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?H^

HARVARD UNIVERSITY

Library of the

Museum of

Comparative Zoology

IVICZ

TRANSACTIONS OF THE u-tjrxr^

SAN DIEGO SOCIETY OF NATURAL HISTORY

VOLUME 21, 1985-1989 JAN 2 9 199U

CONTENTS ^^

HARVARD

\. Motility and calcareous parts in extant and fossil Acrothoracica (Crustacea: Cirripedii)N ^ V t-'^'-'^
based primarily upon new species burrowing in the deep-sea scleractinian coral
Enallopsammia. By Mark J. Grygier and William A. Newman, 29 October 1985 1-22

2. The Sangamon interglacial vertebrate fauna from Rancho la Brisca, Sonora, Mexico. By

Thomas R. Van Devender, Amadeo M. Rea, and Michael L. Smith, 29 October 1985 23-55

3. Floral morphology, nectar production, and breeding systems in Dudleya subgenus
Dudleva (Crassulaceae). By Geoffrey A. Levin and Thomas W. Mulroy, 29 October

1985..^ 57-70

4. Fishes living in deepsea thermal vents in the tropical eastern Pacific, with descriptions of
a new genus and two new species of eelpouts (Zoarcidae). By Richard H. Rosenblatt

and Daniel M. Cohen, 24 February 1986 71-79

5. A lectotype for Dinapate wrightii Horn, the giant palm-borer, and description of a new
species of Dinapate from eastern Mexico (Coleoptera: Bostrichidae). By Kenneth W.

Cooper, 24 February 1986 81-87

6. Holocene terrestrial gastropod faunas from Isla Santa Cruz and Isla Floreana, Galapagos:
evidence for late Holocene declines. By Steven M. Chambers and David W. Steadman,

5 December 1986 89-110

7. Callorhinus gilmorei n. sp., (Carnivora: Otariidae) from the San Diego Formation
(Blancan) and its implications for otariid phylogeny. By Annalisa Berta and Thomas A.

Demere, 5 December 1986 111-126

8. Fossil Tanaidacea. By Frederick R. Schram, Jiirgen Sieg, and Eric Malzahn, 5 December

1986 127-144

9. Another new forest-dwelling frog (Leptodactylidae: Eleutherodactylus) from the Cockpit

Country of Jamaica. By Richard 1. Crombie, 5 December 1986 145-153

10. A new night lizard {Xantusia henshawi) from a sandstone habitat in San Diego County,
California. By L. Lee Grismer and Mark A. Galvan, 5 December 1986 155-165

11. The evolution of helodermatid squamates, with description of a new taxon and a
overview of Varanoidea. By Gregory K. Pregill, Jacques A. Gauthier, and Harry W.

Greene, 5 December 1986 167-202

12. Camaenid land snails (Gastropoda: Pulmonata) from the Eocene of southern California
and their bearing on the history of the American Camaenidae. By Barry Roth. 24

February 1988 203-220

13. Pseudotealliocaris palincsari n. sp., a pygocephalomorph from the Pocono Formation,
Mississippian of Pennsylvania. By Frederick R. Schram, 24 February 1988 221-225

14. A new species of hagfish, genus Eptatretus (Cyclostomata, Myxinidae), from the Pacific
Ocean near Valparaiso, Chile, with new data on E. hischoffi and E. polytrema. By

Robert L. Wisner and Charmion B. McMillan, 24 February 1988 '. 227-244

15. Two crabs, Xandaros sternbergi (Rathbun, 1926) n. gen., and Icriocarcinus xestos n.
gen., n. sp., from the late Cretaceous of San Diego County, California, USA, and Baja
California Norte, Mexico. By Gale A. Bishop, 24 February 1988 245-257

16. A new abyssal hydrothermal verrucomorphan (Cirripedia; Sessilia): The most primitive
living sessile barnacle. By William A. Newman and Robert R. Hessler, 15 February

1989 259-273

17. New stratigraphic and geographic occurrences of Isognomon (Mollusca: Bivalvia) from

the Eocene of California and Oregon. By Richard L. Squires, 30 April 1989 275-282

18. Homology and terminology and higher teleost postcleithral elements. By Michael D.
Gottfried, 15 October 1989 283-290

19. Ranges of offshore decapod crustaceans in the eastern Pacific Ocean. By Mary K.
Wicksten, 15 October 1989 291-316

S A ^-i

^^^Rary

TRANSACTIONS
OF THE SAN DIEGO
SOCIETY OF
NATURAL HISTORY

f^ovzi

1985

H^lume 21 Number 1 pp. 1-22 29 October 1985

^i^i^i^Rsn — —

Motility and calcareous parts in extant and fossil Acrothoracica
(Crustacea: Cirripedia), based primarily upon new species burrowing
in the deep-sea scleractinian coral Enallopsammia

Mark J. Grygier and William A. Newman*

Scripps Institution of Oceanography A-002, La Jolla, CA 92093 USA

Abstract. Four new species of bathyal acrothoracican barnacles of the family Lithoglyptidae are
described: Lithoglyptes viatrix from Hawaii, L. tectoscrobis and Weltneria ligamenta from Tonga, and
W. griggi from the Caribbean island of Grenada. All burrow in ahermatypic corals of the genus
Enallopsammia. Because rostra are very rare in the Acrothoracica, the rostra and calcareous cement
possessed by at least three of these species are of particular interest. Instead of serving simply to attach
the barnacle to the burrow wall, they may be modified into a roof (or trail) sealing the apertural slit
left behind as the barnacle bores across the coral surface. This system is so highly developed in L.
viatrix that some specimens are truly motile and abandon the older parts of their burrows. Other rostral
structures in living and fossil acrothoracicans are reviewed, and criteria are given to distinguish rostra
from calcareous cement. Analogous systems of calcareous structures (cement only) and apertural motility
in the families Cryptophialidae and Trypetesidae, and in various fossil genera are also discussed;
apparently none of these acrothoracicans abandon any part of their burrows, although the bulk of the
mantle may move a considerable distance. A general trend towards loss of the rostrum and calcareous
cement is evident in extant and fossil Acrothoracica that live in shallow environments, but at different
stages of reduction the remaining calcareous parts often have been independently modified to protect
the mantle as the aperture moves to a more favorable position in the substrate. Calcareous parts in
fossil acrothoracican burrows are not always ichnofossils, but may be true body fossils, a fact which
has nomenclatural significance.

Introduction

The Acrothoracica are burrowing barnacles and most species live in shallow water
in calcareous substrates such as coral skeletons and mollusk shells (Tomlinson 1 969).
Their fossil record, almost exclusively in the form of burrows or casts of burrows,
extends back into the Devonian (Rodriguez and Gutschick 1977). The exterior of an
adult acrothoracican consists of a sac-like mantle or carapace, and an attachment disc.
The mantle usually lacks hard parts except for a pair of chitinous opercular bars guarding
the mantle opening (Newman 1971). The acrothoracicans are further distinguished
from ordinary barnacles in having all but the first pair of cirri (mouth cirri or maxil-
lipeds) clustered at the rear end of the thorax. Two suborders and three families are
generally recognized: Pygophora (Lithoglyptidae, Cryptophialidae) with an anus and
biramous terminal cirri, and Apygophora (Trypetesidae) without an anus and with
unbranched cirri.

This paper concerns four new species of relatively large lithoglyptid acrothoracicans
that burrow in living and recently dead branches of the bathyal ahermatypic coral
Enallopsammia. These new species have an unusually deep habitat, and at least 3 of
them possess a rostral plate, a very rare feature in this order (Newman 1971, 1974).
Furthermore, at least one of these species, Lithoglyptes viatrix, is capable of a unique
sort of limited motility. Our efforts to understand the rostrum and its role in motility

* Direct requests for reprints to WAN.

in L. viatrix led us to investigate other types of calcareous structures and modes of
motility in living and fossil Acrothoracica.

Methods and Materials

Coral specimens housing the acrothoracicans were obtained from R. W. Grigg
(Hawaii Institute of Marine Biology), and the National Museum of Natural History
(USNM) in order to study galls formed on them by ascothoracid crustacean parasites
of the family Petrarcidae (Grygier 1981, Zibrowius and Grygier, in prep.). Collection
data accompany each species description given below. Acrothoracicans were detected
by the characteristic apertures of the burrows and, in some cases, by the presence of
light-colored streaks extending across the surface of the coral branches (Fig. 2).

Most of the barnacles had been dried. Those to be dissected were reconditioned
in a weak trisodium phosphate solution for at least a day, either prior to or after
extraction. Prior reconditioning gave better results. Animals were extracted from their
burrows either by dissolution of the coral in dilute HNO3 or by mechanically excising
the surrounding coral with a hand-held, rotary tool (Moto-tool Model no. 1 , Dremel
Mfg. Co., Racine, Wisconsin) and diamond wheel. Later dissolutions were not carried
to completion in order to save as much of the calcareous rostrum in situ as possible.
Dissected parts and occasionally gut contents were examined in glycerine and glycerine
jelly mounts. Drawings were done with cameras lucida on Wild M5 and M20 micro-
scopes.

Occupied burrows of Lithoglyptes viatrix new species, Australophialus melampygos
(Bemdt), L. spinatus Tomlinson and Newman (cf. Newman and TomUnson 1974),
Trypetesa lateralis Tomlinson, and a new species of Trypetesa (Standing and Tomlinson,
in prep.) were selected for special examination. Some burrows of each were excavated
with the cutting wheel described above, or with needles and forceps. For L. viatrix,
dimensions of apertures and exposed "trails" were measured with dividers and a slide
micrometer. Frontal and sagittal thin sections of L. viatrix burrows were done according
to Newman et al. (1969), except that blanks were cut on a low-speed saw (Isomet 1 1-
1 180, Buehler Ltd., Evanston, Illinois) equipped with a diamond cutting wheel.

Taxonomy

Class Cirripedia Burmeister, 1834

Order Acrothoracica Gruvel, 1905

Family Lithoglyptidae Aurivillius, 1892

Tomlinson (1969) defined this family on the basis of the tapered burrow apertures,
lack of a gizzard (gastric mill), possession of caudal appendages in some forms, well-
developed mouth cirri, and a labrum proportionately comparable in size to the paired
mouthparts, as in ordinary barnacles. All of these characters are plesiomorphies, as
shown by comparison with other barnacles. Thus, this family is possibly paraphyletic.
For the most part, lithoglyptid genera are defined by the presence or absence of caudal
appendages and the number of terminal cirri (Table 1).

Variation in opercular bar armament is useful in distinguishing species, but there
are essentially no other diagnostic characters available. The nonmonotypic genera of
lithoglyptids must be suspected of paraphyly or polyphyly. But because of the unre-
solved polychotomies, we are continuing to employ the current, admittedly artificial
classification for reasons of practicality.

Lithoglyptes KunviWms, 1892

Diagnosis. — Lithoglyptids with four pairs of terminal cirri (III-VI) and a pair of
caudal appendages (Table 1).

Figure 1. Lithoglyptes viatrix new species a-m, Females, dissected parts; a, b. Lateral and top view of
opercular region of holotype, carinal end left; c, Labral crest, anterior view, flattened; d, e. Mandibular
gnathobases, most setae omitted except for insertion sites; f. Mandibular palp; g, h, Maxillular gnathobases,
setae omitted in h, most omitted in g but insertion sites shown; i. Maxilla, rear view; j. Mouth cirrus (I); k,
Detail of different mouth cirrus (I), full setation not shown; 1, Typical setation of central part of terminal
cirrus (IV-VI); m, Protopod of left last cirrus (VI) and caudal appendage; n, o, Complemental males; n,
Ventral view; o, Ventral view of diflferent specimen. Scale bars 0.1 mm.

Lithoglyptes viatrix new species
Figures 1-4

Diagnosis. —C&XcSirQons cement and a rostrum are present, although the form of
the rostrum is variable and it may form a roof over an elongate, trench-like burrow.

Table 1 . Distribution of thoracic appendages among lithoglyptid genera (MC, mouth cirrus or maxilliped;
TC, terminal cirrus; CA, caudal appendage or furcal ramus).

Ill

Weltneria

Berndtia

—

Lithoglyptes

—

Balanodytes

—

Kochlorine and

Kochlorinopsis

—

The mantle is elongate, and the carinal margin is nearly straight rather than broadly
curved. The first terminal cirrus (III) has the endopod longer than the exopod.

Ma/m«/. —Approximately 21 whole and 3 partial females, and 2 males, in En-
allopsammia amphelioides (Alcock) [Cairns (1982) considers this a synonym of £".
rostrata (Pourtales)] from 4 localities in the Hawaiian Islands (Table 2). All had been
air-dried. Chamberlain's specimens from Oahu and Grigg's from Kaula Rock are chosen
as type lots because they include most of the specimens examined. The dissected
holotype from Kaula Rock (USNM 210849) and 5 paratypes from both localities
(USNM 210850) are deposited in the National Museum of Natural History. Other
paratypes are deposited in the British Museum (Natural History), Zoology and Pa-
laeontology Departments (Reg. nos. 1984. 140-144 and T8 14, respectively), the Bemice
P. Bishop Museum, Honolulu (Cat. No. B510), the Institute for Paleontology, Uni-
versity of Vienna (IPUW-2523), the San Diego Natural History Museum, San Francisco
State University, and the authors' collections.

Etymology. —From Latin viator (a traveler) with feminine suffix, referring to female
motility.

Description. —VQxmXts: Operculum fusiform (Fig. la, b), that of holotype 2.1 mm
long, 0.7 mm wide, wider toward carinal than rostral end, slightly smaller than burrow
aperture. Sharp denticles interspersed with minute hairs along lateral edges of bars,
faces with scattered papillae; closely-spaced, ffat-topped papillae along medial edges.
Comb collar between carinal halves of opercular bars.

Mantle long (5 specimens 4.3-7.5 mm), tapered, often bent nearly at right angle
just below operculum (Fig. 4d-f); well-muscled, with small bifid or trifid spines. Very
small attachment knob below operculum rostrally. Pair of soft lobes below carinal end
of opercular bars, covered with short setae and bearing short spines mostly along free
edge (Fig. la).

Labral crest with denticles, short setae on surface (Fig. 1 c). Mandibles serrate with
2-4 teeth (Fig. Id, e); inferior angle with 6-12 sharp spines along distal edge; distal
part of blade with short hairs and setae. Mandibular palps tapered, twice as long as
broad, covered with fine hairs, row of setae along posterodistal edge (Fig. 1 f). Superior
angle of maxillule (Fig. 1 g, h) with 2-3 large spines, 2 smaller ones, then a notch with
a few small spines; inferior half of distal margin with numerous medium-sized spines;
faces distally setose with proximal field of cuticular ctenae along superior margin.
Maxillae triangular, as high as broad, with setae on anterior face and both margins,
denser and longer on medial edge (Fig. li).

Mouth cirri with long, arcuate coxae; bases a third as long as coxae, twice as long
as wide (Fig. Ij, k). Anterior ramus 5 -segmented (fifth article often partly or wholly
fused to fourth), posterior one 2-4 segmented. Basis and rami armed mostly posteriorly
with plumose setae, 2 rows on anterior ramus.

Four pairs of terminal cirri, first shortest, second intermediate, third and fourth
longest. Posterior ramus of each (endopod) generally a few articles longer than anterior
ramus (exopod). Among 4 specimens examined, segmental counts rarely varied by
more than 3. A typical segmental count is as follows (?, repeated counts not equal; +,
part of ramus broken off and not counted):

Ill

Right

Exopod

Endopod

33 +

Left

Exopod

43?

