys  to  the 


genera  and  Philippine  species.     Stanford  Ichth.  Bull.,  2(5):    137-156. 

HuBBS,  C.  L.,  AND  L.  C.  HuBBS.  1945.  Bilateral  asymmetry  and  bilateral 
variation  in  fishes.  Papers  Michigan  Acad.  Sci.  Arts  Letters,  30: 
229-310,   1  pi. 


26  BREVIORA  No.    374 

Jones,  S.  1944.  On  the  occurrence  of  diapause  in  the  eggs  of  Indian 
cyprinodonts.   Current  Science  (Bangalore),  13:   107-108. 

KuLKARNi,  C.  V.  1940.  On  the  systematic  position,  structural  modifica- 
tions, bionomics  and  development  of  a  remarkable  new  family  of 
cyprinodont  fishes  from  the  province  of  Bombay.  Rec.  Ind.  Mus.  Cal- 
cutta, 42:  379-423. 

Laale,  H.  W.,  and  D.  J.  McCallion.  1968.  Reversible  developmental 
arrest  in  the  embryo  of  the  zebra-fish,  Brachydanio  rerio.  J.  Exp.  Zool., 
167(1):   117-127,  3  pis. 

Myers,  G.  S.  1928.  The  systematic  position  of  the  phallostethid  fishes, 
with  diagnosis  of  a  new  genus  from  Siam.  Amer.  Mus.  Novitates,  No. 
295,   12  pp. 

1935.     A  new  phallostethid  fish  from  Palawan.    Proc.  Biol. 

Soc.  Washington,  48:  5  6. 

1937.    Notes  on  phallostethid  fishes.    Proc.  U.  S.  Nat.  Mus., 


84(3007):   137-143. 
1947.     The  Amazon  and  its  fishes  .  .  .  Part  3.     Amazonian 


aquarium  fishes.    Aquar.  Journ.,  18(5)    (May,  1947):  6-13,  32. 

Nelson,  K.  1964.  Behavior  and  morphology  in  the  glandulocaudine  fishes 
(Ostariophysi,  Characidae).  Univ.  California  Pub.  Zool.,  75(2): 
59-152. 

NiELSON,  J.  G.,  A.  Jespersen,  and  O.  Munk.  1968.  Spermatophores  in 
Ophidioidea  (Pisces,  Percomorphi).   Galathea  Report,  vol.  9:  239-253. 

Regan,  C.  T.  1913.  Phallostetlius  dunckcri,  a  remarkable  new  cyprino- 
dont fish  from  Johore.    Ann.  Mag.  Nat.  Hist.,  12:  548-555. 

1916.     The  morphology  of  the   cyprinodont  fishes  of  the 

subfamily  Phallostethinae,  with  descriptions  of  a  new  genus  and  two 
new  species.    Proc.  London  Zool.  Soc,  1916:    1-26,  pis.  1-4. 

Rosen,  D.  E.  1964.  The  relationships  and  taxonomic  position  of  the 
halfbeaks,  killifishes,  silversides  and  their  relatives.  Bull.  Amer.  Mus. 
Nat.  Hist.,   127,  art.   5:   217-267,  pis.    14  and   15. 

Smith,  H.  M.      1927.     The  fish  Neostethus  in  Siam.    Science   (n.s.),  65: 

353-355. 
1945.     The  fresh-water  fishes  of  Siam,  or  Thailand.    Bull. 

U.  S.  Nat.  Mus.,  No.  188,  622  pp. 

TeWinkel,  L.  E.  1939.  The  internal  anatomy  of  two  phallostethid  fishes. 
Biol.  Bull.  Woods  Hole,  76(1):   59-69. 

ViLLADOLiD,  D.  v.,  AND  P.  R.  Manacop.  1934.  The  Philippine  Phal- 
lostethidae,  a  description  of  a  new  species,  and  a  report  on  the  biology 
of  Gulaphallns  mirabilis  Herre.  Philippine  J.  Sci.,  55(3):  193-220, 
5  pis. 


1971  PHALLOSTETHIDAE  27 

WoLTERECK,   R.      1942a.     Stufen  der  Ontogenese  und  der   Evolution  von 

Kopulationsorganen  bei  Neostethiden  (Percesoces,  Teleostei).    Intnatl. 

Rev.  Ges.  Hydrobiol.  Hydrogr.,  42:   253-268. 
1942b.     Neue  Organe,  durch  postembryonale  Umkonstruk- 

tion    aus    Fischflossen     entstehend.      Intnatl.    Rev.     Ges.     Hydrobiol. 

Hydrogr.,  42:  317-355. 

WouRMS,  J.  D.  1967.  A  naturally  occurring  vertebrate  dispersion- 
reaggregation  system  subject  to  developmental  arrest.  Dissertation 
Abstracts,  Sect.  B,  27(10-11):    3410-3411. 


BREVIORA 


Miaseiiam    of    Comparative    Zoology 

Cambridge,  Mass.  15  June,  1971  Number  375 

STRUCTURAL  HABITATS  OF  WEST  INDIAN  ANOLIS 
LIZARDS  II.   PUERTO  RICAN  UPLANDS 

Thomas  W.  and   Amy  Schoener^ 


Abstract.  This  paper  reports  differences  in  structural  and  climatic 
iiabitat  between  the  commonest  Anolis  species  of  two  upland  localities  — 
Maricao  and  El  Verde  — •  in  Puerto  Rico. 

Five  of  the  seven  Anolis  species  recorded  at  Maricao  were  studied  in 
detail:  two- — cristatelhis  and  stratitlus — are  major  components  of  the 
warmer  lowland  fauna,  and  three  —  krugi,  evcrmanni,  and  gundlachi  — 
are  representative  of  the  cooler  upland  fauna.  A.  stratiihis  and  evermanni 
tended  to  occupy  higher  and  thicker  perches  than  the  other  species;  krugi 
was  found  on  especially  thin  perches  and  often  on  leaves.  The  trunk- 
crown  species  evermanni  and  stratiilus,  of  very  different  size,  were  virtually 
totally  syntopic  over  the  study  area,  while  the  trunk-ground  species 
cristatelhis  and  gundlachi,  of  very  similar  size,  were  virtually  allopatric. 
Similarities  and  differences  in  climatic  habitat  between  the  species  reflected 
this  microgeography:  stratulus  and  evermanni  were  found  in  fairly  similar 
situations,  though  the  former  tended  to  be  in  opener  areas,  while  cristatellus 
and  evermanni  were  confined  to  open  and  closed  habitats,  respectively.  At 
El  Verde  the  same  species  were  studied,  but  the  open-area  species  cristatel- 
his and  stratulus  were  relatively  rarer.  Structural  and  climatic  habitats 
paralleled  those  at  Maricao,  and  the  trunk-crown  species  were  again  more 
syntopic  than  the  trunk-ground  species. 

In  a  separate  analysis,  it  is  shown  that  the  two  trunk-crown  species  had 
significantly  more  collecting  localities  in  common  than  did  the  two  trunk- 
ground  species.  The  grass-bush  species  pulchellus  and  krugi  were  inter- 
mediate in  this  respect.  It  is  hypothesized  that  the  greater  body  size 
difference  of  the  often  syntopic  trunk-crown  species  may  be  an  adaptation 
preventing  food  overlap,  an  adaptation  which  the  nonsyntopic  trunk-ground 
species  neither  have  nor  need. 


1  Biological  Laboratories  and  Museum  of  Comparative  Zoology,  Harvard 
University,  Cambridge,  Mass.  02138. 


2  BREVIORA  No.    375 

The  possible  evolution  of  climatic  and  size  differences  is  discussed  for 
the  upland  and  lowland  series.  It  is  suggested  that  in  the  broken,  drier 
forest  often  found  in  the  lowlands,  the  trunk-crown  species  would  occur  in 
more  shaded  conditions  on  the  average  than  would  the  trunk-ground  species; 
whereas  in  the  wetter,  more  continuous  forests  of  middle  and  upper  eleva- 
tions, the  reverse  situation  would  be  true.  Therefore,  the  trunk-crown 
species  may  have  been  predisposed  for  greater  spatial  overlap  in  advance  of 
their  coming  together.  That  the  lowland  trunk-crown  species  should  be 
smaller  and  less  sexually  dimorphic  in  size  may  be  a  result  of  greater  aver- 
age overlap  between  it  and  the  corresponding  trunk-ground  species:  possibly 
the  lower  average  vegetation  height  and  the  greater  need  to  avoid  desicca- 
tion makes  separation  by  height  more  difficult  in  the  opener  vegetation  of 
the  lowlands.  No  evidence  to  support  this  latter  speculation  is  found  in 
this  study,  however. 

This  is  the  second  in  a  series  of  papers  describing  the  structural 
habitats  of  some  West  Indian  Anolis  lizards.  Rand  (1964)  has 
documented  extensively  differences  between  seven  Puerto  Rican 
species  in  their  structural  and  chmatic  habitats.  Our  study  will 
also  elucidate  gross  interspecific  differences,  but  its  primary  pur- 
pose is  to  demonstrate  how  the  size  classes  of  each  species  studied 
are  deployed  over  the  vegetation,  with  respect  both  to  others  of 
the  same  species  and  to  similarly  sized  lizards  of  other  species. 
Its  secondary  purpose  is  to  investigate  the  spatial  relationship  be- 
tween stratuliis  and  evermanni,  two  "trunk-crown"  forms  (after 
Rand  and  Williams,  1969;  Williams  and  Rand,  in  preparation) 
of  very  different  size  and  sexual  dimorphism,  occurring  in  differ- 
ent but  overlapping  climatic  and  geographic  areas. 

FORMAT   AND    METHODS 

Data  on  the  structural  habitat  were  gathered  in  the  way  described 
previously  (Schoener  and  Schoener,  1971):  for  each  lizard  seen 
in  the  area,  the  type  of  perch,  perch  height,  and  perch  diameter 
were  noted.  In  addition,  when  the  sun  was  shining  the  lizard  was 
scored  as  to  whether  it  perched  mostly  in  the  sun  or  shade.  Obser- 
vations during  cloudy  weather  were  lumped  into  a  third  chmatic 
category.  As  before,  the  two  of  us  simultaneously  canvassed  an 
area  in  staggered  fashion  so  as  to  minimize  the  possibility  of  miss- 
ing lizards.  In  addition,  we  were  assisted  during  one  afternoon  at 
El  Verde  by  E.  E.  Williams  and  W.  P.  Hall,  III. 


1971  PUERTO  RICAN  ANOLIS  3 

Results  are  presented  here  in  two  ways:  1)  standard,  structural 
habitat  tables  are  given  for  each  area  and  lizard  class  of  interest 
(Tables  3-7),  and  2)  the  occurrence  in  sun,  shade  or  clouds  is 
given  for  each  of  the  same  classes  (Table  2). 

In  order  to  test  for  statistically  significant  differences  in  struc- 
tural and  climatic  habitat  between  the  hzard  classes,  the  multiway 
contingency  approach  used  previously  (Schoener,  1970;  Schoener 
and  Schoener,  1971)  was  again  employed.  This  procedure  deter- 
mines the  strength  of  associations  between  the  lizard  classes  and 
habitat  variables  while  simultaneously  taking  into  account  possible 
associations  between  the  habitat  variables  themselves.  It  is  based 
on  methods  developed  by  Deming  and  Stephan  (1940),  Kullback 
(1959),  and  Bishop  (1969),  and  is  exposited  for  ecologists  by 
Fienberg  (1970);  the  appendix  (page  18)  outlines  its  particular 
application  to  our  data.  In  addition,  the  appendix  contains  Tables 
9-11,  indicating  the  statistical  significance  of  the  comparisons  we 
make  below. 

Our  presentation  begins  with  a  description  of  the  study  sites 
and  their  anohne  inhabitants,  continues  with  a  verbal  summary  of 
differences  in  habitat  between  the  lizard  classes,  and  terminates  in 
a  comparison  of  our  results  to  previous  ones  and  in  a  speculation 
on  the  evolution  of  size  in  relation  to  space  for  certain  Puerto 
Rican  anoles. 

THE   SPECIES 

Ten  species  of  Anolis  are  known  from  Puerto  Rico  (Table  1). 
These  can  be  divided  roughly  into  three  groups  on  the  basis  of 
their  climatic  and  correlated  geographic  ranges  (Rand,  1964;  Wil- 
liams, Rivero  and  Thomas,  1965;  Heatwole  et  al.,  1969;  Web- 
ster, 1969). 

One  group  comprises  those  species  which  occur  modally  in  rela- 
tively humid,  dark  vegetation  at  high,  cool  elevations.  This  group 
consists  of  1 )  evermanni  —  a  medium-large,  green,  trunk-crown 
species,  relatively  sexually  dimorphic  in  size;  2)  gundlachi  —  a 
medium-large,  rust-brown,  relatively  dimorphic  trunk-ground 
species;  3)  krugi  —  a  small,  striped  yellow  and  brown,  relatively 
dimorphic  grass-bush  species;  and  4)  occultus  —  a  very  small, 
grey-white,  relatively  nondimorphic  twig  species.  Two  of  the 
three  species,  evermanni  and  krugi,  are  also  found  at  scattered  wet 


4  BREVIORA  No.    375 

lowland  localities,  probably  in  remnants  of  the  nearly  destroyed 
wet  lowland  forest. 

The  second  group  occurs  modally  in  more  illuminated,  drier 
forest  at  the  warmer  low  to  moderate  elevations.  This  group 
consists  of  1 )  stratulus  —  a  small,  grey-brown,  relatively  non- 
dimorphic  trunk-crown  species;  2)  cristatelhis — a  medium-large, 
brown,  relatively  dimorphic  trunk-ground  species;  and  3)  pulchel- 
lus  —  a  small,  striped  yellow  and  brown,  relatively  dimorphic 
grass-bush  species.  This  group  is  also  widespread  in  the  highly 
disturbed  wet  lowlands  and  overlaps  the  first  most  commonly  at 
mesic  to  wet  intermediate  altitudes,  such  as  the  Maricao  locality 
to  be  described  below.  Additionally,  George  Drewry  (personal 
communication)  has  found  cristatelhis  predominating  in  high- 
altitude,  mossy  forest,  most  of  which  is  above  the  altitudinal  range 
of  gundlachi. 

The  third  group  is  restricted  to  the  arid  southwestern  lowlands 
in  xeric  vegetation.  It  consists  of  1 )  cooki  —  a  medium-large, 
grey-brown,  relatively  dimorphic  trunk-ground  species,  occurring 
sympatrically  with  cristatelhis  over  much  of  its  range;  and  2) 
ponceiisis  —  a  small,  striped  yellow  and  brown,  grass-bush  species 
of  relatively  moderate  sexual  dimorphism.  Notice  that  in  this 
group  there  is  no  trunk-crown  representative. 

A  final  species,  the  nondimorphic  green  giant  ciivieri,  appears 
from  museum  records  to  be  commonest  at  middle  and  upland  ele- 
vations, with  pockets  of  abundance  in  the  wetter  lowlands  such  as 
those  along  the  north  coast. 

LOCALITIES 

The  study  to  be  reported  below  concentrates  on  the  three 
commonest  mostly  upland  species  —  evennanni,  gundlachi  and 
knigi  —  and  two  of  the  three  commonest  widespread  species  — 
cristatelhis  and  stratulus.  All  five  of  these  species  were  found  in 
close  proximity  to  one  another  in  the  Maricao  Insular  Forest,  a 
preserve  in  the  ''monadnock"  region  (Pico,  1950)  of  the  Cordillera 
Central.  Consequently,  several  adjacent  study  sites  of  varying 
shapes  were  marked  ofl"  in  the  preserve  (altitude  =  860-900  m, 
slightly  less  than  4  km  due  south  of  the  town  of  Maricao),  and 
the  anoles  were  observed  therein.  We  distinguished  four  such  areas: 

1.  Forest  interior.  This  area  was  the  most  natural  of  the  four 
studied.     It   contained   forest   of  medium  height    and   somewhat 


1971  PUERTO  RICAN  ANOLIS  5 

broken  canopy,  clinging  to  a  20-40°  mountainside.  The  under- 
story  in  many  places  was  quite  sparse  and  easily  traversed,  but 
where  the  canopy  had  broken,  tangled  grasses  and  ferns  obstructed 
passage.  The  commonest  species  seen  in  this  area  was  gundlachi 
(Table  2).  The  two  trunk-crown  species,  evermanni  and  stratuliis, 
were  also  common  and  appeared  to  be  of  nearly  equal  abundance. 
In  addition,  krugi,  cristatelliis,  and  cuvieri  occurred  as  "trace" 
species.  We  saw  no  occultus  though  they  have  been  collected  there 
(Williams,  Rivero,  and  Thomas,  1965). 

2.  Forest  with  cleared  understory.  This  area  was  adjacent  to 
the  more  undisturbed  forest  and  consisted  of  a  strip  about  30-40 
feet  wide  that  bounded  an  open,  grassy  parking  area.  Although 
the  understory  had  apparently  been  cleared,  nearly  all  the  large 
trees  were  left  standing  and  very  little  sun  penetrated  to  the  ground, 
which  itself  consisted  mostly  of  bare  mud.  In  this  area,  gundlachi 
was  again  the  most  abundantly  seen  species,  followed  by  evermanni 
and  stratuliis,  again  in  nearly  equal  proportions.  A  few  cristatellus 
were  also  seen  at  the  edge  of  the  area. 

3.  Open  forest.  This  area  was  less  elongated  than  Area  (2) 
and  faced  it  from  directly  across  the  parking  area.  Trees  were 
arrayed  in  an  open,  parklike  fashion;  some  overlaid  a  2-to-3-foot 
herbaceous  understory  while  others  grew  among  short  grass.  Much 
sun  penetrated  to  the  ground,  in  contrast  to  Area  (2).  The  most 
abundant  species  seen  here  was  cristatellus.  Again,  evermanni 
and  stratulus  occurred  in  strikingly  similar  proportions.  A  few 
gundlachi  were  seen  along  the  border  between  this  area  and  Area 
(1).  In  addition,  a  few  krugi  inhabited  the  understory  where  it 
had  not  been  chopped  away. 

4.  Secondary  road  edge.  This  area  comprised  a  strip  about 
1 0-20  feet  wide  bordering  Area  ( 1 ) .  The  understory  graded 
from  a  lawnlike  growth  to  dense,  tangled  typical  forest-margin 
vegetation.  The  area  faced  full  sunlight  during  the  morning  hours, 
that  time  of  day  when  the  sun  was  most  likely  to  be  shining  during 
the  period  of  our  study.  Above  the  understory  rose  trees  of  varying 
heights,  with  40-  to  60-foot  Cecropia  emerging  above  the  rest. 
This  area  showed  the  most  equitable  distribution  of  apparent  abun- 
dances for  the  five  species.  A.  stratulus  was  commonest,  but  gund- 
lachi and  evermanni  were  also  rather  frequently  observed.  Less 
abundant  but  far  from  rare  were  cristatellus  and  krugi. 

Wc  studied  the  Maricao  area  during  the  period  June  23-26, 


6  BREVIORA  No.    375 

1969.  Weather  throughout  this  time  was  mostly  sunny  during  the 
morning,  generally  partly  cloudy  during  midday,  and  somewhat 
rainy  during  the  afternoon  —  on  one  occasion  in  the  form  of  a 
severe  thunderstorm.  Rainfall  at  the  nearby  but  lower  town  of 
Maricao  averages  111  inches  per  year  (Pico,  1950). 

To  further  elucidate  the  relationships  between  the  upland  species, 
a  second,  more  humid  area  was  investigated  at  El  Verde  in  the 
Luquillo  rainforest  (340-440  m).  The  study  sites  were  in  parts 
of  the  forest  that  were  and  are  still  the  subjects  of  intensive  and 
extensive  ecological  investigation,  including  a  study  of  its  two 
commonest  Anolis  species  by  Turner,  Gist,  and  Rowland  (Odum, 
1965).  The  area  is  described  in  detail  in  various  reports  (Odum, 
1965;  Kline,  Jordan,  and  Drewry,  1967,  1968).  In  comparison 
to  the  Maricao  forest,  that  at  El  Verde  was  considerably  taller 
and  of  more  continuous  but  still  somewhat  broken  canopy;  the 
understory  was  consequently  sparser  and  there  were  frequent 
boulders  strewn  about  the  forest  floor.  Two  study  sites  are  dis- 
tinguished in  Table  2. 

The  first  begins  near  the  biological  station  and  penetrates  the 
interior  of  the  forest  along  a  trail  that  climbs  upward,  eventually 
terminating  at  an  observation  tower.  Our  records  were  all  taken 
adjacent  to  the  bottom  third  of  the  trail  where  the  grade  was 
closest  to  horizontal.  This  area  was  in  coffee  plantation  until  the 
early  1930's  and  had  not  reached  climax  but  was  still  in  middle 
succession  at  the  time  of  our  study  (G.  E.  Drewry,  personal  com- 
munication). The  second  study  site  contained  roadside  secondary 
vegetation  along  the  forest  margin,  very  close  to  the  first  study  area. 

In  both  study  areas,  gimdlachi  was  the  species  most  frequently 
seen,  although  it  appeared  more  dominant  in  the  forest  interior. 
The  next  most  frequently  encountered  species  was  evermanni,  rela- 
tively more  abundant  along  the  forest  edge.  Three  other  species, 
stratulus,  knigi,  and  ciivieh,  were  rarely  encountered  in  the  forest 
interior;  the  first  two  were  always  observed  in  relatively  open, 
sunny  areas.  The  margin  had,  however,  a  more  equitable  distribu- 
tion of  species:  stratulus,  cristatellus  and  krugi  did  not  appear 
uncommon.  One  cuvieri  was  also  seen.  All  the  relative  abundances 
given  in  Table  2  are,  of  course,  apparent  only  —  they  represent 
what  we  saw  and  are  therefore  biased  in  favor  of  three  species 
{gundlachi,  cristatellus,  and  krugi)  frequently  occurring  at  or 
below  eye  level. 

Observations  were  made  June  29  -July  1,  1969.  Weather  dur- 
ing this  time  was,  in  general,   considerably  overcast  and  rainy. 


1971  PUERTO  RICAN  ANOLIS  7 

the  rain  occurring  intermittently  at  all  times  of  the  day.  Even 
though  we  tried  to  avoid  sunless  periods,  a  heavy  incidence  of 
clouds  is  apparent  in  Table  2.  Rainfall  in  the  vicinity  was  esti- 
mated from  the  weekly  tables  in  Kline,  Jordan,  and  Drewry  ( 1967, 
1968)  as  189  inches  per  year  from  September  1964  through 
August  1966. 

RESULTS 

Differences  between  lizard  classes.  In  the  following  discussion, 
all  comparisons,  unless  otherwise  stated,  are  statistically  significant 
in  the  sense  explained  in  the  appendix.  Each  species  dealt  with  is 
divided  into  two  classes:  1)  small  individuals,  comprising  adult 
females,  subadults,  and  juveniles,  and  2)  adult  males.  The  great 
majority  of  the  former  class  (85-100%)  were  too  large  to  be 
labelled  "juveniles." 

Maricao  open  areas  (Tables  3,  4,  9).  In  order  to  compare  spe- 
cies classes  from  relatively  open  areas  with  respect  to  their  struc- 
tural and  climatic  habitats,  observations  from  the  "open  forest" 
and  "secondary  road  edge"  were  lumped  together.  Only  the  three 
commonest  species  of  these  areas  —  evermanni,  stratulus  and  cris- 
tatellus  —  were  treated  statistically. 

Male  evermanni  perched  higher  than  did  all  other  groups  and 
were  significantly  higher  than  all  but  male  stratulus.  The  latter 
class  occurred  higher  than  small  evermanni  or  cristatellus.  Small- 
sized  stratulus  were  higher  than  small  evermanni  and  all  cristatel- 
lus. Small  evermanni  perched  higher  than  either  male  or  small 
cristatellus. 

Male  evermanni  occurred  on  thicker  perches  than  all  other 
classes.  Male  stratulus  were  on  thicker  perches  than  all  classes  but 
male  evermanni.  Small  evermanni  were  on  thicker  perches  than 
small  stratulus  and  small  cristatellus.  Male  cristatellus  occupied 
thicker  perches  than  did  small  stratulus. 

Within  each  of  the  three  species,  males  perched  on  both  higher 
and  thicker  branches  than  did  small-sized  individuals. 

There  were  significant  differences  in  the  climatic  habitats  of 
stratulus  males  and  the  two  classes  of  cristatellus  (Table  2).  The 
former  occurred  more  often  in  the  sun  and  less  often  in  the  shade 
than  did  either  of  the  latter.  There  was  also  an  overall  tendency 
for  male  stratulus  to  be  seen  more  often  on  cloudy  days.  Small 
stratulus  too  occurred  more  often  in  the  sun  than  did  either  class 


8  BREVIORA  No.    375 

of  cristatellm  and  were  seen  less  often  in  the  shade  and  on  cloudy 
days.  Small-sized  evermanni  were  observed  more  often  in  the 
shade  and  less  often  on  cloudy  days  than  were  male  stratulus; 
sunny  observations  were  of  about  equal  proportions  in  the  two 
classes.  Small  evermanni  were  seen  more  frequently  in  the  sun 
than  male  cristatellus  and  less  frequently  on  cloudy  days;  the  per- 
cent observations  in  the  shade  were  nearly  identical.  Small  ever- 
manni also  occurred  more  frequently  in  sunny  positions  than  did 
female  cristatellus;  the  latter  appeared  more  often  during  cloudy 
weather  and,  to  a  lesser  extent,  in  the  shade.  No  significant  climatic 
differences  were  found  between  the  classes  of  the  same  species. 

Maricao  closed  area  (Tables  5,  6,  10).  Observations  for  two 
study  sites,  the  interior  forest  and  the  forest  with  cleared  under- 
story,  were  lumped  to  compare  the  three  most  common  species  — 
gundlachi,  evermanni  and  stratulus. 

There  was  no  significant  difference  in  perch  height  between  male 
stratulus  and  male  evermanni,  the  two  uppermost  classes  of  anoles. 
Male  evermanni  were,  however,  seen  significantly  higher  than  small 
stratulus  or  the  classes  of  gundlachi.  Male  stratulus  did  not  differ 
significantly  in  height  from  small  evermanni  but  were  observed 
higher  than  either  class  of  gundlachi.  Small  evermanni  were  seen 
slightly  higher  than  small  stratulus  and  all  gundlachi;  small  stratu- 
lus also  occurred  higher  than  did  the  classes  of  gundlachi. 

In  perch  diameter,  male  evermanni  significantly  exceeded  all 
interspecific  classes  but  male  stratulus.  Male  stratulus,  in  turn, 
significantly  exceeded  all  other  interspecific  classes  but  male  gund- 
lachi. Small  evermanni  were  next  in  perch  diameter,  occupying 
thicker  perches  than  either  class  of  gundlachi.  Small  stratulus  and 
male  gundlachi  were  similar  in  perch  diameter,  and  the  former 
occurred  on  thicker  perches  than  small  gundlachi. 

Once  again,  within  the  same  species,  the  larger  classes  occurred 
on  higher  and  thicker  perches  than  did  the  smaller-sized  classes. 

Compared  to  the  other  species,  both  classes  of  gundlachi 
strikingly  avoided  sunny  places.  Small  gundlachi  were  found  sig- 
nificantly more  often  in  the  shade  or  on  cloudy  days  than  any 
class  of  stratulus  or  evermanni.  Male  gundlachi  were  found  more 
often  in  the  shade  than  small  stratulus,  and  more  often  in  the 
shade  and  on  cloudy  days  than  either  class  of  evermanni.  As  was 
the  case  for  the  more  open  area,  small  evermanni  were  found 
considerably  more  often  in  the  shade  and  less  often  during  cloudy 


1971  PUERTO  RICAN  ANOLIS  9 

weather  than  male  stratidus;  inside  the  forest,  however,  they  were 
also  seen  slightly  more  often  in  the  sun.  In  contrast  to  the  opener 
areas,  here  small  evermanni  as  well  differed  significantly  in  the 
above  respects  from  small  stratidus.  No  intraspecific  comparisons 
were  significant. 

El  Verde  (Tables  7,  11).  Observations  for  the  two  areas  dis- 
tinguished in  Table  2  were  combined  to  test  structural  habitat 
differences  at  El  Verde.  Only  the  two  most  abundant  species, 
evermanni  and  gundlachi,  were  considered. 

As  before,  male  and  small  evermanni  were  higher  than  either 
class  of  gundlachi.  Male  and  small  evermanni  also  occupied 
thicker  perches  than  did  small  gundlachi.  Male  gundlachi,  how- 
ever, were  on  greater-diametered  perches  than  small  evermanni 
and  did  not  differ  significantly  from  male  evermanni  in  this  respect, 
though  the  latter  at  Maricao  occupied  thicker  perches.  Intraspe- 
cifically,  males  once  again  were  distributed  over  greater  perch 
heights  and  diameters  than  small  individuals. 

There  were  no  significant  climatic  differences  between  the  lizard 
classes  —  this  is  unsurprising  because  of  the  small  sample  size 
and  preponderance  of  cloudy  weather  at  El  Verde. 

The  common  species  at  El  Verde,  evermanni  and  gundlachi, 
are  similar  in  size  and  sexual  dimorphism  (Table  1)  and  appear 
to  stagger  their  sizes  in  such  a  way  as  to  overlap  most  small  ever- 
manni and  large  gundlachi,  with  respect  to  both  perch  height  and 
perch  diameter. 

The  situation  becomes  more  complex  where  a  third  species, 
stratulus,  is  more  abundant,  as  in  the  Maricao  interior  forest.  The 
two  species  evermanni  and  gundlachi  still  maintain  the  same  spatial 
relationship  between  their  size  classes.  However,  male  stratulus 
are  now  inserted  between  male  evermanni  and  small-sized  ever- 
manni. They  differ  markedly  from  the  former  in  size  (Table  1) 
but  are  only  slightly  smaller  than  the  latter.  There  is  also  rather 
strong  overlap  between  small  stratulus  and  small  evermanni;  the 
latter,  however,  average  a  good  bit  larger.  Small  stratulus  also 
extensively  overlap  male  gundlachi  but  are  very  different  in  size. 
They  differ  greatly  in  both  perch  height  and  diameter  from  the 
similarly  sized  small  gundlachi. 