Endopod

49 +

Medial setae on coxa and basis. Five setae on anterior side of each cirral article (Fig.
11): 3 distal (long, medium long, very short), 2 unequal short ones at midlength, at each
position the most lateral seta longest. Long distal seta on posterior margin of each
article in first pair (III), every 2-3 articles in others; single short seta at longer intervals,
and then usually coincident with a long one.

Caudal appendages 2-segmented, not including basal pedestal, reaching to mid-
length of protopod of last cirrus (Fig. 1 m); second article longer than first or pedestal.
Tuft of about 7 plumose, distal setae on second article, 2-3 on first.

Males: Attached to mantle or to edge of rostrum of 2 different females. One with
pear-shaped body 0.44 mm long, 0.32 mm high (Fig. In). Cuticle at narrow end with
circular striations. Pair of antennules rising directly from body at lower comer of thick
end. Other male V-shaped, 0.5 mm wide, larger arm 0.6 mm long; antennules rising
from long, tapered, antero ventral protrusion (Fig. lo). Antennules in both specimens
4-segmented, first article short, second elongate, third slightly flared distally for at-
tachment, fourth a small appendix of the third.

Burrows. —Corals with burrows were of varying states (Table 2). A few were alive
when collected, as shown by the brown remains of dried tissue. Most were recently
dead, lacking tissue, but still white and little eroded. One, with an extensively pitted
surface and dark deposits of mineral precipitates, had clearly been dead for some time.
The majority of the burrows occur on the surface of the coral opposite that bearing the
calices.

Burrow apertures are key-hole shaped, 0.8-2.5 mm long, and 0.2-1.0 mm wide
(Fig. 2). The carinal end is rounded, while the rostral end tapers to a constriction formed
by a protruding shelf of cement and the end of the rostrum. There is often a light-

Table 2. Enallopsammia amphelioides (Alcock) [? = E. rostrata (Pourtales) of the Atlantic; cf. Cairns 1 982]
branches from Hawaii containing burrows of Lithoglyptes viatrix new species. Coral condition when
collected: 1 , alive, brown; 2, recently dead, white, costae rough; 3, white, costae smooth; 4, white, costae
obliterated, or minor pitting; 5, long dead, grey, considerable pitting. For burrow number, the first entry
is the number of burrows unambiguously assignable to L. viatrix, the entry in parentheses is the number
of other possible acrothoracican burrows (usually very small) of unconfirmed origin.

Collection

Coral Burrow
condition number

Burrow condition

R. Grigg, Sango III, Kaena Pt., Oahu, 9-VIII-1970, 21°35'N,
158°24-25'W, 440-490 m

R. Grigg, Sango III, Kaena Pt., Oahu, 9-VIII-1970,
2I*'35.8'N, 158°24.3-24.9'W, 470-475 m

R. Grigg, Kaena Pt., Oahu, 19-XII-1973, 378 m

R. Grigg, Sango XIII, Kaula Rock, 30-VIII-1971, 21°43.0-
43.8'N, 160°36.5-37.5'W, 386-500 m

T. Chamberlain, Hawaii (Grigg, personal communication;
Makapuu Pt., Oahu, -400 m, 1967)

R. Grigg, Sango XIII, Brooks Banks, 23-VIII-1971, 24°0.9'N,
166°42.5'W, 384-432 m

3
4
3

2
4
3
4
4
1

1 0 Empty

5 Empty, collapsed

5 Empty, except 1 with

an opercular bar

2 Empty

16 5 occupied

5 Empty

24 (1) 1 occupied

25(1) 4 occupied

22 (6) 1 1 occupied

0(1)
8
1
13
7
1

Empty

1 occupied

Empty

Occupied

Figure 2. Burrows and trails of Lithoglyptes viatrix new species on Enallopsammia amphelioides. a, Typical
burrows with short trails (most examples no longer than this); b. Burrow with long trail; c, Two long trails,
the younger one having partly incised the older, arrow pointing to aperture of burrow of unknown origin
(possibly acrothoracican or polychaete); d, Two long trails, younger barnacle having cut completely through
older burrow and trail. Apertures between 1.25 and 2.0 mm long.

colored streak or trail formed by the cement and rostrum extending across the coral
surface. The burrows themselves vary from a typical acrothoracican pit to an elongate
trench roofed over by such a trail.

Figure 3 shows the distribution of trail lengths on several pieces of coral and
compares them with the size of the corresponding burrow apertures. There is no evident
correlation. Most trails are only a few mm long (Fig. 2a), but some are as long as 2
cm, and a number of barnacles, including all those burrowing in calices, seem to have
no trails at all. The exposed surface of a trail has more or less parallel sides as far apart
as the aperture width, but the trail narrows at its extremity. It is generally flush with
the coral surface, with arcuate or chevron-shaped, transverse ridges concave toward
the aperture (Fig. 2b, d). These ridges are growth lines; they penetrate sharply into the
trail, then turn away from the aperture.

Although there are some exceptions, most trails are oriented more or less longi-
tudinally on the coral and, thus, are generally parallel to each other. In some cases one
trail partly overlaps another, or begins in the middle of another (Fig. 2c); the original
trail in such cases is the one partly excised by the other. A burrow aperture may also
cut into an established trail (Fig. 2d), but no trails were observed to cut all the way
across another. A burrow can be straight, or it can twist and turn vagariously in three
dimensions. It is usually curved at least a little (Fig. 2c, d) and may even "bank" as it
bends around an obstruction like a calice or pit. Trails, at least their older portions,
are occasionally overgrown by the host coral. In cross-section or at a break in the coral,
burrow roof material can be seen under a layer of coral skeleton. In other cases, the
burrow roof is collapsed, leaving a deep trench in the coral; no collapsed burrow was
occupied by a barnacle. In one piece of coral, the trails were recessed into trenches but
not overgrown. Two of these recessed trials "sideswiped" each other at different levels
below the coral surface.

10-

E '

E .

r^ 4
CO

• • •

• •

•• • *

— ^

Aperture Length (mm)

Figure 3. Relationship of aperture length to trail length for the type lots of Lithoglyptes viatrix new species
burrowing in Enallopsammia amphelioides. Only trails whose extremities are clearly visible are included;
larger dots are superimposed records.

A typical elongate, horizontal trail is composed of a rostral plate and the cement
holding it in place. This compound structure overlies a horizontal burrow with an
elliptical cross-section higher than wide (Fig. 4a, b). The convex top of the rostrum is
not exposed because of overlying cement. In the rostrum's thickest, central part, several
upwardly convex layers corresponding to growth increments are visible. A thin layer
of cement or cemented tailings lines the sides and bottom of the burrow.

The rostrum is bounded by a chitinous membrane which remains after acid dis-
solution. This chitinous structure retains the shape of the rostrum and exhibits obvious
growth lines. It has a large open end attached to the edges of the extensive, calcium
carbonate-secreting region on the rostral side of the barnacle's mantle (Fig. 4c-f).

The cross-section of the trail (Fig. 4b) also shows how the rostrum is held within
the top of a parallel-sided trench above the burrow lumen by an organo-calcareous
cement (white by reflected light, orange-brown by transmitted) that adheres to the coral
and to the chitinous lining of the upper lining of the rostrum. This cement, which may
not be entirely of secretory origin (Kamens 1981), must be laid down by a different
mantle region than the rostrum-secreting area, likely on the rostral side of the short
neck below the opercular bars.

When subjected to acid, the cement dissolves much more quickly than the rostrum,
at least in part because of the thin chitinous membrane separating the two. When the
thin layer of cement covering the upper side of the rostrum is fully dissolved, this
membrane is evident, and the two calcareous structures are quite distinct. The cement
is a very bright, opaque white, whereas the rostrum is lustrous and translucent, but
uncolored, and appears much less bright.

Comparison. —The 4 pairs of terminal cirri and the caudal appendages are diag-
nostic o{ Lithoglyptes (Tomlinson 1969). Most of the species in this genus have prom-
inent hooks on the operculum and, therefore, can be readily distinguished from L.
viatrix. Those that do not have hooks are L. indicus Aurivillius, L. mitis Tomlinson,

Figure 4. Lithoglyptes viatrix new species, burrow structure and rostral growth, a, Cross-section of burrow
(coral surface hatched, calcareous cement stippled, rostrum with growth lines); b. Detail of burrow roof in
a. c-f, Adult females dissolved out of coral substrate; remaining calcareous part of rostrum stippled, c,
Primitive rostral growth, new layers added away from aperture (precise orientation in coral unclear and
operculum lost); d. Advanced rostral growth, new layers added at apertural end, resulting in bodily translation;
e, Rostral and side views of specimen that initially grew as in d, but stopped moving and grew in place; f.
Rostral and side views of specimen that grew like older stage of e, but was obstructed away from the aperture
by an overgrown thoracican barnacle. Scale bars 1 mm except 0. 1 mm in b.

and some specimens of L. habei (Tomlinson). The last two have bifid rather than simple
opercular spines and teeth. Lithoglyptes indicus has many small spines rather than
scattered papillae over the faces of the opercular bars. It also has elongate rather than
short distal articles on the caudal appendages, and the rostral side of the mantle is at

an angle to the operculum rather than being parallel. The significance of a calcareous
rostrum, not previously known to occur in this genus, is considered in the Discussion.
Associated fauna. —Some empty burrows are secondarily inhabited by a tanaid.
One barnacle-occupied burrow had its aperture covered by a sponge. About a dozen
very small burrows were interspersed among those of L. viatrix (Table 2; Fig. 2c). Their
apertures are elliptical, typically with a constriction in the middle. Perhaps they were
formed by young L. viatrix or by spionid polychaetes, but because none was occupied
this cannot be demonstrated. A number of corals had old, empty galls of an as yet
undiscovered ascothoracid crustacean, presumably a Petrarca species; large, round, po-
rous galls are typical of that genus, which has been found infesting Enallopsammia in
the Atlantic, Pacific and Indian Oceans (Lopez 1974, Zibrowius 1980, Grygier 1981
and in press, Zibrowius and Grygier, in prep.). The corals were often fouled with
bryozoans, foraminiferans, gammaridean amphipods, and juvenile balanomorph bar-
nacles [Chionelasmus darwini (Pilsbry); Newman, in prep.].

Lithoglyptes tectoscrobis new species
Figure 5

Diagnosis. —The calcareous cement and rostrum form a roof over an elongate
trench-like burrow. The mantle is elongate with a tubular distal end, and the carinal
margin is broadly rounded. The first terminal cirrus (III) has an exopod longer than
the endopod.

Material. — Holotype female (USNM 2 10848) in Enallopsammia amphelioides (=?
E. rostrata; see Cairns 1982) collected by Committee for the Coordination of Joint
Prospecting for Mineral Resources in South Pacific Offshore Areas (CCOP/SOPAC),
Tonga Offshore Survey Stat. 78(2)-5, 12-XI-1978, 19°25.0'S, 174°13.4'W, 250-290 m;
forwarded by R. W. Grigg.

Etymology. —From Latin tectum (rooO and scrobis (trench), referring to the roofed
burrow.

Description. —Mantle 5.7 mm long, aside from a narrow, 1 .0 mm long tube at rear;
semicircular in side view, 1.7 mm across at midlength; operculum parallel to rostral
side of mantle (Fig. 5a, b). Operculum 1 .9 mm long, 0.7 mm across, carinal end rounded,
rostral end distinctly tapered (Fig. 5c, d). Lateral edges with irregular denticles and
short, fine hairs; faces with numerous, regularly spaced papillae interspersed among
and dotted with innumerable granules; medial edges with no special armament, but
papillae a little more abundant there. Mantle set with simple, bifid, or trifid spinules,
proximal part also with fine hairs, larger and more abundant toward carinal end. Comb
collar between opercular bars. Pair of small lobes below carinal end of operculum,
thickly set with hairs and bearing about 15 strong teeth each. Long setae on inner
mantle wall near operculum, denser toward carinal end. Attachment knob inconspic-
uous, focus of radial array of mantle muscles; prominent longitudinal muscles also
present. Rostral surface largely an oval, yellow, glandular region. Tube rising from near
back end of this tissue, with proximal half hollow and distal half plugged with several
layers of chitin (Fig. 5e).

Row of conical denticles along crest of labrum (Fig. 5f). Mandibles with 3 narrow
teeth separated by deep notches (Fig. 5g, h); inferior angle with 7-8 small teeth and
large, trifid tooth at very tip; setation as in L. viatrix. Mandibular palps tall, narrow
triangles with posterior row of setae (Fig. 5i). Maxillules as in L. viatrix, but spines
near inferior angle smaller than rest (Fig. 5j). Maxillae a little longer than broad, broadly
pointed, with row of setae along distal margins and other setae scattered over distal
half of anterior face (Fig. 5k).

Bases of mouth cirri half as long as coxae; anterior ramus 5-segmented, posterior
one 3-4-segmented (Fig. 51). Setation similar to L. viatrix.

Four pairs of terminal cirri. First pair shortest, second next shortest, last 2 pairs
equally long. Segmental count of exopod larger than endopod in first pair, reverse in

Figure 5. Lithoglyptes tectoscrobis new species, holotype female, a, b. Lateral and rostral views of whole
animal, shaded region glandular, chitinous rostral lining present (calcareous part dissolved away); c, d.
Operculum, top and side views, papillae and granules shown only for part of one valve; e. Posterior mantle
tube; f, Labral crest, flattened out; g, h. Mandibular gnathobases, only insertion sites shown of many setae;
i, Mandibular palp; j, Maxillular gnathobase; k. Maxilla, front view; 1, Mouth cirri (I), setae omitted; m,
Protopod of last cirrus (VI) and caudal appendage. Scale bars 0. 1 mm except 1 mm in a and b.

second pair, almost equal in third and fourth pairs. Setation as in L. viatrix. Segmental
counts as follows:

III

Right

Exopod

Endopod

Left

Exopod

Endopod

Caudal appendages 2-segmented, on pedestal, reaching to midlength of protopod
of last cirrus (Fig. 5m). Basal article little longer than pedestal, with 2 posterior, sub-
terminal setae; distal article little longer than basal one, with 6 terminal setae.

Eggs. —Oblong mass of about 1 200 yellow, oval (0. 1 8 x 0. 1 3 mm) eggs in mantle
cavity, number estimated volumetrically.

Gut contents. —Apparently of detrital origin, including sponge spicules, yellow-
green globules, a few possible crustacean parts, and large quantities of a granular,
amorphous substance.

^wrrow. —Aperture 1.95 mm long, 0.70 mm wide, a tapered oval narrower at
rostral end. Trail 3.9 mm long, identical in external appearance to those of L. viatrix.
Aside from proximal and distal ends, trial overgrown by coral skeleton. Barnacle
occupying all except innermost part of burrow, where mantle tube continues up and
out toward coral surface.

Comparison. —The only acrothoracican comparable to L. tectoscrohis is L. viatrix,
with which it shares a major specialization— the rostrum employed as a burrow roof
{see Discussion). It differs from L. viatrix in having a tube at the end of the mantle,
even less opercular armament, smaller lobes below the carinal end of the operculum,
and a longer exopod than endopod on the first terminal cirrus. This last character is
highly unusual; all other species of Lithoglyptes, Weltneria, and Berndtia have a longer
endopod than exopod on the homologous limb (III; second terminal cirrus in the last
2 genera) (Tomlinson 1969), although limb II, when present, may have a longer exopod
(cf. W. ligamenta new species below).