In  the  opener  areas  at  Maricao,  the  situation  is  essentially  the 
same  for  both  diameter  and  height  except  that  cristatellus  virtually 
replaces  gundlachi.    Given  that  substitution,  the  only  difference 


10  BREVIORA  No.    375 

that  appears  to  exist  is  a  reversal  in  relative  height  of  small  stratii- 
liis  and  small  evermanni.  This  reversal  allows  a  more  nearly  per- 
fect staggering  of  sizes:  now  male  stratulus  are  further  from  small- 
sized  evermanni .  All  overlaps,  of  course,  are  further  reduced  by 
the  existence  of  climatic  differences  between  the  niches  of  the 
species. 

It  is  important  to  point  out  that  in  many  places  in  the  lowlands 
evermanni  is  absent;  there,  presumably,  cristatelliis  and  stratulus 
often  stagger  their  sizes  in  much  the  same  way  as  do  evermanni 
and  gundlachi.  However,  even  if  the  classes  of  adult  males  over- 
lapped the  most  (see  below),  the  two  lowland  species  probably 
do  not  take  very  similar  food  since  they  are  so  different  in  size  — 
in  contrast  to  gundlachi  and  evermanni.  Moreover,  it  is  interesting 
to  note  that  where  stratulus  and  evermanni  overlap  extensively,  as 
at  Maricao,  there  is  only  a  slightly  greater  tendency  than  at  "pure" 
upland  or  lowland  localities  for  similarly  sized  classes  to  overlap, 
as  a  result  of  the  great  difference  in  size  between  the  two  trunk- 
crown  species. 

Because  of  their  small  sample  size,  classes  of  krugi  were  not 
tested  against  any  other.  However,  if  all  observations  for  krugi 
from  the  three  areas  are  lumped,  and  to  these  are  added  observa- 
tions made  in  high  grass  and  other  secondary  growth  near  the  mid- 
elevation  town  of  Adjuntas,  it  is  possible  to  compare  large  and 
small  krugi  in  structural  habitat.  Table  8  shows  that  males  of 
krugi  occurred  significantly  higher  and  on  thicker  diameters  than 
did  small-sized  lizards.  However,  even  more  striking  was  the 
much  greater  frequency  of  small  krugi  on  leaves.  This  result  is 
consistent  with  those  for  other  species  that  occupy  the  leaf  habitat 
in  a  major  way:  carolinensis  on  Bimini  (Schoener,  1968)  and 
grahami  aquarum  on  Jamaica  (Schoener  and  Schoener,  1971). 
No  climatic  difference  was  found  between  the  two  classes. 

Differences  between  habitat  variables  (Tables  9-11).  In  the 
Maricao  open  area  the  only  significant  height-diameter  associations 
were  those  in  which  thinner  perches  tended  to  be  high  and  thicker 
perches  tended  to  be  low.  Fewer  comparisons  were  significant  in 
the  interior  forest  at  Maricao,  but  those  that  were  showed  a  uni- 
formly opposite  tendency.  This  could  easily  reflect  our  observa- 
tional bias:  fewer  lizards  can  be  seen  in  the  canopy  when  within 
the  forest.  The  one  significant  interaction  at  El  Verde  was  the 
same  as  those  for  the  Maricao  closed  area. 


1971  PUERTO  RICAN  ANOLIS  11 

In  the  open  area  at  Maricao,  there  was  a  tendency,  when  we 
combined  male-evermanni  perches  with  those  of  interspecific 
classes,  for  the  highest  perches  to  occur  in  the  sun  and  the  lowest 
in  the  shade,  as  would  be  expected  from  the  physiognomy  of  the 
vegetation.  A  somewhat  different  result  was  true  for  the  three 
significant  interactions  in  the  interior  vegetation:  high  perches 
were  more  often  used  on  cloudy  days;  the  lowest  perches  were 
still  more  frequently  found  in  the  shade,  however.  At  El  Verde, 
the  one  significant  interaction  (for  male  evermanni  vs.  small  gimd- 
lachi)  was  the  same  as  those  for  the  Maricao  open  area. 

There  were  no  significant  interactions  at  all  between  perch 
diameter  and  insolation  in  the  Maricao  closed  area,  and  only  one 
such  interaction  was  significant  for  the  Maricao  open  area.  This 
was  a  tendency  for  the  combined  perches  used  by  small  stratulus 
and  small  cristatellus  to  be  thinnest  in  the  sun  and  thickest  on 
cloudy  days.  At  El  Verde,  in  contrast,  perches  of  male  evermanni 
and  male  giindlachi  were  significantly  thickest  in  the  sun  and  thin- 
nest in  the  shade.  The  combined  perches  for  male  evermanni  and 
male  gimdlachi  also  were  thinnest  in  the  shade,  but  the  thickest 
perches  were  used  during  cloudy  weather.  Both  these  interactions 
may  again  primarily  represent  the  greater  ease  of  seeing  a  lizard 
on  the  thin  branches  and  twigs  of  the  understory  than  on  similarly 
sized  branches  belonging  to  the  high  canopy  of  the  El  Verde  rain- 
forest. They  could,  however,  also  reflect  real  differences  in  utili- 
zation of  the  habitat  by  lizards:  for  example,  during  the  rather 
brief  sunny  periods  at  El  Verde,  lizards  may  have  moved  onto 
broader  surfaces  to  bask  more  effectively. 

CONCLUSION 

Although  we  have  concentrated  on  differences  between  the  size 
classes  of  the  lizards  at  Maricao  and  El  Verde,  our  results  for 
species  agree  well  with  those  reported  by  Rand  (1964)  in  his 
pioneering  study  of  the  structural  habitat  of  species  from  all  areas 
of  Puerto  Rico.  In  that  study  Rand  pointed  out  the  size  difference 
between  the  two  trunk-crown  species,  stratulus  and  evermanni, 
and  suggested  that,  because  of  their  similarity  in  climatic  habitat 
(as  measured  by  body  and  air  temperature,  as  well  as  shade  vs. 
sun  records),  these  two  species  should  in  general  show  a  greater 
amount  of  spatial  overlap  than  the  trunk-ground  or  grass-bush 


12  BREVIORA  No.    375 

species.  Although  in  an  area  near  the  town  of  Maricao  the  few 
stratulus  seen  by  Rand  did  not  seem  to  overlap  evermanni  much 
in  horizontal  habitat,  we  have  shown  above  that  in  our  areas  at 
the  Maricao  Insular  Forest,  the  two  species  were  quite  syntopic 
and  sometimes  were  of  nearly  identical  apparent  abundance  (Table 
2).  Thus  we  saw  62  evermanni  and  66  stratulus  in  the  forest  in- 
terior, 20  evermanni  and  17  stratulus  in  the  forest  with  cleared 
understory,  70  evermanni  and  72  stratulus  in  the  open  forest,  and 
36  evermanni  and  138  stratulus  along  the  road  edge.  Even  at 
our  study  site  at  El  Verde,  where  evermanni  was  seen  more  fre- 
quently (67  evermanni  and  7  stratulus  in  the  interior  and  31 
evermanni  and  11  stratulus  along  the  forest  margin),  stratulus  was 
interspersed  throughout  evermanni's  horizontal  range,  although  in 
the  interior  it  was  seen  only  in  fairly  open  places,  such  as  on 
sunny  spots  along  the  trail,  high  on  emergent  trees,  and  on  stream- 
side  boulders.  G.  E.  Drewry  (personal  communication)  has,  how- 
ever, seen  stratulus  more  commonly  than  evermanni  in  the  more 
closed,  relatively  less  leafy  canopy  of  certain  other  areas  at  El 
Verde. 

The  extensive  syntopy  of  the  trunk-crown  species  is  in  striking 
contrast  to  the  trunk-ground  species  we  studied.  For  example,  in 
the  forest  interior  at  Maricao  we  saw  243  gundlachi  and  1  cristatel- 
lus.  In  the  open  forest  at  Maricao  we  saw  175  cristatellus  and  8 
gundlachi.  In  the  interior  forest  at  El  Verde  we  saw  243  gundlachi 
and  0  cristatellus.  All  three  of  these  areas  were  relatively  equi- 
lateral in  shape.  In  the  more  elongated,  marginal  areas  we  saw 
more  equitable  proportions  of  the  two:  33  gundlachi  and  6  cris- 
tatellus in  the  forest  with  cleared  understory  at  Maricao,  50  gund- 
lachi and  25  cristatellus  along  the  Maricao  secondary  road  edge, 
and  51  gundlachi  and  14  cristatellus  along  the  edge  locality  of  El 
Verde.  At  the  second  of  these  areas,  where  the  numbers  are  closest 
to  identity,  we  noted  that  along  a  strip  about  ten  feet  wide  cris- 
tatellus and  gundlachi  were  perching  upon  the  same  vegetation, 
although  under  different  climatic  conditions:  cristatellus  was  espe- 
cially common  during  sunny  days,  whereas  the  majority  of  the 
gundlachi  individuals  were  seen  under  overcast  skies.  Thus,  even 
though  there  is  spatial  overlap  of  cristatellus  and  gundlachi  in 
marginal  areas,  it  is  largely  nonsynchronous. 

We  can  test  differences  in  the  relative  abundances  of  trunk- 
ground  vs.  trunk-crown  species  by  constructing  2x2  contingency 


1971  PUERTO  RICAN  ANOLIS  13 

tables  and  running  chi-square  or  exact  tests.  If  this  is  done  for 
the  six  study  areas,  it  is  seen  that  the  relative  proportions  of  the 
two  trunk-ground  species  are  significantly  different  from  those  of 
the  two  trunk-crown  species  in  the  El  Verde  interior  forest, 
Maricao  interior  forest,  Maricao  road  edge,  and  Maricao  open 
forest  at  the  1  percent  level  and  in  the  Maricao  forest  with  cleared 
understory  at  the  5  percent  level.  Only  the  ecomorphs  in  the  El 
Verde  forest  margin  show  nonsignificant  differences  in  propor- 
tions. In  summary,  we  can  conclude  that  at  our  study  sites  the 
trunk-ground  species  were  practically  allopatric,  whereas  the 
trunk-crown  species  overlapped  broadly. 

There  exists  a  second  way  in  which  the  degree  of  horizontal 
spatial  overlap  between  the  species  belonging  to  various  habitat 
categories  may  be  detected.  Museum  localities  are  usually  dis- 
tinguished horizontally,  that  is,  as  points  on  a  map.  Therefore,  we 
have  Usted  all  the  localities  at  which  specimens  of  the  six  common 
Puerto  Rican  species  from  the  Museum  of  Comparative  Zoology 
(Harvard)  and  the  University  of  Michigan  Museum  have  been 
collected.  There  were  91  such  localities  for  cristateUus  and  gund- 
lachi  combined,  and  only  7  of  these  (7.7%  )  were  held  in  common 
between  the  two  species.  In  contrast,  9  of  45  locahties  (20%) 
were  held  in  common  between  evermawu  and  stratiilus.  This  pro- 
portion was  significantly  different  by  a  chi-squared  test  (P  <  0.05). 
The  grass-bush  species,  kriigi  and  pulchellus,  were  intermediate  in 
this  regard:  8  of  59  localities  (13.6%)  were  held  in  common. 
This  proportion  did  not  differ  significantly  from  trunk-crown  or 
trunk-ground  species.  While  the  comparisons  involve  the  error 
that  not  all  species  inhabiting  a  given  locality  will  be  taken  by 
collectors,  usually  because  of  differential  abundance  and/or  acces- 
sibility, that  error  should  counteract  the  pattern  brought  out  in 
this  analysis.  That  is  to  say,  because  the  two  trunk-crown  species 
are  seen  less  often  and  are  more  difficult  to  capture,  there  is  less 
likelihood  of  both  being  collected  at  any  given  locality  than  both 
trunk-ground  forms. 

It  therefore  appears  clear  that  the  relatively  great  body-size 
difference  between  the  trunk-crown  species  in  Puerto  Rico  is 
associated  with  their  relatively  great  spatial  overlap.  Presumably 
this  size  difference  in  part  helps  the  species  to  avoid  resource  com- 
petition by  being  associated  with  and  facilitating  differences  in  the 
diet,  especially  with  regard  to  prey  size.  However,  while  the  asso- 
ciation is  presumably  adaptive,  the  mechanism  whereby  it  came 


14  BREVIORA  No.    375 

about  is  unclear.  That  is,  did  the  species  differ  in  size  to  begin 
with  and  so  were  able  to  overlap  spatially  when  they  came  together 
to  a  great  degree,  or  were  the  size  differences  largely  evolved  in 
response  to  a  predisposition  for  spatial  overlap  in  the  trunk-crown 
forms?  We  can  crystallize  the  relevant  problems  by  asking  three 
questions: 

1.  (a)  Why  should  any  of  the  three  structural  habitat 
groups  —  trunk-crown,  trunk-ground,  and  grass-bush  — 
contains  species  which  differ  markedly  in  size?  (b)  Why 
should  it  be  the  trunk-crown  group,  and  that  only,  which 
contains  such  species?  There  is  thus  an  existence  and 
uniqueness  part  to  this  question. 

2.  Given  that  the  trunk-crown  species  show  the 
greatest  size  differential,  why  should  the  lowland  dry- 
area  form  be  the  smaller,  and  the  upland  wet-area  form 
be  the  larger? 

3.  Why  should  the  lowland  trunk-crown  species  be 
much  less  sexually  dimorphic  in  size  than  the  upland 
species? 

We  can  gain  some  insight  into  the  first  question  by  ranking 
separately  for  upland  and  lowland  forest  the  modal  habitats  of 
the  three  kinds  of  species  on  a  darkness  or  humidity  or  coolness 
gradient  (we  assume  the  three  to  be  highly  correlated).  In  middle 
and  upper  elevation  forest,  such  as  that  at  El  Verde  and  Maricao, 
the  darkest  vegetation  is  the  understory,  and  the  most  exposed 
vegetation  lies  along  margins  and  in  the  canopy.  Therefore  we 
would  expect  the  trunk-ground  species,  which  primarily  inhabit 
the  lowest  layer  of  the  forest,  to  be  better  adapted  to  dark,  cool 
conditions  than  either  the  trunk-crown  species  —  found  largely 
in  the  canopy  or  somewhat  lower  —  or  the  grass-bush  species, 
found  mostly  along  margins.  However,  the  situation  is  different 
for  the  lowland  forest.  Much  lowland  forest  in  Puerto  Rico,  par- 
ticularly in  the  south,  is  and  must  have  been  for  some  time  of 
xeric  aspect.  It  is  characteristic  of  such  forest,  as  well  as  of  much 
coastal  woodland  elsewhere,  to  have  a  relatively  broken  canopy, 
with  much  light  penetrating  to  the  understory  and  with  the  largest 
trees  being  often  quite  dispersed.  The  patchiness  is  intensified 
during  the  dry  season  by  some  but  not  all  trees  undergoing  partial 
or  complete  leaf  drop.  The  darkest  places  for  an  arboreal  lizard 
in   such   veeetation   are  often    associated   with   the   largest  trees, 


1971  PUERTO   RICAN   ANOLIS  15 

especially  often  within  or  directly  under  the  crown.  Although  that 
fraction  of  the  understory  immediately  beneath  such  trees  will 
also  usually  be  shaded,  the  average  degree  of  shading  of  the  under- 
story as  a  whole  should  be  considerably  less  than  in  the  humid 
forest  of  middle  and  upper  elevations.  The  grass-bush  habitat 
should  be  even  less  shaded.  Consequently,  the  trunk-crown  habi- 
tat should  in  the  lowlands  be  on  the  average  the  darkest  and  cool- 
est; the  trunk-ground  habitat  should  be  intermediate  and  the 
grass-bush  habitat  should  be  on  the  average  the  hottest  and  most 
illuminated,  even  though  there  are  places  in  these  latter  two  habi- 
tats as  shaded  as  any  in  the  crown  and  on  the  upper  trunk.  It 
also  follows  that  within  the  lowland  trunk-ground  habitat,  there 
should  be  a  greater  diversity  of  shade  regimes  than  in  the  upland 
trunk-ground  habitat.  This  implies  that  in  the  lowlands  large 
adult  males,  which  prefer  thick  perches,  are  more  likely  to  find 
such  perches  shadier  than  the  average  small-diametered  perch 
preferred  by  the  females.  This  difference  should  scarcely  exist  for 
the  upland  species.  Therefore,  there  should  be  a  greater  intersexual 
difference  in  climatic  habitat  for  the  lowland  trunk-ground  form 
than  for  the  upland  trunk-ground  form. 

Matching  species  with  structural  habitat  and  combining  the 
upland  and  lowland  species  into  a  single  ranking,  as  would  be 
appropriate  for  the  many  intermediate  localities  on  the  island,  we 
should  obtain  from  sunniest  to  shadiest:  piilchelliis  >  cristatel- 
lus  >  stratulus  >=  evermanni  =  krugi  >  gundlachi.  Notice 
that  the  trunk-ground  and  grass-bush  species  are  widely  separated, 
but  that  the  trunk-crown  species  are  adjacent.  That  is,  the 
lowland  trunk-crown  species  should  occur  in  the  darkest  part 
of  its  habitat  and  the  upland  trunk-crown  species  in  the  sunniest 
part  of  its  habitat.  Consequently,  there  should  be  a  great  deal  of 
spatial  overlap  in  intermediate  areas  on  the  basis  of  climatic  habi- 
tat alone.  This  means  that  much  of  the  size  difference  could 
well  have  evolved  as  a  necessary  adjunct  to  climatic  preferenda 
of  the  trunk-crown  species,  preferenda  which  have  developed  inde- 
pendently of  one  another  as  adaptations  to  the  prevalent  vegeta- 
tional  structure.  No  such  size  difference  need  have  evolved  for 
the  trunk-ground  or  grass-bush  species,  farther  apart  on  the 
climatical  spectrum. 

The  temperature  data  of  Rand  (1964,  fig.  4),  particularly  those 
for  the  air,  fit  for  the  most  part  the  inequality  stated  above.    Thus, 


16  BREVIORA  No.    375 

among  the  primarily  lowland  species,  pulchellus  occurs  at  the 
warmest  temperatures,  cristatellus  at  cooler  temperatures,  (with 
great  variance,  perhaps  because  of  intersexual  differences)  and 
stratulus  the  coolest.  Almost  identical  to  stratulus  is  evermanni, 
whereas  gundlachi  is  about  the  same  as  evermanni  and  therefore 
warmer  than  predicted,  possibly  because  the  highest  evermanni 
could  not  be  sampled.  Values  for  gundlachi  fall  below  the  bulk 
of  the  cristatellus  observations.  Air  temperatures  for  krugi  are 
somewhat  higher  than  those  for  evermanni  but  markedly  below 
the  majority  of  the  pulchellus  observations. 

Rand  (1964)  also  provides  information  on  species  within  five 
locahties  as  to  their  degree  of  occurrence  in  shade.  This  again 
depicts  stratulus  and  evermanni  as  differing  little,  while  the  other 
groups  differ  a  good  deal.  Also  shown  is  that  cristatellus  and 
stratulus  can  be  fairly  similar  in  their  shade  occurrences,  though 
in  all  cases  stratulus  occupied  the  deeper  shade.  A.  gundlachi  and 
evermanni  are,  however,  very  different,  the  former  being,  of  course, 
more  often  in  shady  positions.  In  the  two  localities  where  both 
krugi  and  pulchellus  were  found,  they  showed  practically  no  over- 
lap in  their  shade  occurrences. 

The  climatic  data  we  have  gathered  at  Maricao,  which  are  of 
a  different  sort  than  those  presented  by  Rand,  also  support  the 
greater  similarity  of  the  trunk-crown  species  in  their  climatic 
habitats  than  the  trunk-ground  forms.  There  is  not  even  any 
consistent  tendency  for  one  or  the  other  of  stratulus  or  evermanni 
to  be  found  more  often  in  the  sun  among  the  Maricao  localities, 
although  evermanni,  if  any,  appears  commoner  there.  This  may 
in  part,  of  course,  be  an  artifact  of  observation;  at  El  Verde,  as 
we  judge  from  the  few  stratulus  data,  the  situation  appeared  to 
be  reversed.  The  two  trunk-ground  species  cannot  be  compared 
in  most  places  because  one  or  the  other  is  nearly  absent,  but  along 
the  secondary  road  edge,  as  mentioned,  gundlachi  was  much  more 
likely  to  be  seen  during  cloudy  weather.  At  El  Verde,  despite 
the  preponderance  of  overcast  skies,  cristatellus  were  seen  several 
times  more  frequently  in  the  sun  than  gundlachi. 

A  second  aspect  of  the  above  scheme  that  can  be  checked  from 
our  data  is  the  climatic  relation  between  trunk-ground  and  trunk- 
crown  forms.  Although  evermanni  and  gundlachi  showed  striking 
differences  in  the  expected  direction,  stratulus  and  cristatellus  did 
not.    In  fact,  stratulus  were  seen  significantly  more  often  in  the 


1971  PUERTO  RICAN  ANOLIS  17 

sun  in  the  open  area  at  Maricao  (see  above).  Possibly  this  was 
an  artifact  of  observation,  but  it  is  more  likely  that  in  the  shade 
cristaielliis  perches  averaged  warmer  than  did  those  of  stratidus 
because  of  the  more  exposed  nature  of  the  vegetation  on  which 
it  perched.  But  Heatwole  (1968;  Heatwole  et  ai,  1969)  showed 
that  individuals  of  stratidus  and  cristatellus  in  "an  open  park-like 
situation"  at  Rio  Piedras  did  not  differ  significantly  in  their  air 
or  substrate  temperatures.  However,  Heatwole  et  al.  (1969) 
have  found  that  even  under  apparently  identical  mean  environ- 
mental temperatures,  the  body  temperatures  of  stratulus  average 
lower  than  those  of  cristatellus.  Furthermore,  cristatellus  shows 
greater  resistance  to  high  temperatures  and  does  not  tolerate  low 
ones  as  well  as  stratulus. 

Heatwole  et  al.  conclude  both  from  these  physiological  prop- 
erties and  Rand's  data  that  "although  the  two  species  have  similar 
ecologies  and  distributions,  in  some  cases  coexisting  under  appar- 
ently identical  conditions,  there  is  a  tendency  for  A.  cristatellus  to 
utilize  the  warmer  (less  shaded)  habitats  than  A.  stratulus."  Their 
conclusion  agrees  well  with  the  scheme  we  have  outlined  above. 

The  second  question  posed  above  may  be  related  to  the  relative 
degree  of  overlap  between  trunk-ground  and  trunk-crown  forms 
in  the  two  areas.  If  we  could  show  that  the  lowland  species  are 
more  likely  to  overlap  spatially  than  the  upland  forms,  then  we 
could  argue  that  the  smaller  size  of  stratulus  may  have  evolved  in 
part  as  a  response  to  that  overlap  and  thus  served  as  a  preadapta- 
tion for  any  further  displacement  that  might  have  occurred  between 
the  trunk-crown  species.  Rand's  structural  habitat  grids  show 
practically  no  differences  in  percent  overlap  (62.5%  vs.  61%) 
between  the  two  species  pairs.  However,  his  data  were  from  sev- 
eral localities  and  all  size  classes  combined.  Even  if  only  adult 
males  are  considered  and  our  data  for  particular  locahties  used, 
results  are  inconsistent:  percent  overlap  for  evermanni  and  gund- 
lachi  is  35  percent  in  the  forest  interior  at  Maricao  and  72  per- 
cent at  El  Verde,  whereas  that  for  stratulus  and  cristatellus  is  30 
percent  along  the  Maricao  road  and  50  percent  in  the  Maricao 
open  forest.  It  is  possible  that  these  results  are  artifacts  of  the 
greater  difficulty  of  seeing  a  trunk-crown  species  in  the  canopy 
when  within  a  continuous  forest  than  when  along  a  forest  margin 
or  in  a  very  open  area.  That  error  would  tend  to  minimize  differ- 
ences between  evermanni  and  gundlachi  and  is  almost  certainly 


18  BREVIORA  No.    375 

in  part  responsible  for  the  high  overlap  value  at  El  Verde.  One 
might  argue,  a  priori,  that  because  of  the  greater  average  height 
of  rainforest  such  as  that  at  El  Verde,  overlap  between  two  spe- 
cies segregated  mainly  by  height  should  be  less  than  in  drier  forest. 
Furthermore,  even  though  the  species  are  physiologically  adapted 
to  different  thermal  environments,  it  is  possible  that  in  the  dry 
lowlands  the  greater  danger  of  desiccation  forces  cristatelliis  and 
stratuliis  together  in  shaded  situations  during  a  large  portion  of 
the  day;  in  the  uplands,  however,  no  such  problem  need  arise, 
and  the  more  exposed  species,  in  this  case  evermarmi,  can  occur 
in  sunny  or  open  places  most  of  the  day.  This  is  perhaps  the  rea- 
son why  less  difference  was  found  between  the  climatic  habitats 
of  cristatellus  and  stratuliis  than  between  gnndlaclii  and  evermanni 
in  our  study.  Any  overlap  between  the  first  pair  should  be  espe- 
cially severe  for  male  cristatellus  because  they  more  frequently 
occupy  the  relatively  large  trees  which  stratulus  inhabit. 

If  the  explanation  above  be  correct,  that  is,  had  stratulus  evolved 
small  size  in  part  to  alleviate  competition  with  male  cristatellus, 
then  the  reduced  sexual  dimorphism  of  stratulus  would  automati- 
cally follow,  since  it  is  the  male  that  would  be  displaced. 

ACKNOWLEDGMENTS 

We  thank  G.  E.  Drewry,  A.  S.  Rand,  T.  P.  Webster,  and  E.  E. 
Williams  for  critical  comments  on  the  manuscript  and  S.  D.  Fien- 
berg  for  statistical  advice.  We  also  thank  G.  E.  Drewry  for  his 
hospitality  at  the  Puerto  Rican  Nuclear  Center  field  station  at 
El  Verde  and  K.  Horton  for  typing  the  tables  photographed  directly 
for  this  article.  Rand,  Webster  and  Williams  were  all  in  the  field 
with  us  during  some  part  of  this  study,  and  their  previous  experi- 
ence with  the  island  greatly  facilitated  our  work.  In  addition, 
Williams  and  W.  P.  Hall  III  contributed  some  observations  to  our 
data  from  El  Verde.  Research  was  partly  supported  by  NFS 
grants  GB  6944  and  B  01 980 IX  to  E.  E.  Williams. 

STATISTICAL  APPENDIX 

This  appendix  briefly  reiterates  the  description  of  the  statistical 
treatment  of  the  structural  and  climatic  habitat  data  given  in  detail 
elsewhere  (Schoener  and  Schoener,  1971).  Four  variables  — 
lizard  class,  climatic  category,  perch  height  and  perch  diameter  — 
were  used  to  set  up  4-way  contingency  tables.    For  the  lizard  and 


1971  PUERTO  RICAN  ANOLIS  19 

climatic  variables,  two  (the  classes  being  compared)  and  three 
(sun,  shade,  and  clouds)  categories  (levels),  respectively,  were 
used.  For  perch  height  and  diameter,  two  levels  each  were  chosen 
by  separately  determining  the  point  of  maximum  difference  in 
cumulative  frequency  between  the  distributions  of  the  habitat 
variable  for  the  two  lizard  classes  being  compared.  Data  were 
broken  at  this  point,  all  observations  less  than  or  equal  to  that 
number  being  cast  into  one  category  and  all  greater  than  that 
number  being  cast  into  the  other.  Table  12  lists  critical  values 
for  height  and  diameter  groupings.  As  before,  an  iterative  pro- 
cedure (Deming  and  Stephan,  1940;  Bishop,  1969;  Fienberg, 
1970)  was  used  to  fit  the  data  to  models  containing  all  six  2-way 
interactions.  One  by  one,  interactions  were  dropped  if  differences 
between  models  were  not  significant  at  the  5  percent  level  accord- 
ing to  difference  in  the  log-likelihood  ratio  chi-square  (Kullback, 
1959;  Ku  and  Kullback,  1968).  Results  are  summarized  in 
Tables  9-1 1 .  The  following  key  applies  to  the  numbers  in  the 
body  of  the  table: 

1  —  the  interaction  was  significant  every  time  it  was  tested  in 
the  removal  procedure; 

2  —  the  interaction  was  significant  at  least  at  the  termination 
of  the  procedure; 

3  —  the  interaction  was  significant  when  removed  from  the  most 
inclusive  model    (with  six  interactions)   but  not  at  termination; 

4  —  the  interaction  was  significant  sometime  during  the  pro- 
cedure but  not  at  the  beginning  or  end; 

0  —  the  interaction  was  never  significant. 
As  can  be  seen,  nearly  all  interactions  could  be  labelled  "0"  or 
"l."  There  was  no  set  of  models  for  a  particular  4-way  table 
which  never  gave  a  x"  value  denoting  a  satisfactory  fit  of  the  model 
at  the  5  percent  level,  regardless  of  what  interactions  were  re- 
moved. Therefore  we  did  not  test  for  3-way  interactions.  There 
were  only  three  tables  with  zero  margins.  These  could  be,  and 
therefore  were,  handled  in  the  way  given  by  Fienberg   (1970). 

LITERATURE    CITED 

Bishop,  Y.  M.  M.  1969.  Full  contingency  tables,  logits,  and  split  con- 
tingency tables.    Biometrics,  25:   383-400. 

Deming,  W.  E.,  and  F.  F.  Stephan.  1940.  On  a  least  squares  adjustment 
of  a  sampled  frequency  table  when  the  expected  marginal  totals  are 
known.    Ann.  Math.  Stat.,  11:  427-444. 


20  BREVIORA  No.    375 

FiENBERG,  S.  E.  1970.  The  analysis  of  multidimensional  contingency 
tables.    Ecology,   51:   419-433. 

Heatwole,  H.     1968.     Relationship  of  escape  behavior  and  camouflage  in 

anoline  lizards.     Copeia,  1968:   109-113. 
,  T.  Lin,  E.  Villalou,   A.   Muniz,  and  A.   Matta.      1969. 

Some  aspects  of  the  thermal  ecology  of  Puerto  Rican  anoline  lizards. 

J.  Herpetology,  3:  65-78. 

Kline,  J.  R.,  C.  F.  Jordan,  and  G.  E.  Drewry.  1967,  1968.  The  rain 
forest  project  annual  reports.   Puerto  Rico  Nuclear  Center,  Puerto  Rico. 

Ku,  H.  H.,  and  S.  Kullback.  1968.  Interactions  in  multi-dimensional 
contingency  tables:  an  information  theoretic  approach.  J.  Res.  Natl. 
Bur.  Standards  -  Mathematical  Sciences,  728:    159-199. 

Kullback,  S.  1959.  Information  Theory  and  Statistics.  Dover  Publica- 
tions, New  York. 

Odum,  H.  T.  1965.  The  rain  forest  project  annual  report  FY-65.  Puerto 
Rico  Nuclear  Center,  Puerto  Rico. 

Pico,  R.  1950.  The  geographic  regions  of  Puerto  Rico.  Univ.  Puerto  Rico 
Press.    Rio  Piedras,  Puerto  Rico.    256  pp. 

Rand,  A.  S.  1964.  Ecological  distribution  in  anoline  lizards  of  Puerto 
Rico.    Ecology,  45:   745-752. 

,  and  E.  E.  Williams,  1969.    Anoles  of  La  Palma:  aspects  of 

their  ecological  relationships.     Breviora,  No.  327:    1-19. 

Schoener,  T.  W.  1968.  The  Anolis  lizards  of  Bimini:  resource  partition- 
ing in  a  complex  fauna.    Ecology,  49:  704-726. 

. 1969.     Size  patterns  in  West  Indian  Anolis  lizards.     I.     Size 

and  species  diversity.    Syst.  Zool.,   18:    386-401. 

1970.       Nonsynchronous    spatial    overlap     of    lizards     in 


patchy  habitats.    Ecology,  51:  408-418. 
,    AND    A.    Schoener.      1971.      Structural    habitats    of    West 


Indian  Anolis  lizards.    I.    Lowland  Jamaica.    Breviora,  No.  368:    1-53. 

Webster,  T.  P.  1969.  Ecological  observations  on  Anolis  occult  us  Wil- 
liams and  Rivero  (Sauria,  Iguanidae).     Breviora,  No.  312:   1-5. 

Williams.  E.  E..  and  A.  S.  Rand.  The  structure  of  diversity  in  Anolis  liz- 
ards,   in  prep. 

,    J.    A.    RivERO,    AND    R.    Thomas.      1965.      A    new    anole 

(Sauria,  Iguanidae)   from  Puerto  Rico.     Breviora,  No.  231:    1-18. 


1971  PUERTO  RICAN  ANOLIS  21 


TABLES 


22 


BREVIORA 


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PUF.RTO   RICAN   ANOI.IS 


23 


Table  2.   cliiratic  and  geographic  occurrence  of  Puerto  Rican  anoles. 


Percent  Occurrence 


Lizard  Class 


Sun 


Shade    Clouds 


Maricao,  forest  interior 


evermanni 

adult 
male 

everraanni 

small 

gundlachi 

adult 
male 

gundlachi 

small 

stratulus 

adult 
male 

stratulus 

small 

cristatellus 

adult 

male 

crista tellus 

small 

krugi 

adult 
male 

krugi 

small 

cuvieri 

large 

aricao,  forest,  clea 

evermanni 

adult 
male 

evermanni 

small 

gundlachi 

adult 
male 

gundlachi 

small 

stratulus 

adult 
male 

stratulus 

small 

cristatellus 

adult 

male 

cristatellus 

small 

krugi 

adult 
male 

I-.rugi 

small 

cuvieri 

large 

53.8 


11.5 


50.0 


28.6 

0 

0 
33.3 

9.1 


66.7 


16.7 

57.1 
25.0 

16.0 
0 

18.2 


33.3 


Sun  or   Sample 
Shade     Size 


34.6 


44 

.4 

22 

.2 

27.8 

17 

1 

34 

.3 

45.7 

15 

6 

32 

4 

48.0 

31 

8 

4 

5 

63.6 

31 

8 

13. 

6 

47.7 

0 

0 

100.0 

50.0 


83.3 

14.3 
75.0 

84.0 
66.7 

72.7 


5.6 
2.9 

4.0 
0 

6.8 
0 


26 

36 
70 

173 
22 

4  4 

1 

0 
2 

0 

1 


14 
8 

25 
6 

11 
0 

6 
0 

0 
0 


Percent 

Compo- 
sition 


6.9 

9.6 

18.7 

46.1 
5.9 

11.7 
0.3 


0.5 

0.3 

7.9 

18.4 
10.5 

32.9 
7.9 

14.5 
7.9 


24 

BREVIORA 

No.  375 

ass 

Percent 

Occurrence 

Sample 
Size 

Lizard  CI 

Sun 

Shade 

Clouds 

Sun  or 
Shade 

Percent 
Compo- 
sition 

Maricao,  open 

forest 

evermanni 

adult 
male 

33.3 

28.6 

33.3 

4.8 

21 

6.2 

evermanni 

small 

44.9 

28.6 

20.4 

6.1 

49 

14.5 

gundlachi 

adult 
male 

0 

gundlachi 

small 

12.5 

50.0 

25.0 

12.5 

8 

2.4 

stratulus 

adult 
male 

40.5 

8.1 

45.9 

5.4 

37 

11.0 

stratulus 

small 

22.9 

37.1 

37.1 

2.9 

35 

10.4 

crista tellus 

adult 
male 

22.0 

26.0 

50.0 

2.0 

50 

14.8 

cristatellus 

small 

22.4 

32.0 

41.6 

4.0 

125 

37.1 

krugi 

adult 
male 

28.6 

42.9 

28.6 

0 

7 

2.1 

krugi 

small 

0 

60.0 

40.0 

0 

5 

1.5 

cuvieri 

large 

0 

Maricao,  secondary  road 

edge 

evermanni 

adult 
male 

78.3 

0 

21.7 

0 

23 

8.3 

evermanni 

small 

69.2 

7.7 

23.1 

0 

13 

4.7 

gundlachi 

adult 
male 

11.1 

27.8 

61.1 

0 

18 

6.5 

gundlachi 

small 

15.6 

3.1 

78.1 

3.1 

32 

11.5 

stratulus 

adult 
male 

55.6 

7.4 

33.3 

3.7 

54 

19.4 

stratulus 

small 

59.5 

8.3 

31.0 

1.2 

84 

30.2 

cristatellus 

adult 
male 

33.3 

33.3 

16.7 

16.7 

6 

2.2 

cristatellus 

small 

36.8 

21.1 

31.6 

10.5 

19 

6.8 

krugi 

adult 
male 

0 

25.0 

50.0 

25.0 

4 

1.4 

krugi 

small 

4.0 

16.0 

76.0 

4.0 

25 

9.0 

cuvieri 

large 

0 

El  Verde,  interior 

evermanni 

adult 
male 

5.6 

33.3 

61.0 

0 

18 

5.6 

evermanni 

small 

3.9 

27.6 

68.6 

0 

51 

15.7 

gundlachi 

adult 
male 

7.1 

32.5 

59.8 

0.6 

169 

52.2 

gundlachi 

small 

5.4 

41.9 

52.7 

0 

74 

22.8 

1971  PUERTO  RICAN  ANOLIS  25 


stratulus 

adult 
male 

100.0 

0 

0 

0 

1 

0.3 

stratulus 

small 

33.3 

33.3 

33.3 

0 

6 

1.9 

cristatellus 

adult 
male 

0 

cristatellus 

small 

0 

krugi 

adult 
male 

50.0 

0 

50.0 

0 

2 

0.6 

krugi 

small 

0 

0 

100.0 

0 

4 

1.2 

cuvieri 

small 

0 

0 

100.0 

0 

1 

0.3 

El  Verde,  edge 

evermanni 

adult 
male 

46.2 

23.1 

30.8 

0 

13 

9.5 

evermanni 

small 

27.8 

16.7 

55.6 

0 

18 

13.1 

gundlachi 

adult 
male 

8.3 

36.1 

52.8 

2.8 

36 

26.3 

gundlachi 

small 

13.3 

26.7 

60.0 

0 

15 

10.9 

stratulus 

adult 
male 

67.7 

0 

33.3 

0 

3 

2.2 

stratulus 

small 

37.5 

12.5 

37.5 

0 

8 

5.8 

cristatellus 

adult 
male 

50.0 

0 

50.0 

0 

6 

4.4 

cristatellus 

small 

25.0 

25.0 

50.0 

0 

8 

5.8 

krugi 

adult 
male 

16.7 

16.7 

66.7 

0 

6 

4.4 

krugi 

small 

21.7 

26.1 

52.2 

0 

23 

16.8 

cuvieri 

small 

100.0 

0 

0 

0 

1 

0.7 

26 


BREVIORA 


No.  375 


Table  3.   Maricao  secondary  road  edge.   Percent  observations  in 
various  structural  habitat  categories.   H  =  >20';  G  =  ground;  R  = 
rocks;  N  =  sample  size. 


^^^^iameter 

Ht.  ^-^in.) 

(feet)  ^-v,^^^ 

>5 

5-2  1/2    2 

1/4-7/8 

7/8-1/8 

le 

aves 

Total 

N  =  54 

male 

stratulus    H  =  11 

G  =  0    R  = 

•  0 

10.5-20 

4 

17 

4 

0 

0 

25 

5-10 

9 

17 

6 

0 

0 

32 

3-4  3/4 

9 

4 

4 

0 

0 

17 

<3 

9 

4 

4 

0 

0 

17 

Total 

31 

42 

18 

0 

0 

N  =  84 

small 

stratulus 

H  =  2 

G  =  0    R  = 

=  0 

10.5-20 

4 

8 

7 

1 

0 

20 

5-10 

4 

13 

13 

6 

0 

36 

3-4  3/4 

2 

6 

5 

5 

0 

18 

<3 

10 

6 

6 

1 

2 

23 

Total 

20 

33 

31 

13 

2 

N  =  6 

male 

cristatellus 

H  =  0 

G  =  0    R 

=  0 

10.5-20 

0 

0 

0 

0 

0 

0 

5-10 

0 

0 

0 

0 

0 

0 

3-4  3/4 

17 

17 

0 

0 

0 

34 

<3 

33 

17 

17 

0 

0 

77 

Total 

50 

34 

17 

0 

0 

N  =  19 

small 

cristatellus  H  =  0 

G  =  11 

R  = 

0 

10.5-20 

0 

0 

0 

0 

0 

0 

5-10 

0 

0 

0 

0 

0 

0 

3-4  3/4 

5 

0 

0 

0 

0 

5 

<3 

16 

26 

26 

16 

0 

84 

Total 


21 


26 


26 


16 


97: 


PUERTO   RICAN   ANOLIS 


27 


N  =  23 

male 

everinanni 

H 

=  4 

G  =  0 

R  = 

0 

10.5-20 

22 

17 

0 

0 

0 

39 

5-10 

9 

13 

0 

0 

4 

26 

3-4  3/4 

17 

0 

0 

0 

0 

17 

<3 

13 

0 

0 

0 

0 

13 

Total 

61 

30 

0 

0 

0 

N  =  13 

small 

evermanni 

H 

=  0 

G  =  0 

R  = 

0 

10.5-20 

0 

8 

0 

0 

0 

8 

5-10 

0 

15 

0 

0 

8 

23 

3-4  3/4 

8 

0 

0 

0 

0 

8 

<3 

46 

15 

0 

0 

0 

61 

Total 

54 

38 

0 

0 

8 

Table  4.  Maricao  open  forest.  Percent  observations  in  various 
structural  habitat  categories.  H  =  >20';  G  =  ground;  R  =  rocks;  N  = 
sample  size. 


JDiameter 
Ht.  ^\^(in.) 
(feet) 


>5    5-2  1/2    2  1/4-7/8    7/8-1/8    leaves    Total 


N  =  37 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 


male  stratulus 

H 

=  0 

G  = 

=  0 

R  = 

=  0 

0     22 

0 

0 

0 

8      16 

11 

5 

0 

3       3 

0 

5 

0 

5      19 

3 

0 

0 

22 

40 
11 
27 


14 


10 


N  =  35 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 


small  stratulus 

H  = 

0 

G  = 

=  0 

R  = 

=  0 

0      3 

0 

0 

0 

3      6 

19 

13 

0 

9      0 

11 

9 

0 

14       9 

6 

0 

0 

3 

41 
29 
29 


26 


18 


36 


22 


28 


BREVIORA 


No.  375 


N  =  50 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 

•M  =  12  5 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 

N  =  21 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 


male 

cristatellus 

H  = 

=  0 

G 

=  6 

R  = 

=  0 

0 

6 

0 

0 

0 

4 

4 

10 

2 

0 

8 

0 

12 

2 

0 

.20 

10 

7 

7 

2 

32 


20 


29 


11 


small 

crista 

te 

llus 

H  = 

0 

G  = 

12 

R 

=  1 

0 

2 

0 

0 

0 

0 

2 

5 

2 

0 

2 

2 

2 

3 

1 

11 

23 

16 

15 

2 

13 


29 


23 


20 


male 

evermanni 

H 

=  0 

G  = 

=  10 

R  = 

0 

5 

19 

7 

2 

0 

5 

5 

14 

5 

0 

10 

5 

0 

0 

0 

14 

0 

0 

0 

0 

6 
20 
22 

46 


2 

9 

9 

67 


33 
29 
15 

14 


34 


29 


21 


N  =  49 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 


small 

evermanni 

H  = 

6 

G 

=  2 

R  = 

0 

2 

6 

2 

4 

0 

4 

6 

12 

10. 

0 

0 

2 

4 

0 

0 

16 

10 

8 

2 

2 

14 

32 

6 

38 


22 


24 


26 


16 


1971 


PUERTO  RICAN  ANOLIS 


29 


Table  5.   Maricao  forest  with  cleared  understory.   Percent 
observations  in  various  structural  habitat  categories.   H  =  >20' 
G  =  ground;  R  =  rocks;  N  =  sample  size. 


^iameter 
Ht.  ^^-.^^in.) 
(feet) 


>5    5-2  1/2    2  1/4-7/8    7/8-1/8    leaves   Total 


N  =  6 

10.5-20 
5-10 
3-4  3/4 
<3 

Total 


male 

stratulus 

H 

=  50 

G  = 

0 

R  =  0 

0 

17 

0 

0 

0 

17 

17 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

17 

34 

0 

0 


N  =  11 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 


small 

stratulus 

H 

= 

0 

G  = 

0 

R  =  0 

0 

9 

0 

0 

0 

9 

18 

9 

9 

0 

0 

0 

0 

0 

0 

18 

18 

9 

0 

0 

9 

45 

0 

45 


27 


45 


N  =  8 

10.5-20 
5-10 
3-4  3/4 
<3 

Total 


male  gundlac 

hi 

H 

=  0 

G  = 

=  0    R  = 

0 

0      0 

0 

0 

0 

0      12 

12 

25 

0 

0      12 

0 

12 

0 

0       0 

19 

6 

0 

0 
49 
24 
25 


24 


31 


43 


N  =  25 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 


small  gundlachi 

H  = 

0 

G  = 

=  0 

R  = 

=  0 

0      0 

0 

0 

0 

4      4 

4 

4 

0 

0      16 

8 

4 

0 

4      12 

28 

12 

0 

0 
16 
28 
56 


32 


40 


20 


30 

BREVIORA 

No 

.  375 

N  =  6 

male 

evermanni 

H  =  0 

G  =  0    R  =  0 

10.5-20 

17 

0 

0 

0 

17 

34 

5-10 

0 

33 

17 

0 

0 

50 

3-4  3/4 

0 

0 

0 

0 

0 

0 

<3 

0 

17 

0 

0 

0 

17 

Total 

17 

50 

17 

0 

17 

N  =  14 

small 

evermanni 

H  =  0 

G  =  7    R  =  0 

10.5-20 

0 

0 

0 

0 

0 

0 

5-10 

7 

14 

14 

0 

0 

35 

3-4  3/4 

0 

0 

0 

0 

0 

0 

<3 

36 

21 

0 

0 

0 

57 

Total 

43 

35 

14 

0 

0 

Table  6.   Maricao  forest  interior, 
various  structural  habitat  categories, 
rocks;  N  =  sample  size. 


Percent  observations  in 
H  =  >20';  G  =  ground;  R  = 


^\Diameter 
Ht.  ^\(in.) 
(feet)  ^v^ 

>5 

5-2  1/2 

2  1/4-7/8    7/8-1/8 

leaves 

Total 

N  =  22 

male 

stratulus 

H  =  5    G  =  0 

R  = 

0 

10.5-20 

0 

32 

5          0 

0 

37 

5-10 

5 

14 

7         11 

5 

42 

3-4  3/4 

0 

0 

9          0 

0 

9 

<3 

5 

5 

0          0 

0 

10 

Total 

10 

51 

21          11 

5 

N  =  44 

small 

stratulus 

H  =  2    G  =  2 

R 

=  0 

10.5-20 

2 

2 

2          2 

2 

10 

5-10 

5 

5 

16         11 

7 

44 

3-4  3/4 

0 

0 

2          2 

0 

4 

<3 

2 

9 

20           2 

2 

35 

Total 


16 


40 


17 


11 


1971 


PUERTO   RICAN  ANOLIS 


31 


N 

=  70 

10.5-20 

5-10 

3-4  3/4 

<3 

Total 

N 

=  173 

10.5-20 

5-10 

3-4  3/4 

<3 

Total 

N 

=  26 

10.5-20 

5-10 

3-4  3/4 

<3 

Total 

N  =  36 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 


male  gundlachi 

H 

=  0 

G  = 

1    R  =  0 

0      0 

0 

0 

0 

4      4 

6 

4 

0 

1     11 

13 

7 

1 

9     11 

11 

13 

1 

14 


26 


small  gundlachi 

0  0 

1  1 
0  1 
3      9 


30 

H  =  0 

0 

0 

5 

23 


G  = 


24 

8 
0 
3 
4 

29 


R  =  1 


0 

0 

1 

11 


35 


24 


20 


4     11 

28 

36 

12 

male  evermanni 

H 

=  8 

G  = 

=  0    R  = 

=  0 

15      4 

8 

0 

0 

12      12 

12 

8 

0 

0      8 

0 

0 

8 

8       0 

0 

0 

0 

0 
18 
33 
45 


0 
5 

11 
75 


27 
44 
16 


small 

evermanni 

H  = 

3 

G 

=  3 

R  = 

0 

0 

8 

11 

0 

0 

0 

6 

17 

14 

3 

0 

3 

6 

3 

3 

0 

6 

8 

8 

0 

19 
40 
15 
24 


23 


42 


25 


32 


BREVIORA 


No.  375 


Table  7.   El  Verde.   Percent  observations  in  various  structural 
habitat  categories.   H  =  >20';  G  =  ground;  R  =  rocks;  N  =  sample  size. 


^^"'----.Diaineter 

Ht.^^^in.) 

(feet)  ^^..^^ 

>5 

5-2  1/2 

2  1/4-7/0 

7/8-1/8 

leaves 

Total 

N  =  205 

male 

gundlachi 

H  =  0    G  =  2 

R  = 

1 

10.5-20 

0 

3 

0 

0 

0 

3 

5-10 

15 

10 

12 

7 

0 

44 

3-4  3/4 

8 

12 

9 

3 

0 

32 

<3 

9 

4 

2 

1 

0 

16 

Total 

32 

29 

23 

11 

0 

N  =  89 

small 

gundlachi 

H  =  0   G 

=  4 

R 

=  3 

10.5-20 

0 

0 

0 

0 

0 

0 

5-10 

0 

8 

8 

6 

1 

23 

3-4  3/4 

4 

5 

9 

10 

0 

28 

<3 

6 

12 

9 

12 

0 

39 

Total 

10 

25 

26 

28 

1 

N  =  31 

male 

evermcinni 

H  =  0    G  = 

=  3 

R  = 

0 

10.5-20 

6 

0 

6 

0 

0 

12 

5-10 

16 

3 

10 

6 

3 

38 

3-4  3/4 

13 

3 

13 

0 

0 

29 

<3 

10 

3 

3 

0 

0 

16 

Total 

45 

9 

32 

6 

3 

N  =  69 

small 

evermanni 

H  =  1    G 

=  6 

R 

=  3 

10.5-20 

6 

1 

0 

1 

1 

9 

5-10 

1 

4 

12 

9 

6 

32 

3-4  3/4 

4 

3 

3 

9 

0 

19 

<3 

13 

9 

2 

4 

0 

28 

Total 

24 

17 

17 

23 

7 

1971 


PUERTO  RICAN  ANOLIS 


33 


Table  8.   A.  krugi,  all  localities  combined.   Percent  observa- 
tions in  various  structural  habitat  categories.   H  =  >20';  G  =  ground; 
R  =  rocks;  N  =  sample  size. 


^iameter 
Ht.  ^\(in.) 
(feet) 


>5    5-2  1/2    2  1/4-7/8   7/8-1/8    leaves   Total 


N  =  33 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 

N  =  83 
10.5-20 
5-10 
3-4  3/4 
<3 

Total 


male  krugi 
0  3 
0  0 
0  0 
0      0 


H  =  0    G 

0 

6 

12 

3 


0 


R  =  0 
3 
30 
6 

12 


21 


51 


0 

15 

6 

3 


24 


small  krugi 

H  = 

0 

G  = 

4 

R  =  0 

0      0 

0 

0 

0 

0      0 

0 

1 

5 

0      0 

0 

7 

16 

0      0 

2 

11 

54 

6 
51 
24 
18 


0 

6 

23 

67 


19 


75 


34 


BREVIORA 


No.   375 


w 

G 
O 
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u 

(fl 
(1) 

to 

C 
0) 

o 

0 
«3 
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■M 

m 

s 

u 
o 

O 

o 
c 
(0 
o 

•H 

c 

en 

■H 


n3 
o 

•H 

tn 
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en 


0) 


en  0) 
> 

0) 


ITS 


tn 

0 

i-\ 

rH 

0) 

rH 

+J 

iH 

fl 

(0 

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e 

tn 

U) 

■H 

i-i 

u 

tn 

:3 

iH 

tH 

(U 

0) 

iH 

+J 

03 

(0 

g 

-M 

tn 

•H 

M 

U 

H      H      H 


*       *       * 

O      <H      r-H      iH 


rH 


CO 

en 

3 

3 

rH 

CO 

r-i 

rH 

•rl 

CO 

3 

rH 

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c 

3 

rH 

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-P 

C 

c 

iH 

3 

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03 

C 

(13 

3 

+J 

(0 

p 

(0 

P 

+J 

(0 

+J 

tn 

E 

S^ 

(fl 

U 

CO 

•H 

M 

0) 

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4J 

■H 

u 

Q) 

> 

+J 

CO 

^ 

u 

> 

Q) 

CO 

U 

(U 

03 

e 

(0 


03 


oj 

e 

en 


03 

e 


03 

e 

en 


* 
Q 


Q      U 


m 


u    u 


pq 


U     U 


CQ 


(U    CO  -H 


pq 


PQ 


CQ 


tn 

tn 

3 

3 

H 

tn 

rH 

rH 

•rl 

tn 

3 

rH 

Q) 

•rl 

C 

3 

H 

0) 

4J 

C 

c 

rH 

3 

p 

03 

G 

OJ 

3 

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03 

4-> 

08 

e 

JJ 

03 

4J 

tn 

e 

^ 

03 

M 

to 

•H 

M 

tu 

sh 

+) 

■r) 

>H 

<u 

> 

4J 

tn 

U 

tj 

> 

(U 

to 

u 

0) 

(U 


0) 

e 


03 


(1)  rH  0)  rH 

rH  03  rH  03 

OJ  g  5  6 

6  tn  E  CO     S     to 


1971 


PUERTO  RICAN  ANOLIS 


35 


t(     Cn     Cm     fc, 
H      H      H      fM 


O     O 


O      O 


O      O 


M 

w 

3 

3 

-H 

03 

r-l 

rH 

•H 

w 

3 

iH 

(D 

•H 

c 

3 

rH 

Q) 

-p 

c 

c 

<-i 

3 

-p 

(0 

c 

nj 

P 

-P 

nJ 

4J 

(0 

e 

-P 

(0 

•p 

01 

£ 

H 

(0 

M 

w 

•H 

V-i 

<i> 

U 

-P 

•H 

>-< 

0) 

> 

-P 

in 

^ 

o 

> 

0) 

(0 

0 

(U 

0)     H 


0) 

rH 

(0 


to 
g 


(0 
6 

01 


»3 

CO 

•OT3 

3 

3 

^ 

_o 

"o 

"o 

T3 

c 

C 

"^ 

ca 

4-* 

CO 

v 

<u 

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cs 

o 

XI 

•4— • 

_c 

T3 
C 

<u 

03 

u 

o 

C 

s 

3 

o-  II 


1)-' 
x:  _ 

^"§ 

CO   C 


(1)     c/5 


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>< 

«  -Q 
C  C 

lo    C    oj 

3    D. 

CQ--: 
(u  oj  ■;: 

3  J=    t« 
C/5 


■2    C    CO 

ra    3    u. 

X    c/5    OJ 

X 

o  c  5 


c/5     Ca 

^ 

OX 

C 

u 

O 

S 

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IJ 

Q. 

c 


36 


BREVIORA 


No.  375 


0) 

u 

u 
o 

•H 

u 

0) 

-p 
c 

-H 

o 

n3 
O 
•H 

u 

M 

o 
m 

(U 

u 
c 

(0 

u 

•H 

m 

•H 

c 

en 

•H 

w 

rH 

o 

•rH 

4-1 

m 

•H 

4J 


(0 


CO    0) 

> 


•H 

C 

c 

Q) 

0) 

rH 

e 

IB 

)-i 

e 

Q) 

> 

0) 

•H 
3 


•rH 

Xl 

u 

rH    H 

e  G 


U3 

H    rH 

CO 


W 

3 

rH 

(U 

3 

H 

H-> 

fl 

m 

g 

^ 

-p 

CO 

He 


■K 

rH 


tS) 


OJ 


m 

•H 

•H 

to 

^ 

■H 

x; 

•H 

C 

3 

^ 

u 

c 

c 

rH 

3 

o 

fl 

c 

to 

3 

+J 

(0 

H 

OJ 

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(0 

rH 

T) 

g 

p 

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3 

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tn 

3 

Di 

> 

0) 

(0 

tJ> 

0 

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E 


(0 
6 


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6 


g 


(U    W    H 


Q     Q     U     U 


U     U 

O       O       CN       rH 


*        * 

u    u 

H     H     O 


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<   < 


tn 

-H 

w 

3 

•H 

a:: 

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3 

rH 

X! 

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rH 

3 

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nJ 

C 

3 

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m 

H 

nj 

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g 

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u 

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c 

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3 

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w 

Cn 

0) 

(0 

g 


H 

g 
en 


g 


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c: 

g 
u 

> 


(0 
E 
C/3 


1971 


PUERTO  RICAN  ANOLIS 


37 


5  5 

(N      O      O      O       fN 


O      O      O      O  O 


•3 


o    o    o  o    o 


O  o      o     o 


O  O      o      o     O 


o    o     o     o    o 


tn 

•H 

•rH 

w 

3 

•H 

x: 

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c 

3 

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^ 

u 

C 

c 

rH 

3 

u 

(0 

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fd 

3 

■P 

(fl 

H 

m 

H 

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(fl 

rH 

13 

g 

M 

(0 

M 

T) 

c 

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Q) 

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G 

3 

0) 

> 

■P 

m 

3 

Di 

> 

QJ 

W 

D^ 

0) 

0)  iH  dJ  rH  (1)  H 

iH  (0  iH  nj  >H  ftj 

(0  g  (0  e  2  s 

g  in  g  ui  6  w 


3    N 

O 

T!    (/3 

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_  -C 

•73 

^    II 

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u.S 

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III 

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U    3 

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2i  ll  =  . 

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—    3    0, 

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l""^ 

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,,  ='-^ 

c^    ^ 

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C3 

Q  E 

38 


BREVIORA 


No.  375 


Table   11.      Statistical   significance   for  El  Verde." 


^^^^Group  vs. 

Gro^i^^i^ht 

vs.      ^""~\^ 

male 

small 

male 

small 

Diameter   ^""^ 

evermanni 

evermanni 

gundlachi 

gundlachi 

male  evermanni 

1 

2 

1 

small  evermanni 

1* 

1* 

1 

male  gundlachi 

0 

1 

1 

small  gundlachi 

1* 

1* 

1* 

^"^^^Group  vs. 

Hei^h^-^°1^^^°'^ 

vs.      ^"^-^^ 

diameter     ^~^--^^^ 

male  evermanni 

0 

0 

0 

small  evermanni 

0 

0 

0 

male  gundlachi 

0 

0 

0 

small  gundlachi 

1(A) 

0 

0 

^""--.^eight  vs. 

^^^^insolaticn 

Diameter^^^^^ 

vs.        ^^-^^^ 

insolation     ^~^^ 

-^ 

male  evermanni 

0 

0 

1(F) 

small  evermanni 

0 

0 

0 

male  gundlachi 

1(K) 

0 

0 

small  gundlachi 

2(L) 

0 

0 

"  *  =  species  at  top  has  larger  value;  A  =  small  diameters  at  low  perches; 
F  =  highest  in  sun  and  lowest  in  shade;  K  =:  thickest  in  sun  and  thinnest 
in  shade;  L  r=  thinnest  in  shade  and  thickest  in  clouds:  for  interpretation 
of  numbers,  see  "Statistical  appendix." 