Weltneria Bemdt, 1 907

Diagnosis. — Lithoglyptids with 5 pairs of terminal cirri (II-VI) and a pair of caudal
appendages (Table 1).

Weltneria ligamenta new species
Figure 6

Diagnosis. —Opercular bars are connected by a conspicuous, bipartite "ligament."
No setae or marginal teeth are present on opercular bars.

Material. — Holotype female (USNM 210846) from same collection as lithoglyptes
tectoscrohis new species.

Etymology. —From Latin ligamentum (a band or tie), referring to the remarkably
well-developed ligament connecting the opercular bars.

Description. —Typical, sac-like mantle. Operculum 2.7 mm long, 0.6 mm across
at widest point (about 'Z? of way from rostral end); bars connected there by pair of
elevated, oval longitudinally aligned, medially fused "ligaments" one-fourth as long as
bars (Fig. 6a, b). Opercular armament feeble, numerous small papillae scattered over
faces and margins, no apical hooks. Carinal half of medial margins crenulate, paralleled
internally by comb collar. Mantle wall below operculum scaly, with small papillae;
heavier spines along carinal edge.

BuUate labrum with curved setae on each side, crest with evenly spaced denticles
(Fig. 6c). One mandible serrate, with 4 teeth, other with 5 (Fig. 6d, e); inferior angle
with 2-4 heavy spines; faces sparsely covered with setae, inferior margin with long,
fine hairs. Triangular mandibular palps flanking labrum, about twice as long as wide,
with setae along posterior edge, few distal setae along edge (Fig. 6d). Maxillules with
strong spine at superior comer, about 10 lesser spines in 3 loose clusters along cutting
edge; faces with few strong, distal setae, distal part of inferior margin with many long,
fine setae (Fig. 6f, g). Maxillae joined basally, longer than broad with blunt tips; abundant
setae along distal margin and down anterior face (Fig. 6h).

One mouth cirrus lost in dissection. Other well-developed, with long, curved coxa
(possibly secondarily jointed at about '/3 length), short setose basis (Fig. 6i); anterior
ramus 6-segmented, each article well-armed with setae; posterior ramus 3-segmented,
first article longest, all setose (Fig. 6j).

III

Exopod

52 +

Endopod

53 +

. 54 +

Exopod

41 +

Endopod

57 +

Five pairs of terminal cirri. First shorter than others, exopod much longer than
endopod. Other cirri progressively longer, exopods slightly shorter than endopods.
Setation as in L. viatrix (Fig. 6k). Segmental counts ± 1 (2 counts) as follows:

Right
Left

Caudal appendages biarticulate, half as long as coxa of last cirrus, each article with
heavy terminal setation (Fig. 6 1 ).

Burrow. —Coral broken at burrow and portion bearing rostral half of burrow lost,
so existence of calcareous rostrum un verifiable; carinal end of aperture round.

Comparison. — Weltneria ligamenta fits the diagnosis of the genus given by Tom-
linson (1969) in having 5 pairs of terminal cirri and caudal appendages. It differs from
the 6 previously described species in the unique development of an opercular "ligament"
and in the lack of setae and marginal teeth on the operculum.

Weltneria griggi new species
Figure 7

Diagnosis. —A calcareous rostrum is present. The opercular bars have abundant
long setae, simple spines along the lateral edges, papillae along the medial edges, and
more complex spines laterally on the faces.

Material. -HoXoXy^Q female (USNM 210847), dried. Collected 22-1-1972, R/V
Oregon Sta. 11722, 3r46'N, 79°15'W (vicinity of Blake Plateau), 402 m, in Enallo-
psammia rostrata.

Etymology. —'H^mcd for R. W. Grigg (Hawaii Institute of Marine Biology), in
appreciation for amassing the coral collections in which most of the material described
herein was discovered.

Description. —M?in\\Q a simple sac 5.8 x 3.6 mm (Fig. 7a). Longitudinal muscu-
lature clearly evident. Small papillae and bifid or trifid spinules scattered about (Fig.
7b), and sub-opercular region with hairs, more extensive along carinal side. Rostrally
upswept opercular bars 2.5 mm long, each 0.43 mm across just rostrad of midlength
(Fig. 7c, d). Rostral half generally wider than carinal half, but tips equally sharp. Long
setae on faces and along lateral edge, short setae along medial edge. Sharp spines along
lateral edge, blunt papillae along medial edge. Smaller papillae on medial half of face;
tall, simple or bifid spines on lateral half Comb collar present. Thorax bent into the
shape of an S within mantle (Fig. 7e).

Bullate labrum with cuticular ctenae and lateral setae; crest with row of blunt
denticles (Fig. 71). Mandibles with 3 teeth, inferior angle blunt or divided into several
small teeth, setation heavy, but absent on superior tooth (Fig. 7g, h); mandibular palps
narrow with many setae distally and posteriorly (Fig. 7g). Maxillules with 2 large and
2 small superior teeth, a gap, and about 10 inferior teeth; setation typical (Fig. 7i, j).
Maxillae broad, triangular, with row of long, medial setae, as well as shorter anterior
and lateral setae (Fig. 7k).

Mouth cirri with long, slightly arched coxae and short, non-setose bases (Fig. 71).
Anterior ramus with 4 segments in one, 3 in other, posterior with 5 segments in both,
and setation essentially the same in both despite different segment number (Fig. 7m).

Five pairs of terminal cirri. Cirral articles armed as in L. viatrix. First cirrus
shortest, second next longer, other 3 pairs about same length, exopods apparently shorter
than endopods, but not confirmed in all limbs (many broken off); segmental counts as
follows:

Right
Left

Exopod
Endopod
Exopod
Endopod

?
?
?

III

30
?

41
?

46
?

39
48
47
46

Figure 6. Weltneria ligamenta new species, holotype female, a, b. Lateral and top views of operculum,
ligament shaded (arrow); c, Labrum and mandibular palps, rear view; d, e. Mandibular gnathobases, d with
palp, only some setae shown in full, setae omitted from e; f, g, Maxillular gnathobases, setae not shown in
full in f, omitted in g; h, Maxillae, rear view; i. Mouth cirrus (I), arrow pointing to possible secondary joint
in coxa (or break); j, Rami of i; k, Typical setation of middle part of terminal cirrus (III-VI); 1, Caudal
appendage (removed from pedestal). Scale bars 0. 1 mm except 1 mm in a and b.

Figure 7. Weltneria griggi new species, holotype female, a, Whole animal, lateral view, cuticle of rostrum
shown, remaining part of rostrum stippled; b, Types of mantle spines; c, d. Lateral and top view of an
opercular valve; e. Cutaway view of mantle, showing folded thorax and terminal cirri; f, Labrum, side view;
g, Mandibular gnathobase and mandibular palp; h, Inferior angle of other mandible; i, j, Maxillular gnatho-
bases, setae omitted in j; k. Maxilla; 1, Mouth cirrus (I), some muscles shown; m. Rami of 1, most setae only
shown as bases; n, Protopod of last terminal cirrus (VI) and caudal appendage; o, Detail of caudal appendage
in n. Scale bars 0. 1 mm except 1 mm in a and e.

Caudal appendages 2-segmented, less than half as long as coxa of last cirrus (Fig. 7n,
o); articles equal, first with 2-3 anterior setae, second with 1 short, several long, plumose
setae.

Burrow.— Apenure 2.5 x 1.2 mm; 0.65 mm of trail visible on coral surface.

Comparison. —The 5 pairs of terminal cirri and caudal appendages assign this
specimen to Weltneria (Tomlinson 1969). Like W. hessleri Ne-wman, and W. exargilla

Newman, W. griggi lives in deep water and has a calcareous rostrum. However, this
plate has a different shape and orientation, being transitional towards those of Litho-
glyptes viatrix and L. tectoscrobis {see Discussion). The opercular armament differs
from both of the earlier rostrate species of Weltneria, and there are fewer articles on
the rami of the mouth cirri. Weltneria griggi differs from W. spinosa Bemdt in lacking
a pair of opercular hooks, and from that species and the remaining three, W. hirsuta
(Tomlinson), W. reticulata Tomlinson, and W. aapta Tomlinson, in having only simple,
not bifid, lateral opercular spines. Unlike W. ligamenta, W. griggi has no "ligament"
joining its much more heavily armed opercular bars.

Discussion
The Rostrum and Motility in Lithoglyptes viatrix

Weltneria hessleri and W. exargilla. North Atlantic abyssal inhabitants of calcar-
eous and muddy bottoms, respectively, were the first acrothoracicans found to have a
calcareous rostrum (Newman 1971, 1974). Their rostrum is a triangular plate, much
like that of scalpelloid barnacles, but it is cemented to the burrow wall (Fig. 8, la). The
umbo is apical and projects freely; successive growth increments are added at the bottom
edge as the animal burrows deeper into the substrate. Turquier (1978) disputed that
this plate is homologous with the scalpelloid rostrum because he inferred that its
position was not "rostral." Newman (1982) refuted the objection; the plate is rostral
in form and position, but its homology with the rostrum of ordinary barnacles can,
without additional evidence, always be doubted. In any event, it is a structural feature
of these acrothoracicans, distinct from secreted, calcified cement.

Newman (1974) pointed out that the so-called cement discs, composed of uncal-
cified cement and exuvia, and which anchor most acrothoracicans within their burrows,
sometimes have a rostrum-like appearance {see examples in Tomlinson 1969). It is not
possible to tell from wholly decalcified specimens (the usual technique for extracting
the barnacles) whether a rostrum or just a cement disc was involved. However, there
are two ways to tell the difference in untreated specimens. If two distinct sorts of
material are exposed, either in section or by partial dissolution, as in L. viatrix, it is
likely that one is the rostrum and the other the cement holding it in place. We urge
future investigators to examine at least some burrows mechanically before acid dis-
solution in order to verify the presence or absence of a rostrum. For example, we so
treated Lithoglyptes spinatus and found no rostrum, just cement. The calcareous shield
in the burrows o^ Lithoglyptes indicus is of calcified cement only and is not a rostrum,
since no cuticular lining or other organic trace is left after dissolution in acid (Auri villius
1894).

The burrows, and especially the rostra, of L. viatrix are extremely variable. Some-
times the animal digs into the coral substrate while producing a rostrum with an apical
umbo near the operculum, in the same manner as Newman's Weltneria species (Fig.
4c). At the other extreme, the burrow and rostrum develop in a horizontal direction,
with the umbo at the end farthest from the operculum (Fig. 4d). New growth increments
are added at the opercular end and cemented laterally to the burrow walls, forming the
longer of the so-called trails described in detail above. The horizontal burrow is ap-
parently excavated by the carinal end of the mantle as newly secreted rostrum and
cement advance the animal against the carinal wall of the aperture. The spines on the
lobes below the operculum probably play an important role in the abrasion process,
likely combined with chemical action (Kamens 1981).

Most L. viatrix are intermediate between these two extremes (Fig. 4e, 0 in having
trails about as long as the burrow apertures. The rostra in such individuals have a
variety of forms, revealed upon dissolution, that reflect changes in proportion of the
vertical and longitudinal components in growth (growth referring to the addition of
increments to the rostrum relative to the surface of the coral). One can assume that
the cues regulating this behavior involve orientation to currents, avoidance of burial,
interference from neighboring barnacles, obstructions to growth (such as balanomorph

barnacles and coral calices), etc., but the relative importance of such cues cannot be
estimated without experimental evidence.

In cases where burrow excavation proceeds horizontally, the animal does not
remain attached at the origin of the burrow, passively growing to occupy newly available
space. Rather, the animal is carried along as rostral growth continues, and as a whole
abandons the older part of the burrow (Figs. 4d, e; 8, Ic). It may eventually move
farther than its body length. If the old burrow were not roofed by the rostrum, the
barnacle would be vulnerable to attack from the rear; apparently because of the trail
no foreign organisms were ever found in the evacuated part of a barnacle-occupied
burrow. Sometimes secondary inhabitants (tanaids, etc.) live in empty burrows. It is
unlikely that one burrow successfully crosses another because accidental intrusion into
an abandoned burrow invites attacks from predators.

Homologues and Analogues in Extant Forms

Lithoglyptes tectoscrobis has an elongate, horizontal rostrum like some specimens
of L. viatrix. Since only one specimen was available to us, we cannot say whether this
is typical, or if this species shows the same range of growth forms as L. viatrix. Weltneria
griggi has a rostrum that exhibits both vertical and horizontal growth (Fig. 8, lb). Again,
the range of its behavior is not known. Weltneria hessleri and W. exargilla, the only
previously known deep-sea lithoglyptid acrothoracicans, both have more conventional,
vertically oriented rostra. One begins to suspect that most large, deep-water acrothoraci-
cans have rostra. Weltneria ligamenta may have had one, too, but unfortunately the
part of the coral that would have borne it was unavailable for examination. In all the
cases so far mentioned, it is certain that the rostra are homologous.

Noll (1875), in his drawings of Kochlorine hamata from Cadiz, Spain, shows
grooves in the gastropod shell substrate (Haliotis tuberculata Linne) leading to burrow
apertures. He attributed the grooves to abortive attempts of the newly settled cyprid
larvae to begin excavation. Where known, however, the larvae do not begin to burrow
until after attachment and metamorphosis (Batham and Tomlinson 1965, Turquier
1 970). Therefore, the floor of these grooves is more likely the cement layer over a partly
horizontal rostrum, or the rostrum itself We have as yet been unable to obtain spec-
imens of this species in situ to confirm this suspicion.

All of the foregoing examples have been from the primitive family Lithoglyptidae.
This is not surprising. If the rostrum is a holdover from a thoracican barnacle ancestor,
its presence is a plesiomorphic condition liable to be maintained in one or more lines
of descent.

An analogue to the situation in L. viatrix is provided by Australophialus melam-
pygos, a representative of the more plesiomorphic genus of the otherwise advanced
Cryptophialidae, living in shells such as that of the mussel Perna canaliculus Gmelin
from New Zealand. Batham and Tomlinson (1965) photographed burrow apertures
that had a white streak extending from each of them, which they interpreted as accu-
mulations of tailings (sensu Darwin 1854; see below). In reexamining this species, we
discovered that the white streak is a cement burrow roof, as in L. viatrix, but that there
is no rostrum and the mantle is not attached to the roof (Fig. 8, lib). There is a normal
cement disc at the end of the burrow holding the barnacle in place. As the aperture
moves, apparently to even out the inter-apertural distances, the mantle expands in the
carinal direction, no part of the burrow being evacuated. Some burrowing takes place
around the edges of the cement disc, which is eventually replaced by a larger, deeper
one. Tomlinson (1969) shows such a series of cement discs in this species and also in
A. utinomii Tomlinson (Fig. 8, Ila).