1971 


PUERTO  RICAN  ANOLIS 


39 


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(0    g 

> 


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0)  Xi 

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\  \  \  \  \ 

rH  n  iH  iH  iH 

rH  CN  IX)  fN  CO 


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BREVIORA 

Mmseiuinii   of   Coiniiparative    Zoology 

Cambridge,  Mass.  15  June,  1971  Number  376 


Podocnemis  venezuelensis,  a  new  fossil  pelomedusid  (Tes- 
tudines,  Pleurodira)  from  the  Pliocene  of  Venezuela  and 
a  review  of  the   history  of  Podocnemis  in  South   America 

Roger   Conant   Wood^ 

and 

Maria  Lourdes  Diaz  de  Gamero- 

Abstract.  Podocnemis  venezuelensis,  a  new  species  of  pelomedusid 
turtle  from  the  mid-Pliocene  (Huayquerian)  of  Venezuela  is  described. 
Present  evidence  is  insufficient  for  determining  whether  it  was  a  marine 
or  a  fresh  water  form.  Previously  described  South  American  fossil  species 
that  have  been  attributed  to  Podocnemis  are  discussed.  Of  these,  only 
two  —  P.  bassleri  and  P.  elegans  —  are  surely  referable  to  this  genus.  It 
is  concluded  that  the  fossil  record  of  Podocnemis  is  not  yet  adequate  for 
reconstructing  its  evolutionary  history  on  this  continent. 

Resumen.  Se  describe  una  nueva  especie  de  tortuga  pelomedusida 
del  Plioceno  medio  (Huayqueriense)  de  Venezuela,  Podocnemis  venezu- 
elensis. Las  presentes  pruebas  son  insuficientes  para  determinar  si  fue  de 
aguas  marinas  o  de  agua  dulce.  Se  discuten  las  especies  suramericanas 
fosiles  que  han  sido  atribuidas  a  Podocnemis.  De  estas,  solo  dos — P.  bass- 
leri y  P.  elegans  —  son  valederas.  Se  concluye  que  el  registro  fosil  de 
este  genero  no  es  aiin  adecuado  para  la  reconstrucion  de  su  historia  evo- 
lutiva  en  este  continente. 

INTRODUCTION 

Only  one  species  of  fossil  turtle,  Podocnemis  geologorum 
(Simpson,  1943),  has  ever  been  formally  described  from  Vene- 
zuela.   Other  occurrences  of  Venezuelan  fossil  chelonians  have, 


1  Museum  of  Comparative  Zoology,  Harvard  University. 

2  Escuela    de    Geologia    y    Minas,    Universidad   Central    de    Venezuela, 
Caracas. 


2  BREVIORA  No.    376 

however,  occasionally  been  mentioned:  Swinton  (1928)  referred 
three  specimens  "too  fragmentary  for  specific  determination,"  of 
Pliocene  or  Pleistocene  age  (Van  Frank,  1957:  22n),  to  "Testuclo 
sp.";  and  Royo  y  Gomez  (1960)  published  a  faunal  list  of  fossil 
vertebrates  discovered  in  what  is  now  known  as  the  upper  member 
of  the  Urumaco  Formation,  that  included  ".  .  .  varios  capara- 
zones  completos  .  .  .  de  tortugas  palustres  (Podocnemys)  .  .  .  ." 
which  he  believed  to  be  of  mid-Miocene  age.  Unfortunately,  the 
untimely  death  of  Royo  y  Gomez  in  1961  prevented  his  describing 
any  of  this  material.  The  specimens,  however,  are  preserved  in 
the  collections  of  the  Universidad  Central  de  Venezuela  in  Ca- 
racas. Except  for  one  report  on  rodent  remains  (Pascual  and  Diaz 
de  Gamero,  1969)  and  another  on  a  new  gavial  (Sill,  1970), 
nothing  has  been  published  on  them.  The  fossil  turtles  are  de- 
scribed here. 

Abbreviations  used  in  this  paper  are: 
AMNH  —  the  American  Museum  of  Natural  History,  New  York 
MCN  —  Museo  de  Ciencias  Naturales,  Caracas 
VF  —  Laboratorio  de  Paleontologia,  Escuela  de  Geologia  de  la 
Facultad  de  Ingeniera  de  la  Universidad  Central  de  Venezuela 
(Caracas). 

CLASSIFICATION    AND    DESCRIPTION 

Order  Testudines 
Suborder  Pleiirodira 
Family    Peloiiiedusidae 

Genus  Podocnemis 

A  cautionary  word  is  appropriate  concerning  the  attribution  of 
fossil  material  to  Podocnemis.  Most  extinct  species  of  this  genus 
are  known  solely  from  shell  material.  However,  at  least  one  other 
fossil  genus,  Botliremys,  has  a  shell  that  is  virtually  indistinguish- 
able from  that  of  Podocnemis.  In  fact,  two  purported  species  of 
Podocnemis,  P.  barberi  (Schmidt,  1940)  and  P.  alabamae  (Zan- 
gerl,  1948),  were  originally  described  on  the  basis  of  shell  material 
that,  upon  the  later  discovery  of  associated  skull  material,  has 
subsequently  been  referred  to  the  genus  Botliremys  (GafTney  and 
Zangerl,  1968).  Conceivably,  therefore,  when  skulls  become 
known  for  some  of  the  fossil  species  now  referred  to  Podocnemis 


1971  NEW    VENEZUELAN    FOSSIL    PELOMEDUSID  3 

on  the  basis  of  their  shells,  it  may  be  necessary  to  transfer  them 
elsewhere.  The  new  species  described  in  this  paper  is  placed  in 
Podocnemis  with  this  caveat. 

Podocnemis  venezuelensis  sp.  nov. 
(Figures  1-3  and  Plates  I-V ) 

Type.  VF  1176,  a  complete  carapace,  slightly  flattened,  includ- 
ing much  of  the  axial  buttresses  and  the  pelves,  the  latter  badly 
damaged.  Also,  VF  1173,  a  fairly  complete  but  badly  fractured 
plastron  lacking  only  the  entoplastron  and  epiplastra.  Although 
bearing  a  diff'erent  number,  the  plastron  is  of  an  appropriate  size 
and  state  of  preservation  so  that  we  believe  it  highly  probable 
that  both  of  these  shell  elements  are  from  the  same  individual 
(see  Plate  IV).  Unfortunately,  none  of  Royo  y  Gomez's  notes 
contain  information  bearing  on  this  point. 

Hypodigm.  The  type,  and  VF  1174,  a  plastron  lacking  the 
posterior  lobe;  VF  1175,  the  anterior  one-third  of  a  carapace;  VF 
1177,  a  complete  carapace  and  plastron,  considerably  flattened, 
of  a  relatively  small  individual;  VF  1177a,  a  nearly  complete 
carapace  and  plastron  of  the  largest  individual  in  the  sample, 
lacking  only  the  pygal  and  posterior  portions  of  both  eleventh 
peripherals;  VF  1177b,  the  left  epiplastron,  hyoplastron,  and  left 
one-half  of  the  entoplastron,  plus  several  pleurals  attached  to  part 
of  the  bridge,  probably  all  belonging  to  the  same  individual;  VF 
1059,  the  distal  end  of  a  right  humerus. 

Horizon  and  locality.  The  "capa  de  huesos"  or  "capa  de  tor- 
tugas"  (Pascual  and  Diaz  de  Gamero,  1969:  373  and  map)  of 
the  upper  member  of  the  Urumaco  Formation,  probably  of  mid- 
Pliocene  (Huayquerian)  age,  north  of  Campo  El  Mamon,  state 
of  Falcon,  Venezuela. 

The  Uramaco  Formation  is  divided  into  three  members,  desig- 
nated as  lower,  middle,  and  upper.  The  lower  and  middle  mem- 
bers are  largely,  if  not  entirely,  of  marine  origin  while  the  upper 
member  apparently  includes  both  littoral  or  deltaic  as  well  as  more 
strictly  terrestrial  facies.  Marine  molluscs  from  the  middle  mem- 
ber were  the  basis  for  the  original  age  determination  of  mid- 
Miocene  for  this  formation.  This  was  subsequently  revised  to  late 
Miocene.  However,  the  recent  study  of  Pascual  and  Diaz  de 
Gamero  (1969:  379)  indicates  that  at  least  the  "bone  bed"  of 
the  uppermost  part  of  the  upper  member  is  probably  of  middle 


BREVIORA 


No.  376 


Figure.  1  Reconstruction  of  the  shell  of  Podocnemis  venezuelensis 
(dorsal  view).  The  scale  represents  a  length  of  15  centimeters.  The  posi- 
tions of  the  axial  and  inguinal  buttresses  as  well  as  of  the  iliac  scars  of 
the  pelvis  on  the  visceral  surface  of  the  carapace  are  indicated  by  the 
broken  lines. 


1971 


NEW    VENEZUELAN    FOSSIL    PELOMEDUSID 


Figure  2.  Reconstruction  of  the  shell  of  Podocnemis  veneziielensis 
(ventral  view).  Same  scale  as  in  Fig.  1.  The  positions  of  the  pelvic  scars 
on  the  visceral  surface  of  the  plastron  are  indicated  by  the  broken  lines. 


6  BREVIORA  No.    376 

Pliocene  (Huayquerian)  age.  Palynological  evidence  appears  to 
confirm  this  date  (A.  E.  Gonzalez  Guzman,  personal  communica- 
tion). It  is  possible  that  there  may  be  a  temporal  hiatus  between 
the  middle  and  upper  members  of  the  Urumaco  Formation  that 
cannot  be  detected  structurally;  an  explanation  of  this  nature 
would  account  for  the  different  age  determinations  of  the  middle 
and  upper  members  of  the  Urumaco  Formation. 

Diagnosis.  Differs  from  all  other  species  of  Podocnemis  in 
totally  lacking  neural  bones. 

Description.  It  is  unfortunate  that  a  gypsiferous  encrustation 
on  the  external  surfaces  of  all  of  the  specimens  obscures  most  of 
the  bone  sutures  and  virtually  all  scute  sulci.  Nevertheless,  an 
essentially  complete  osteological  description  of  the  shell  is  possible 
from  examination  of  the  visceral  surfaces  of  the  type  and  some 
other,  less  complete  specimens.  Although  the  outlines  of  any  par- 
ticular bone  may  differ  somewhat  from  the  external  to  the  internal 
surface  of  the  shell,  as  Dacque  (1912:  290  and  fig.  7)  has  demon- 
strated, it  is  nonetheless  possible  to  make  a  reasonable  reconstruc- 
tion of  the  shell  of  a  typical  representative  of  the  species  (see 
Figures  1  and  2 ) . 

Adult  specimens  of  Podocnemis  venezuelensis  attained  a  rather 
large  size.  The  three  complete  carapaces  in  our  sample  range 
from  approximately  46  to  67  centimeters'  in  length.  Of  the  eight 
living  species  of  Podocnemis,  only  two,  P.  expansa  and  P.  unifilis, 
are  reported  to  reach  a  larger  maximum  size. 

In  cross  section,  the  arch  of  the  carapace  is  very  flat;  in  outline 
it  is  somewhat  oval  and  greatly  expanded  posteriorly.  The  external 
surface  of  the  carapace  is  completely  smooth.  No  significant  in- 
dentation occurs  in  the  nuchal  region.  Well-developed  axial  and 
inguinal  buttresses  unite  the  carapace  to  the  plastron.  The  plastron 
itself  is  essentially  flat  and  of  nearly  uniform  thickness  throughout. 

The  outstanding  feature  of  the  carapace,  and  indeed  the  char- 
acter permitting  definition  of  a  new  species,  is  the  complete  ab- 
sence of  neural  bones.  Otherwise,  the  carapace  is  typical  of  other 
South  American  representatives  of  the  genus.  The  nuchal  bone 
is  roughly  pentagonal  and  slightly  broader  than  long  in  its  maxi- 
mum dimensions;  its  postero-lateral  borders  are  bowed  outwards 


1  The  larger  number  represents  the  estimated  total  length  of  VF  11 77a; 
its  actual  midline  length  as  preserved  is  60.1  centimeters. 


1971 


NEW    VENEZUELAN    FOSSIL    PELOMEDUSID 


slightly.  There  is  no  indentation  at  the  midline  of  the  anterior 
margin.  The  eight  pairs  of  pleurals  meet  in  the  midline.  As  in 
all  pelomedusids,  there  are  eleven  pairs  of  peripherals.  The  pygal 
is  trapezoidal  and  the  suprapygal  is  roughly  subtriangular.  But- 
tresses of  the  axial  and  inguinal  notches  are  attached  to  the  under- 
sides of  the  first  and  fifth  pleurals  respectively.  The  iliac  scars  of 
the  pelvis  are  situated  on  the  visceral  surfaces  of  the  seventh  and 
eighth  pair  of  pleurals. 

Of  the  three  elements  of  the  plastron,  the  bridge  is  the  longest 
while  the  anterior  lobe  is  the  shortest.  The  anterior  plastral  lobe 
is  U-shaped  and  does  not  extend  beyond  the  anterior  lip  of  the 
carapace.  The  lateral  margins  of  the  posterior  lobe  are  straight 
rather  than  curved  and  are  inclined  medially  so  that  the  posterior 
lobe  becomes  narrower  toward  the  rear.  The  entoplastron  is 
diamond-shaped  and  has  a  slight  U-shaped  ridge  with  the  open 
end  facing  anteriorly  on  its  visceral  surface;  this  is  presumably 
for  the  attachment  of  neck  muscles.  At  the  midline  junction  of  the 
epiplastra  there  is  a  pronounced  protuberance  on  the  visceral  side. 
The  mesoplastra  are  subrounded  to  hexagonal  elements  situated 


^ 


^ 


Figure  3.  The  shape  of  the  anal  notch  in  three  specimens  of  Podocnemis 
veneziielensis  (from  left  to  right,  VF  1177,  VF  1173  and  VF  1177a).  The 
arrow  points  toward  the  anterior  end  of  the  shell.  The  scale  represents 
a  length  of  10  centimeters. 


8  BREVIORA  No.    376 

laterally  at  the  base  of  the  bridge.  (These  can  best  be  observed 
on  the  internal  surface  of  VF  1174;  see  Plate  V.)  There  is  some 
variation  in  the  shape  of  the  anal  notch;  in  the  smallest  specimen, 
VF  1 177,  it  is  V-shaped,  but  in  the  two  larger  examples,  VF  1 173 
and  VF  11 77a,  it  is  broader  at  its  base  and  thus  tends  to  be  more 
U-shaped  (Fig.  3).  This  structural  difference  may  be  due  to  sexual 
dimorphism.  If  so,  however,  it  is  not  possible  to  specify  which 
type  represents  the  males  and  which  the  females  in  this  species. 
Normally,  male  turtles  can  be  distinguished  from  females  by  the 
characteristic  depression  on  the  posterior  lobe  of  their  plastrons, 
but  it  is  not  possible  to  determine  whether  or  not  these  existed  in 
the  present  sample  because,  in  the  course  of  fossilization,  all  the 
plastra  have  been  somewhat  depressed  inward  along  the  midline. 
Size  alone  is  not  a  useful  criterion  for  identifying  the  sexes  in 
Podocneinis.  In  all  but  one  of  the  living  South  American  species 
of  this  genus  mature  females  are  invariably  larger  than  males.  The 
reverse  is  true,  however,  for  P.  dumeriliana  (F.  Medem,  personal 
communication ) .  Nor  does  the  shape  of  the  anal  notch  necessarily 
provide  a  reliable  method  of  sex  determination.  Although  in  at 
least  one  species,  P.  lewyana,  males  can  be  identified  solely  on 
the  basis  of  this  character,  there  are  other  species  (e.g.,  P.  vogli) 
in  which  the  two  sexes  appear  to  have  similarly  shaped  anal 
notches,  while  in  still  others  (e.g.,  P.  unifilis)  the  shape  of  the 
anal  notch  varies  considerably  but  evidently  also  randomly  with 
respect  to  sex. 

Pelvic  scars  on  the  plastron  appear  to  be  disposed  in  essentially 
the  same  positions  as  in  the  living  South  American  species. 
Although  partial  pelves  have  been  preserved  in  several  of  the 
specimens  (VF  1173,  1176,  1177,  and  perhaps  also  1177a),  none 
of  these  are  well  enough  preserved  to  describe  in  detail. 

The  distal  half  of  a  right  humerus  (VF  1059)  is  all  that  is 
known  of  the  appendicular  skeleton.  Nothing  serves  to  distinguish 
this  limb  fragment  from  comparable  portions  of  this  same  bone 
in  other  species  of  Podocnemis. 

Virtually  no  scute  sulci  can  be  detected  in  any  of  the  specimens 
available  for  study.  This  is  disappointing  because  their  arrange- 
ment, particularly  on  the  anterior  plastral  lobe,  is  sometimes  of 
taxonomic  sianificance. 


1971  NEW    VENEZUELAN    FOSSIL    PELOMEDUSID  9 

DISCUSSION 

Taxonomic  considerations.  Within  the  suborder  Pleurodira, 
the  presence  or  absence  of  neural  bones  has  been  accorded  vary- 
ing taxonomic  significance.  Those  chelyid  species  that  do  possess 
neurals  usually  have  a  variable  number,  and  in  certain  species  of 
this  family  neurals  evidently  may  or  may  not  be  present  in  diff"erent 
individuals  of  the  same  population.  Consequently,  whether  or 
not  a  chelyid  carapace  includes  some  neurals,  and  if  so,  how  many, 
has  never  been  considered  a  useful  taxonomic  character ^  Most 
pelomedusid  species,  however,  have  a  neural  series  that  does  not 
deviate  from  a  modal  number  (usually  6-8)  by  more  than  one 
or,  occasionally,  two.  Only  two  exceptions  to  this  typical  condition 
are  known  within  the  family,  both  involving  extinct  taxa  from  the 
Eocene  of  Tunisia-.  Gajsachelys  (de  Stefano,  1903;  Bergounioux, 
1952;  1955;  1956),  hke  some  chelyids,  appears  to  have  had  a 
rather  variable  number  of  irregularly  shaped  neurals.  Eusarkia 
(Bergounioux,  1952;  1956),  described  on  the  basis  of  a  single 
specimen,  has  no  neurals  and  on  the  basis  of  this  and  several  other 
characters  noted  by  Bergounioux  we  believe  that  it  was  probably 
appropriate  to  propose  a  new  genus.  But  in  no  case  has  the 
absence  of  neurals  alone  been  used  as  a  taxonomic  character, 
either  at  the  generic  or  the  specific  level,  within  the  Pleurodira 
(or  among  any  other  chelonians  for  that  matter). 

Why,  then,  have  we  described  the  Urumaco  fossil  pelomedusids 
as  a  new  species  of  Podocnemis?  In  view  of  their  strong  overall 
resemblance  to  the  living  South  American  species  of  this  genus 
it  seems  inappropriate  to  propose  a  new  genus  on  the  basis  of  a 
single  character  which,  by  itself,  is  not  highly  unusual  nor  of 
particularly  great  taxonomic  significance  among  other  members 
of  the  suborder.  On  the  other  hand,  since  the  absence  of  neurals 
is  clearly  a  constant  character  within  the  Venezuelan  sample,  this 


1  No  adequate  osteological  descriptions  of  any  living  chelyid  species 
have  ever  been  published,  so  that  reliable  data  are  not  actually  available 
regarding  the  extent   of  intraspecific   variation   in  the  number  of  neurals. 

-One  of  us  (RCW)  is  preparing  a  discussion  of  the  taxonomic  status 
of  the  Tunisian  fossil  turtles  for  publication  elsewhere.  In  this  paper 
Euclastochelys  (Bergounioux,  1955;  1956)  is  considered  to  be  synonymous 
with  Gajsachelys. 


10  BREVIORA  No.    376 

feature  can  hardly  be  regarded  as  an  aberrant  condition  of  no 
taxonomic  consequence.  Thus,  by  a  process  of  elimination,  the 
only  alternative  is  to  choose  a  procedure  intermediate  between 
regarding  the  lack  of  neurals  as  of  enormous  taxonomic  impor- 
tance or  as  of  none  at  all  and  describe  the  Venezuelan  material 
as  a  new  species. 

Ecological  considerations.  The  small  vertebrate  fauna  with 
which  Podocnemis  veneziielensis  is  associated  (Royo  y  Gomez, 
1960:  509;  Pascual  and  Diaz  de  Gamero,  1969:  370  and  374) 
is  not  adequate  for  determining  with  any  degree  of  certainty  what 
the  probable  habitat  of  this  species  might  have  been.  The  mam- 
mals —  a  eumegamyine  rodent  and  a  toxodontid  —  were  un- 
doubtedly strictly  terrestrial  forms,  while  the  crocodilians  pre- 
sumably spent  most  of  their  time  in  streams,  lakes,  or  swamps. 
The  fish  —  sharks,  sawfish,  rays,  catfish,  and  an  unidentified 
teleost  —  appear  to  be  a  mixture  of  marine  and  fresh  water  forms. 
If  all  these  fossils  were  collected  from  a  single  horizon,  as  the 
scanty  field  evidence  would  suggest,  then  the  stratum  in  which 
they  occur  must  represent  an  estuarine  facies.  On  the  basis  of 
present  evidence,  therefore,  it  is  impossible  to  determine  unequiv- 
ocally whether  P.  veneziielensis  was  a  marine  or  a  fresh  water 
form.  To  be  able  to  do  so  would  be  particularly  interesting  be- 
cause, while  all  living  pelomedusids  are  inhabitants  of  fresh  waters, 
in  the  past  some  were  marine  and  others  were  fresh  water  forms 
(Wood,  MS).  If  P.  veneziielensis  were,  in  fact,  marine,  it  would 
be  the  last  recorded  pelomedusid  so  adapted. 

No  hving  species  of  Podocnemis  (or  any  other  fresh  water 
turtle)  are  found  in  the  Maracaibo  basin,  in  which  the  type  local- 
ity of  P.  veneziielensis  lies,  although  they  are  common  to  the 
south  and  east  of  this  enclave  in  Venezuela  as  well  as  to  the  west 
of  it  in  Colombia.  Thus,  P.  veneziielensis  occurs  outside  the  pres- 
ent range  of  the  genus.  Should  P.  veneziielensis  eventually  prove 
to  be  a  fresh  water  rather  than  a  marine  form,  its  extinction  may 
be  explicable  in  terms  of  the  Pleistocene  climatic  history  of  tropical 
South  America.  The  Maracaibo  basin  is  ringed  by  mountains 
except  on  its  seaward  side  and  hence  is  effectively  isolated  from 
adjacent  land  areas.  Conceivably,  a  period  or  periods  of  aridity 
during  the  Pleistocene  (and  evidence  for  severe  climatic  fluctua- 
tions in  the  tropics  during  this  epoch  is  accumulating  —  cf .  Van- 
zolini   and   Williams,    1970:    94-103)    may   have   eliminated   P. 


1971  NEW    VENEZUELAN    FOSSIL    PELOMEDUSID  11 

venezuelensis,  a  form  presumably  endemic  to  the  basin,  while  the 
surrounding  mountain  barrier  prevented  subsequent  recolonization 
by  other  species. 

The  fossil  record  of  Podocnemis  in  South  America.  Few  fossil 
species  of  Podocnemis  have  been  described  from  this  continent 
and  several  of  these  are  known  from  such  inadequate  material 
that  it  is  questionable  whether  or  not  they  should  be  referred  to 
the  genus. 

As  previously  noted,  Simpson  (1943)  has  described  a  partial 
carapace  and  plastron  from  Venezuela  as  Podocnemis  geolo- 
gorum^.  The  single  known  specimen  was  recovered  from  fluvia- 
tile  beds  of  Miocene  age.  Without  a  doubt,  this  fossil  represents 
some  kind  of  pleurodire  because  of  the  union  of  its  pelvis  with 
both  carapace  and  plastron.  Whether  this  specimen  actually  rep- 
resents a  pelomedusid  instead  of  a  chelyid,  however,  is  not  entirely 
clear.  Although  Simpson  (1943:  57)  commented  "Es  muy  po- 
sible  la  existencia  en  esta  especie  de  un  mesoplastron  tipo  Podoc- 
nemis de  buen  tamafio,"  the  presence  or  absence  of  this  pair  of 
bones,  the  critical  character  for  distinguishing  members  of  one 
pleurodiran  family  from  the  other,  cannot  be  determined.  Very 
few  potentially  useful  taxonomic  characters  can,  in  fact,  be  dis- 
cerned. On  the  carapace,  only  two  pleurals  separate  the  last 
neural  from  the  suprapygal.  There  appears  to  be  a  deep  indenta- 
tion in  the  posterior  edge  of  the  pygal  at  the  midline,  and  this, 
together  with  similar  but  not  quite  so  pronounced  indentations 
in  the  tenth  and  eleventh  peripherals,  gives  the  rear  margin  of 
the  carapace  a  serrated  appearance.  Whereas  the  last  vertebral 
was  broader  than  long,  the  two  preceding  ones  were  longer  than 
broad.  The  anal  notch  of  the  plastron  is  rather  deep  and  narrow, 
and  the  lateral  margins  of  the  posterior  lobe  are  sinuous.  As  a 
consequence,  the  xiphiplastral  tips  are  much  more  elongate  than 
in  any  other  taxon  yet  described  as  a  pelomedusid.  Simpson 
(1943:  61)  considered  the  deep  anal  notch  and  serrations  along 
the  posterior  border  of  the  carapace  to  be  the  species-specific 
characters  of  P.  geologorum,  and  indeed,  these  are  quite  distinctive 
and  indicate  the  validity  of  the  species.    Unfortunately,  however, 


1  When  Simpson  described  the  type  of  P.  geologorum.  it  was  catalogued 
as  AMNH  6781.  It  now  belongs  to  the  collections  of  the  Museo  de  Ciencias 
Naturales,  Caracas,  and  bears  the  number  MCN  915. 


12  BREVIORA  No.    376 

on  the  basis  of  present  evidence  there  is  no  reason  to  believe  that 
P.  geologorum  is  really  a  species  of  Podocnemis  or,  for  that  mat- 
ter, of  any  pelomedusid.  It  cannot  yet  be  confidently  allocated  to 
either  of  the  two  pleurodiran  families  to  which  it  must  belong, 
the  Chelyidae  or  the  Pelomedusidae.  Thus,  until  better  material 
of  this  taxon  becomes  available,  P.  geologorum  should  be  listed 
as  Pleurodira  incertae  sedis. 

Three  species  of  Podocnemis  —  P.  harrisi  (Pacheco,  1913),  P. 
brasiliensis  (Staesche,  1937)\  and  P.  elegans  (Suarez,  1969)  — 
have  been  described  from  three  widely  separated  localities  within 
the  Bauri'i  Formation  of  southern  Brazil.  These  sediments  repre- 
sent terrestrial  deposition,  with  fluvial  and  alluvial  plain  beds 
predominating,  and  are  probably  of  late  Cretaceous  (Senonian) 
age  (Oliveira,  1956:  53-54).  The  only  specimens  ever  referred 
to  P.  harrisi  were  a  nearly  complete  right  xiphiplastron  and  sev- 
eral peripherals  (Pacheco,  1913:  37,  pi.  3  [figs.  6a-e],  pi.  4 
[fig.  6]).  Ischial  and  pubic  scars  on  the  visceral  surface  of  the 
xiphiplastron  clearly  indicate  that  some  kind  of  pleurodire  is  rep- 
resented, but  no  other  taxonomically  useful  evidence  exists.  It 
is  therefore  impossible  to  determine  whether  P.  harrisi  is  a  chelyid 
or  a  pelomedusid.  Reference  of  this  species  to  Podocnemis  was 
unjustifiable,  as  Schmidt  noted  long  ago  (1931:  253).  Further- 
more, since  the  type  material  is  now  apparently  lost  (Price,  1953: 
10),  "P.  harrisi"  must  be  regarded  as  a  nomen  vanum. 

On  the  basis  of  some  photographs  of  a  partial  plastron,  a  car- 
apace fragment-,  and  three  associated  pleurals,  Staesche  (1937) 
described  P.  brasiliensis.  The  xiphiplastra  of  this  species  do  not 
appear  to  dift'er  in  any  appreciable  way  from  those  of  P.  harrisi, 
and  therefore  Simpson  (1943:  61)  may  well  have  been  correct 
in  suggesting  that  P.  brasiliensis  is  a  synonym  of  P.  harrisi, 
although  Staesche  (1937:  302-303)  noted  that  his  material  dif- 
fered in  that  it  represented  a  somewhat  larger  individual  with  a 
difl'erent  kind  of  sculpturing  on  the  external  surface  of  the  shell, 
factors  which  might  or  might  not  be  of  taxonomic  significance. 

1  Staesche  (1944)  is  merely  a  translation  of  Staesche  (1937)  from 
German  into  Portuguese. 

-This  carapace  fragment,  together  with  a  previously  undescribed  ante- 
rior lobe  of  a  plastron  from  the  same  locality,  was  subsequently  referred 
to  a  new  genus  and  species,  Roxochelys  wanderleyi,  by  Price  (1953). 


1971  NEW    VENEZUELAN    FOSSIL    PELOMEDUSID  13 

Small,  laterally  placed  mesoplastra  were  present,  even  though  no 
longer  preserved,  so  that  P.  brasiiiensis  is  clearly  a  pelomedusid. 
An  appropriate  generic  determination  cannot  at  present  be  made, 
however,  because  much  of  the  anterior  plastral  lobe,  so  critical 
for  pelomedusid  shell  taxonomy,  is  missing.  Thus,  the  specimen 
can  neither  be  certainly  referred  to  Podocnemis  nor,  owing  it  its 
imperfect  preservation,  can  any  species-specific  characters  be 
established.  Until  better  material  is  available,  therefore,  the  plas- 
tron and  pleurals  to  which  the  name  P.  brasiiiensis  now  applies 
should  be  designated  as  Pelomedusidae  gen.  et  sp.  indet.  {"Podoc- 
nemis brasiiiensis"  Staesche). 

Unlike  the  other  two  dubious  "species"  of  Podocnemis  from  the 
Baurii  Formation,  P.  elegans  is  clearly  valid  and  referable  to  this 
genus.  It  is  the  only  South  American  fossil  pelomedusid  yet 
described  for  which  associated  shells  and  skulls  have  been  re- 
covered. Furthermore,  it  is  the  oldest  representative  of  Podoc- 
nemis known  anywhere.  It  was  described  on  the  basis  of  two 
specimens,  an  essentially  complete  shell  and  a  well-preserved  skull 
belonging  to  a  different  individual.  A  detailed  description  of  this 
species  will  not  be  presented  here  since  an  account,  based  on  addi- 
tional new  material  as  well  as  the  original  hypodigm,  is  being  pre- 
pared by  one  of  us  (RCW)  for  separate  publication.  Some  of  the 
salient  characters  may  be  briefly  noted,  however.  In  most  respects 
the  shell  is  typical  of  all  South  American  species  of  Podocnemis, 
but  the  shapes  of  the  first  two  neurals  are  unique:  instead  of  being 
spindle-shaped,  the  first  is  hexagonal,  with  the  postero-lateral  sides 
much  shorter  than  the  antero-lateral  ones;  and  the  second,  rather 
than  being  hexagonal,  is  subrectangular.  A  unique  feature  of  the 
skull  is  the  total  absence  of  triturating  ridges  on  the  palatal  surface 
of  the  upper  jaw.  All  other  species  have  from  one  to  three  triturat- 
ing ridges,  the  exact  number  being  characteristic  of  different  spe- 
cies.   In  addition,  there  does  not  seem  to  be  an  antero-posterior 


1  Suarez  (1969:  37)  stated:  "Designamos  como  tipo  da  nova  especie  a 
carapaca  e  plastrao  com  craneo  e  diversos  elementos  esqueletais  .  .  ." 
The  shell  and  skeletal  elements  belong  to  one  individual  and  there  is  in 
fact  a  badly  crushed  skull  (which  was  not  illustrated  or  discussed)  asso- 
ciated with  them,  but  it  is  not  the  skull  described  by  Suarez.  This  is  an 
isolated  one  from  a  much  larger  individual.  Both  specimens  are  in  the 
paleontological  collections  of  the  Faculdade  de  Filosofia.  Ciencias  e  Letras 
de  Presidente  Prudente:  they  bear  no  catalog  numbers. 


14  BREVIORA  No.    376 

forehead  groove  between  the  orbits.  Of  the  other  South  American 
species  of  Podocnemis,  only  P.  dumeriliana  lacks  this  groove. 
Perhaps  the  most  extraordinary  aspect  of  the  skull  of  P.  elegans 
is  its  modern  appearance;  archaic  or  ancestral  features  that  one 
might  expect  to  find  in  such  an  ancient  species  are  notably  lacking. 
Cattoi  and  Freiberg  (1958)  described  Podocnemis  argentinensis 
from  the  Santa  Barbara  Formation^  in  the  Province  of  Jujuy, 
Argentina.  It  is  known  from  a  large  part  of  a  plastron,  lacking 
the  terminal  portions  of  the  anterior  and  posterior  lobes  as  well 
as  much  of  the  bridges,  and  most  of  the  right  epiplastron  of  a 
second  individual.  The  systematic  position  of  this  form  is  uncer- 
tain. Laterally  placed  mesoplastra  were  definitely  present,  as 
evidenced  by  the  semicircular  excavations  on  either  side  of  the 
plastron  at  the  base  of  the  bridge,  so  that  argentinensis  clearly 
represents  some  kind  of  pelomedusid.  Too  little  of  the  shell  has 
been  preserved,  however,  to  permit  assignment  to  Podocnemis 
with  any  degree  of  confidence.  At  a  lower  taxonomic  level,  the 
characters  used  to  define  the  species  are  in  some  cases  questionable 
and  in  others  of  little  or  no  taxonomic  significance.  Cattoi  and 
Freiberg  described  the  entoplastron  as  cordiform,  but  in  their 
figure  and  plate  it  appears  to  be  quadrangular.  Examination  of 
the  specimen  itself  indicates  that  the  entoplastron  is  slightly  dam- 
aged anteriorly  and  that  it  was  probably  diamond-shaped  orig- 
inally. Small,  triangular  gular  scutes  are  characteristic  of  most 
pelomedusids,  but  the  relatively  small  intergular,  which  was  prob- 
ably pentagonal,  is  certainly  reminiscent  of  the  condition  typical 
of  South  American  species  of  Podocnemis  and  the  North  American 
Bothremys  (Gaftney  and  Zangerl,  1968).  The  various  scute  pro- 
portions cited  by  Cattoi  and  Freiberg  in  their  diagnosis  yield  no 
useful  taxonomic  information.  Anastomosing  vermiculations  cover 
the  external  plastral  surface  as  in  the  majority  of  pelomedusid 


1  Various  ages  have  been  assigned  to  this  stratigraphic  unit,  formerly 
referred  to  as  the  Margas  Multicolores.  Cattoi  and  Freiberg  placed  it  in 
the  late  Cretaceous,  while  Bardack  (1961)  considered  it  to  be  middle 
Tertiary.  The  recent  discovery  of  a  mammal  skull  high  in  the  formation 
indicates  a  Paleocene  or  early  Eocene  age  (R.  Pascual,  personal  com- 
munication). There  is  some  uncertainty  as  to  whether  these  beds  are  of 
marine  or  terrestrial  origin  (Cattoi  and  Freiberg,  1958:  59). 


1971  NEW    VENEZUELAN    FOSSIL    PELOMEDUSID  15 

genera'.  Until  better  material  becomes  available,  it  will  not  be 
possible  to  determine  the  systematic  position  of  this  turtle.  In 
the  meantime,  it  must  be  referred  to  as  Pelomedusidae  gen.  et  sp. 
indet.     {'Podocnemis  argentinensis"  Cattoi  and  Freiberg). 

The  type  and  only  specimen  of  Podocnemis  bassleri  (Williams, 
1956)  is  a  large,  exceedingly  well-preserved  skull.  It  was  collected 
in  eastern  Peru  from  beds  of  the  Contamana  Group,  which  in- 
cludes sediments  believed  to  range  in  age  from  Eocene  to  possibly 
at  late  as  Pliocene.  Williams,  on  the  basis  of  information  supplied 
by  Kummel,  reported  that  the  skull  "came  from  the  uppermost 
part  of  the  .  .  .  group,"  which  suggests  that  its  age  falls  within 
the  latter  part  of  the  Tertiary.  He  further  remarked  that  "The 
fossil  itself  is  so  close  to  a  Recent  species  as  to  tend  to  support 
the  latest  date  geologically  permissible."  The  skull  differs  only 
in  minor  details  from  that  of  the  living  P.  expansa.  It  seems  fairly 
certain  that  P.  bassleri  was  closely  related,  if  not  directly  ancestral, 
to  this  species. 

Unfortunately,  the  evolutionary  history  of  Podocnemis  in  South 
America  cannot  be  reconstructed  on  the  basis  of  present  informa- 
tion. Only  three  fossil  species  —  P.  bassleri,  P.  elegans,  and  P. 
venezuelensis  —  are  of  unquestionable  validity.  One  of  these, 
P.  bassleri,  is  clearly  very  closely  related  to  P.  expansa.  The  rela- 
tionships of  the  other  two  extinct  species  to  living  South  American 
forms  are  uncertain,  owing  to  their  distinctive  shell  characters. 
With  the  exception  of  P.  lewyand'-,  the  living  South  American 
species  of  Podocnemis  are  all  strikingly  similar  in  terms  of  shell 


1  Cattoi  and  Freiberg's  figure  I  shows  the  entoplastron  as  being  nearly 
encompassed  by  unusually  large  epiplastra.  a  condition  unknown  in  any 
other  chelonians  that  we  are  aware  of.  However,  their  sketch  does  not 
accurately  represent  the  positions  of  the  sutures  between  the  epiplastra 
and  hyoplastra;  these  are,  in  fact,  disposed  in  typical  pelomedusid  fashion, 
extending  outward  from  the  lateral  apices  of  the  entoplastron. 

-Through  the  courtesy  of  Professor  F.  Medem,  one  of  us  (RCW)  has 
been  able  to  examine  a  series  of  six  P.  lewyana  shells  in  the  collections 
of  the  Instituto  Roberto  Franco  at  Villavicencio,  Colombia.  None  of  these 
has  a  suprapygal  bone  on  the  carapace;  instead,  each  of  the  last  (eighth) 
pleurals  is  subtriangular,  not  trapezia!  as  is  the  case  in  other  species  of  the 
genus,  and  these  pleurals  are  in  continuous  contact  along  the  midline  from 
the  posterior  end  of  the  seventh  pair  of  pleurals  to  the  pygal. 


16  BREVIORA  No.    376 

morphology.  Only  small  structural  details  characteristic  of  each 
taxon  permit  differentiation  among  them  on  the  basis  of  shells 
alone.  P.  venezuelensis  stands  markedly  apart  from  all  other  spe- 
cies of  the  genus  in  its  total  lack  of  neurals,  and  certainly  could 
not  have  given  rise  to  any  of  the  living  forms.  Nothing  remotely 
resembling  the  shapes  of  the  first  two  neurals  in  P.  elegans  is  en- 
countered elsewhere  in  the  genus.  So  conservative  in  structure  is 
this  part  of  the  shell  in  all  other  species  (except,  of  course,  for 
P.  venezuelensis ) ,  and  so  radically  different  is  it  in  P.  elegans,  that 
this  species  could  hardly  have  been  ancestral  to  any  or  all  of  the 
later  species  known  from  South  America.  Thus,  neither  P.  elegans 
nor  P.  venezuelensis  has  any  obvious  relationship  to  living  species 
of  the  genus  or  to  each  other.  A  much  better  fossil  record  for 
Podocnemis  will  be  necessary  before  a  meaningful  picture  of  its 
evolutionary  history  in  South  America  can  be  formulated. 

ACKNOWLEDGMENTS 

We  are  particularly  grateful  to  Senora  Frances  Charlton  de 
Rivero,  retired  professor  of  paleontology  at  the  Escuela  de  Geo- 
logia  y  Minas  in  Caracas,  not  only  for  her  gracious  hospitality  but 
also  for  having  provided  laboratory  facilities  while  the  material 
here  described  was  being  studied.  Both  authors  have  examined 
the  type  specimen  of  "Podocnemis''  geologorum  and  one  of  us 
(RCW)  has  also  been  able  to  examine  the  types  of  "P.  argen- 
tinensis,"  P.  bassleri,  and  "P.  brasiliensis."  We  would  like  to  thank 
the  curators  of  the  various  institutions  at  which  these  fossils  are 
housed  for  permission  to  study  them.  Through  the  kindness  of 
Professor  Jose  Martin  Suarez,  RCW  has  not  only  been  able  to 
study  the  type  material  of  P.  elegans  but  also  to  visit  the  locality 
from  which  it  was  recovered.  Without  a  generous  grant  to  RCW 
from  the  National  Geographic  Society,  none  of  this  work  would 
have  been  possible.  We  are  much  obliged  to  Professors  F.  Medem, 
B.  Patterson,  P.  E.  Vanzolini,  and  E.  E.  Williams,  and  to  Dr.  M. 
Freiberg  for  their  comments  and  discussions  on  various  aspects 
of  this  manuscript. 


1971  NEW    VENEZUELAN    FOSSIL    PELOMEDUSID  17 

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Staesche,  K.     1937.     Podocneinis  hrasiliensis  n.  sp.  aus  der  Oberen  Kreide 

Brasiliens.    Neues  Jahrb.  Min.,  Geol.  Palaont.,   77:   291-309. 
. 1944.     Uma  tartaruga  do  cretaceo  superior  do  Brasil.    Dep. 

Nac.  Prod.  Min.,  Div.  Geol.  Min.,  Bol.  114:    1-24,  pis.    16-20. 

Stefano,  G.  de.  1903.  Nuovi  rettili  degli  strati  a  fosfato  della  Tunisia. 
Bol.  Soc.  Geol.  Ital.,  22:  51-80. 

Suarez,  J.  M.  1969.  Urn  quelonio  da  formagao  Bauru.  Dept.  Geografia, 
Fac.  de  Filos.,  Cien.  Letras  Pres.  Prudente,  No.  2:   35-54. 

SwiNTON,  W.  E.  1928.  Note  on  the  fossil  reptilia  collected  by  Mr.  Don- 
ald Stewart  in   Venezuela.    Quart.  Jour.  Geol.  Soc,  84,   Pt.  3:    583. 

Van    Frank.    R.      1957.      A    fossil    collection    from    northern    Venezuela. 

1.  Toxodontidae    (Mammalia,   Notoungulata).    American   Mus.   Novi- 

tates.  No.   1850:    1-38. 
Vanzolini,  p.  E.,  and  E.  E.  Williams.      1970.     South  American  anoles: 

the  geographic  differentiation  and  evolution  of  the  Anolis  chrysolepis 

species   group    (Sauria,   Iguanidae).    Arq.    Zool..    S.    Paulo,    19(1-2): 

1-124. 
Williams,  E.  E.    1956.   Podocneinis  bassleri,  a  new  species  of  pelomedusid 

turtle  from  the  late  Tertiary  of  Peru.    American  Mus.  Novitates,  No. 

1782:    1-10. 
Zangerl,    R.      1948.     The   vertebrate   fauna  of  the   Selma   Formation   of 

Alabama,   part    11.    The   pleurodiran    turtles.    Fieldiana:    Geol.   Mem. 

3(2):    19-56. 


197 


NF.W    VENEZUELAN    FOSSIL    PELOMEDUSID 


19 


15  cm 


Plate  L    Dorsal   view  of  the  type  carapace   (VF   1176)    of  Podocnemis 
veneziielensis. 


20 


BREVIORA 


No.  376 


15  cm 


Plate  II.    View  of  the  visceral  surface  of  the  type  carapace  (VF  1176) 
of  Podocnemis  venezuelensis.    Note  the  absence  of  neural  bones. 


1971 


NEW    VENEZUELAN    FOSSIL    PELOMEDUSID 


21 


-^ 


^•^^. 


V:^'' 


i 


t-r     '■ 


15    cm 


Plate  ill.  View  of  the  visceral  surface  of  the  type  plastron  of  Pocloc- 
neinis  veneziielensis  (VF  1173).  showing  the  disposition  of  the  pelvic 
attachments  to  it. 


22 


BREVIORA 


No.  376 


■^-    '^■■<%5 


15  cm 


Plate  IV.  Ventral  view  of  the  type  shell  of  Potlocneiuis  vcnezuelensis, 
with  the  plastron  (VF  1173)  positioned  correctly  in  relation  to  the  carapace 
(VF  1176). 


1971 


NEW    VENEZUELAN    FOSSIL    PELOMEDUSID 


23 


Plate  V.  The  visceral  surface  of  VF  1174.  a  partial  plastron  of  Podoc- 
nemis  venezneleii.sis,  showing  clearly  the  outlines  of  the  laterally  placed 
mesoplastra. 


BREVIORA 

MmseiLim   of   Comparative   Zoology 

CAMBRrocE,  Mass.  15  June.   1971  Number  377 

THE  CHANARES  (ARGENTINA)  TRIASSIC  REPTILE  FAUNA 
IX.     THE  CHANARES  FORMATION 

Alfred   Sherwood   Romer 


Abstract.  The  term  "Chanares  Formation"  should  be  retained  for  the 
fossihferous  beds  so  named  by  Romer  and  Jensen;  the  type  section  of  the 
"Ischichuca  Formation"  is  homologous  with  part  of  the  overlying  Los 
Rastros  Formation. 

With  the  discovery  of  a  rich  Triassic  reptilian  fauna  in  the 
Chafiares-Gualo  region  of  La  Rioja  Province,  Mr.  James  Jensen 
and  I  set  about  the  task  of  determining  the  stratigraphic  sequence 
of  the  area  (Romer  and  Jensen,  1966).  It  was  soon  apparent  that, 
despite  complex  faulting,  a  series  of  formations  with  clear-cut 
boundaries  could  be  distinguished,  and  in  the  Arroyo  del  Agua 
Escondida  the  entire  local  series  could  be  seen  in  proper  sequence. 

The  area  is  part  of  a  basin  of  late  Paleozoic  and  early  Mesozoic 
deposition  lying  in  western  La  Rioja  Province  and  an  adjacent 
portion  of  San  Juan,  extending  roughly  from  the  western  flanks 
of  the  Sanogasta  Range  on  the  east  to  the  Rio  Bermejo  on  the 
west,  and  from  the  region  of  Villa  Union  south  to  the  northern 
end  of  the  Valle  Fertil  range.  The  center  of  this  area  is  the  flat 
Campo  de  Talampaya,  and  I  shall  term  this  cuenca  the  Talampaya 
Basin.  Little  attention  had  ever  been  given  to  the  geology  of  our 
area  of  interest  in  the  eastern  part  of  the  basin,  but  considerable 
work  had  been  done  in  the  western  part.  It  was  obvious  that  the 
thickness  and  nature  of  the  sediments  varied  greatly  from  one 
basin  area  to  another,  and  the  situation  was  further  complicated  by 
the  fact  that  there  had  been  much  volcanic  activity.  As  far  as 
possible  we  utilized  formation  names  already  in  the  literature; 
\vhcn  no  similarities  to  named  formations  in  other  areas  in  the 
hasin  were  discernible,  new  names  were  given.  The  formations 
named  by  us  are  shown  in  the  right  hand  column  of  the  table.  The 


2  BREVIORA  No.    377 

three  formations  latest  in  time  —  Los  Colorados,  Ischigualasto^ 
and  Los  Rastros  —  are  comparable  to  those  so  named  to  the  west, 
across  the  Campo  de  Talampaya,  although  much  thinner  in  our 
area  in  each  instance.  Below  the  normal  beds  of  the  Los  Rastros, 
strongly  carbonaceous  in  nature,  are  some  70  meters  of  evenly 
bedded  volcanic  ash  sediments  in  which  fossil  reptiles  are  abun- 
dant. Despite  the  fact  that  these  strata  are  quite  conformable 
with  the  overlying  Los  Rastros  deposits,  they  are,  as  layers  of 
white  to  bluish  white  ash,  quite  distinctive  in  character  and,  since 
they  are  the  bearers  of  our  fauna,  we  ventured  to  separate  them 
from  the  Los  Rastros  as  a  distinct  Chanares  Formation.  Below 
them,  unconformably,  are  red  and  white  sandstones  which  are 
roughly  comparable  to  those  generally  assigned  to  "Paganzo  IIL" 
Since  this  is  not  a  proper  stratigraphic  term,  we  have  given  them 
the  name  of  the  Tarjados  Formation.  Beneath  them,  again,  are 
thick  series  of  soft  sandstones,  perhaps  also  part  of  the  "Paganzo 
III"  complex,  for  which  we  have  found  no  clear  equivalents  in 
other  parts  of  the  basin,  and  which  we  have  named  the  Talam- 
paya Formation. 

In  general,  I  think,  this  terminology  has  been  accepted.  The 
one  exception  is  that  Sr.  Bonaparte  (1967,  1969,  etc.)  has  ob- 
jected to  our  term  "Chaiiares  Formation,"  and  maintains  that 
these  beds  should  bear  the  name  "Ischichuca  Formation."  Despite 
the  high  regard  I  have  for  Sr.  Bonaparte's  work  in  the  collection 
and  description  of  Triassic  fossils,  I  believe  that  this  usage  is  inde- 
fensible. A  review  of  the  history  of  stratigraphic  work  in  this 
region  is  necessary. 

The  first  serious  study  of  this  region  was  that  of  Bodenbender 
(1911).  His  stratigraphic  section  in  this  basin  is  given  in  the  first 
column  of  the  table.  He  believed  that  the  sediments  in  this  area 
extended  from  the  Carboniferous  to  the  Cretaceous,  and  for  the 
lower  beds  in  the  region  invented  the  term  "Paganzo,"  divided 
into  "Paganzo  I"  for  light  colored  sediments  which  he  believed 
(apparently  correctly)  to  be  of  Carboniferous  age,  "Paganzo  II," 
for  red  sandstones  which  (again  probably  correctly)  he  thought 
were  Permian,  and  "Paganzo  III,"  for  beds,  mainly  reddish  sand- 
stones, which   (with  less  assurance)   he  claimed  to  be  Triassic. 


^  Sr.  R.  R.  de  la  Vega  has  pointed  out  to  me  that  the  correct  spelling 
should  be  Ichigualasto,  but  the  "improper"  version  has  become  so  embedded 
in  the  literature  that  it  seems  impossible  to  eradicate  it. 


1971  THE    CHANARES    FORMATION  3 

"Rhaetic"  was  a  favorite  term  with  early  German  workers  in  South 
American  geology,  favored  perhaps  because  of  its  rather  vague 
meaning,  and  to  the  "Rhaetic"  he  assigned  a  very  considerable 
thickness  of  beds  including  yellow  and  variegated  shales,  coal 
shales,  and  coal  seams.  Above  these  (beyond  some  indeterminate 
beds  in  the  region  of  Cerro  Morado,  which  he  suggested  were 
possibly  Jurassic)  the  depositional  series  terminated  with  thick 
red  sandstones  which  he  believed  to  be  Cretaceous  in  age  and 
termed  the  "Cretaceo  Andino." 

A  more  thorough  study  of  the  beds  of  the  western  part  of  the 
basin  was  undertaken  in  the  1940's  by  Frenguelli  and  by  de  la 
Mota.  Frenguelli  mainly  visited  the  region  of  the  Ischigualasto 
Valley,  drained  to  the  west  by  the  Rio  de  la  Pena,  and  published 
his  results  in  1948.  Bodenbender's  "Cretaceo  Andino"  beds  were 
termed  by  him  the  "Estratos  de  Gualo,"  and  their  presumed  age 
reduced,  reasonably,  from  Cretaceous  to  "Rhaetic."  In  Boden- 
bender's  erstwhile  "Rhaetic"  series  he  distinguished  an  upper  mem- 
ber as  the  Ischigualasto  Formation  —  a  series  of  variegated  shales 
and  some  sandstones  characteristic  of  the  Ischigualasto  Valley  west 
of  the  red  bluffs  of  the  "Gualo."  These  beds  are  now  known  to 
possess  a  very  considerable  fauna  of  Triassic  (?  Ladinian  or  pos- 
sibly Carnian)  age.  Below  the  Ischigualasto,  to  the  west,  and 
traversed  by  the  difficult  gorge  of  the  La  Pena,  are  rugged  hills  of 
sandstones  and  shales  including  coal  seams,  in  which  footprints 
had  been  discovered  (Huene,  1931).  As  Frenguelli  notes  (1948: 
191),  he  did  not  penetrate  much  farther  to  the  west  through  the 
rugged  country  in  the  Ischigualasto-La  Pena  region  than  the  Que- 
brada  de  los  Rastros,  where  a  coal  mine  is  located  and  where  the 
footprints  were  found;  some  data  were  furnished  him  by  Ramac- 
cioni  and  Heim,  who  studied  the  coal  beds  (Heim,  1949).  They 
informed  him  that  these  "Rhaetic"  beds  were  underlain,  to  the 
west,  by  red  "Paganzo"  sandstones  which  he  cites  as  "Paganzo  11" 
(they  are  actually  of  "Paganzo  III"  age). 

The  total  thickness  of  the  "Rhaetic"  beds  below  the  Ischigua- 
lasto Formation  in  this  region  was  estimated  as  600-650  meters. 
Frenguelli  made  this  area  the  type  section  of  the  Los  Rastros 
Formation,  to  which  he  assigned  the  upper  400-450  meters  of 
these  beds  —  i.e.,  about  two-thirds,  on  his  reckoning.  As  can  be 
seen  from  the  sections  of  Ortiz,  mentioned  later,  under  this  defini- 
tion of  the  Los  Rastros  the  formation  would  include  essentially 


4  BREVIORA  No.    377 

the  whole  of  the  coal-bearing  portion  of  the  "Rhaetic"  beds.  In  de- 
fault of  personal  knowledge  of  the  lower  beds  in  the  Ischigualasto- 
La  Pena  region,  Frenguelli  turned  to  the  region  of  Cerro  Bola, 
some  70  km  to  the  north,  which  had  been  studied  in  detail  by  de 
la  Mota  (whose  results  are  recorded  in  an  unpublished  thesis  at 
the  University  of  La  Plata ).^  Equivalents  of  the  "Gualo"  and 
Ischigualasto  beds  are  readily  determinable  in  the  Cerro  Bola 
region.  Between  the  Ischigualasto  and  "Paganzo  III"  there  are 
here,  much  as  in  the  Ischigualasto  region,  some  500-550  meters 
of  "Rhaetic"  beds  of  sandstones,  shales,  and  coal  seams.  The 
upper  250-300  meters  of  these  beds  were  equated  by  de  la  Mota 
and  Frenguelli  with  the  type  Los  Rastros;  they  contain  occasional 
carbonaceous  seams,  but  consist  mainly  of  shales  and  fine-grained 
olive-green  sands.  The  beds  below,  with  a  thickness  of  about  250 
meters,  are  here  the  main  coal-bearing  strata,  dominantly  black 
or  grey-black  in  color,  with  some  intercalations  of  thin  olive-green 
sands.  These  beds  were  named  the  Ischichuca  Formation,  the 
type  section  being  located  in  the  quebrada  of  that  name  south  of 
Cerro  Bola.  Below  the  Ischichuca  Formation  lies  "Paganzo  III." 
This  consists  mainly  of  coarse  red  sandstone  and  intercalated 
volcanic  beds;  between  the  beds  of  "Paganzo  111"  proper  and  the 
Ischichuca  are  30-40  meters  of  coarse  grey  to  reddish  conglom- 
erates which  de  la  Mota  assigned  to  "Paganzo  III." 

Frenguelli's  sections  of  the  basin,  derived  from  two  areas  70 
km  apart,  are  given  in  the  second  and  third  columns  of  our  table. 
In  1953  Groeber  and  Stipanicic  (pp.  87-93),  in  their  review  of 
the  Triassic,  followed  FrengueUi,  as  given  in  our  column  4,  ex- 
cept that  his  "Estratos  de  Gualo"  are  renamed  "Estratos  de  los 
Colorados,"  (since  de  la  Mota  had  pointed  out  to  them  that  the 
Mogote  del  Gualo  lies  at  a  much  lower  stratigraphic  position  than 
FrengueUi  beheved). 

A  decade  later  than  the  visit  of  Frenguelli  to  the  Talampaya 
Basin,  study  of  the  region  to  the  west  of  Ischigualasto,  down  the 
La  Peiia,  was  undertaken  by  Ortiz  on  behalf  of  the  Yacimientos 
Petroliferos  Fiscales.  His  work  was  done  in  1964,  and  his  sections 
and  maps  were  promptly  circulated,  although  publication  of  his 
work  was  not  made  until  1968.    As  his  sections  show,  the  actual 


1  Resumes  of  de  la  Mota's  findings  are  given  by  Frenguelli  (1948:   197- 
208)  and  by  Groeber  and  Stipanicic  (1953:  93-95). 


1971  TMF    CHANARES    FORMATION  5 

sequence  of  the  "Rhaetic"  beds  here,  below  the  Ischigualasto,  dif- 
fers considerably  from  that  imagined  by  Frenguelli  and  studied 
by  him  in  the  Cerro  Sola  region,  and  the  strata  are  considerably 
thicker  than  had  been  believed.  The  upper  part  of  the  type  Los 
Rastros  Formation,  to  about  250  meters,  consists  mainly  of  grey 
sandstones  with  intervening  shales  and  only  a  few  coal  seams. 
Below  this,  but  also  included  by  Frenguelli  —  entirely  or  at  least 
for  their  most  part  —  in  the  type  section  of  the  Los  Rastros  For- 
mation are  about  400  meters  of  beds  in  which  dark  carbonaceous 
shales  and  coal  seams  predominate,  with  intervals  of  olive-green 
shales.  Below  the  coal  beds,  again,  are  about  450  meters  of  con- 
glomeratic sandstones,  light  in  color,  in  which  coals  are  little 
developed.  Still  farther  down  to  the  west  appear  the  red  sand- 
stones of  "Paganzo  IIL" 

It  is  clear  that  Frenguelli's  nomenclature  of  the  Los  Rastros 
and  Ischichuca  beds  in  the  two  regions,  that  of  the  La  Pena  and 
the  Ischichuca  quebrada,  is  conflicting.  The  beds  assigned  to  the 
Los  Rastros  in  the  Ischichuca  region  include  only  the  upper  part 
of  the  type  Los  Rastros;  the  middle,  coal-bearing  section  of  the 
beds  which  were  included  in  the  type  Los  Rastros  in  the  La  Pena 
region,  form  to  the  north  practically  the  entire  Ischichuca  Forma- 
tion. The  lowest  portion  of  the  "Rhaetic"  beds  in  the  La  Peiia 
area  has  no  counterpart  in  the  north,  unless  it  be  the  thin  series 
of  conglomerates  that  were  mentioned  above  as  transitional  from 
"Paganzo  III"  to  Ischichuca.  As  Ortiz  points  out,  the  entire  series 
of  beds  from  "Paganzo  III"  up  to  the  Ischigualasto  forms  a  single 
cycle  of  deposition,  to  the  whole  of  which  the  formation  name 
Los  Rastros  should  properly  be  applied.  Further,  since  the  sup- 
posed Ischichuca  Formation  is  merely  a  portion  of  the  Los  Ras- 
tros —  the  lower  portion  by  Frenguelli's  definition,  the  middle 
portion  under  Ortiz's  suggestion  —  the  term  "Ischichuca"  should 
be  abandoned,  as  simply  a  partial  synonym  of  Los  Rastros. 