Other living analogues are Trypetesa lampas (Hancock) of the North Atlantic,
described by Darwin (1854) as Alcippe lampas, and by an undescribed species of
Trypetesa from North Carolina (Standing and Tomlinson, in prep.) (Fig. 8, III). The
latter settles on the lip of gastropod mollusk shells inhabited by hermit crabs. It then
burrows toward the interior, sometimes reorienting 1 80° before doing so. In many cases
the burrow aperture is a normal ellipse, but often there is an additional, narrow, curved

slit from the rostral end. This slit may extend a short distance in T. lampas, or several
times the length of the opercular part of the aperture in the new species of Trypetesa
and in some specimens of T. lateralis. The edges of the slit in all but the last species
are formed of a secreted white substance reminiscent of the cement in L. viatrix (Fig.
8, III). Darwin (1854), contrary to Hancock (1849), considered the calcareous rims to
be inorganic accumulations, rather than secretions of the animal. Kamens (1981) stud-
ied the burrows of T. lampas with SEM and chemical tests and showed that the
calcareous part of these deposits probably originates from the inhabited gastropod shell
as a breakdown product, not as a precipitation of dissolved CaCOj, but as redeposited
calcareous spherules. He could not determine the source of the organic matrix, but
most acrothoracicans are capable of secreting an uncalcified, organic cement, so we
think it likely that such a substance serves as the organic matrix here. The calcified
cement of other acrothoracicans, including L. viatrix, may have a similar compound
origin. We did not observe lines of deposition noted by Darwin (1854) and Kamens
(1981), but the exposed surfaces were generally worn flush with the surface of the snail
shell and, therefore, the lines of deposition may have been abraded away by the actions
of the hermit crab.

Trypetesa is weakly attached within the burrow. In T. lampas this is accomplished
by a disc-like mantle expansion (Fig. 8, Ilia), and very weakly if at all in the undescribed
species by the tip of a long, prow-shaped mantle projection (peduncular rudiment) (Fig.
8, Illb). The slit itself is closed by a thin, tough, membranous material in both species,
and there is no rostrum.

Fossil Acrothoracica with Roofed Burrows

Zapfe (1936) described and provided photographs of Miocene acrothoracican bur-
rows in the gastropods Pyrula cornuta Agassiz (apertural view of shell and an enlarge-
ment of a region of same) and Fasciolaria tarbelliana Grateloup (apertural view of
shell). The same two photographs of Pyrula were published by Hantzschel (1962:W23 1;
fig. 144, la and b, and 1975:35; fig. 83, 2c and d) as borings of the ichnogenus Zapfella
in the gastropod Galeodes (Volema) cornuta from the lower Miocene of Hungary. The
photographs of Galeodes show grooves leading away from the narrow end of the aperture
in several cases, much like Noll's (1875) drawing of Kochlorine hamata discussed above.
Saint-Seine (1954) apparently considered these specimens specifically distinct from her
Zapfella pattei, but in that genus. We could not examine that specimen because it was
destroyed in World War II (F. F. Steininger, personal communication), but we were
able to obtain the infested shell ofF. tarbelliana (IPUW-2522/84). Three of its burrows
have a short, L. vza/r/jc-like trail with a few chevrons (growth lines) on the surface of
a sunken roof (rostrum?) and apparently cement on the walls of the trench above the
suspected rostrum. It seems that much of the rostrum and some of the cement had
been eroded away. This is the best candidate for a fossil homologue of the L. viatrix
rostrum system. Although more study is required, Zapfe's specimens most likely rep-
resent primitive lithoglyptids, but from shallow rather than deep water.

Other fossil analogues of the L. viatrix system, perhaps homologous with the
Trypetesa system, are represented by Rogerella Saint-Seine {see especially Codez and
Saint-Seine 1958) of the Mesozoic and Tertiary. Rogerella has one end of the burrow
aperture wider than the other, and the narrow end produced to a greater or lesser extent
into a "peduncular slit" lined on one or both sides with a "bourrelet" of calcareous
lamellae, seldom well-preserved. Although originally limited to burrows in echinoid
tests (Saint-Seine 1951, 1956), this genus was later broadened to include similar burrows
in all sorts of substrates (Codez and Saint-Seine 1958), and now 4 species have been
named {see also Schlaudt and Young 1960, Voigt 1967).

In Rogerella lecointrei Saint-Seine, the bourrelets (one or a pair) are raised above
the surface of the sea urchin test, and the calcareous lamellae are oblique, their medial
edges pointing away from the main part of the aperture. The bourrelets are apparently
continuous with a calcareous lining of the burrow, which becomes thinner and may
disappear toward the burrow floor. If they were continuous across the peduncular slit,

which was never observed to be the case in these fossils, the bourrelets would resemble
the chevron-incised trails of L. viatrix. If never closed over, then the bourrelets are
like the calcareous rims in Trypetesa species.

In Rogerella mathieui Saint-Seine the bourrelets are much more fragile and are
very easily lost to erosion, due to the burrow widening suddenly below them. Its burrow
is reported to be very deep beneath the entire opercular slit. The bourrelets are rarely
preserved in the remaining 2 species, but Voigt (1967) notes that the narrow part of
the aperture in R. caudata Voigt, which is often bent at a sharp angle to the rest of the
aperture, is bounded on both sides by barnacle-secreted, calcareous deposits. Unlike
R. lecointrei, these bourrelets are sunk into the surface of the host oyster, not raised
above it.

We propose that Rogerella bourrelets are of calcified cement laid down by the
barnacle. The question remains as to whether the peduncular slit is natural or an artifact.
A long burrow like that of L. viatrix would be similar to those of R. lecointrei if the
former were moderately eroded to remove superficial cement and the rostrum itself
removed by differential erosion, solution, or simple mechanical loss (the last being
possible because the rostrum is separated from the cement by a chitinous cuticle).
However, well-preserved specimens oi R. lecointrei exist that show no sign of substrate
erosion (Saint-Seine 1951). Although the burrow shape is unknown in R. lecointrei,
the very deep burrow of R. mathieui is quite unlike the long burrows of L. viatrix,
which are not very deep, and become shallower away from the aperture.

It may be more reasonable to assume that the burrows o^ Rogerella were produced
by something akin to the Trypetesa species discussed above; the peduncular slit may
be a real opening, not a product of surface erosion or rostrum loss. Saint-Seine's
descriptive reconstruction of the Rogerella barnacle (Codez and Saint-Seine 1958)
includes a "peduncle" attached at the end of the slit, supposedly the original larval
attachment site. The slit had formed as the operculum moved away from the attachment
site, and the lengthening peduncle was partly roofed over and protected by secreted
bourrelets (calcareous cement). As in A. melampygos, the attachment site is fixed and
no bodily translation occurred, just growth. The French authors cite Tomlinson's (1955)
description of Trypetesa lateralis in support of this model, noting the homy attachment
knob borne on a stalk (or "peduncle") longer than usual in the Acrothoracica. The
undescribed species of Trypetesa from North Carolina, with its very large, distally
anchored peduncular rudiment and cement secretions narrowing the open slit above
it, is an almost exact analogue to Rogerella. A close phylogenetic relationship between
the two genera cannot be discounted.

Nomenclatural Significance of Fossil Acrothoracican Hard Parts

As a matter of interest to paleontologists, fossil acrothoracican burrows are ich-
nofossils (Hantzschel 1975), but the calcareous structures associated with them are
sometimes body fossils. A rostrum (which may be present in Zapfe's 1936 specimens)
is part of the barnacle's body, although structures composed entirely of mineralized
cement (as we suspect for Rogerella's bourrelets) are not. The significance of this dis-
tinction is that the International Code of Zoological Nomenclature, Third Edition (Art.
23, g, iii) treats the names of ichnofossils differently from body fossils with regard to
the Principle of Priority. It will be necessary in future paleontological studies of ac-
rothoracicans to make explicit whether new taxa are ichnotaxa or not.

Strategies of Motility

Acrothoracicans have several different means of attaching themselves within their
burrows, and most of them have a limited capacity for motility after settling. Motility
is best defined functionally as displacement of the burrow aperture across its substrate;
this may involve growth, bodily translation, or both. Various combinations of attach-
ment mechanisms and growth patterns form coherent sequences of intermediate stages
from the primitive condition exemplified by Weltneria hessleri and W. exargilla.

There are three kinds of extra-mantle structures. A rostrum is a calcareous body

plate firmly attached to the mantle and invested in a chitinous cuticle. There is also
mineralized cement, either anchoring the rostrum or the mantle in place, and/or serving
a protective function. Most non-rostrate acrothoracicans attach themselves to the bur-
row wall by a secreted, non-calcareous cement disc that incorporates successively larger
parts of the exuvia at each molt (known exception: Lithoglyptes indicus with a calcareous
cement disc). Mineralized and organic cement may be produced by different parts of
the mantle in the same species, but often only one or the other is present.

Our conception of the sequential alterations from a primitive, immotile acro-
thoracican with a vertical rostrum held in place by mineralized cement (e.g., Weltneria
exargilla), presently confirmed only in bathyal and abyssal forms, is shown in Figure
8. One strategy is to retain the rostrum and mineralized cement, but to add a horizontal
component to rostral growth. This keeps the mantle protected by a hard cover as the
aperture moves small distances (e.g., Weltneria griggi). The selective advantages of
motility, allowing resituation of the mantle opening if the original settling site proved
unfavorable, led to a rotation of the mantle so it could remain attached to the under
side of a horizontal rostral burrow roof Lithoglyptes tectoscrobis retains a narrow
connection to the older end of the burrow (its mantle tube). Lithoglyptes viatrix has
lost even this connection, making it the first and only truly motile acrothoracican known.

Another highly successful strategy in shallow seas was to lose the rostrum. Lith-
oglyptes indicus, with its attachment disc of calcareous cement, may illustrate an early
stage in this process. In all other cases known, the calcareous component of the cement
stopped being incorporated, at least in the cement disc. However, mineralized cement
is still produced near the operculum in some forms where it has been convergently
adopted as a roofing material for a shifting aperture [Australophialus melampygos,
Trypetesa (point already made for T. lampas by Kamens 1981), and Rogerella]. All
such species rely on mantle growth to force the aperture along. In some cases {A.
melampygos, T. lampas) the distal end of the mantle is broadly stuck to the burrow
wall so the animals cannot move. Their capacity to reposition themselves is more
limited than the undescribed Trypetesa species and R. lecointrei, whose burrow aper-
tures are as adjustable as those of L. viatrix. The Carolinian Trypetesa is barely attached
to the distal end of the burrow, but part of the mantle remains at the initial site of
attachment. The peduncular rudiment is free to grow and elongate as the body and the
opercular part of the mantle move farther from their initial position.

The last stage in this sequence is the loss of calcareous structures altogether (e.g.,
A. utinomii, L. spinatus). Possibly most extant acrothoracicans fall into this category.
However, aside from the presence of chitin (exuvia), the composition of few cement
discs is known, and we suspect a facultative ability to produce a short, mineralized
cement roof may not be uncommon, given the obvious advantages of post-settlement
reorientation.

Paleobiology

There are three important considerations that emerge from the foregoing: 1) Ac-
rothoracicans first appeared in the Paleozoic and apparently occupied a greater variety
of skeletal substrates in the Mesozoic than they do today [brachiopods, belemnites,
and echinoids as well as corals, bryozoans, and gastropod and bivalve mollusks, for
example (Tomlinson 1969)]. At least part of this additional diversity was due to species
with hard parts {Rogerella in echinoid tests); 2) acrothoracicans with obvious calcareous
hard parts were apparently more abundant in shallow water in the Mesozoic and
Tertiary than they are today; and 3) extant shallow- water acrothoracicans with calcareous
hard parts tend to occupy relictual regions such as New Zealand {Australophialus), or
biogeographical transition zones {Trypetesa; Newman 1979), while those with the most
primitive or plesiomorphic calcareous hard parts are found in the deep sea ( Weltneria
species and Lithoglyptes species). All this suggests that hard parts have not been evo-
lutionarily favored except in certain refugial habitats. Whether this has to do with small
size as a refuge from predation in most extant acrothoracicans (those with calcareous

parts tending to be relatively large), or to more subtle metabolic or energy budget-
related causes, is unclear.

It was noted above that the calcareous hard parts of Lithoglyptes viatrix from the
Pacific were very similar to those of a Lower Miocene form from Hungary, described
and figured by Zapfe (1936). This is not surprising because, as Fleming (1979) has
pointed out, much of the Tertiary marine fauna of the Indo-Pacific, replacing that which
became extinct in the Cretaceous, is Tethyan and holds its closest known affinities with
the Tertiary marine fauna of Europe.

Conclusions

We have distinguished several different kinds of acrothoracican burrows and cal-
careous structures associated with them, and discussed the implications for the behavior
and morphology of the housed barnacles. These findings apply equally well to extant
and fossil burrows, for we have discovered living analogies among several unusual
kinds of fossil acrothoracican burrows. Neontologists should now be able to correctly
interpret acrothoracican extra-mantle structures, and paleontologists can use such struc-
tures to better reconstruct the morphology, life style, and ecological pressures on the
barnacles that once inhabited the burrows they may find.

Acknowledgments

We thank Dr. R. W. Grigg (Hawaii Institute of Marine Biology) and Dr. S. D.
Cairns (USNM) for loaning us host corals; Drs. W. Klepal and F. F. Steininger (Uni-
versity of Vienna) for arranging a loan of Zapfe's bored fossil snail; Dr. J. Tomlinson
(San Francisco State University) for letting us examine the undescribed Trypetesa
species and its burrow, and to prepare and publish the figure of their relationships; Dr.
B. A. Foster (Auckland University) for sending specimens of Australophialus melam-
pygos in Perna shells; Dr. V. A. Zullo (University of North Carolina at Wilmington)
for loaning us a copy of Kamens' thesis; and N. Freres for preparing some of the
illustrations. Comments on the manuscript by H. R. Spivey, J. T. Tomlinson, and two
anonymous reviewers were greatly appreciated. One of us (MJG) was aided by an NSF
Graduate Fellowship and by two travel grants to Hawaii from Scripps Institution of
Oceanography. This work was partly supported by NSF Grant DEB 78-15052.

Literature Cited

Aurivillius, C. W. S. 1892. Neue Cirripedien aus
dem Atlantischen, Indischen und Stillen Ocean.
Ofersigt af Kongliga Vetenskaps-Akademiens
Forhandlingar 49(3): 123-1 34.

. 1894. Studien iiber Cirripedien. Bihang

till Kongliga Svenska Vetenskaps-Akademiens
Handlingar 26(7): 1-107, 9 pis.

Batham, E. J., and J. T. Tomlinson. 1965. On
Cryptophialus melampygos Bemdt, a small
boring barnacle of the order Acrothoracica
abundant in some New Zealand molluscs.
Transactions of the Royal Society of New Zea-
land 7(9): 14 1-1 54.

Bemdt, W. 1907. Uber das System der Acro-
thoracica. Archiv fur Naturgeschichte 73(Bd.
1, H. 2):287-289.

Burmeister, H. 1834. Beitrage zur Naturge-
schichte der Rankenfusser (Cirripedia). G. Rei-
mer, Berlin.

Cairns, S. D. 1982. Antarctic and subantarctic
Scleractinia. Antarctic Research Series 34(1):
1-74.

Codez, J., and R. de Saint-Seine. 1958. Revision
des Cirripedes Acrothoraciques fossiles. Bul-

letin de la Societe Geologique de France (6)7:
699-719, pis. XXXVII-XXXIX.

Darwin, C. 1854. A Monograph on the Sub-class
Cirripedia, with Figures of All the Species. The
Balanidae, (or Sessile Cirripedes); the Verru-
cidae, etc., etc., etc. Ray Society, London (re-
printed 1954, J. Cramer, Weinheim).

Fleming, C. A. 1979. Evolution of the South Pa-
cific marine biota: the expanding fossil record.
Proceedings of the International Symposium
on Marine Biogeography and Evolution in the
Southern Hemisphere, Auckland, New Zea-
land, 17-20 July 1978. New Zealand Depart-
ment of Scientific and Industrial Research In-
formation Series 137:5-26.