The  Triassic  sequence  in  the  Talampaya-Ischigualasto  basin  as 
interpreted  by  Ortiz  is  given  in  column  5  of  our  table.  Our  own 
interpretation,  given  in  column  7  and  mentioned  earlier,  is  in 
most  regards  comparable.  The  identity  of  the  Los  Colorados  and 
Ischigualasto  formations  is  perfectly  clear;  we  have  given  names, 
as  the  Tarjados  and  Talampaya  formations,  to  the  red  sandstones 
and  underlying  finer  sandstone  beds  that  have  previously  been 
referred  to  under  the  vague  generic  term  "Paganzo  III."  We  have, 
with  Ortiz,  agreed  that  the  coal-bearing  sandstones  and  shales  of 


6  BREVIORA  No.    377 

the  "Rhaetic"  should  be  considered  as  a  single  Los  Rastros  For- 
mation rather  than  be  subdivided  in  two  in  a  confusing  fashion. 
Our  one  difference  has  been  in  distinguishing  the  lowest  part  of 
this  cycle  as  a  separate  Chanares  Formation  because  of  its  dis- 
tinctive nature  and,  especially,  because  of  the  paleontological 
importance  of  this  unit. 

Bonaparte,  independently  of  Ortiz,  studied  the  lower  western 
portion  of  the  beds  which  Ortiz  has  described  and,  like  Ortiz  and 
in  contrast  to  Frenguelli's  hypothetical  interpretation,  finds  that 
the  lower  part  of  the  Los  Rastros  complex  consists  of  light  colored 
shales  without  coal  seams,  and  thus  is  somewhat  comparable  to 
our  Chanares  beds.  He  is,  further,  to  be  congratulated  for  finding 
in  them  fossils  which  are  presumably  comparable  to  those  from 
the  Chanares.  Quite  probably  the  lowest  section  of  the  Los  Ras- 
tros of  Ortiz  and  the  Chanares  beds  are  homologous  (although 
the  Los  Rastros  beds  contain  conglomerates,  quite  in  contrast  with 
the  even  bedding  of  the  Chanares).  How  should  the  matter  be 
treated?  It  may  be  advocated  either  that  the  Chanares  be  con- 
sidered as  a  lower  member  of  the  Los  Rastros  or  that  the  lower 
segment  of  the  Los  Rastros  in  the  La  Peiia  area  be  considered  as 
a  separate  Chanares  Formation. 

Bonaparte,  however,  would  go  further  and  revive  the  term 
"Ischichuca"  for  these  beds.  Essentially,  his  argument  is  that 
since  these  beds  in  the  La  Pena  region  were  termed  Ischichuca 
by  Frenguelli  (who  had  never  seen  them  and  was  ignorant  of 
their  nature),  the  name  should  be  retained.  To  so  argue,  however, 
is  to  violate  the  basic  principles  of  stratigraphic  nomenclature. 
One  should  refer  to  the  type  section  of  the  Ischichuca,  70  km  to 
the  north.  The  type  Ischichuca  consists  of  the  main  coal-bearing 
section  of  the  "Rhaetic."  As  Ortiz  has  shown,  the  supposed 
"Ischichuca"  in  the  La  Pena  region  is  at  a  higher  stratigraphic 
level  than  the  beds  with  which  we  are  concerned  and  is,  by  Fren- 
guelli's  definition,  equivalent  to  part  of  the  Los  Rastros.  No  two 
sets  of  beds  could  differ  more  in  nature  than  the  blackish  "coal 
measures"  of  the  Ischichuca  and  the  clear  white  ash  of  the 
Chaiiares.  Both  the  nature  of  the  beds  and  their  stratigraphic 
position  distinguish  clearly  the  type  "Ischichuca"  from  the  lower 
Los  Rastros  and  Chanares  beds.  The  use  of  "Ischichuca"  for  the 
latter  strata  cannot  be  defended. 


1971 


THE    CHANARES   FORMATION 


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8  BREVIORA  No.    377 

REFERENCES  CITED 

BoDENBENDER,  G.  1911.  Constitucion  geologica  de  la  parte  meridional  de 
la  Rioja  y  regiones  limitrofes  (Republica  Argentina).  Bol.  Acad.  Nac. 
Cienc.  Cordoba,  19:   1-220. 

Bonaparte,  J.  F.     1967.     Comentario  sobre  la  "Formacion  Chanares"  de 

la  cuenca  Triasica  de  Ischigualasto-Villa  Union.    (San  Juan-La  Rioja). 

Acta  Geol.  Lilloana,  9:    115-119. 
1969.    Datos  sobre  la  evolucion  paleoecologica  en  las  forma- 

ciones  Triasicas   de    Ischigualasto-Villa   Union    (San  Juan-La   Rioja). 

Acta  Geol.  Lilloana,  10:    189-206. 

Frenguelli,  J.  1948.  Estratigrafia  y  edad  del  llamado  Retico  en  la 
Argentina.    Gaea,  An.  Soc.  Argentina  Est.  Geogr.,  8:   159-309. 

Groeber,  P.F.C,  and  p.  N.  Stipanicic.  1953.  Geografia  de  la  Republica 
Argentina,  II    (Primera  Parte):   Triasico.    Buenos  Aires.    Pp.   13-141. 

Heim,  a.      1949.     Estudio  geologico  del  carbon  "Retico"  y  del  Valle  de 

la  Pena   (provincias  de  San   Juan   y   La   Rioja).    Bol.   Dir.  Gen.   Ind. 

Min.,  69:    1-31. 
Huene,   F.      1931.      Die   fossilen   Fahrten    im    Rhat   von   Ischigualasto   in 

Nordwest-Argentinien.    Palaeobiologica,  4:    99-112. 
OrtIz,  a.     1968.    Los  denominados  Estratos  de  Ischichuca  como  seccion 

media  de  Formacion  Los  Rastros.    Actas  III,  Jorn.   Geol.  Argentina, 

1:   333-339. 
RoMER,  A.  S.,  AND  J.  A.  Jensen.     1966.    The  Chanares  (Argentina)  Trias- 

sic  reptile  fauna.     II.  Sketch  of  the  geology  of  the  Rio  Chanares-Rio 

Gualo  region.    Breviora,  No.  252:    1-20. 


BREVIORA 

Musenim   of   Compsirative   Zoology 

Cambridge,  Mass.  15  June,   1971  Number   378 

THE  CHANARES  (ARGENTINA)  TRIASSIC  REPTILE  FAUNA 

X.     TWO  NEW  BUT  INCOMPLETELY  KNOWN 
LONG-LIMBED  PSEUDOSUCHIANS. 

Alfred    Sherwood    Romer 


Abstract.  Two  types  of  hind  limbs,  with  which  incomplete  remains 
of  other  skeletal  parts  are  associated,  are  described  as  new  genera  and 
species,  Lagerpeton  chanarensis  and  Lagosiichus  talampayensis.  Both  have 
long  and  slender  legs,  with  the  tibia  longer  than  the  femur,  and  a  long 
slender  foot.  They  differ,  however,  in  foot  construction,  for  in  Lagerpeton 
digit  II  is  short  and  digit  IV  the  longest  of  the  series,  whereas  in  Lago- 
siichus metatarsals  II-IV  are  subequal  in  length  and  digit  III  the  longest 
in  the  foot. 

INTRODUCTION 

In  the  pseudosuchian  material  collected  by  the  La  Plata-Harvard 
expedition  of  1964-1965,  there  are  several  forms  represented  by 
nearly  complete  skeletal  material.  In  addition,  however,  in  this 
collection  and  among  specimens  collected  later  by  Sr.  Bonaparte 
of  the  Instituto  Lillo  of  Tucuman,  there  are  less  complete  remains 
of  further  pseudosuchians.  Two  such  forms  are  represented  by 
materials  including  hind  limbs  of  unusual  and  advanced  char- 
acter; these  will  be  described  here. 

Lagerpeton  chanarensis  gen.  et  sp.  nov. 

Holotype.  La  Plata  Museum  No.  64-XI-14-10  (field  number 
64),  a  hind  leg,  collected  from  the  Chanares  Formation  in  La 
Rioja  Province,  Argentina,  about  AVi  miles  east  of  the  mouth 
of  Rio  Chaiiares. 

Combined  generic  and  specific  diagnosis.  A  pseudosuchian; 
hind  limb  very  long  and  slender;  femur  with  articular  head  sharply 
set  off  from  shaft;  tibia  and  fibula  longer  than  femur;  astragalus 


BREVIORA 


No.  378 


and  calcaneum  fused  and  applied  closely  to  tibia  and  fibula;  toe 
IV  longest  of  the  hind  leg  digits;  toe  II  much  shorter  than  III  or 
IV;  toe  V  represented  by  short  metatarsal  only. 

Description.  The  type  specimen  (Fig.  1 )  was  found  quite 
isolated,  not  articulated  with  or  accompanied  by  other  skeletal 
materials.  The  femur  is  long  and  slender,  with  a  length  of  77  mm. 
It  has  the  typical  sigmoidal  archosaur  shape.  The  well-ossified 
curved  articular  area  of  the  head  is  pronounced  and  set  off  at  a 
sharp  angle  from  the  shaft.   A  marked  angulation  of  the  posterior 


Figure  1.     Right  hind  leg  of  Lagerpeton,  holotype.     Left,  external  view; 
center,  extensor  surface  of  foot;  right,  internal  view.    X  1/2. 


1971  LAGERPETON  AND  LAGOSUCHUS  3 

margin  of  the  shaft  indicates  the  point  of  insertion  of  muscula- 
ture, presumably  the  iliofemoralis.  On  the  medial  surface  below 
the  head,  there  is  a  well-developed  fourth  trochanter  in  the  shape 
of  a  pronounced  ridge,  presumably  for  the  insertion  of  the 
caudifemoralis. 

The  epipodials  are  even  more  elongate  and  slender  than  the 
femur;  the  tibia  measures  92  mm  in  length,  and  is  thus  about  120 
per  cent  the  length  of  the  femur.  The  tibia  is  well  expanded 
proximally  for  a  broad  double  articulation  with  the  distal  end  of 
the  femur.  The  fibula  is  incomplete  in  the  type,  and  I  have  in 
my  figure  restored  the  proximal  end  from  a  specimen,  discussed 
below,  in  the  Instituto  Lillo  collection.  It  is,  as  always,  a  slender 
strap  of  bone  expanded  at  either  end;  proximally,  it  articulates 
with  the  lateral  surface  of  the  distal  end  of  the  femur. 

The  proximal  tarsals  are  of  unusual  construction  for  a  theco- 
dont. Astragalus  and  calcaneum  are  completely  fused  in  the  type 
specimen;  in  their  combined  outline  they  conform  to  the  area  of 
the  distal  end  of  tibia  plus  fibula,  and  this  astragalo-calcaneum  is 
closely  applied  to  these  two  elements,  although  not  fused  with 
them.  Further  contributing  to  the  close  union  of  the  astragalo- 
calcaneum  with  the  epipodials  is  a  triangular  flange  of  bone  extend- 
ing upward  from  this  element  posteriorly  over  the  lower  ends  of 
tibia  and  fibula.  There  is  here  no  indication  of  the  crocodiloid 
calcaneal  tuber  frequently  found  in  pseudosuchians. 

The  usual  two  distal  tarsals  are  present.  A  more  medial  and 
larger  element  is  present  on  the  ventral  surface,  above  the  third 
metatarsal;  the  lateral  element  caps  metatarsal  IV. 

Like  the  main  limb  elements,  the  foot  is  long  and  slender,  the 
toes  apparently  lying  close  together  in  life.  Toe  V  is  represented 
only  by  a  short,  pointed  metapodial;  the  other  toes  are  complete, 
with  the  primitive  phalangeal  formula  of  2,  3,  4,  5.  The  terminal 
phalanges  of  toes  I-IV  are  sharp  claws,  somewhat  curved.  Most 
unusual  for  an  archosaur,  the  toes  are  primitive  in  one  regard, 
namely  that  toe  IV  is  the  longest  of  the  series.  Digit  I  is,  as  often, 
short;  digit  II  is  also  shortened,  its  metapodial  having  but  about 
half  the  length  of  those  of  its  lateral  neighbors.  The  total  lengths 
of  the  digits^  from  toe  I  outward,  are  21,  49,  69,  85,  and  18  mm. 
Metapodial  lengths  are  8,  24,  45,  48,  and  18  mm. 

In  the  Instituto  Lillo  collections  is  a  specimen  that  includes  a 
hind  Ice  similar  to  that  of  the  type  in  size,  bone  proportions,  and 


4  BREVIORA  No.    378 

structure.  The  femur  is  75  mm  in  length,  the  tibia  (not  perfectly 
preserved)  about  90  mm.  The  femur  is  closely  comparable  to 
that  of  the  type  with  its  sharply  set  off  head  and  prominent 
trochanteric  ridge.  Toe  I  is  not  preserved,  but  toes  II-IV  resemble 
closely  those  of  the  type,  with  metapodial  lengths  of  23,  42,  and 
47  mm,  and  total  toe  lengths  of  48,  74,  and  87  mm. 

With  this  specimen  is  a  pelvis  which  is  apparently  nearly  com- 
plete, but  in  its  present  state  of  preparation  is  seen  only  from 
its  ventral  aspect.  The  ischia  are  well  developed  and  extend  far 
backward  with  a  long  symphysis.  Below  and  somewhat  to  the 
rear  of  the  level  of  the  acetabulum  their  broad  external  surfaces 
are  convex  in  section,  giving  this  region  a  "swollen"  appearance. 

Lagosuchus  talampayensis  gen.  et  sp.  nov. 

Holotype.  La  Plata  Museum  No.  64-XI-14-11  (in  part). 
Remains  included  in  a  slab  collected  from  the  Chaiiares  Forma- 
tion in  La  Rioja  Province,  Argentina,  about  2  km  north  of  the 
mouth  of  Rio  Chaiiares. 

Combined  generic  and  specific  diagnosis.  A  pseudosuchian; 
hind  limb  similar  in  many  regards  to  that  of  Lagerpeton;  limb 
long  and  slender;  femur  with  articular  head  sharply  set  off  from 
shaft;  tibia  and  fibula  longer  than  femur;  astragalus  and  calcaneum 
fused  and  applied  closely  to  tibia  and  fibula.  Digit  I  short,  digit 
V  represented  by  short  metatarsal  only;  digits  II-IV  subequal  in 
metatarsal  length,  but  digit  III  longest  of  the  series. 

Description.  A  slab  from  the  Chaiiares  exhibits  on  one  surface 
the  greater  part  of  the  skeleton  of  a  small  ornithosuchid  which  I 
hope  to  describe  in  a  later  number  of  this  series.  On  the  other 
surface  of  the  slab  are  scattered  materials  pertaining  to  a  still 
smaller  pseudosuchian.  Best  preserved  are  nearly  complete  and 
articulated  hind  limbs  (Fig.  2).  Although  considerably  smaller, 
these  limbs  in  their  proportions  resemble  those  of  Lagerpeton,  and 
I  at  first  assumed  that  the  specimen  was  an  immature  individual 
of  that  genus.  The  foot  structure,  however,  shows  that  we  are 
dealing  with  a  discrete  form  of  smaller  size. 

As  in  Lagerpeton,  the  limbs  are  long  and  slender;  the  head  of 
the  femur  is  set  off  sharply  from  the  shaft  and  the  trochanteric 
ridge  is  well  developed.  As  in  Lagerpeton  the  lower  leg  is  longer 
than  the  femur,  the  two  femora,  as  preserved,  having  lengths  of 
38  and  39  mm,  the  associated  tibiae  47  and  approximately  48  mm. 


1971 


LAGERPETON  AND  LAGOSUCHUS 


Figure  2.    Hind  foot  of  Lagosuchus,  in  ventral  view.    Composite  of  type 
and  a  specimen  in  the  Instituto  Lillo.    1   1/2  X  size  of  holotype. 


The  proximal  tarsal  region  is  poorly  preserved  in  the  type.  Two 
well-developed  distal  tarsals  are  present.  Of  the  right  foot,  only 
metapodials,  incomplete  distally,  are  visible.  The  left  foot  is  well 
preserved  as  regards  the  metatarsals  and  a  portion  of  the  pha- 
langes. The  digits  are  elongate  and  slender;  metapodials  II-IV  are, 
as  preserved,  parallel  to  one  another  and  closely  apposed.  Digit 
I,  with  a  metapodial  length  of  15  mm,  is  short;  metapodials  II-IV 
have  lengths  of  23,  26,  and  25  mm;  metapodial  V,  broad  at  its 
head,  tapers,  as  preserved,  to  a  point  at  11  mm.  The  two  pha- 
langes appropriate  to  digit  I  are  present,  as  are  single  proximal  pha- 
langes articulated  with  metatarsals  II  and  III,  and  several  disarticu- 
lated phalanges  (one  a  clawed  ungual). 

Scattered  about  the  slab  are  disconnected  series  of  vertebrae 
with  average  lengths  of  centra  of  7.5  mm  in  the  best  preserved 


6  RREVIORA  No.    378 

region.  There  are,  further,  remains  of  pectoral  limbs.  In  the 
better  preserved  of  these  the  humerus  has  a  length  of  26  mm, 
the  radius  16  mm.  As  one  might  expect  from  the  nature  of  the 
long  hind  legs,  the  front  limbs  thus  appear  to  be  much  reduced 
in  size,  the  combined  length  of  the  long  bones  of  the  "arm"  being 
less  than  half  that  of  the  corresponding  hind  leg  elements. 

A  specimen  in  the  Instituto  Lillo  collection  includes  much  of 
the  posterior  part  of  a  skeleton  that  is  closely  comparable  to  the 
type  of  Lagosiichus  except  for  somewhat  larger  size.  Much  of 
both  hind  legs  is  preserved  in  articulation.  Right  and  left  femora 
measure  55  and  56  mm  in  length,  the  tibiae  72  and  70  mm. 

As  in  Lagerpeton,  astragalus  and  calcaneum  are  united  and 
closely  applied  to  tibia  and  fibula.  Here,  however,  the  line  of 
suture  between  the  two  proximal  tarsals  is  still  visible,  and  a 
small  spur  of  bone  (not  seen  in  Lagerpeton)  projects  backward 
from  the  fibular  edge  of  the  astragalo-calcaneum.  There  is  no 
proximal  extension  of  the  astragalo-calcaneum  of  the  sort  seen 
in  Lagerpeton.  The  two  distal  tarsals  are  present  lying  above  the 
metatarsal  heads. 

The  feet  are  incompletely  preserved,  but  except  for  somewhat 
larger  size,  they  compare  well  with  those  of  the  type.  On  the  right 
foot  metatarsals  II  and  IV  have  lengths  of  34  and  38  mm,  respec- 
tively; lengths  of  metatarsals  I-IV  on  the  left  foot  are:  23,  35, 
39,  and  38  mm.  No  phalanges  are  present  on  metatarsal  I,  but 
two  phalanges,  with  lengths  of  9  and  7  mm  are  present  on  the 
second  digit,  three  phalanges  with  lengths  of  12,  8,  and  5  mm  on 
digit  III,  and  four  phalanges  with  lengths  of  6,  5,  4,  and  4  mm 
on  digit  IV.  Metatarsal  V,  broad  at  the  base  and  tapering  distally, 
is  incomplete,  with  a  length  as  preserved  of  10  mm. 

In  Figure  2  the  foot  is  restored  as  a  composite  of  the  type  and 
the  Instituto  Lillo  specimen  just  described,  with  allowance  made 
for  the  difference  in  size  of  the  two  specimens.  The  more  distal 
phalanges  are  restored  on  digits  II-IV.  As  restored,  digital  lengths 
of  the  Instituto  Lillo  specimen  are,  from  digit  I  outward:  36,  56, 
69,  and  62  mm.  Here,  in  contrast  to  Lagerpeton,  there  has  de- 
veloped the  "typical"  archosaur  foot,  with  toe  I  relatively  short, 
toe  V  reduced,  and  toe  III  the  longest  of  the  II-III-IV  series. 

Associated  are  remains  of  the  pelvic  girdle.  The  acetabula  (into 
which  the  femoral  heads  were  inserted  when  the  specimen  was 
recovered)    are  small  and  deep,  strongly  overhung  dorsally  by 


1971  LAGERPETON  AND  LAGOSUCHUS  7 

the  iliac  rim.  The  acetabular  construction  plus  the  nature  of  the 
femoral  head  indicate  rather  surely  that  the  femur  moved  in  a 
fore-and-aft  plane  close  to  the  body.  The  ilium  (Fig.  3)  is  of 
peculiar  structure.  Above  the  acetabulum  it  constricts  to  a  rela- 
tively narrow  neck.  Here  there  projects  anterolaterally  a  short 
but  stout,  blunt-ended  process  of  a  sort  otherwise  unknown  to  me; 
it  is  possible  that  it  afforded  an  origin  for  an  iliofemoralis  externus 
muscle  as  in  the  case  of  a  somewhat  similar  process  in  some 
ornithischians    (cf.    Romer,    1927)    and    Poposaurus    (Colbert, 


Figure  3.  Right  ilium  and  head  of  femur  of  Lagosiichiis:  external 
process  on  ilium  restored  from  left  side.  From  a  specimen  in  the  Institute 
Lillo.     X  4/3. 


1961).  Above  the  "neck,"  the  ihum  expands  to  form  a  short 
blade.  In  all  "normal"  thecodonts  the  iliac  blade  is  a  simple  single 
vertical  structure;  here,  however,  there  lies,  internal  to  the  normal 
external  blade,  a  broad  trough,  comparable  to  that  seen  in  ophia- 
codonts,  presumably  for  accommodation  of  dorsal  axial  muscles. 
Shallow  posteriorly,  this  trough  deepens  and  broadens  anteriorly. 
Medial  to  this  trough  is  a  second  iliac  blade,  tilted  somewhat 
medially,  to  the  inner  surface  of  which  the  sacral  ribs  pre- 
sumably articulated.  Lateral  and  medial  blades  join  anteriorly, 
closing  the  dorsal  trough  at  this  end.  I  know  of  such  an  iliac 
"trough"  structure  in  only  one  other  archosaur.  In  Hesperosuchus, 
Colbert  (1952)  found  in  the  pelvic  region  an  element  which  should 
have  been  an  ihum  but  which,  because  of  its  pecuHar  nature,  he 
concluded  could  not  be  that  element.  Its  main  peculiarity  is  its 
possession  of  a  dorsal  "trough"  comparable  to  that  of  Lagositchus. 
Parts  of  pubis  and  ischium  are  present  in  this  specimen.    It  is 


8  BREVIORA  No.    378 

clear  that  both  pubis  and  ischium  take  part  in  the  acetabulum, 
but  in  default  of  a  better  preserved  specimen  I  refrain  from  dis- 
cussion of  this  portion  of  the  girdle. 

Found  close  to  the  limbs  and  pelvic  remains  were  two  series  of 
vertebrae.  One  appears  to  include  sacrals,  followed  by  nine  prox- 
imal caudals.  The  mean  length  of  these  caudal  centra  is  approx- 
imately 7  mm.  A  first  chevron  is  present  between  caudals  three 
and  four;  its  length  is  13.5  mm;  those  following  decrease  in  length, 
the  fourth  of  the  series  measuring  10  mm.  A  second  series  of 
vertebrae  includes  30  segments,  apparently  running  to  the  tip  of 
the  tail.  The  first  dozen,  poorly  preserved,  appear  to  have  a  mean 
length  of  centra  of  about  7  mm;  more  posteriorly,  the  length 
increases  to  about  1  cm  per  segment.  Chevrons,  gradually  decreas- 
ing in  length  to  a  nubbin,  are  present,  as  preserved,  to  a  position 
between  the  tenth  and  eleventh  from  the  end  of  the  series. 

A  further  Instituto  Lillo  specimen  that  may  pertain  to  Lago- 
suchus  includes  an  imperfect  pelvis  and  much  of  the  hind  legs. 
As  in  both  genera  described  in  the  present  paper,  the  tibia  is  longer 
than  the  femur,  with  measurements  of  the  right  leg  elements  of 
48  and  42  mm,  respectively.  As  in  Lagosuchus,  metatarsals  II-IV 
are  subequal  in  length,  with  measurements  of  24,  28,  and  27  mm 
for  these  metapodials  in  the  left  foot.  Possibly  associated  is  a 
fragment  of  maxilla  or  dentary  bearing  small  teeth  spaced  a  bit 
more  than  a  millimeter  apart.  A  number  of  posterior  dorsal  verte- 
brae are  present,  with  an  average  central  length  of  5.5  mm  and  a 
height  of  7.5  to  8  mm. 

DISCUSSION 

So  distinctive  are  the  hind  legs  which  are  the  major  preserved 
portions  of  the  two  forms  described  above  that  formal  systematic 
description  of  them  seems  justified  despite  the  paucity  of  further 
associated  anatomical  structures.  Greater  length  of  tibia  than  of 
femur  is  generally  regarded  as  associated  with  speed.  Greater 
length  of  lower  leg  than  thigh  is  present  in  relatively  few  cases 
among  even  presumably  bipedal  archosaurs  —  a  few  thecodonts, 
such  as  Scleromochlus,  small  coelurosaurs,  and  to  a  slight  degree 
in  some  camosaurs.  The  sharply  inturned  head  of  the  femur  indi- 
cates that  the  hind  legs  were  carried  close  to  and  beneath  the 
trunk  and  the  suggestion  that  we  are  dealing  with  a  biped  is  in- 
creased by  the  shortness  of  the  front  legs  of  Lagosuchus. 


1971  LAGERPETON  AND  LAGOSUCHUS  9 

It  is  surprising  to  find  so  advanced  a  type  of  limb  at  such  an 
early  stage  of  the  Triassic  (probably  Anisian  in  terms  of  the  marine 
series).  In  the  preceding  Cynognathiis  stage  of  the  "Eotriassic," 
thecodonts  more  advanced  than  protcrosuchians  such  as  Chasma- 
tosaurus  and  Erythrosuchus  were  represented  only  by  Euparkeria, 
as  recently  ably  described  by  Ewer  (1965).  Euparkeria  was  ad- 
vancing toward  a  bipedal  habitus,  but  was  still  relatively  primitive. 
One  would  have  expected  that,  in  the  Anisian,  pseudosuchians 
would  not  have  advanced  far  beyond  this  level,  and  that  forms 
with  limbs  of  such  an  advanced  sort  as  seen  in  the  two  types  just 
discussed  should  have  been  characteristic  only  of  a  much  later 
stage  of  the  Triassic.  Obviously,  as  these  forms  indicate,  this 
assumption  is  incorrect.  It  would  seem  that  advance  and  radiation 
among  thecodonts  occurred  rapidly  in  early  Triassic  times;  beliefs 
to  the  contrary  were  due  to  our  lack  of  knowledge  of  middle 
Triassic  faunas;  study  of  South  American  forms  is  now  bringing 
such  faunas  into  the  picture. 

As  was  first  clearly  brought  out  by  Krebs  (1963),  two  distinct 
types  of  tarsal  joints  developed  among  thecodonts.  In  one,  re- 
tained by  crocodilians,  the  main  joint  between  lower  leg  and  foot 
lay  between  astragalus  and  calcaneum.  The  second  type  of  joint 
is  that  found  in  dinosaurs,  in  which  the  proximal  tarsals  were 
functionally  combined  with  the  lower  leg,  the  distal  tarsals  united 
with  the  foot.  Both  forms  here  described  are  of  the  second  type. 
However,  the  presence  of  a  small  spur  on  the  calcaneal  region  of 
Lagosuchus  suggests  the  possibility  that  a  transition  from  one  type 
to  the  other  may  have  been  possible.  Fusion  of  the  two  proximal 
elements  is  a  condition  rare  even  in  "advanced"  dinosaurs.  The 
development  of  a  proximal  flange  from  the  astragalo-calcaneum, 
seen  in  Lagerpeton,  is  a  condition  found  in  various  theropods,  but 
in  these  forms  the  flange  is  developed  on  the  extensor  rather  than 
the  flexor  surface  of  the  lower  leg. 

With  the  marked  expansion  of  our  knowledge  of  thecodonts 
that  is  currently  taking  place,  classification  of  the  group  can  be 
at  best  but  a  provisional  matter,  and  an  attempt  to  place  the  two 
genera  just  discussed  in  a  "solid"  systematic  position  is  unjustified. 
It  is  certain  that  the  two  have  no  association  with  the  series  of 
forms  which  appear  to  have  crocodilian  relationships,  and  the  tar- 
sal construction  suggests  that  the  two  are  connected  in  some 
fashion  with  a  radiation  leading  toward  the  dinosaurs  and,  par- 
ticularly,   toward    the    coelurosaurian    group    of    the    Saurischia. 


10  BREVIORA  No.    378 

Whether  either  of  the  two,  however,  can  be  regarded  as  close  to 
the  direct  line  leading  to  such  dinosaurs  is  doubtful.  Lagerpeton 
is,  on  the  one  hand,  advanced  in  tarsal  construction  and,  on  the 
other,  primitive  or  specialized  in  the  matter  of  relative  length  of 
digit  IV.  Lagosuchus  is  more  orthodox  in  digital  construction, 
but  precocious  in  astragalo-calcanear  fusion,  and  specialized  in 
iliac  construction. 

There  is  a  classic  story  of  the  man  who  "mounted  his  horse 
and  galloped  off  in  all  directions."  The  history  of  thecodonts,  we 
are  coming  to  realize,  seems  to  have  followed  this  pattern.  We 
have  as  yet  no  clues  as  to  the  course  followed  toward  birds  or 
pterosaurs.  Various  thecodonts  seem  to  have  trended  toward  a 
crocodilian  type  of  organization.  The  ornithischian  pattern  is  so 
distinctive  that  at  the  present  we  can  reasonably  consider  the 
Ornithischia  as  definitely  monophyletic  in  origin.  This  is  not  the 
case  with  the  Saurischia.  The  presence  in  the  later  Triassic  of 
apparent  sauropod  ancestors  of  seemingly  primitive  quadrupedal 
nature  suggests  a  polyphyletic  origin  of  that  order.  What  of  the 
"prosauropods"  of  the  late  Triassic,  the  coelurosaurs,  the  advanced 
theropods  of  the  Jurassic  and  Cretaceous?  Quite  possibly  the 
Saurischia  are  a  polyphyletic  group  that  took  origin  from  a  "mixed 
grill"  of  thecodonts  —  a  varied  assemblage  amongst  which  the  two 
forms  here  described  are  to  be  included. 

I  am  indebted  to  the  National  Science  Foundation,  grants 
GB-2454  and  GB-8171,  for  aid  in  the  collection,  preparation, 
and  publication  of  the  La  Plata-Harvard  materials,  and  I  am  grate- 
ful to  Sr.  Bonaparte  for  the  privilege  of  studying  the  Chan  ares 
thecodont  material  which  he  has  collected. 

REFERENCES  CITED 

Colbert,    E.    H.      1952.      A    pseudosuchian    reptile    from    Arizona.     Bull. 

American  Mus.  Nat.  Hist..  99:  561-592. 
. 1961.     The  Triassic  reptile,  Poposaiints.     Fieldiana.     Geol- 
ogy, 14:   59-78. 
Ewer,  R.   F.      1965.     The   anatomy  of  the  thecodont    reptile  Eiiparkeria 

capensis    Broom.     Philos.    Trans.    Roy.  Soc.    London,    Ser.     B,    248: 

379-435. 
Krebs,  B.     1963.     Bau  imd  Funktion  des  Tarsus  eines  Pseudosuchiers  aus 

der  Trias  des  Monte  San  Giorgio  (Kanton  Tessin,  Schweiz).    Palaont. 

Z.,   37:    88-95. 
Romer,  a.  S.      1927.     The  development  of  the  thigh  musculature  of  tlic 

chick.    Jour.  Morph.  Physiol.,  43:   347-385. 


BREVIORA 

Museum   of    Comparative   Zoology 

CAMBRrocE,  Mass.  15  June,  1971  Number  379 

THE  CHANARES  (ARGENTINA)  TRIASSIC 

REPTILE  FAUNA  XI.  TWO  NEW  LONG-SNOUTED 

THECODONTS,  CHANARESUCHUS  AND  GUALOSUCHUS 

Alfred  Sherwood  Romer 


Abstract.  A  description  is  given  of  the  skull  and  jaws  of  two  new 
thecodonts,  Chanaresuchiis  bonapartei  and  Gualosuchus  reigi.  from  the 
early  Middle  Triassic  Chanares  Formation  of  Argentina.  The  two  forms 
here  described  plus  Cerritosaurus  and  Proterochampsa  are  closely  related 
and  may  be  included  in  the  single  family  Proterochampsidae.  Their 
structure  is  in  many  regards  so  primitive  that  this  family  should  be  in- 
cluded in  the  thecodont  suborder  Proterosuchia.  Suggested  relationships 
of  members  of  the  family  to  crocodilians  and  phytosaurs  are  discussed. 

INTRODUCTION 

Commonest  of  all  thecodont  remains  so  far  discovered  in  the 
Chaiiares  Formation  are  those  of  Chanaresuchus  bonapartei  and 
Gualosuchus  reigi.  Considerable  material,  particularly  of  Cha- 
naresuchus, was  found  by  the  La  Plata-Harvard  expedition  of 
1964-65,  and  further  specimens,  which  Sr.  Bonaparte  has  been 
kind  enough  to  let  me  study,  are  in  the  collections  of  the  Instituto 
Lillo  of  Tucuman.  In  the  present  paper  I  will  confine  myself  to 
description  of  the  skulls  and  jaws  of  these  two  closely  related 
forms;  I  hope  shortly  to  give  an  account  of  the  postcranial  skel- 
eton of  Chanaresuchus. 

I  gratefully  acknowledge  grants  from  the  National  Science 
Foundation  that  covered  most  of  the  expenses  of  collection  and 
preparation  of  the  materials,  and  for  aid  in  publication. 

Chanaresuchus  bonapartei,  gen.  et  sp.  nov. 

Holotype.  La  Plata  Museum  1964-XI-14-12  (field  no.  47), 
a  skull  and  jaws  together  with   postcranial   remains.    Collected 


2  BREVIORA  No.    379 

from  the  Chanares  Formation,  in  La  Rioja  Province,  about  half 
a  mile  southeast  of  a  volcanic  plug  in  the  valley  of  the  south  fork 
of  the  Chanares  River. 

Combined  generic  and  specific  characters.  A  thecodont  of 
modest  size  (largest  known  skull  about  260  mm  in  length). 
Skull  long  and  low;  broad  posteriorly;  slithke  external  nares 
placed  close  together  dorsally  some  distance  back  of  tip  of  snout; 
antorbital  vacuity  small;  postfrontal  absent;  no  pineal  opening; 
parietals  swing  sharply  outward  posteriorly,  above  superior  tem- 
poral fenestrae,  toward  meeting  with  squamosals;  suspensorium 
far  back  of  occiput,  and  lateral  fenestra  hence  elongate  antero- 
posteriorly.  Very  elongate  choanae  partially  covered  below  by  a 
secondary  palate.  Pterygoid  and  palatine  toothed.  Basal  articu- 
lation of  braincase  and  palate  movable.  A  long  if  narrow  inter- 
pterygoid  vacuity,  exposing  a  slender  parasphenoid  rostrum. 

The  generic  name  refers  to  the  Chanares  River  and  Forma- 
tion. The  specific  name  is  given  in  honor  of  Sr.  Jose  Bonaparte, 
able  collector  and  describer  of  Triassic  reptiles. 

Description  (Figs.  1-3).  Considerable  skull  material  of 
Chanaresuchus  is  available.  Most  notable  in  the  La  Plata-Harvard 
collection,  in  addition  to  the  holotype,  are  MCZ  4037  (field  no. 
154),  which  includes  a  large  skull  and  jaws,  and  MCZ  4039 
(field  no.  81),  the  well-preserved  left  half  of  a  small  skull.  Skull 
lengths  of  these  three  specimens  (measured  to  the  quadrate)  are, 
respectively,  211  mm,  260  mm,  and  155  mm.  MCZ  4036  con- 
sists of  a  slab  containing,  as  well  as  considerable  postcranial 
material,  two  rather  poor  skulls  of  about  the  size  of  the  holo- 
type. 

The  dermal  bones  of  the  skull  are  ornamented,  particularly  on 
the  skull  table,  with  ridges  radiating  from  centers  of  ossification. 
The  degree  of  sculpturing  appears  to  vary  with  size  and  presumed 
age;  it  is  little  developed  on  MCZ  4039,  somewhat  more  prom- 
inent on  the  type,  and  the  largest  skull,  MCZ  4037,  is  quite 
rugose. 

The  skull  is  long,  low,  slender-snouted,  broad  posteriorly. 
Snout  elongation  is  clearly  shown  by  the  length  of  premaxillae, 
nasals,  and  frontals,  and  by  proportionate  measurements.  If,  for 
example,  the  anteroposterior  diameter  of  the  orbit  be  taken  as  a 
base,  the  facial  length,  anterior  to  the  orbit,  is  about  AVi  times 
the    length    of    the    orbit    itself,    whereas    in    other    thecodonts 


1971  CHANARESUCHUS  AND  GUALOSUCHUS  3 

(phytosaurs  excepted)  this  measurement  is  typically  no  more 
than  two  or  three  times  the  orbital  diameter.  There  is,  further, 
a  considerable  degree  of  postorbital  length.  From  the  post- 
orbital  bar  to  the  tip  of  the  quadrate,  the  distance  is  about  21/2 
times  the  orbital  diameter,  whereas  in  pseudosuchians  this  dis- 
tance is  almost  invariably  considerably  less,  and  is  sometimes 
not  even  equal  to  orbital  diameter.  It  is  difficult  to  select  a 
standard  against  which  skull  height  may  be  objectively  measured, 
but  it  may  be  noted  that  even  in  the  postfacial  region  of  the 
skull,  where  flattening  is  less  pronounced  than  in  the  snout,  the 
skull  height  is  not  sufficient  to  give  space  for  the  eyes  in  the 
lateral  wall  and  the  orbits  are,  in  consequence,  incised  into  the 
skuU  roof. 

The  tip  of  the  snout  is  sUghtly  decurved.  Dorsal  and  lateral 
surfaces  of  the  skull  are  clearly  marked  off  from  one  another. 
The  dorsal  surface  is  nearly  flat,  although  rising  along  the  length 
of  the  snout  to  then  become  horizontal  in  plane  along  the  length 
of  the  skull  table.  On  either  side  a  well-marked  ridge,  separating 
lateral  and  dorsal  surfaces,  develops  at  the  level  of  the  nares 
and  continues  back  to  the  anterodorsal  angle  of  the  orbit,  where 
there  is  a  modestly  developed  lateral  projection.  A  similar  pro- 
jecting angle  is  present  at  the  posterior  margin  of  the  orbit,  and 
a  clear-cut  angle  separating  roof  from  "cheek"  continues  along 
the  bar  separating  the  temporal  fenestrae. 

The  external  nares  are  elongate  slitlike  structures,  dorsally 
placed  and  close  together,  separated  only  by  a  narrow  bony  bar. 
In  contrast  to  the  subterminal  position  seen  in  many  thecodonts, 
they  are  placed  well  back  of  the  snout  tip;  grooves  leading  into 
the  narial  openings  are  present  anteriorly  and  posteriorly.  Deep 
to  the  external  nares,  and  separated  from  the  narial  margins  at 
all  points,  is  seen  a  sheet  of  bone  within  which  is  found,  on 
either  side,  an  opening  of  considerably  smaller  size  than  the 
narial  opening.  At  first  glance  one  would  assume  that  these 
openings  are  the  choanae;  however,  as  discussed  below,  they  are 
apparently  anterior  palatal  foramina  for  the  vomeronasal  organs, 
and  this  bony  sheet  forms  a  short  secondary  palate.  This  sec- 
ondary palate  is  separated  from  the  bone  rimming  the  narial 
margin  for  only  a  short  distance  on  the  anterior  and  lateral 
margins;  medially,  however,  the  bony  sheets  of  the  two  sides 
appear  to  meet  one  another  below  and  free  from  the  bar  sepa- 
rating the  two  nares,  and  the  opening  posteriorly  between  the 


BREVIORA 


No.   379 


narial  margin  and  the  secondary  palate  leads  into  a  short  naso- 
palatine duct. 

The  antorbital  fenestra  is  a  small  triangular  opening,  the  apex 
of  the  triangle  lying  anteriorly,  at  about  one-third  the  distance 
from  orbit  to  snout  tip,  the  posterior  base  separated  from  the 
orbit  by  a  narrow  bony  bar.  The  orbits  are  large  (as,  presumably 
were  the  eyes)  and  are  subcircular  in  shape;  on  the  lateral  sur- 
face they  occupy  nearly  the  whole  height  of  the  skull,  leaving 
but  a  narrow  bar  of  bone  between  them  and  the  lower  skull 
margin.  Dorsally  their  semicircular  margins  cut  far  into  the 
sides  of  the  skull  table.  The  upper  rim  is  slightly  elevated;  as 
mentioned,  there  are  pronounced  projections  anteriorly  and  pos- 
teriorly at  the  junction  of  dorsal  and  lateral  portions  of  the 
orbital  boundaries. 

There  is  no  parietal  foramen.  The  superior  temporal  fenestra 
is  well  developed,   facing  directly  dorsally,   and  is  triangular  in 


Figure  1.  Chanaresuchus  bonapartei,  skull  in  dorsal  view.  This  and 
Figs.  2-5  are  based  on  the  holotype,  with  additions  from  other  specimens. 
Abbreviations  for  Figs.  1-7:  an,  angular;  ar,  articular;  bo,  basioccipital; 
c,  coronoid;  d,  dentary;  ec,  ectopterygoid;  /,  frontal;  ;,  jugal;  /,  lacrimal; 
m,  maxilla;  n,  nasal;  op,  opisthotic;  p,  parietal;  part,  prearticular;  pi,  pala- 
tine; pm,  premaxilla;  pa,  postorbital;  pp,  postparietal;  prf,  prefrontal; 
ps,  parasphenoid;  pt,  pterygoid;  q,  quadrate;  qj,  quadratojugal;  san,  sur- 
angular;  sac,  supraoccipital;  sp,  splenial;  sq,  squamosal;  v,  vomer. 


1971  CHANARESUCHUS  AND  GUALOSUCHUS  5 

shape,  with  an  anterior  base  and  a  posterior  apex.  The  lateral 
temporal  opening  is,  as  noted  above,  elongate  anteroposteriorly, 
in  contrast  to  its  much  shorter  span  in  most  archosaurs;  its  pos- 
terior margin  is  somewhat  convex  in  outline,  suggestive  of  the 
initiation  of  the  V-shape  of  this  border  in  many  archosaurs.  In 
strong  contrast  with  most  archosaurs,  the  suspensorial  region 
slants  far  back  ventrally,  the  jaw  articulation  lying  some  distance 
back  of  the  level  of  the  occiput.  The  back  margin  of  the  sus- 
pensorial region  is  somewhat  concave;  this,  plus  a  slight  dorsal 
spur,  shows  the  initiation  of  the  type  of  otic  notch  characteristic 
of  many  more  advanced  archosaurs.  The  occiput  slants  diago- 
nally downward  and  backward  from  the  posterior  margin  of  the 
narrow  medial  portion  of  the  skull  table. 

Of  individual  dermal  roofing  elements,  the  premaxillae  are 
elongate,  in  conformity  with  general  snout  elongation.  They 
form  most  of  the  boundaries  of  the  external  nares.  The  pre- 
maxilla  sends  a  long  and  well-developed  process  backward  ex- 
ternal to  the  naris,  excluding  the  maxilla  from  the  narial  border 
and  terminating  in  a  slender  tip  between  maxilla  and  nasal. 
Medially,  conjoined  slender  processes  from  the  two  premaxillae 
form  a  narrow  bar  separating  the  nares  and  extending  back  some 
distance  beyond  tht  narial  region  to  taper  between  and  below 
the  anterior  tips  of  nasal  processes  that  meet  them.  There  is  no 
evidence  of  a  separate  septomaxilla,  reported  as  existing  in  this 
region  in  phytosaurs.  Like  the  premaxillae,  the  nasals  are  elon- 
gate They  enter  into  the  posterior  border  of  the  external  nares 
for  a  short  distance  and  extend  far  backward  to  meet  the  frontals 
in  a  zig-zag  transverse  suture;  laterally  there  is  a  long  line  of 
suture  with  the  maxillae  and  a  short  contact  with  the  prefrontals. 
The  frontals,  as  indicated  by  the  development  of  their  radiating 
surface  ridges,  are  somewhat  elongated  anteriorly.  Laterally  they 
have  a  long  contact  with  the  prefrontals  anteriorly  and  a  short 
posterior  contact  with  the  postorbitals;  they  enter  broadly  into 
the  dorsal  rims  of  the  orbits.  The  parietals  are  short  anteropos- 
teriorly, as  regards  their  development  on  the  skull  table.  They 
have  a  transverse  suture  with  the  frontals  in  the  middle  portion 
of  the  roof;  lateral  to  this,  the  line  of  suture  with  the  frontals 
retreats  sharply  posteriorly,  then  turns  forward  again,  allowing 
the  parietals  contact  with  the  postorbitals.  This  lateral  extension 
of  the  parietal  forms  the  anterior  border  of  the  superior  temporal 


6  BREVIORA  No.    379 

fenestra.  The  posterior  end  of  the  skull  roof  is  narrow;  on 
either  side,  however,  each  parietal  sends,  posterolaterally,  a  long 
process  to  meet  and  overlap  the  medial  surface  of  the  squamosal 
behind  the  superior  temporal  fenestra.  Narrow  dorsally  but 
broadening  below,  the  medial  surface  of  this  process  forms  the 
upper  lateral  boundary  of  the  occipital  plate  and  laterally  forms 
the  medial  boundary  of  the  superior  temporal  fenestra.  This 
boundary  is  sharply  marked  off  dorsally;  more  ventrally,  how- 
ever, the  parietal  slants  outward  to  meet,  obviously,  the  prootic 
area  of  the  otic  region  of  the  braincase. 

Laterally,  the  premaxilla  continues  back  some  distance  along 
the  margin  of  the  upper  jaw  before  being  succeeded  by  the  elon- 
gate maxilla.  The  latter  element  gradually  increases  in  depth, 
posteriorly,  to  occupy  the  entire  height  of  the  side  of  the  snout 
anterior  to  the  antorbital  fenestra.  The  maxilla  extends  upward 
beyond  the  ridge  separating  lateral  and  dorsal  skull  surfaces  to 
form  a  lateral  strip  of  the  dorsal  surface  for,  roughly,  the  length 
of  the  nasal.  When  the  antorbital  opening  is  reached,  the  maxilla 
extends  but  a  short  distance  backward  above  this  opening.  Below, 
however,  it  forms  the  fenestral  border  for  most  of  its  length,  to 
be  finally  succeeded  by  the  jugal.  Posteriorly  the  maxilla  tapers 
downward  in  depth  to  terminate  at  about  the  level  of  the  posterior 
border  of  the  orbit.  The  lacrimal  forms  most  of  the  bar  sepa- 
rating orbit  and  antorbital  fenestra  and  (although  the  line  of 
suture  is  none  too  clear)  appears  to  extend  forward  above  this 
fenestra  for  most  of  its  length  on  the  lateral  skull  surface. 

The  prefrontal  forms  a  triangular  area  on  the  skull  roof, 
bounded  medially  by  nasal  and  frontal,  posterolaterally  by  the 
orbital  margin  and  laterally  by  the  ridge  separating  dorsal  and 
lateral  margins  of  the  snout.  It  forms  a  prominent  projection 
over  the  anterodorsal  margin  of  the  orbit  and  sends  a  process. 


Figure  2.     Chanaresiichus  bonapartei,  type  skull  in  side  view.     X   4/9. 


1971  CHANARESUCHUS  AND  GUALOSUCHUS  7 

reinforcing  the  lacrimal,  part  way  down  the  bar  separating  orbit 
and  antorbital  fenestra.  There  is  no  postfrontal  clement.  The 
postorbital  is  well  developed.  Its  center  of  ossification  is  a  prom- 
inent elevation  at  the  posterodorsal  corner  of  the  orbit,  whence 
it  extends  in  three  directions.  Medially,  it  extends  over  the  skull 
roof  surface  to  meet  the  frontal  anteriorly  and,  more  posteriorly, 
the  parietal.  This  process  forms  anteriorly  part  of  the  orbital 
rim,  and  posteriorly  a  small  portion  of  the  boundary  of  the  upper 
temporal  fenestra.  A  posterior  flange  extends  backward  to  form 
much  of  the  upper  border  of  the  lateral  temporal  fenestra,  grad- 
ually tapering  backward  to  give  place  to  the  squamosal.  Ven- 
trally  the  postorbital  extends  downward  to  form  the  upper  part 
of  the  bar  separating  orbit  and  lateral  temporal  fenestra.  The 
jugal,  in  normal  fashion,  forms  the  lower  margin  of  the  orbit 
and  much  of  the  lower  margin  of  the  lateral  temporal  fenestra. 
Anteriorly  it  reaches  the  posteroventral  margin  of  the  antorbital 
fenestra,  and  it  forms  the  lower  part  of  the  postorbital  bar. 

The  squamosal,  in  a  fashion  somewhat  analogous  to  the  post- 
orbital, sends  out  three  processes  from  a  center  located  dorso- 
posterior  to  the  lateral  temporal  fenestra.  An  anteromedial 
process  runs  forward  to  join  laterally  the  process  of  the  parietal, 
which  forms  the  medial  wall  of  the  superior  temporal  fenestra. 
A  long  and  strong  process  runs  anteriorly  to  meet  the  postorbital 
in  a  long  diagonal  suture  and  to  form,  in  conjunction  with  that 
element,  the  bar  lying  between  the  lateral  margin  of  the  upper 
temporal  fenestra  and  the  upper  boundary  of  the  lateral  temporal 
fenestra.  A  broad  but  thin  process  runs  ventrally  to  form  the 
posterior  boundary  of  the  lateral  temporal  fenestra;  this  meets 
the  quadratojugal  ventrally  and  posteriorly  has  a  long  suture 
with  the  quadrate.  The  squamosal,  as  in  thecodonts  generally, 
sends  a  short  spur  backward  above  the  head  of  the  quadrate. 
The  quadratojugal  forms  the  posterior  part  of  the  bar  below  the 
lateral  temporal  fenestra  and  then  curves  sharply  upward  to  meet 
the  squamosal  and  to  form  the  lower  part  of  the  posterior  mar- 
gin of  this  fenestra.  Posteriorly,  at  the  junction  of  its  two  limbs, 
the  quadratojugal  is  thickened  and  is  in  intimate  contact  with 
the  quadrate. 

As  noted  above,  the  occipital  surface  of  the  skull  slants  back- 
ward as  well  as  downward.  The  posterior  rami  of  the  parietals 
form  vertical  walls  that  bound  the  occiput  on  either  side.   At  the 


8  BREVIORA  No.    379 

apex  of  the  occipital  surface  is  a  small  triangular  postparietal, 
which  faces  backward  as  much  as  upward  and  plays  no  part  in 
the  dorsal  surface  of  the  skull.  Below  this  is  a  large  supraoc- 
cipital,  essentially  triangular  except  for  truncation  of  its  narrow 
anterodorsal  extremity.  On  either  side  this  plate  articulates  with 
the  proximal  part  of  the  posterior  processes  of  the  parietals. 
Dorsally  the  bone  has  a  prominent  medial  ridge;  ventrally  this 
element  forms  the  upper  margin  of  the  foramen  magnum.  The 
lateral  margins  of  the  foramen  are  formed  by  the  exoccipitals, 
which  are  fused  with  the  opisthotics  to  form  long  and  slender 
paroccipital  processes  extending  laterally  to  abut  against  the 
inner  surfaces  of  the  squamosals  dorsally;  this  articulation  is  a 
loose  one,  with  the  presence  of  kineticism.  Possibly  a  small  post- 
temporal  fenestra  may  have  been  present  above  the  paroccipital 
process;  if  present,  however,  it  cannot  have  been  more  than  a 
slender  slit.  The  exoccipital  forms  a  dorsolateral  fraction  of  the 
occipital  condyle;  the  condyle  is,  however,  mainly  formed  by  the 
basioccipital.  The  condyle  is  circular  in  outline  and  essentially 
convex  with,  however,  a  slight  median  excavation,  presumably 
for  the  anterior  termination  of  the  notochord.  I  regret  that  the 
condition  of  the  material  is  such  that  I  have  been  unable  to  make 
out  the  vagus  and  hypoglossal  foramina  nor  the  lateral  surface 
of  the  braincase  in  the  otic  region.  I  have  not  found  a  stapes, 
and  can  say  nothing  regarding  the  possible  presence  of  epiptery- 
goid  or  laterosphenoid. 

In  correlation  with  snout  elongation,  the  anterior  part  of  the 
palate  is  much  modified.  Medially  a  pair  of  stout  processes 
formed  by  the  premaxillae  extend  backward  in  the  midline;  be- 
hind them,  the  central  area  is  continued  by  narrow  paired  vomers, 
bearing  a  row  of  small  teeth.  Posteriorly  the  vomers  diverge 
somewhat  to  accommodate  between  them  the  anterior  tips  of 
the  pterygoids.  At  their  posterior  ends  the  vomers  are  in  contact 
with  the  palatines,  the  anterior  ends  of  which  have  a  concave 
border,  meeting  the  vomers  medially  and  the  elongate  maxillae 
laterally. 

In  "typical"  tetrapods  the  choanae  are  situated  well  forward, 
as  rounded  or  oval  openings,  bounded  anteriorly  by  the  pre- 
maxillae, laterally  by  the  maxillae,  posteriorly  by  the  palatines 
and  medially  by  the  vomers.  If  we  look  for  the  equivalent  of 
the  normal  choanae  here,  we  find  a  pair  of  long  and  narrow  areas 


1971 


CHANARESUCHUS  AND  GUALOSUCHUS 


Figure  3.     Chanaresuchiis  bonapartei,  type  skull  in  palatal  view.    X  4/9. 


reaching  about  half  the  length  of  the  skull,  from  the  premaxillary 
region  to  the  position  of  the  "incised"  anterior  ends  of  the 
palatines.  This  elongation  of  the  original  choanal  region  is  ob- 
viously related  to  snout  elongation.  From  the  palatines  for  some 
distance  forward  there  are  open  choanae.  But,  farther  forward, 
there  is  a  sheet  of  bone  apparently  pertaining  to  the  maxillae, 
which  extends  medially  across  the  choanal  areas  from  the  max- 
illae to  gain  a  contact  with  the  posterior  portions  of  the  stout 
ventral  processes  of  the  premaxillae  and  the  edges  of  the  vomers. 
More  anteriorly  this  sheet  is  broken  by  oval  openings,  already 
mentioned  in  connection  with  the  skull  roof.  It  is  reasonable  to 
believe  that  these  openings  are  anterior  palatine  foramina  for 
access  to  the  mouth  cavity  of  vomeronasal  organs  (Jacobson's 
organs),  and  that  the  transverse  sheet  of  bone  between  these 
openings  and  the  true  choanae  is  a  definite,  if  short,  secondary 
palate  formed  for  facilitation  of  underwater  breathing  in  this 
long-snouted  animal. 

Much  more  normal  and  primitive  in  construction  is  the  pos- 
terior portion  of  the  palatal  surface.  Anterior  to  the  occipital 
condyle,  there  are  projecting  basisphenoidal  tubera,  connected 
by  an  incised  transverse  fine,  concave  posteriorly,  which  pre- 
sumably marked  the  anterior  limit  of  subvertebral  musculature. 


10  BREVIORA  No.    379 

Lines  extending  posteromedially  from  the  tubera  suggest  an  ex- 
tension of  parasphenoidal  dermal  ossification  backward  over  part 
of  the  basioccipital  area.  Anterior  to  the  tubera,  the  combined 
basisphenoid-parasphenoid  contracts  somewhat  in  width,  then 
expands  again  to  the  projecting  spherical  basal  articular  proc- 
esses, on  which  it  is  obvious  the  pterygoids  had  considerable 
freedom  of  movement.  Paired  foramina  for  the  carotid  arteries 
are  present  between  these  processes.  A  slender  parasphenoid 
rostrum  extends  far  forward  along  the  midline  of  the  interptery- 
goid  vacuity.  Of  the  elements  of  the  posterior  part  of  the  palate, 
the  palatine  occupies  an  area  between  the  posterior  end  of  the 
choana  anteriorly  and  the  palatine  fenestra  posteriorly,  and  be- 
tween the  maxilla  laterally  and  the  pterygoid  medially.  It  bears 
ventrally  an  anteroposterior  row  of  small  teeth.  The  pterygoids 
are  highly  developed.  Their  slim  anterior  ends  extend  far  forward 
between  the  vomers.  A  short  distance  back  of  their  anterior 
termination  the  two  pterygoids  diverge  slightly,  so  that  a  long 
but  narrow  interpterygoid  vacuity  is  developed.  Along  the 
medial  border  each  pterygoid  carries  a  long  row  of  small  teeth; 
this  series  terminates  just  above  the  region  of  the  basal  articula- 
tion with  the  braincase.  A  second  row  of  small  teeth  is  present 
on  a  distinct  ridge  that  slants  diagonally  backward  and  medially 
from  a  point  near  the  posterior  end  of  the  palatine  to  terminate 
somewhat  short  of  the  basal  articular  region.  The  palatal  fenestra 
is  of  considerable  extent,  bounded  laterally  by  the  jugal  and  incised 
medially  into  the  posterior  part  of  the  palatine  and  the  adjacent 
portion  of  the  pterygoid.  Back  of  the  fenestra  the  palatal  ramus 
of  the  pterygoid  expands  widely  laterally.  Part  of  this  expansion 
is  presumably  formed  by  an  ectopterygoid,  but  I  have  not  been 
able  to  detect  a  pterygoid-ectopterygoid  suture.  Anteriorly  the 
lateral  margin  of  this  expansion  is  sutured  to  the  jugal;  posteriorly 
there  is  a  constriction  in  width,  and  the  bone  slants  ventrally  to 
form  a  stout  transverse  pterygoid  flange,  broadening  distally.  The 
palatal  portion  of  the  pterygoid  terminates  medially  and  pos- 
teriorly in  a  short  spur  beneath  which  is  the  socket  for  reception 
of  the  articular  process  of  the  basisphenoid.  Lateral  to  this  area, 
there  arises  a  typical  quadrate  flange  of  the  pterygoid,  of  modest 
height,  which  posteriorly  meets  the  quadrate. 


97: 


CHANARESUCHUS  AND  GUALOSUCHUS 


The  quadrate  bone  is  well  developed.  Its  posterior  end  is  a 
thickened  articular  area,  widened  transversely  and  convex  at  both 
internal  and  external  ends;  it  appears  that  the  quadratojugal  (as 
often)  takes  part  to  some  degree  in  the  lateral  condyle.  The 
main  shaft  of  the  quadrate  extends  upward,  to  terminate  in  a 
recess  on  the  under  surface  of  the  squamosal  at  and  close  to  its 
posterior  spur.  This  ascending  ramus  of  the  quadrate  is  broad 
ventrally,  gradually  contracting  in  width  dorsally,  and  has  a 
concave  posterior  margin.  It  faces  as  much  posteriorly  as  later- 
ally, at  an  angle  to  the  adjacent  areas  of  the  quadratojugal  and 
descending  ramus  of  the  squamosal.  As  generally,  a  foramen  is 
present  on  this  surface  between  quadrate  and  quadratojugal.  The 
ascending  ramus  presents  a  broad,  forward-slanting,  medial  sur- 
face that  is  covered  anteriorly  by  the  quadrate  ramus  of  the 
pterygoid. 