Gruvel, A. 1905. Monographic des Cirrhipedes
ou Thecostraces. Masson et C'^ Editeurs, Paris
(reprinted 1965, A. Asher&Co.. Amsterdam).

Grygier, M.J. 1981. Pctrarca okadai. a new crus-
tacean (Maxillopoda: Ascothoracica) from the
Great Barrier Reef the first shallow-water rec-
ord of the genus. Journal of Crustacean Biology
1:183-189.

. In press. New ascothoracid crustacean en-

doparasites of Scleractinia. Journal of Natural
History 19.

Hancock, A. 1 849. Notice of the occurrence on
the British coast of a burrowing barnacle be-
longing to a new order of the class Cirripedia.
Annals and Magazine of Natural History
(2)4(23):305-314, pis. VIII, IX.

Hantzschel, W. 1962. Trace fossils and problem-
atica. pp. W177-W245 in R. C. Moore (ed.).
Treatise on Invertebrate Paleontology, Part W
Miscellanea. Geological Society of America.

. 1975. Trace fossils and problematica, sec-
ond edition (revised and enlarged), pp. Wl-
W269 in C. Teichert (ed.). Treatise on Inver-
tebrate Paleontology, Part W Miscellanea, Sup-
plement 1 , Geological Society of America.

Kamens, T. C. 1981. Mechanism of shell pene-
tration by the burrowing barnacle Trypetesa
lampas (Cirripedia: Acrothoracica): An ultra-
structural study. M.S. Thesis, University of
Delaware.

Lopez, J. 1974. Contribution a I'etude d'une es-
pece du genre Petrarca (Fowler). Memoire
presente a I'Universite de Nancy pour I'obtenir
du diplome d'etudes approfondies en biologic
animale mention biologic des Arthropodes, 40
pp.

Newman, W. A. 1971. A deep-sea burrowing bar-
nacle (Cirripedia: Acrothoracica) from Ber-
muda. Journal of Zoology, London 165:423-
429.

. 1974. Two new deep-sea Cirripedia (As-

cothoracica and Acrothoracica) from the At-
lantic. Journal of the Marine Biological As-
sociation of the United Kingdom 54:437-456.

. 1979. The Califomian Transition Zone:

significance of short-range endemics, pp. 399-
416 /« J. Gray and A. Boucot (eds.). Historical
Biogeography, Plate Tectonics, and the Chang-
ing Environment. 37th Annual Biological Col-
loquium. Corvallis, Oregon State University
Press.

. 1982. Part 3: Cirripedia. pp. 197-221 in

L. G. Abele (ed.). The Biology of Crustacea,
Vol. 1, Systematics, the Fossil Record, and
Biogeography. Academic Press, New York.

, and J. T. Tomlinson. 1974. Ontogenetic

dimorphism in Lithoglyptes (Cirripedia: Ac-
rothoracica). Crustaceana 27(2):204-208.

, V. A. ZuUo, and T.H. Withers. 1969. Cir-
ripedia. pp. R206-R295 in R. C. Moore (ed.).
Treatise on Invertebrate Paleontology, Part R

(Arthropoda 1), Vol. 1. Geological Society of
America.

Noll, F. C. 1875. Kochlorine hamata N., ein boh-
rendes Cirriped. Zietschrift fiir Wissenschaft-
liche Zoologie 25:1 14-128, pi. VI.

Rodriguez, J., and R. C. Gutschick. 1977. Bar-
nacle borings in live and dead hosts from the
Louisiana Limestone (Famennian) of Mis-
souri. Journal of Paleontology 51:718-724.

Saint-Seine, R. de. 1951. Un Cirripede Acro-
thoracique du Cretace: Rogerella lecointrei, n.
g., n. sp. Comptes Rendus de I'Academie des
Sciences Paris 233:1051-1053.

. 1954. Existance de Cirripedes Acrotho-

raciques des le Lias: Zapfella pattei nov. gen.,
nov. sp. Bulletin de la Societe Geologique de
France (6)4:447-451, pi. XVIII-XX.

1956. Les Cirripedes Acrothoraciques

echinicoles. Bulletin de la Societe Geologique
de France (6)5:299-303, pi. XVI-XVII.

Schlaudt, C. M., and K. Young. 1960. Acrotho-
racic barnacles from the Texas Permian and
Cretaceous. Journal of Paleontology 34:903-
907, pis. 119-120.

Tomlinson, J. T. 1955. The morphology of an
acrothoracican barnacle, Trypetesa lateralis.
Journal of Morphology 96:97-122.

. 1969. The burrowing barnacles (Cirri-
pedia: order Acrothoracica). United States Na-
tional Museum Bulletin 296:1-162.

Turquier, Y. 1970. Recherches sur la biologic des
Cirripedes Acrothoraciques. III. La metamor-
phose des cypris femelles de Trypetesa lampas
(Hancock) et de T. nassarioides Turquier. Ar-
chives de Zoologie Experimentale & Generale
111:573-627.

. 1978. Le tegument des Cirripedes Acro-
thoraciques. Archives de Zoologie Experimen-
tale & Generale 1 19:107-125.

Voigt, E. 1967. ijber einen neuen acrothoraciden
Cirripedier aus dem Essenen Griinsand (Cen-
oman). Abhandlungen und Verhandlungen des
Naturwissenschaftlichen Vereins in Hamburg.
N. F. Bd. 1966 1 1:1 17-121, pi. III-IV.

Zapfe, H. 1936. Spuren bohrender Cirripedier in
Gastropoden-Gehausen des Miozans. Senck-
enbergiana 18(3/4): 130-1 34.

Zibrowius, H. 1980. Les Scleractiniares de la Med-
iterranee et de FAtlantique nord-oriental.
Memoires de ITnstitut Oceanographique, Mo-
naco 11:1-284. (3 vol.).

^^A^"^

^^^rS^Y

TRANSACTIONS
OF THE SAN DIEGO
SOCIETY OF
NATURAL HISTORY

Volume 21 Number 2 pp. 23-55 29 October 1985

The Sangamon interglacial vertebrate fauna from
Rancho la Brisca, Sonora, Mexico

Thomas R. Van Devender

Arizona- Sonora Desert Museum. Route 9, Box 900, Tucson, AZ 85743 USA

Amadeo M. Rea

San Diego Natural History Museum, P.O. Box 1390. San Diego. CA 92112 USA

Michael L. Smith

Museum of Zoology, University of Michigan, Ann Arbor, MI 48109 USA

Abstract. Bones of 5 1 species of vertebrates including fish, amphibians, reptiles, birds, and mam-
mals were recovered from a sedimentary deposit at Rancho la Brisca in north-central Sonora, Mexico.
The fauna was preserved in a marshy cienega habitat with 49.0% of the species and 87.2% of the
identified bones representing aquatic and semiaquatic animals. The most common animals in the fauna
are Kinosternon sonoriense (Sonoran Mud Turtle) and Rana ''pipiens'' -complex (Leopard Frog).

The presence of Bison species (Bison) in association with Mammuthus species (Mammoth), Equus
cf. tau (Pygmy Onager), and Camelops species (Camel) places the fauna in the Rancholabrean Land
Mammal Age. Bufo cf kelloggi (Little Mexican Toad), B. mazatlanensis (Sinaloa Toad), Leptodactylus
melanonotus (Sabinal Frog), Pternohyla fodiens (Burrowing Treefrog), and Masticophis cf mentovarius
(Tropical Whipsnake) are subtropical thomscrub or Sonoran Desert animals that presently occur to the
south and/or west of la Brisca. Bufo alvarius (Colorado River Toad), cf Callisaurus draconoides (Zebra-
tailed Lizard), and Sceloporus cf clarkii (Clark's Spiny Lizard) are other Sonoran Desert animals that
suggest a paleoclimate with warm winters and a well-developed summer monsoon. The best modem
analog for the paleocommunity would be about 240 km SSE on the Rio Yaqui. The subtropical elements
in the la Brisca fauna make it unlikely that the fauna was deposited during a glacial period, considering
that the Late Wisconsin paleoclimatic reconstructions for Arizona based on plant remains in packrat
middens suggest glacial climates with mild, wet winters and cool, dry summers. The fauna represents
an interglacial environment subsequent to the appearance of Bison about 150 000 years ago in the
Sangamon Interglacial and with a climate similar to that of the Late Holocene of the last 4000 years.

The distributions of fish and mud turtles suggest past stream connections between the Gila River
drainage in southeastern Arizona and the rivers in Sonora. In contrast, Pseudemys scripta (Yaqui Slider)
apparently never entered Arizona, although it reaches north-central Sonora today.

Resumen. Un deposito aluvial en Rancho la Brisca, Sonora, ha producido fosiles de 5 1 vertebrados.
Se incluyen peces, amfibios, reptiles, mamiferos, y aves. El 49% de la especies y el 87.2% de los huesos
identificados pertenecen a animales acuaticos o semiacuaticos, confirmando la surgerencia que el ya-
cimiento representa una cienega. Los huesos mas corrientes pertenecen a Kinosternon sonoriense (Tor-
tuga de Barro Sonorense) y Rana ''pipiens" -complex (Rana Pardal). La fauna se refiere a la edad de
mamiferoterrestre de Rancholabrea implicado por las presencia de Bison species (Bisonte) con Mam-
muthus species (Mamut), Equus cf tau (Caballo), y Camelops species (Camello).

Bufo cf. kelloggi (Sapito Mexicano), B. mazatlanensis (Sapo Sinaloense), Leptodactylus mela-
nonotus (Rana Sabinal), Pternohyla fodiens (Rana Arborea Minera), y Masticophis cf mentovarius
(Elicante) se ubican hoy al sudeste de la Brisca en el Desierto Sonorense o en al bosque espinoso. Se
incluyen tambien otros animales del Desierto Sonorense como Bufo alvarius (Sapo del Rio Colorado),
cf Callisaurus draconoides (Lagartija con Cola de Cebra), y Sceloporus cf clarkii (Lagartija Espinosa
de Clark). Estos animales indican un clima en cual las temperaturas del inviemo son moderadas y
occurren fuertes lluvias estivales.

Clima semejante al que se sugiere en encuentra 240 km SSE cerca el Rio Yaqui. El yacimiento
probablemente no se formo en periodo glacial ya que se encuentran varies elementos subtropicales.
Reconstrucciones del clima de Arizona durante el periodo Wisconsin insinuan el mayor porcentaje de

la precipitacion anual en el inviemo, temperaturas moderadas en el inviemo, y veranos secos pero
atemperados. La fauna en vez se refiere a un interglacial despues de 150 000 anos en el Sangamon
Interglacial y con clima semejante al Holoceno Ultimo hace 4000 anos a hoy. Las distribuciones de
los paces y tortugas de barro sugieren conexiones historicas entre los desagues de Arizona y Sonora.
Sin embargo, Pseudemys scripta (Resbalador Yaqui) no aparece en Arizona aunque hoy se encuentra
en la parte norte-central de Sonora.

Introduction

In 1975, a vertebrate fossil locality near Rancho la Brisca was discovered during
a survey of the archaeological and paleontological resources of the Rio San Miguel
drainage in Sonora, Mexico, by the Centro Regional del Noroeste of the Instituto
Nacional de Antropologia e Historia in Hermosillo. We report specimens collected
from 1975-1982 (Table 1). In June 1978, 29 burlap bags of sediment were washed
through fine mesh (ca. 2 mm) screens to recover bones of small vertebrates. Most of
the fossils have been deposited into the vertebrate paleontological collections in the
Instituto de Geologia in Mexico City (IGCU 2546-260 1). Individual specimen numbers
were not provided and have not been included in the text for specimens deposited in
this collection. Duplicate specimens and casts are in the University of Arizona Lab-
oratory of Paleontology (UALP) collections. The site is UALP locality #7627; all
specimen numbers in the text are UALP catalog numbers. The amphibian, reptile, and
small mammal material was identified using Van Devender's osteological collection
(TRV). Terminology for most of the anuran post-cranial elements follows that of Gaup
(1896). Bird remains were identified using Rea's osteological collection (AMR). Fish
remains were compared to skeletons at the University of Michigan Museum of Zoology
(UMMZ). Extinct mammals and birds were identified by comparison with fossils in
the UALP and the Los Angeles County Museum (LACM) collections. The present
distributions of amphibians and reptiles in Sonora were determined from specimens
in the herpetological collection in the Department of Ecology and Evolutionary Biology,
University of Arizona (UAZ). Extinct animals in the systematics section are marked
by daggers (f).

Environmental Setting and Geology

The fossil locality is in north-central Sonora near Rancho la Brisca on the Rio
Santo Domingo, an upper tributary of the Rio San Miguel (Fig. 1). Rancho Agua Fria
and the old mission site of Saracachi are 5 km S where there is a large cienega (marshy
area) in the stream valley (Fig. 2). The site is 33 km NE of Cucurpe, 180 km NNE of
Hermosillo, and 90 km S of the United States border.

The vegetation at the site is a desert-grassland at about 1000 m elevation that is
between the Arizona Upland subdivision of the Sonoran Desert (Shreve 1964) and
Mexican oak woodlands (Fig. 3). Important perennials on the slopes near the site include
Prosopis velutina (Velvet Mesquite), Juniperus erythrocarpa (Redberry Juniper), Mi-
mosa biuncifera (Wait-a-minute Bush), and M. dysocarpa (Gatuno). Quercus emoryi
(Emory Oak or Bellota), Celtis reticulata (Netleaf Hackberry), and Juglans major (Ar-
izona Walnut) are on areas with deeper soil below. Salix nigra (Goodding Willow),
Fraxinus pennsylvanica (Velvet Ash), Populus fremontii (Fremont Cottonwood), and,
locally, P. monticola (Sonoran Cottonwood), occur along the Rio Santo Domingo. The
canyon flora includes Ficus petiolaris (Fig) at its northern limit and occasional Acer
grandidentatum (Big Tooth Maple) at its southern limit. The stream is perennial and
harbors such species as Gila purpurea (Yaqui Chub), Rana ''pipiens" -complex (Leopard
Frog), Kinosternon sonoriense (Sonoran Mud Turtle), and Thamnophis cyrtopsis (Black-
necked Garter Snake). A disjunct, southern population of Sciurus arizonensis (Arizona
Gray Squirrel) lives in the riparian trees. The area is used mostly for grazing with some
local agriculture and gold mining.

Climatic records for Saracachi at 930 m elevation are available in Hastings and
Humphrey (1969). The mean annual temperature is 16.5°C; the coldest and hottest
months are January (8.3°C) and July (25.3°C), respectively. The mean annual precip-

Figure 1 . Map of Sonora and adjacent Arizona. Stippled area is Sinaloan thomscrub vegetation after Brown
and Lowe (1977). Boundary of Sonoran Desert after Shreve (1964).

itation is 466.8 mm, with 64% falling from June through August. These records are
based on only a few years of data (1942-1946), but are similar to longer records for
Cucurpe and Arizpe.

Between Rancho Agua Fria and Rancho la Brisca, the stream has incised into a
narrow canyon in the coarse, well-indurated stream gravels. Near la Brisca, the canyon

Figure 2. Saracachi Cienega in April 1977. Rana '^ pipiens" -comx)\&\ (Leopard Frog) and Kinosternon
sonoriense (Sonoran Mud Turtle) are common. Pseudemys scripta (Yaqui Slider) was observed in the open
water in middle of photo. The trees on edge of water are Salix nigra (Goodding Willow), Celtis reticulata
(Netleaf Hackberry), and Prosopis velutina (Velvet Mesquite). The columnar cactus on hill in background is
Carnegiea gigantea (Saguaro).

;:3

Figure 3. General view of the Rancho la Brisca vertebrate fossil locality in April 1976. Deposits are on
the hillside in the center of photo obscured by trees. Most of the trees are Prospis velutina (Velvet Mesquite),
with a few Quercus emoryi (Bellota).

Figure 4. Unit 2 of the Rancho la Bnsca venebraie fossil locality. Fossil bone was weathering out of the
fine-grained sediments in lower center of photo. Screen wash samples came from this area as well.

widens where the fossils were found, about 1 5 m above the canyon floor in a small
unit of remnant sediments deposited on the gravels (Fig. 4). There are three well-defined
sedimentary units in the stratigraphic section: (1) a lower buff mudstone with a little
gravel, about 3 m thick; (2) a middle buff mudstone with less gravel, about 2 m thick;
and (3) an upper reddish gravel, about 2 m thick. Bone was found in the lower two
units in fine clays with sparse gravel up to about 10 mm in size. The bone is well-
mineralized and mostly dark brown or black. Fragile specimens (e.g., frog ilia and snake
vertebrae) show no signs of transport damage, suggesting in situ deposition. Samples
from the two mudstones, extracted for pollen using both acid and heavy liquid extraction
techniques, were sterile (R. S. Thompson and V. Markgraf, personal communication).
Two deposits with similar lithologies and perched positions on the rim of the valley
were seen within 5 km of the la Brisca site (R. S. White, personal communication).

Annotated Account of Fossil Taxa

Class Osteichthyes— Bony Fishes

Order Cypriniformes— Minnows and Minnowlike Fishes

Family Catastomidae— Suckers

Catostomus wigginsi Herre and Brock— Opata Sucker

Material. —MdiXxWa, dentary, metapterygoid and ceratohyal.

Comments.— Tht fossils are from suckers of 80-115 mm standard length (SL).
Comparative material of C wigginsi (UMMZ 202388-S) is from the Rio Santo Do-
mingo at Rancho la Brisca.

Castostomus wigginsi is distinguished from the other five described species of
Mexican Catostomus on characters of the dentary. The gnathic ramus of the dentary
is more attenuate in C wigginsi than in C. clarki (Desert Sucker) and bears a narrower
groove for the labial cartilage. The gnathic sensory canal pore is not united with the
crest for Meckel's cartilage to form a single complex structure as it is in C. bernardini
(Yaqui Sucker) and C. conchas (Rio Conchos Sucker), and the sensory pore is nearer
the symphysis than is the crest for Meckel's cartilage. The coronoid process of the
dentary is not deflected laterally as in C. plebeius (Rio Grande Sucker); the posterior
surface of the gnathic ramus is flat, not concave; the anterior end of the groove for the
labial cartilage is visible in mesial view. Catostomus wigginsi is distinguished from C.
insignis (Sonoran Sucker) by the highly elevated coronoid process in the former.

The dorsal keel of the maxilla of C. wigginsi is distinct from that of Catostomus
plebeius in that it is flexed anteroventrally. In C. wigginsi the ceratohyal is long and
slender, much less robust than in C. plebeius, C. bernardini, or C. insignis, and is
without ventral ornamentation as in C. insignis. The la Brisca fossils agree with C.
wigginsi in the above characters.

This is the only fossil record for C wigginsi and the genus Catostomus reported
from Mexico. Catostomus wigginsi is endemic to the Rio Sonora and its tributary, the
Rio San Miguel, although there is a single record for the Rio Moctezuma, tributary to
the Rio Yaqui (UMMZ 161467; Hendrickson et al. 1980). Catostomus bernardini has
been collected once in the Rio Sonora system (UMMZ 161453); it is otherwise known
from Pacific slope drainages from the Rio Yaqui to the Rio Sinaloa. Since C. wigginsi
has not been collected subsequently from the Rio Yaqui drainage, nor C. bernardini
from the Rio Sonora, we regard these records as erroneous.

The Opata Sucker is a small species of Catostomus; breeding individuals are less
than 1 10 mm SL at Rancho la Brisca today. It is typically associated with moderate
to swift currents and sand or gravel substrate in rivers or small streams with pools or
other cover.

Family Cyprinidae— Minnows
Agosia chrysogaster Girard— Longfin Dace

Material. —Right pharyngeal arch lacking posterior limb and fourth tooth.

Comments. —The fossil resembles recent material of Agosia chrysogaster from the
Rio San Miguel drainage (UMMZ 202389-S). The pharyngeal arch is attenuate and its
anterior limb is shorter than its dentigerous portion. The teeth bear weak hooks and
are moderately compressed, but are not as compressed or crowded as in species of
Pimephales and Campostoma; they are more closely spaced than in Notropis ornatus
(Ornate Shiner) or N.formosus (Beautiful Shiner). The fossil differs slightly from recent
material of A. chrysogaster in having smaller terminal hooks on the teeth.

Agosia occurs naturally in the Gila and Bill Williams drainages of southwestern
United States (Minckley 1973) and in the Magdalena, Sonora, Yaqui, and Sinaloa river
systems of Mexico. These are all considered to be A. chrysogaster, although the Mexican
populations may be a distinct species (Miller 1958). A. chrysogaster is abundant in
most Sonoran Desert streams below 1 500 m (Minckley 1973, Hendrickson et al. 1980);
it has not been reported previously as a fossil.

Genus and species indeterminate

Material. —A fragmentary left opercle.

Comments. —This bone can be assigned to the Cyprinidae based on the shape of
the dilator process; the articulating cotyla and most of the body of the bone are missing.
The specimen is too large to be Agosia, Campostoma, Notropis formosus, N. ornatus,
or Pimephales. It agrees in size with Gila, but diagnostic features are lacking.

Cyprinidontiformes— Pupfish and Killifish

Family Poeciliidae — Topminnows

Poeciliopsis accident alis Baird and Girard — Gila Topminnow

or
P. monacha-occidentalis —All-female Topminnow

Material. —Two left opercles.

Comments. —The dilator process of the opercle is rounded and does not extend
beyond the dorsal margin of the opercle. The articulating cotyla is oblong dorsoventrally
and matches modem material in shape and arrangement of its supporting struts. Poe-
ciliopsis occidentalis and P. monacha-occidentalis are distinguishable on dental char-
acters which, unfortunately, are not evident on the fossil material.

The natural range of the Gila Topminnow includes the Gila River of Arizona and
New Mexico and the Pacific coastal drainages of Sonora south to the Rio Mayo. In the
Mexican part of its range, it is host to the all-female hybridogenetic form, P. monacha-
occidentalis. Both forms occur at Rancho la Brisca today, although P. monacha-occi-
dentalis was rare (2.2%) in our field collection which constitutes one of the northernmost
records of the all-female form {see Moore et al. 1970). Poeciliopsis occidentalis was
widespread and abundant in two surveys of Sonoran fishes (Branson et al. 1960, Hen-
drickson et al. 1 980). It is associated with moderate current below riffles or along stream
margins and characteristically occurs over sandy substrates (Minckley 1973). We col-
lected it in the Saracachi Cienega (Fig. 2).

This is the only fossil poeciliid reported from Mexico. Alvarez and Aguilar (1957)
described a fossil poeciliid, Poeciliopsis maldonadoi, from deposits of unknown age
(possibly Recent) in El Salvador. Some of that material later proved to be of the genus
Poecilia, and P. maldonadoi may prove to be a synonym of the living species P.
turrubarensis (Rosen and Bailey 1963).

Class Amphibia— Amphibians

Order Anura— Toads and Frogs

Family Bufonidae— Toads

Bufo alvarius Girard— Colorado River Toad

Material. —Frontoparietals (Fig. 5 A), scapula (1 1599), ilia (3; 1 1600; Fig. 5B).

Bufo cf. alvarius

Material. -Dentaries (2; 11601), exoccipital, nasal, vertebrae (5; 11603-11604),
humeri (2; 1 1602), radioulna.

Comments. —The fossils are from toads of 1 10-160 mm snout-vent length (SVL).
Today only B. alvarius and B. marinus (Marine Toad) reach this and larger sizes. Bufo
woodhousei bexarensis (Friesenhahn Cave Toad), an extinct late Pleistocene form in
Texas, reached body lengths of 160 mm, but had a narrow frontoparietal with tubular
dorsal ornamentation (Mecham 1959, Tihen 1962a) quite different than the la Brisca
fossil. Bufo alvarius and B. marinus are in the B. valliceps (Gulf Coast Toad) species
group of Tihen (1962/?). Both species have wide frontoparietals shaped similar to those
of the fossil, but B. marinus has heavier, more rugose dorsal ornamentation with
prominent ridges oriented obliquely to the anterior-posterior axis of the bone (Fig. 5 A).
The anterior edge of the frontoparietal in our reference specimens is more squared-off'
than in the fossil. The ilia referred to B. alvarius have a broader dorsal prominence
without the pronounced knob of B. marinus (Fig. 5B). The scapula of B. alvarius differs
from that of B. marinus in that the articular surface is slightly smaller, and in that the
acromial portion is relatively narrow. The larger la Brisca toad fossils could all be from
B. alvarius, but B. marinus cannot be eliminated from consideration on the bones
listed as B. cf. alvarius.

Fig. A

•■5

Fig. B

i:s?i^^22ft^

Figure 5. Bufo alvarius (Colorado River Toad). A. Right frontoparietal, B. Right ilium (UALP 10151).

This is the only Rancholabrean fossil record for B. alvarius. Lindsay (1 984) reported
B. alvarius from Irvingtonian deposits from the mouth of the Colorado River in the
Gulf of California at El Golfo, Sonora (C. A. Shaw, personal communication 1985).
Tihen {\962a) identified Bufo cf alvarius from the Blancan Benson (=Post Ranch)
Fauna in Cochise County, Arizona. Johnson et al. (1975) dated this fauna at 3. 1 million
years ago using the paleomagnetic stratigraphy in the San Pedro River Valley. Bufo
alvarius is a large toad restricted to desertscrub and thomscrub plant communities in
the Sonoran Desert from southern Arizona to northern Sinaloa (Fouquette 1970). It
presently occurs near the la Brisca fossil site. Bufo marinus is a toad of more tropical
environments that reaches its northern limit in southernmost Sonora.

Bufo cf cognatus Say— Great Plains Toad

Material— 'L. humerus.

Comments.— ThQ humerus lacking the medial crest was from a female toad of
about 60 mm SVL. The bone was relatively poorly ossified, and the radial condyle was
unfused. The fossil is similar to the humeri of reference B. cognatus of the same size,
although it is slightly more robust. Bufo cognatus was reported as a Late Wisconsin
fossil from Friesenhahn Cave and the Groesbeck Local Fauna in Texas (Holman 1 969a).

Bufo cognatus occurs from the Great Plains south into south-central Mexico and west
to southeastern California, Baja California, and most of Sonora.

Bufo cf. kelloggi Taylor— Little Mexican Toad

Material. —Humeri (6L, 3R; 1 1605), sacral vertebra.

Comments. —The fossils are from individuals of 30-35 mm SVL. All appear to
be males, although the medial crest is only weakly developed in B. kelloggi. The humeri
of B. retifonnis and B. punctatus are not as well ossified at this size. Bufo debilis is
closer in size to B. kelloggi, but most mature at 40-45 mm SVL. Male Leptodactylus
melanonotus are of similar size, but have better developed medial crests, more flattened
shafts between the middle and the radial condyle (eminentia capitalis of Gaup 1896),
and the lateral crest and epicondyle are equally well-developed.

Bufo kelloggi has not been reported previously in the fossil record. Bufo kelloggi
is the smallest toad in the Bufo punctatus group of Ferguson and Lowe (1969) which
also includes B. punctatus, B. retiformis, and B. debilis. It is found in coastal subtropical
lowlands from Nayarit to as far north as central Sonora in the vicinity of Hermosillo,
with an outlying population near Santa Ana (Hulse 1977). The la Brisca site is northeast
of its present range.

Bufo mazatlanensis Taylor— Sinaloa Toad

Material.— K. basioccipital/frontoparietal, humeri (2L; 1 1607), ilia (2L, 2R; 1 1606;
Fig. 6).

Bufo species— Toad

Material— Eihmoids (2), basioccipital, atlas, sacral vertebra, urostyle, humerus,
radioulnae (3; 11610), tibiofibulae (5; 1 1609).

Comments. —The fused basioccipital and frontoparietal are from a toad of about
90 mm SVL. The frontoparietal is broad and moderately rugose without a well-de-
veloped ridge for cranial crests. Bufo alvarius also has a broad frontoparietal without
a crest, but has a strongly papillose or echinate dorsal surface. The frontoparietal of B.
cognatus is narrow with a well-developed cranial crest. The condyloid fossa lateral to
the occipital condyle is relatively larger in B. alvarius than in B. mazatlanensis and B.
cognatus. The fossil resembles reference B. mazatlanensis.

The humeri referred to Bufo mazatlanensis are from a female of about 65 mm
SVL, and a male of about 82 mm SVL. The radial condyle is well-rounded; the ulnar
or medial epicondyle is well-developed; the lateral crest and lateral epicondyle are
present, but not protruding.

The ilia referred to Bufo mazatlanensis are all from toads of 75-80 mm SVL and
have low, broad dorsal prominences that are fairly flat on top, rugose or not, and with
a broad, deep ventral acetabular expansion (Fig. 6). The dorsal prominences of B.
alvarius, B. cognatus, B. woodhousei, and B. microscaphus are higher. The ventral
acetabular expansion of 5. alvarius is deep, but not broad. The bones identified as Bufo
species could all be from B. mazatlanensis.

Bufo mazatlanensis does not have a previous fossil record. It is a member of the
B. valliceps group found in the tropical lowlands of northwestern Mexico from southern
Sinaloa northward to central Sonora. The northernmost collections are from the narrows
of the Rio Sonora near Ures 140 km S of la Brisca.

Bufo punctatus Baird and Girard — Red-spotted Toad

or
Bufo retiformis Sanders and Smith— Sonoran Green Toad

Material. -WwrnQvi (3R, 4L; 10150, 11608).

Comments.— ThQSQ humeri are from mature male toads 45-55 mm SVL. The
radial condyles are well-ossified. The male medial crests may be well-developed. Male

Figure 6. Left ilium (UALP 1 1606) of Bufo mazatlanensis (Sinaloa Toad).

Hylactophryne augusti are similar in size to the fossils, but the distal end of the humerus
is relatively wider in this species, and the ulnar and epicondyles are well-developed.
The humeri of most other Bufo and Rana are larger. The humeri of B. punctatus and
B. retiformis are very similar to each other.

Bufo punctatus has been recorded from the Late Pleistocene and Holocene sedi-
ments of Dry Cave, Guadalupe Mountains, southeastern New Mexico (Holman 1970),
and Howell's Ridge Cave, Little Hatchet Mountains, southwestern New Mexico (Van
Devender and Worthington 1977). Bufo punctatus was reported from Late Wisconsin/
Early Holocene deposits in Deadman Cave, Santa Catalina Mountains, Pima County,
Arizona (Mead et al. 1984). Its bones were also found in packrat middens from the
Sonoran Desert (Van Devender and Mead 1978). Two Late Wisconsin midden spec-
imens from near Tucson, Arizona, were associated with a radiocarbon date of 12 1 30 ±
500 B.P. (radiocarbon years before present). Three Early Holocene midden specimens
from the Whipple Mountains, California, were associated with dates of 10 930 ± 170
B.P. and 10 330 ± 300 B.P. Bufo retiformis does not have a previous fossil record.