In  correlation  with  skull  length,  the  jaw  is  long  and  slender 
anteriorly  (Figs.  4,  5).  The  symphysis  is  poorly  represented  in 
available  material  but  was  obviously  weak  and  formed  mainly  — 
perhaps  entirely  —  by  the  dentary.  For  much  of  the  length  of 
the  muzzle  the  dentary  forms  almost  the  entire  outer  surface  of 
the  ramus  —  a  surface  that  slants  markedly  inward  below,  rather 
than  being  directed  vertically  downward.  Posteriorly  the  bone 
forks,  the  two  branches  enclosing  between  them  the  anterior  end 
of  the  long  external  mandibular  fenestra.  The  upper  branch  ex- 
tends along  the  upper  margin  of  the  ramus  to  the  end  of  the  tooth 


Figure  4.     Cluijuircsiicliiis  bonapartei,  jaw  of  type  in  lateroventral  view. 
X  4/9. 


row,  where  it  is  replaced  by  the  surangular;  the  lower  branch 
extends  backward  below  the  fenestra  for  some  distance,  applied 
to  the  outer  surface  of  the  angular.  The  splenial  is  exposed  at 
the  lower  edge  of  the  external  surface.  The  posterior  portion  of 
the  external  surface  is  made  up  almost  entirely  by  the  surangular 
and  angular.   The  former  bone  runs  backward  along  the  curving 


12 


BREVIORA 


No.   379 


upper  margin  of  the  ramus,  whence  a  dorsally  facing  area  of  the 
surangular  extends  inward  above  the  lateral  border  of  the  man- 
dibular fossa.  The  angular  extends  backward  below  the  lateral 
mandibular  fenestra,  the  two  elements  meeting  at  the  posterior 
end  of  the  fenestra,  whence  a  ridge,  with  which  the  suture  be- 
tween the  two  elements  is  associated,  runs  posteriorly.  The 
suture  is  indistinct  posteriorly  but  the  conjoined  angular  and 
surangular  extend  backward  nearly  to  the  posterior  end  of  the 
jaw,  sheathing  the  articular  laterally.  On  the  inner  surface  the 
splenial  lines  the  jaw  for  nearly  its  full  height  for  most  of  the 
length  of  the  tooth  row.  Beyond  this  point  its  upper  margin 
slants  gradually  downward  to  the  termination  of  the  bone  well 
posteriorly.  It  is  succeeded  posteriorly  on  the  inner  surface  by 
the  prearticular,  which,  narrow  anteriorly,  follows  the  splenial 
downward  and  backward.  The  prearticular  forms  the  inner  bor- 
der of  the  mandibular  fossa,  the  surangular  the  outer  border. 
A  coronoid  is  present,  but  seen  only  as  a  disarticulated  element. 
I  have  restored  it,  in  Figure  5,  with  some  doubt,  in  its  probable 
position.    It  appears  to  have  extended  forward  as  a  thin  sliver 


Figure    5.     Chanaresuchus    bonapartei,    jaw    of    type    in    medial    view. 
X   4/9. 


of  bone  between  the  dentary  and  splenial  and  more  posteriorly 
appears  to  have  been  applied  to  the  inner  surface  of  the  surangu- 
lar. Posteriorly,  the  surangular  thickens  on  its  inner  surface  to 
form  the  back  margin  of  the  mandibular  fossa.  The  prearticular 
fuses  posteriorly  with  the  articular.  This  stout  element  appears 
to  have  been  but  loosely  attached  to  the  surangular  and  angular, 
since  it  has  separated  from  them  in  the  two  available  specimens 
with  jaws  in  the  La  Plata-Harvard  collection.  The  articular  oc- 
cupies the  full  height  of  the  inner  surface  of  the  jaw  at  its  pos- 
terior end;  it  is  braced  anteriorly  by  the  medial  extension  of  the 
surangular  mentioned  above,  and  is  nearly  completely  covered 
externally  by  the  thin  posterior  extension  of  the  conjoined  angular 


1971  CHANARESUCHUS  AND  GUALOSUCHUS  13 

plus  surangular.  There  is  little  development  of  a  retroarticular 
process,  but  the  bone  extends  somewhat  ventroposteriorly.  The 
articular  surface  of  the  articular,  as  of  the  quadrate,  is  trans- 
versely broadened,  with  median  and  lateral  concavities  corre- 
sponding to  the  pair  of  convexities  on  the  quadrate.  There  is  a 
pronounced  process  developed  on  the  medial  surface  just  below 
the  level  of  the  articular  surface. 

The  marginal  dentition  is  but  imperfectly  preserved  in  avail- 
able specimens.  The  teeth  are  of  a  common  archosaurian  type, 
somewhat  compressed  mediolaterally,  hence  with  an  oval  section, 
sharp-pointed,  and  backwardly  curved  distally.  The  insertion  is 
protothecodont.  There  appear  to  have  been  six  teeth,  the  last 
small,  on  the  elongate  premaxilla,  about  18  on  the  maxilla,  and 
about  the  same  number  on  the  dentary.  As  in  many  reptiles, 
there  appears  to  have  been  a  high  degree  of  replacement  of  teeth 
in  essentially  alternating  fashion,  so  that  for  much  of  the  jaw 
length  alternate  teeth  are  well  developed,  those  between  barely 
erupted  or  represented  by  empty  sockets. 

GuALOSUCHUS  REiGi,  gen.  et  sp.  nov. 

Holotype.  La  Plata  Museum  1964-XI-14-13  (field  no.  75), 
including  most  of  the  right  half  of  skull  and  jaws  and  a  limited 
amount  of  postcranial  material.  Collected  from  the  Chanares 
Formation,  from  the  valley  of  the  north  fork  of  the  Chanares 
River,  La  Rioja  Province,  about  five  miles  east  of  the  point  where 
this  stream  debouches  into  the  Talampaya  plain. 

Combined  generic  and  specific  characters.  Similar  to  Cha- 
naresuchus  in  nearly  all  regards,  but  larger;  posterior  portion  of 
skull  deeper  but  with  a  narrower  skull  table  than  in  Chanare- 
suchiis;  orbit  taller  than  in  that  genus  and  less  incised  into  skull 
roof;  parietals  extend  in  paired  fashion  farther  back  on  skull 
table  than  in  Chanaresuchus  and  diverge  less  sharply  posteriorly 
toward  the  squamosals;  superior  temporal  openings  proportion- 
ately narrow  and  more  elongate. 

The  generic  name,  by  analogy  with  Chanaresuchus,  refers  to 
the  Gualo  River,  which,  with  the  Chanares,  drains  most  of  the 
known  area  of  exposure  of  the  Chanares  Formation.  The  specific 
name  is  in  honor  of  Sr.  Osvaldo  A.  Reig,  an  active  student  of 
archosaur  evolution. 


14  BREVIORA  No.    379 

Gualosuchus  is  represented  in  the  Harvard-La  Plata  collections 
only  by  the  holotype,  which  includes  the  dermal  bones  of  the 
right  side  of  the  skull  roof,  the  pterygoids,  right  palatine,  most 
of  the  right  lower  jaw  and  a  number  of  postcranial  elements. 
Further  materials,  including  a  second  skull,  are  present  in  the 
Instituto  Lillo  collections.  The  length  of  the  holotype  skull  (Figs. 
6,  7),  measured  to  the  quadrate,  is  about  325  mm;  the  Instituto 
Lillo  skull,  presumably  that  of  a  young  individual,  is  much 
smaller.  Quite  probably  the  holotype  represents  a  "mature"  speci- 
men; it  is  nearly  a  quarter  larger  than  the  largest  known  skull  of 
Chaiuiresuchus.  The  skull  of  the  holotype  is  highly  rugose,  pre- 
sumably in  correlation  with  large  size;  this  feature  has  made 
identification  of  sutures  difficult. 

In  every  major  structural  feature  the  Gualosuchus  skull  closely 
resembles  that  of  Chanaresuchus.  In  consequence,  detailed  de- 
scription is  unnecessary;  mention  need  be  made  only  of  points 
in  which  the  two  genera  differ.  As  in  Chanaresuchus,  the  skull 
is  long  and  low;  the  proportions  of  snout  length  to  total  skull 
length  are  much  the  same  in  the  two  genera,  and  both  have  the 
same  anteroposterior  elongation  of  the  lateral  temporal  fenestra. 
The  skull  of  Gualosuchus,  however,  is  much  less  depressed  pos- 
teriorly than  that  of  Chanaresuchus,  and  less  broad.  In  Cha- 
naresuchus, for  example,  the  height  of  the  skull  at  the  orbit  is 
little  more  than  15  per  cent  the  skull  length;  in  Gualosuchus 
about  22  per  cent,  and  the  comparable  figures  at  midlength  of 
the  lateral  temporal  fenestra  are  17  per  cent  and  24  per  cent. 
In  relation  to  greater  depth  at  the  orbit,  this  opening,  which  is 
subcircular  in  lateral  view  in  Chanaresuchus,  is  taller  and  sub- 
quadrate  in  shape  in  Gualosuchus  and  is  much  less  incised  into 
the  skull  roof.  Part  of  the  contrast  in  depth  is  due  to  the  greater 
depth  of  the  maxilla  and  jugal  beneath  the  antorbital  vacuity, 
orbit,  and  the  anterior  part  of  the  lateral  fenestra.  The  differ- 
ences in  breadth  between  the  two  genera  relate  mainly  to  differ- 
ences in  width  of  the  skuU  table.  In  Chanaresuchus  the  width 
across  the  postorbital-squamosal  bars  bordering  the  skull  table  on 
either  side,  is  nearly  a  third  the  measurement  of  skull  length;  in 
the  Gualosuchus  type  this  width  is  but  a  quarter  the  skull  length. 
This  difference  in  table  proportions  results  in  contrasts  in  the 
pattern  of  the  posterior  part  of  the  skull  roof.  In  Chanaresuchus 
the  superior  temporal  fenestrae  are  relatively  short  and  broad 


97: 


CHANARESUCHUS  AND  GUALOSUCHUS 


15 


and  slant  outward  posteriorly;  in  Gualosuchus  these  openings  are 
relatively  long  and  narrow  and  lie  on  a  direcdy  anteroposterior 
line.  In  Chanaresuchus  the  two  parietals  are  united  on  the  skull 
table  for  only  a  short  distance  before  they  diverge  sharply  to 
extend  outward  and  backward  to  meet  the  squamosals;  in  Gualo- 
suchus, in  contrast,  the  parietals  extend  backward  in  contact 
with  one  another  for  a  considerable  distance  before  diverging,  at 
a  lesser  angle,  toward  the  squamosals. 


Figure  6.     Gualosuchus  reigi,  holotype  skull  in  dorsal  view.    X    1/3. 


Figure  7.     Gualosuchus  reigi,  holotype  skull  in  lateral  view.    X  1/3. 


16  BREVIORA  No.    379 

The  disarticulated  pterygoids  and  right  palatine  are  very  simi- 
lar in  construction  to  those  of  Chanaresuchus.  Most  of  the  right 
ramus  of  the  lower  jaw  is  preserved  in  the  type.  It  had  been 
somewhat  weathered  before  recovery,  but  in  all  observable  fea- 
tures it  agrees  well  with  the  Chanaresuchus  jaw. 

DISCUSSION 

Chanaresuchus  and  Gualosuchus  are  closely  related;  they  ap- 
pear to  be  almost  identical  in  all  structural  features  and  as  far 
as  known  differ  only  in  size  and  in  skull  proportions,  the  Gualo- 
suchus skull  being  relatively  narrower  and  taller  posteriorly.  We 
need  not  search  far  to  find  relatives.  It  is  obvious  that  Cerrito- 
saurus  described  by  Price  (1946)  from  the  slightly  later  Santa 
Maria  beds  of  Brazil  is  a  close  relative,  as  shown  by  similar 
skull  proportions,  slitlike  dorsally-placed  nostrils,  loss  of  post- 
frontal  element,  absence  of  the  parietal  foramen,  comparable 
shape  of  the  lateral  temporal  fenestra,  and  posterior  situation 
of  the  jaw  articulation.  Possibly  some  of  the  thecodont  material 
from  the  Manda  beds  may  pertain  to  a  related  type,  but  this 
material  is  too  fragmentary  to  allow  positive  determination. 

Quite  surely,  however,  a  further  South  American  relative  is 
Proterochampsa  (Reig,  1959;  Sill,  1967).  A  number  of  points 
of  resemblance  to  Chanaresuchus  and  Gualosuchus  can  be  seen 
in  the  figures  of  Reig  and  Sill,  and  further  unpublished  observa- 
tions and  study  of  the  Proterochampsa  specimens  in  the  fight  of 
our  better  knowledge  of  the  Chanares  forms  strongly  suggest  that 
the  relationship  is  close  indeed.  The  Proterochampsa  skufis  are 
even  more  flattened  than  in  Chanaresuchus  (although  this  may 
be  due  in  part  to  post-mortem  crushing) .  The  skull  is  sculptured 
as  regards  its  dermal  roofing  elements  in  very  rugose  fashion, 
presumably  in  correlation  with  the  fact  that  its  size  is  consider- 
ably greater  than  that  of  either  of  the  Chanares  forms.  This 
rugose  condition  makes  for  difficulty  and  doubt  in  the  determina- 
tion of  sutures.  The  skull  proportions,  with  a  long  slender  snout 
and  a  broad  posterior  region,  are  identical  with  those  in  the 
earlier  genera.  The  outlines  of  the  external  nares  are  imperfectly 
preserved,  but  the  structure  here  is  apparently  the  same  as  in 
Chanaresuchus  and  Gualosuchus.  The  antorbital  fenestrae  are 
smafi,  as  in  those  genera;  the  orbit,  subcircular  in  shape  as  in 
Chanaresuchus,  is  strongly  incised  into  the  skull  table;  because 


1971  CHANARESUCHUS  AND  GUALOSUCHUS  17 

of  the  great  flattening  of  the  skull,  these  openings  face  nearly 
directly  dorsally  rather  than  laterally.  The  pattern  of  the  posterior 
part  of  the  skull  table,  with  a  pineal  opening  absent,  and  the 
posterolateral  extensions  of  the  parietals  swinging  broadly  out- 
ward, closely  resembles  that  of  the  Chafiares  genera.  As  in  those 
forms,  the  lateral  temporal  fenestra  is  large  and  long  anteropos- 
teriorly;  the  jaw  articulation  is  far  back  of  the  occiput,  and,  as 
in  the  earlier  genera,  there  is  but  a  slight  projection  of  the 
squamosal  above  the  incipient  archosaur  otic  notch.  The  lower 
jaw  structure,  as  far  as  can  be  made  out,  is  similar  to  that  of  the 
forms  here  described. 

The  palate  is  poorly  seen,  but  recent  study  indicates  that  the 
posterior  portion  of  it  was  quite  similar  to  that  of  Chanaresuchus 
and  Gualosiichus.  As  in  those  genera,  the  basal  articulation  was 
movable  and  an  interpterygoid  vacuity  present,  in  which,  as  in 
the  genera  here  described,  there  projected  forward  a  slender 
parasphenoidal  rostrum.  A  row  of  denticles  was  present,  as  in 
the  Chanares  forms,  on  the  palatine  as  well  as  denticle  rows  on 
the  pterygoid. 

Again,  as  in  these  forms,  the  anterior  ends  of  the  palatines 
were  notched  for  the  posterior  margins  of  the  choanae.  Forward 
of  this  point  little  can  be  made  out  regarding  palatal  structure. 
Both  Reig  and  Sill  restore  this  area  with  a  small  choana  and  a 
long  secondary  palate.  This  is,  however,  uncertain  and  the 
situation  here  may  well  have  been  much  the  same  as  in  the 
Chaiiares  forms. 

In  sum,  Proterochampsa  in  all  observable  features  appears  to 
be  very  similar  in  cranial  structure  to  Chanaresuchus,  Gualo- 
suchus  and  Cerhtosaurus;  the  differences  between  them  are  cer- 
tainly not  more  than  of  generic  value,  and  all  four  may  be 
reasonably  grouped  within  the  single  family  Proterochampsidae, 
erected  by  Sill  (1967)  for  the  reception  of  Proterochampsa. 

The  general  structure  of  these  four  genera  is  strongly  suggestive 
of  amphibious  habits,  not  improbably  paralleling  those  of  the 
later  phytosaurs  and  crocodilians.  The  postcranial  skeleton  ap- 
pears to  have  the  general  proportions  of  crocodilians  (although 
without  diagnostic  crocodihan  characteristics).  The  slender 
snout,  flattened  skull,  the  trend  for  a  dorsal  facing  of  the  orbits 
and  the  dorsal  position  of  the  nostrils  are  all  suggestive  of  water- 
dwelling  habits. 


18  BREVIORA  No.    379 

What  is  the  pedigree  of  these  forms?  Currently,  as  regards 
classification  of  thecodonts,  one  tends  to  sort  out  a  few  early  and 
primitive  genera  as  the  Proterosuchia,  separate  off  as  advanced 
types  the  Phytosauria  and  (in  some  fashion  or  other)  crocodilian 
ancestors,  and,  having  done  this,  "lump"  all  remaining  forms  as 
members  of  the  suborder  Pseudosuchia.  One's  first  inclination 
would  be  to  include  the  Proterochampsidae  in  this  last  general 
category.  Further  consideration,  however,  suggests  that  the 
proterochampsids  are  too  primitive  structurally  to  be  placed  in 
the  Pseudosuchia.  In  a  few  regards  our  forms  are  advanced  or 
specialized  —  dorsal  position  of  the  nares,  loss  of  the  postfrontal 
and  of  the  parietal  foramen,  structure  of  the  anterior  part  of  the 
palate,  and  an  advanced  jaw  structure.  But  there  are  many 
primitive  features  —  for  example,  small  size  of  the  antorbital 
opening,  posterior  position  of  the  suspensorium,  long  antero- 
posterior extent  of  the  lateral  temporal  fenestra,  presence  of  a 
movable  basal  articulation,  retention  of  an  interpterygoid  vacuity 
and  retention  of  palatal  teeth.  Typical  pseudosuchians  are  ad- 
vanced in  all  these  characters.  Euparkeria,  recently  well  described 
by  Ewer  (1965),  which  is  either  reckoned  as  a  primitive  pseudo- 
suchian  or  as  an  advanced  proterosuchian  leading  toward  the 
pseudosuchians,  is  as  primitive  as  the  proterochampsids  in  most 
of  the  features  listed.  But  even  Euparkeria  is  more  advanced  in 
some  features,  such  as  the  relatively  large  antorbital  fenestra  and, 
more  significantly,  shortening  of  the  lateral  temporal  fenestra  and 
forward  movement  of  the  suspensorial  region. 

One  is  thus  tempted  to  consider  a  direct  origin  of  the  protero- 
champsids from  a  proterosuchian  ancestor.  Charig  and  Reig 
(1970)  list  some  27  structural  features  that  are  characteristic  of 
proterosuchians,  16  of  which  (2-17)  pertain  to  the  cranium.  In 
the  greater  part  of  these  characters,  the  Proterochampsidae  are 
in  agreement  with  the  Proterosuchia.  They  differ  in  a  few  points: 
(2,  part)  absence  of  a  postfrontal  and  of  a  parietal  foramen; 
(5,  part)  nonterminal  position  of  external  nares;  (9)  a  slight 
projection  of  the  squamosal  back  beyond  the  head  of  the  quadrate 
(present,  however,  in  Chasmatosaiirus);  (13)  formation  of  an 
incipient  secondary  palate;  (14)  the  presence  or  absence  of  an 
epipterygoid  is  unknown.  In  all  other  points  the  Proterochamp- 
sidae are  in  full  agreement  with  the  Proterosuchia:  (2,  part)  a 
median  postparietal  present;   (3)    well-developed  and  projecting 


1971  CHANARESUCHUS  AND  GUALOSUCHUS  19 

prefrontal;  (4)  short  and  broad  parietal;  (5,  part)  exclusion  of 
maxilla  from  naris  by  premaxilla;  (6)  moderate  size  of  antorbital 
vacuity;  (7)  superior  temporal  fenestra  facing  dorsally;  (8)  no 
V-shaped  lateral  temporal  fenestra;  (10)  Uttle  development  of 
otic  notch;  (11)  jaw^  articulation  well  behind  condyle;  (12) 
interpterygoid  vacuity  present;  (15)  marginal  teeth  more  or  less 
isodont;  and,  (16)  tooth  insertion  subthecodont.  To  this  long 
list  of  primitive  characters  may  be  added  the  presence  of  a  mov- 
able basipterygoid  articulation,  and  retention  of  palatal  teeth. 
It  seems  clear  that  the  Proterochampsidae  are  of  direct  protero- 
suchian  derivation  and,  despite  a  few  advances,  may  best  be 
classified  as  a  family  of  the  Proterosuchia. 

Further,  one's  attention  can  be  immediately  directed  to  Pro- 
terosuchus  [Champsosaurus]  as  a  proterosuchian  probably  not 
far  removed  from  the  near  ancestry  of  the  Proterochampsidae. 
Reig  (1959),  Sill  (1967),  and  Walker  (1968)  have  each  in 
turn  commented  on  the  similarity  of  Proterochampsa  to  ''Clias- 
matosaurus.''  Apart  from  the  nasal  apparatus,  little  change  is 
needed  to  transform  "Chasmatosaurus"  into  a  proterochampsid 
—  reduction  of  the  downward  curvature  of  the  snout,  loss  of  the 
postfrontal  bone,  and  modification  of  the  posterior  part  of  the 
lower  jaw.  Two  changes  anteriorly  are  needed  —  an  upward  and 
backward  shift  of  the  external  nares  and,  with  further  elongation 
of  the  already  slitlike  choanae  of  ''Chasmatosaurus,""  initiation 
of  a  secondary  palate.  The  proterochampsids  can  be  reasonably 
considered  to  be  direct  and  relatively  unmodified  descendants  of 
a  proterosuchian  of  "chasmatosaurid"  type. 

Were  the  Proterochampsidae  a  sterile  line  or  could  they  have 
given  rise  to  more  advanced  archosaurs  of  any  sort?  The  two 
possibilities  are  the  Phytosauria  and  Crocodilia.  Reig  and  Sill 
believe  Proterochampsa  to  be  an  ancestral  crocodile;  Walker 
(1968,  1970)  denies  the  crocodilian  affinities  of  Proterochampsa 
but  suggests  relationships  to  phytosaurs,  while,  on  the  other 
hand,  he  suggests  that  Cerritosaurus  is  a  crocodile  relative. 

I  see  little  positive  evidence  to  support  relationship  of  any 
member  of  the  Proterochampsidae  to  the  Crocodilia.  As  far  as  I 
am  aware,  the  postcranial  skeleton  of  Clianaresuchus  shows  none 
of  the  significantly  crocodihan  features  of  coracoid,  pubis,  etc., 
that  are  characteristic  of  Triassic  "pre-crocodilians."  As  regards 
the  skull,  Reig  calls  attention,  in  addition  to  the  beginning  of  a 


20  BREVIORA  No.    379 

secondary  palate,  to  the  rather  crocodihan  skull  proportions, 
particularly  those  of  the  table.  Sill  gives  a  careful  and  detailed 
analysis  of  skull  structure,  but,  apart  from  the  secondary  palate, 
cannot  point  out  any  feature  in  which  Proterochampsa  approaches 
crocodilian  conditions;  at  best,  it  exhibits  features  that  may  have 
been  present  in  the  remote  ancestors  of  the  Crocodiha,  and  that 
are,  essentially,  those  present  in  generahzed  ancestral  thecodonts. 
The  posterior  portion  of  the  palate,  for  example,  is  of  an  ex- 
tremely primitive  pattern,  markedly  modified  in  all  nonprotero- 
suchian  thecodonts.  Notably  primitive  is  the  suspensorial  region, 
with  the  jaw  articulation  far  to  the  rear  of  the  occiput  and  the 
lateral  temporal  opening  greatly  elongated.  To  attain  the  croco- 
dilian condition  it  seems  structurally  necessary  for  this  region  to 
pass  through  the  pseudosuchian  stage  of  a  short  lateral  temporal 
region  with  a  V-shaped  posterior  boundary,  followed  by  closure 
of  the  upper  part  of  the  lateral  vacuity,  a  forward  shift  of  the 
upper  end  of  the  quadrate  and,  finally,  downward  closure  of  the 
squamosal  back  of  the  otic  notch.  There  is  not,  in  protero- 
champsids,  the  slightest  trace  of  the  beginning  of  this  highly 
important  series  of  structural  changes;  these  forms  are  not  a 
whit  more  advanced  than  the  archaic  thecodont  "'Chasmato- 
saurusy  The  posterior  part  of  the  proterochampsid  jaw,  again, 
is  specialized  in  a  noncrocodilian  fashion.  Finally,  the  movement 
of  the  external  nares  upward  and  backward  along  the  skull  roof 
is  a  structural  feature  that  is  not  primitive  or  merely  "neutral" 
in  nature,  but  is  in  direct  contrast  to  the  situation  expected  in  an 
ancestor  of  the  Crocodilia,  in  which  the  nostrils  are  persistently 
terminal  in  position  in  almost  every  case. 

In  short,  for  positive  signs  of  crocodilian  relationships  of  the 
proterochampsids,  we  are  reduced  to  the  presence  of  a  short 
secondary  palate.  It  is  possible,  but  difficult,  to  imagine  this 
structure  being  expanded  and  modified  to  form  the  elongate 
secondary  palatal  structure  seen  in  true  crocodilians.  It  seems 
more  probable,  at  present,  to  believe  that  the  development  of  this 
structure  plus  the  backward  movement  of  the  external  nares, 
represent  an  attempt,  parallel  to  that  of  crocodilian  ancestors, 
to  improve  respiration  in  a  long-snouted  amphibious  reptile. 

If  we  turn  from  the  proterochampsids  to  a  series  of  later 
Triassic  archosaurs,  such  as  Notochampsa,  Erythrochampsa, 
Protosuchus,    and    the    recently    described    Orthosuchiis    (Nash, 


1971  CHANARESUCHUS  AND  GUALOSUCHUS  21 

1968;  cf.  Walker,  1970),  we  find  a  series  of  forms  in  which 
there  is  little  development  of  a  secondary  palate,  but  in  which 
there  are  numerous  positive  indications  of  crocodilian  relation- 
ship, such  as  the  series  of  crocodilian  postcranial  characters  that 
arc  absent  in  proterochampsids,  progress  in  the  development  of 
the  crocodilian  type  of  suspensorial  and  otic  regions,  presence 
of  supraorbital  bones,  fusion  of  braincase  and  palate  ventrally. 
There  is  little  indication  that  these  forms  are  directly  derived 
from  such  archaic  and  essentially  proterosuchian  forms  as  the 
proterochampsids;  rather,  it  would  seem,  the  crocodile  ancestors 
advanced  from  the  proterosuchian  to  the  pseudosuchian  stage 
of  thecodont  development,  and  then  began  to  specialize  in  the 
direction  of  the  Crocodilia. 

Although  Walker  (1968),  as  noted  above,  suggested  that 
Cerritosaiinis  might  be  related  to  crocodilian  ancestry,  he  denies 
this  for  its  relative  Proterochampsa,  and  suggests,  in  contrast, 
that  this  genus  might  have  been  ancestral  to  the  phytosaurs.  Most 
of  the  items  listed  by  him  as  phytosaurian  similarities  appear  to 
be  of  little  weight  and  could  be  countered  by  other  features 
wherein  Proterochampsa  differs  from  possible  "proto-parasuch- 
ians"  (as,  for  example,  in  loss  of  postfrontals  in  proterochamp- 
sids). The  one  seemingly  important  and  suggestive  feature  is  the 
movement  of  the  nares,  as  slitlike  structures,  well  back  onto  the 
dorsal  skull  surface.  This  could  well  be  an  initiation  of  the  strong 
posterior  narial  trend  seen  in  phytosaurs.  But  in  default  of 
intermediate  forms,  the  gap  between  such  a  proterochampsid  as 
Chanaresiichus  and  a  typical  phytosaur  is  so  great  as  to  make 
an  assumption  of  relationship,  in  the  present  state  of  our  knowl- 
edge of  thecodonts,  little  more  than  an  interesting  possibility. 

LITERATURE    CITED 

Charig,  a.  J.,  AND  O.  A.  Reig.     1970.     The  classification  of  the  Protero- 

suchia.    Biol.  J.  Linn  Soc,  2:    125-171. 
Ewer,  R.   F.     1965.     The   anatomy   of  the   thecodont   reptile   Eiiparkeiia 

capensis  Broom.    Phil.  Trans.  Roy.  Soc.  London,  ser.  B,  248:   379- 

435. 
Nash,    D.     1968.     A    crocodile    from    the    Upper    Triassic    of    Lesotho. 

J.  Zool.  London,  156:    163-179. 
Price,  L.  L     1946.     Sobre  um  novo  pseudosuquio  do  Triassico  superior 

do  Rio  Grande  do  Sul.    Bol.  Serv.  Geol.  Min.  Brasil,  120:  7-38. 


22  BREVIORA  No.    379 

Reig,  O.  a.  1959.  Primeros  datos  descriptivos  sobre  nuevos  reptiles 
arcosaurios  del  Triasico  de  Ischigualasto  (San  Juan,  Argentina). 
Rev.  Asoc.  Geol.  Argentina,  13:  257-270. 

Sill,  W.  D.     1967.     Prolerochampsa  barrionuevoi  and  the  early  evolution 

of  the  Crocodilia.    Bull.  Mus.  Comp.  Zool.,  135:   415-446. 
Walker,  A.  D.      1968.     Protosuchus,  Proterochampsa,  and  the  origin  of 

phytosaurs  and  crocodiles.    Geol.  Mag.,  105:   1-14. 
1970.     A   revision   of   the   Jurassic   reptile   Hallopiis   victor 

(Marsh),  with  remarks  on  the  classification  of  crocodiles.    Phil.  Trans. 

Roy.  Soc.  London,  ser.  B,  257:  323-372. 


^'^ 


Harvard  MCZ 


3  2044  066  302  787 


DOES  NOT  CIRCULATE