Bufo punctatus is widespread in many habitats in the southwestern United States
and Mexico. Bufo retiformis is a Sonoran Desert animal found from central Sonora
north of Guaymas into south-central Arizona in Organ Pipe Cactus National Monument
and on the Papago Indian Reservation (Hulse 1978).

Family Hylidae— Treefrogs
Hyla arenicolor Cope— Canyon Treefrog

Material. -\\\2i{^U 8R; 11636).

Hyla species— Treefrog

Material. —Vertebrae (2; 11611), sacral vertebrae (3; 11612), urostyles (2; 11613),
radioulna, tibiofibula.

Comments. —The ilia are referred to H. arenicolor because: (1) the dorsal and
ventral acetabular expansions (posterior and anterior pelvic spines of Gaup 1896) are
subequal (the dorsal acetabular expansion is relatively smaller in H. regilla); (2) larger

size for maturity of the bone than in H. eximia; (3) relatively larger acetabulum for
size of ilial head than in H. cadaverina; (4) a relatively low, broad dorsal prominence
without a well-developed "knob" compared to H. regilla and H. eximia. Pternohyla
fodiens is a larger treefrog which has the dorsal prominence oriented more dorsally
than in Hyla. The fossils appear to have ossified at a relatively smaller body size (by
40 mm SVL) than does H. arenicolor today, and the "knob" on the ilial prominence
is somewhat better developed. The la Brisca bones identified only as Hyla species could
be from H. arenicolor as well. The sacral and trunk vertebrae resemble Hyla. but
apparently are from mature individuals with body sizes of 35-40 mm SVL rather than
today's 40-45 mm SVL. The urostyles, radioulna and tibiofibula are not sufficiently
distinct to refer them to species.

The only previous Late Pleistocene and Holocene records for Hyla arenicolor are
from Howell's Ridge Cave, New Mexico (Van Devender and Worthington 1 977). Today
it is widespread in canyon habitats in the mountains of the southwestern United Stales
and Mexico and lives at the fossil locality today.

Pternohyla fodiens Boulenger— Burrowing Treefrog

Ma?ma/. — Basioccipital, dentary, humerus.

Comments. —The basioccipital is referred to P. fodiens because: (1) the occipital
condyle is a rounded knob rather than a flattened, elongate surface; (2) the epiotic
eminence (terms follow Sanders 1953) is a prominent knob; (3) the prootic-transverse
process is expanded; (4) the basioccipital is not fused to the frontoparietal as it is in
adult Hylactophryne augusti and Bufo mazatlanensis.

The fossil dentary is referred to P. fodiens because: (1) it is larger than in Lepto-
dactylus melanonotus and Bufo kelloggi, but smaller than in female Hylactophryne
augusti, Bufo alvarius, B. cognatus, and B. mazatlanensis; (2) the medial flange is well-
developed on the ventral border of Meckel's canal just anterior to the articular surface
as in Hyla, but not Bufo punctatus and B. retiformis; (3) the dentary is thicker and
curves more laterally and ventrally than Hyla arenicolor.

The fossil humerus has the broad distal end with the narrow shaft of the hylids,
but it is larger (ca. 60 mm SVL) and stouter than adult Hyla arenicolor (45 mm SVL).
The humerus of Smilisca baudini, a large subtropical treefrog, is not well-ossified at
65 mm SVL and has a broader distal end. Both the lateral or ulnar epicondyle project
distally, while the radial condyle projects beyond both.

Pternohyla fodiens does not have a previous fossil record. It lives in dry subtropical
habitats from Jalisco and Michoacan northward along the west coast of Mexico through
Sinaloa and Sonora and into Arizona on the Papago Indian Reservation (Trueb 1969).
The la Brisca site is probably just to the northeast of the nearest Sonoran populations.

Family Leptodactylidae— Tropical Frogs
Hylactophryne augusti (Duges)— Barking Frog

Ma/ma/.— Scapula, tibiofibulae (3; 11640; Fig. 7).

Comments.— ThQ fossils are from frogs of about 45-55 mm SVL. Hylactophryne
augusti is sexually dimorphic with females reaching 90 mm SVL and males about 55
mm SVL. Reference skeletons of female H. augusti of 63 mm, 67 mm, and 89 mm
SVL, as well as of many species of Eleutherodactylus and Leptodactylus, were available
for comparison.

The scapula was referred to H. augusti because: (1) the acromion and glenoid
portions of the scapula are not parallel as in Rana; (2) the anterior margin in the "waist"
is less curved than in Bufo and Scaphiopus; (3) the notch between the acromial and
glenoid portions of the scapula is relatively broad and angled; (4) the articular surface
is relatively large.

Bufo and Scaphiopus (Pelobatidae) have relatively short tibiofibulae with the ends
much wider than the middle. Rana (Ranidae) and Hyla (Hylidae) have longer, slender
tibiofibulae that are flexed in the middle. The fossils and the leptodactylid reference

mm
1-5

Figure 7. Tibiofibula of Hylactophryne augusti (Barking Frog).

specimens are moderately long and have straighter shafts with the ends and middle
less disparate in size than in Bufo and Scaphiopus (Fig. 7). The distal end of the la
Brisca fossil is missing, but the proximal end has well-ossified epiphyses with prominent
lateral ridges similar to those on our reference leptodactylids. This articular surface in
bufonids, pelobatids, ranids, and hylids is less ossified and usually separates from the
shaft in maceration. The fossils are somewhat more robust than the reference specimens.
Hylactophryne (as Eleutherodactylus) augusti was reported from Late Wisconsin
deposits in Frieshenhahn Cave, Bexar County (Mecham 1959) and Schulze Cave,
Edwards County (Holman \969b), Texas. Hylactophryne augusti is a secretive, rock-
dwelling frog that is found in many habitats from southeastern Arizona (Bezy et al.
1966), southeastern New Mexico, and central Texas south through Mexico to the
Isthmus of Tehuantepec (Zweifel 1967). In Arizona, it is rare in habitats similar to the
la Brisca fossil site.

Leptodactylus melanonotus (Hallowell)— Sabinal Frog

Material— YtrXobrsiQ (2; 11617), ilia (3R, L; 11616), scapula, humerus (R, L;
11614), radioulna (11615), tibiofibulae (5).

Comments.— Tht vertebrae were referred to L. melanonotus because: (1) of the
small size (ca. 40 mm SVL); (2) the broad neural arch that is not flattened dorsally (as
in Bufo kelloggi); (3) the relatively large neural canal; (4) the round transverse processes;
(5) the relatively short centrum (larger in Hyla).

The fossil ilia are easily separated from those of anurans other than ranids and
leptodactylids by the presence of a dorsal crest. The fossils can be separated from small
Rana (ca. 33 and 39 mm SVL) by the dorsal crests being lower and the dorsal prom-
inence being well-ossified without the porous texture of immature bone. They are
referred to Leptodactylus melanonotus rather than male Hylactophryne augusti because
of the well-developed dorsal prominence and small size.

The scapulae of leptodactylids and ranids differ from those of other anurans by
the glenoid surface being shifted medially, such that it parallels that acromial surface.
The fossil scapula was referred to L. melanonotus rather than Rana because it is

relatively short and broad and is from a very small, mature individual (ca. 35 mm
SVL).

The fossil humeri were from individuals of about 33 mm and 37 mm SVL and
were referred to L. melanonotus rather than other small anurans {Bufo kelloggi, Gas-
trophryne olivacea, hylids) because of the exceptionally well-developed medial crest of
males. The fossil radioulna is referred to L. melanonotus because of its very small size
and stockiness. The tibiofibulae were referred to L. melanonotus because of their small
size, straightness, and relative thickness in the center of the shaft.

Leptodactylus melanonotus does not have a previous fossil record. It is a tiny frog
in a tropical family found from central Sonora south into Central America. It is the
northernmost species of Leptodactylus; Hylactophryne is the only other leptodactylid
that occurs farther north. The nearest population of Leptodactylus melanonotus to the
la Brisca site is southeast of Hermosillo. In southern Sonora, it lives in subtropical
riparian habitats with perennial surface water.

Family Microhylidae— Narrow-mouth Toads
Gastrophryne cf. olivacea (Hallo well)— Great Plains Narrow-mouth Toad

MarmW. -Sacral vertebrate (2; 1 1620), ilia (2R, L; 1 1619), humeri (2R, 2L; 11618).

Comments. —The sacral vertebrae are small with the transverse processes expanded
into wings, but not fused to the urostyle as in Scaphiopus. The sacral vertebra of Bufo
kelloggi, another small fossorial "toad," is similar, but does not have the paired anterior
cotyles.

The ilia of Gastrophryne are very distinctive and differ from other small anurans
including Acris, Bufo, Hyla and Pseudacris in the following combination of characters:
(1) the head of ilium is at sharper angle with the shaft; (2) dorsal acetabular expansion
is greatly reduced; (3) ventral acetabular expansion is moderately deep but very broad.
The humeri are also very distinctive and exhibit the following characters: (1) well-
ossified at a very small size; (2) the shaft is relatively straight; (3) the lateral epicondyle
is very poorly developed; (4) the lateral crests poorly developed or absent; (5) the
posterior surface opposite the ulnar condyle is rounded rather than flattened.

Gastrophryne olivacea has been reported from the Sangamon Clear Creek local
fauna, Denton County, Texas (Holman 1969a). This species is widespread in grassland
habitats from the Great Plains to south-central Arizona; and south in subtropical
lowlands through Sonora and Sinaloa to Nayarit (Nelson 1972). It probably lives near
the la Brisca site today.

Family Pelobatidae— Spadefoot Toads
Scaphiopus couchi Baird— Couch's Spadefoot Toad

Material.— At\as, vertebrae (2; 11624), ilia (2; 11623), scapula, radioulnae (2;
11621), tibiofibula (11622).

Scaphiopus species— Spadefoot Toad

Material. —Ilia, radioulnae (5).

Comments. —The atlas is referred to Scaphiopus because it has short broad cotyles
(glenoid cavities of Gaup 1896) that are separated medially, and to S. couchi rather
than 5". hammondi because the neural arch is relatively smooth and the posterior
condyle is usually fused. The vertebrae are from individuals of 60-70 mm SVL and
referred to Scaphiopus because the neural spine is absent; there is a well-developed
spine on the posterior margin of the neural arch, and the condyles and cotyles are
rounded and relatively small. Again, the condyles are fused as in S. couchi and not S.
hammondi.

The ilia are from individuals of 70-75 mm SVL and referred to Scaphiopus because
the dorsal prominence is lacking. In 5". couchi the ventral acetabular expansion is
broader where the shaft meets the acetabulum than it is in S. hammondi. The ilia

identified as Scaphiopus species are less complete, but are from individuals of 65-70
mm SVL and could be from S. couchi as well.

The fossil scapulae have the glenoid surface posterior to the acromial surface as
in Bufo, Hylactophryne, and Scaphiopus, and not medial as in Rana. The anterior
margin is curved into the "waist" as in Bufo and Scaphiopus, but not broad and angled
as in Hylactophryne. In Scaphiopus, the articular surface is relatively small, and the
acromial surface is relatively narrow. Scaphiopus couchi has a slender scapula that
broadens and becomes better ossified with age. Scaphiopus hammondi has a broader
scapula that is in some ways more similar to Bufo. The fossil was from an individual
approximately 50 mm SVL.

The fossil radioulnae are referred to S. couchi because: (1) of large size (ca. 75 mm
SVL); (2) the "neck" is very broad with a well-developed crest on the ulna; (3) the
olecranon and capitulum on the proximal end are relatively narrow. The radioulnae
identified as Scaphiopus species are from smaller individuals and could represent S.
couchi as well.

The tibiofibulae oi Scaphiopus are distinctive because the tibia and fibula are fused
into an arc on the proximal end where they contact the distal end of the femur, and
the cartilaginous ends are simple and not ossified. In other anuran families, the tibia
and fibula are separated more at the proximal end, and the cartilaginous articular
surfaces are well-developed and can become well-ossified at maturity. The fossil is
referred to S. couchi rather than S. hammondi because it is from a large individual
and because the center portion of the bone is relatively thick.

Scaphiopus cf. couchi was reported from Late Pleistocene or Holocene deposits of
Bishop's Cap, (Brattstrom 1964) and Howell's Ridge Cave (Van Devender and Wor-
thington 1977), New Mexico. Scaphiopus couchi was reported in the Late Wisconsin/
Early Holocene deposits in Deadman Cave, Pima County, Arizona (Mead et al. 1984).
Its bones were found in an Early Holocene packrat midden dated at 8 1 50 ± 260 B.P.
from near Wellton, Yuma County, Arizona (Van Devender and Mead 1978). Sca-
phiopus couchi is widespread in many habitats from the southern Great Plains west to
southwestern California and south to Baja California, Nayarit, and central Mexico
(Wasserman 1970). It probably lives at the la Brisca site today.

Family Ranidae— Frogs
Rana ""pipiens"" Shreber-Complex— Leopard Frog

Material— M2i\\\\diQ (2R, 2L; 11626), dentaries (2R, L; 11627), ethmoid, trunk
vertebrae (3; 1 1632), sacral vertebrae (5; 1 1633), ilia (17; 1 1631), urostyles (7), fused
pelvis, ischia (2), coracoid, scapulae (6R, 2L; 1 1628), humeri (2R, 2L; 1 1629), radioul-
nae (4R, 2L; 11 630), tibiofibulae (2).

Comments. —The fossil maxillae are referred to R. ''pipiens" because: (1) relatively
large teeth (smaller in Hyla) are present (lacking in Bufo); (2) moderate size; (3) relatively
smooth surface (rugose in Pternohyla). The dentary is referred to R. ''pipiens" because
the flange on the ventral edge of Meckel's groove posterior to the coronoid process is
broad and not indented dorsally. The fossil ethmoid is thin and high compared to Bufo
and Hylactophryne. The fossil vertebrae have broad, oval cotyles and condyles and the
prezygapophysial surfaces are strongly angled dorsally. The sacral vertebrae are referred
to R. ""pipiens'' because they possess an anterior condyle rather than a cotyle (Bufo,
Hylactophyrne, Hyla, Leptodactylus, Pternohyla); they are not fused to the urostyle
(Scaphiopus), and the transverse accessory processes are not expanded distally into
"wings" (Scaphiopus, Gastrophryne, Bufo kelloggi). The ilia are referred to R. ""pipiens""
because: (1) the dorsal crest is well-developed; (2) the dorsal prominence is at a sharper
angle than in leptodactylids (Eleutherodactylus, Hylactophryne, Leptodactylus); (3) the
dorsal acetabular expansion is slightly higher than the ventral acetabuler expansion.
The urostyles are referred to R. ""pipiens'' because of the (1) high dorsal coccygial spine
along most of the body; (2) large oval vertebral canal above oval paired anterior cotyles
(glenoid cavities); (3) relatively little space between the cotyles and the anterior end of
the coccygial spine.

The fossil scapulae are referred to R. '"pipiens"" because: (1) the glenoid portion is
shifted medially so that it parallels the acromial portion; (2) the size is large compared
to Leptodactylus melanonotus. The fossil humeri are referred to R. '"pipiens"' because
of a narrow shaft, and a small distal end of the lateral epicondyle. The fossil radioulnae
are referred to R. ""pipiens" rather than R. larahumare {TarahumaTa Frog). Ranapipiens
{sensu lato) has been segregated into a complex of closely related species that inhabit
virtually all aquatic habitats in North America. No attempt was made to distinguish
the fossils from the southwestern species in this complex {R. berlandieri, R. blairi. R.
chiricahuensis, R. magnaocularis, R. pipiens, R. yavapaiensis; see discussion and ref-
erences in Platz and Frost 1984). Leopard Frogs are common in the la Brisca area today
(UAZ 42422). Rana ""pipiens"" is common in many paleofaunas that range in age from
at least the Late Miocene to many southwestern Late Pleistocene faunas (Holman
1969a). The only previous fossil record in Mexico is from a Rancholabrean cave deposit
in Tamaulipas (Holman 1969c).

Class Reptilia— Reptiles

Order Testudines — Turtles

Family Emydidae— Pond Turtles

of. Terrapene— Box Turtle

Material.— L. peripheral.

Comments. —The fossil is the anterior half of the eighth or ninth left peripheral
that is similar to some of the robust Rancholabrean box turtles (e.g., Terrapene Carolina
putnami). The bone is very thick and flared, with a well-developed dorsal trough, or
"rain gutter." The fossil differs from T. ornata (Ornate Box Turtle) in its thickness and
in that the sulci for the marginal scutes are not angled.

Although robust T. Carolina have a rich late Pleistocene fossil record east of the
Continental Divide (Milstead 1967, 1969), the only fossil box turtles from farther west
are early Blancan (late Pliocene) Terrapene species (cf T. ornata) and Rancholabrean
T. ornata from Arizona (Moodie and Van Devender 1978). Terrapene ornata is found
from the Great Plains to southeastern Arizona and into north-central Sonora. Terrapene
nelsoni (Sonoran Spotted Box Turtle) is a Mexican species in the T. ornata group that
barely enters southern Sonora from the south in tropical deciduous forest (Milstead
and Tinkle 1967). Male T nelsoni can have flared peripherals. Rhinoclemmys pul-
cherrima (Central American Wood Turtle) is a terrestrial and semi-aquatic neotropical
emydid with a well-developed "rain gutter" that also enters southern Sonora.

Pseudemys scripta Schoepff'— Yaqui Slider

Material. —Nuchal (10156, cast; Fig. 8), neural, pleural fragments (8; 10143, 10420-
10421, 15445), peripherals (6; 10144, 11625), ilium, hyoplastron (15444).

Comments.— The la Brisca fossils are from a large emydine turtle and have the
strong ridging characteristic o^ Pseudemys scripta. The lateral edges of the first vertebral
scute are concave medially on the nuchal bone (Fig. 8). The anterolateral comers of
this scute contact the lateral edge of the nuchal bones; the comers are more often well
within the nuchal bone. We have not tried to refer the specimens to a modem or fossil
subspecies off. scripta, although the nuchal is not as thick and rugose as late Pleistocene
specimens from east of the Continental Divide. An adult P. scripta yaqiiia collected
from the Saracachi Cienega (Fig. 2) is fairly small for the species (210 mm carapace
length) and has a strongly flattened shell. Larger individuals, including an old melanistic
adult, have been observed in the cienega. The maximum adult size of this turtle is
larger and the shells are more domed in the Rio Yaqui and the Rio Mayo. The fossil
pleurals from Rancho la Brisca are from individuals of about 275 mm carapace length.
One specimen has a fairly uniform thickness of 4.7 mm and is relatively flat, suggesting
a flattened shell. Domed shells have pleurals that are more curved, and differentially
thickened medially at the articular surface with the vertebral bones. The pleurals are
somewhat thicker than modem shells of similar-sized individuals. The hyoplastron is
from a small juvenile with large unfused areas between the bones of the plastron.

Figure 8. Nuchal bone (UALP 101 56, cast) of Pseudemys scripta (Yaqui Slider).

Pseudemys scripta is a common fossil in deposits of Pliocene to late Pleistocene
age in the eastern and central United States. The la Brisca specimen is the first Ran-
cholabrean record west of the Continental Divide. Lindsay (1984) reported Chrysemys
{=Pseudemys) from Irvingtonian deposits at El Golfo, Sonora, at the mouth of the
Colorado River (C. A. Shaw, personal communication 1985). Presently, P. scripta is a
sporadic inhabitant of the rivers of Sonora as far north as the Rio Bavispe drainage
(UAZ 39965) in northeastern Sonora.

Family Kinostemidae— Mud Turtles
Kinosternon flavescens Agassiz— Yellow Mud Turtle

Material. — Hypoplastron.

Comments.— The fossil Kinosternon material from la Brisca was identified by John
B. Iverson, Earlham College. A single hypoplastron was referred to K. flavescens rather
than to K. sonoriense because the sulcus for the femoral scute is parallel to the posterior
margin.

Fossils of Kinosternon flavescens have been reported from late Hemphillian and
Blancan deposits in Nebraska (Holman 1972), Kansas (Fichter 1 969), and Texas (Rogers
1976). Kinosternon arizonense, described by Gilmore (1922) from the Blancan Benson
Fauna, Cochise County, Arizona, is now considered a subspecies of K. flavescens (Iver-
son 1919a). Kinosternon flavescens was in the Folsom cultural levels at the Lubbock
Lake Site, Lubbock County, Texas, at about 1 1 000 to 10 000 years ago (Johnson 1974).
The la Brisca specimen is the only Rancholabrean record from west of the Continental
Divide and Mexico.

Kinosternon flavescens presently ranges from Illinois south into northeastern Mex-
ico and southwest to Arizona and Sonora. K. f. arizonense is locally common in a
number of areas between Caborca and Hermosillo (J. Iverson, personal communication
1982). It has not been collected near la Brisca.

Kinosternon sonoriense LeConte— Sonoran Mud Turtle

Ma/ma/. -Cervical vertebra (10422), nuchals (2; 10428), neurals(4; 10145, 10429),
pygal (10423), 8th and 9th right peripherals (10424-10425), epiplastral fragments (12;

Figure 9. Left and right hypoplastra (UALP 10147) of Kinosternon sonoriense (Sonoran Mud Turtle).

10146, 10426), hyoplastra(8; 10147, 10427, 1 1 137), hypoplastra (10148, 11138; Fig.
9), xiphiplastra (10149).

Kinosternon species— Mud Turtle

Material— T>QnX2ivy, humeri (2), femora (3), ilium, ischia (3), neurals (5), supra-
pygal, pleural fragments (71; 15435, 15439-15440), peripherals (61; 15441-15443),
epiplastra (3), hyoplastra (10; 15437), hypoplastra (7), xiphiplastra (2; 15436).

Comments. —Most of the Kinosternon specimens identified to species are referred
to K. sonoriense. The sutures on the right eighth peripheral bone show that the ninth
marginal scute is not raised as in K. flavescens. The most common fossils at the la
Brisca site are Kinosternon species; most of these are probably from K. sonoriense.

Kinosternon sonoriense is a common aquatic turtle in southern Arizona, Chihua-
hua, and northern Sonora (Iverson 1976); it is replaced by K. alamosae and K. integrum
(Alamos and Sinaloan Mud Turtles) in southern Sonora. Numerous specimens have
been collected from Sonora, including one from 5 km below Cucurpe in the Rio San
Miguel (UAZ 36509), and a series from the Saracachi Cienega (TRV 2716; Fig. 2). It
occurs in the stream below the la Brisca site today. Kinosternon sonoriense has no
previous fossil record.

Order Squamata— Lizards and Snakes

Suborder Sauria— Lizards

Family Iquanidae— Iguanid Lizards

cf Callisaurus draconoides Blainville— Zebra-tailed Lizard

Material. —Anterior half of frontal.

Comments. —This incomplete specimen resembles Callisaurus draconoides in (1)
size; (2) the deeply excavated ventral surface; (3) the ventrolateral edges having heavy
angular surfaces; (4) the relatively narrow anterior end and a relatively broad interorbital
width. Sceloporus (several species) and Holbrookia texana (Greater Earless Lizard) are
broader to the anterior. The ventral surface of the frontal is relatively shallowly ex-
cavated in Sceloporus and Holbrookia maculata (Lesser Earless Lizard). The interorbital
portion of the frontal in H. maculata is very thin. The only previous fossil record for
Callisaurus draconoides is from Late Wisconsin/Early Holocene deposits in Deadman
Cave, Santa Catalina Mountains, Pima County, Arizona (Mead et al. 1984). This
cursorial lizard is a Sonoran Desert species most often found in desertscrub and thorn-
scrub habitats. In the la Brisca area, it follows sandy washes up into oak woodland.

Sceloporus cf. clarkii Baird and Girard— Clark's Spiny Lizard

Material. — Dentary, parietal, jugal.

Comments. —The dentary is from a large lizard in the Sceloporus spinosus group
based on (1) size; (2) tricuspid tooth crowns; (3) transversely expanded tooth bases; (4)
Meckel's canal closed, but not fused; (5) dentary relatively deep below Meckel's canal.
The teeth are more slender than 5. magister (Desert Spiny Lizard) and relatively larger
than the large subspecies of S. undulatus elongatus (Northern Plateau Lizard), or S.
occidentalis (Western Fence Lizard). The parietal and jugal also compare well with S.
clarkii, but are less diagnostic. Sceloporus cf. clarkii was reported from Late Wisconsin/
Early Holocene deposits in Deadman Cave, Santa Catalina Mountains, Pima County,
Arizona (Mead et al. 1 984). Sceloporus clarkii lives in habitats ranging from subtropical
thomscrub in Sinaloa and southern Sonora to oak woodland in the Sierra Madre and
in southern Arizona. It occurs today near the fossil site.

Suborder Serpentes— Snakes

Family Colubridae— Colubrid Snakes

Hypsiglena torquata (Giinther)— Night Snake

Material. —Vertebra.

Comments.— This small colubrid was identified as Hypsiglena torquata on the
following characters: (1) small size; (2) condyle and cotyle small and round; (3) neural
spine moderately high; (4) accessory processes short, pointed, and oriented anteriorly;
(5) relatively short vertebrae, and zygosphene curved down from the anterior. Sonora
semiannualata (Ground Snake) and Chionactis occipitalis (Banded Sand Snake) have
lower neural spines and more elongate vertebrae. Chilomeniscus cinctus (Shovel-nosed
Snake) has longer accessory processes that are more perpendicular to the long axis of
the vertebrae. Hypsiglena torquata was common in late Pleistocene and Holocene
sediments in Howell's Ridge Cave, southwestern New Mexico (Van Devender and
Worthington 1977). Hypsiglena torquata was reported from the Late Wisconsin/Early
Holocene deposits in Deadman Cave, Pima County, Arizona (Mead et al. 1984). It has
been found in eight packrat middens of Late Wisconsin and Early Holocene age from
the Grand Canyon south into the Sonoran Desert in Arizona and California (Van
Devender, Phillips, and Mead 1977; Van Devender and Mead 1978; Mead and Phillips
1981). Hypsiglena torquata is widely distibuted in habitats ranging from woods and
desertscrub to pine forests (Van Devender and Lowe 1977).

Masticophis cf. mentovarius (Dumeril, Bibron and Dumeril)— Tropical Whipsnake

Material. -Middorsal vertebrae (20; 10152, 10430, 11139; Fig. 10), cervical ver-
tebrae (5; 11634).

Comments. —Most of these vertebrae are from a very large colubrid snake; e.g.,
centrum lengths of 7.0-8.3 mm (x = 8.0 mm, « = 16) for mid-dorsal vertebrae (Fig.
10) and 6.4-6.7 mm (x = 6.5 mm, n = 4) for cervical vertebrae. Sonoran colubrids
reaching this size include Drymarchon corais (Indigo Snake), Masticophis (several
species), and Pituophis melanoleucus (Bullsnake). Spilotes pullatus (Tropical Ratsnake)
is a large colubrid that occurs farther south in Mexico. The la Brisca fossils differ from
those of Pituophis melanoleucus and Spilotes pullatus in being more elongate and the
cotyle and condyle are round and much smaller. The average centrum length/neural
arch width (cl/naw) ratio for the large la Brisca vertebrae is 1.24 (range 1.21-2.32, n =
15) for mid-dorsal vertebrae. A small vertebrae (cl = 6.36 mm) has a cl/naw ratio of
1.41. This is the upper range for Drymarchon corais (Auffenberg 1963) and within the
range o^ Masticophis. A sample of 20 middorsal vertebrae averaged 1.49 (range 1.45-
1.53) in a M.flagellum (Red Racer, Coachwhip) of 1076 mm SVL (TRV 433: Mexico:
Sonora: 4.3 km E Navojoa) and 1 .30 (range 1 .23-1 .42) in a specimen of M mentovarius
(Tropical Whipsnake) of 1 570 mm SVL (TRV 1735: Costa Rica: Guanacaste Province).
The la Brisca specimens are referred to Masticophis rather than Drymarchon corais

^^■44^v

Figure 10. Vertebra (dorsal view) of Masticophis cf. mentovarius (Tropical Whipsnake).

because: (1) the neural spine is much lower and longer and lacks the bevelled anterior
edge (ibid); (2) the accessory processes are longer and oblique to the anterior as viewed
from above (they are lateral in D. corais); (3) the cotyle and condyle are round and
relatively smaller. The la Brisca specimens are from a snake of about 1500 mm SVL,
which is close to the maximum sizes for several species of Masticophis {M. flagellum,
M. bilineatus, and M. taeniatus; Wilson 1970). Masticophis mentovarius reaches 1886
mm SVL (Johnson 1977, 1982). Although the record size for the northern subspecies
M. m. stholatus is only 1 120 mm SVL (Johnson 1977), animals of at least 1600-1700
mm SVL have been observed in Sonora (H. Lawlor, personal communication). The
vertebrae most closely resemble a large M. mentovarius.

Although vertebrae o{ Masticophis and Coluber are common late Pleistocene fossils
(Auffenberg 1963, Brattstrom 1954, 1958, Hill 1971, Holman 1969a, Van Devender
and Mead 1978), the only previous fossil record for M. mentovarius is from Holocene
Cave deposits in Yucatan, Mexico (Langebartel 1953).

Masticophis flagellum and M. bilineatus (Sonoran Whipsnake) probably live at la
Brisca today. Masticophis m. striolatus has been collected at Santa Ana de Yecora,
Sonora (UAZ 40078; 270 km SSE la Brisca) and has been observed on the Rio Yaqui
east of Hermosillo (240 km SSE la Brisca).

Salvadora species— Patch-nosed Snake

Material. —Vertebra.

Comments.— The elongate, medium-sized vertebra is from Salvadora. The con-
dyle, cotyle, and neural canal are relatively smaller than in similar-sized Masticophis
or Coluber, but larger than in Opheodrys (Green Snake), which also has somewhat
longer accessory processes. The vertebrae of Salvadora hexalepsis (Desert Patch-nosed
Snake) and S. grahamiae (Mountain Patch-nosed Snake) are very similar. Late Wis-
consin and Holocene fossils of Salvadora species are known from Dry Cave, Eddy
County (Holman 1970) and Howell's Ridge Cave, Grant County (Van Devender and
Worthington 1977), New Mexico, and Deadman Cave, Pima County, Arizona (Mead
et al. 1984). Patch-nosed Snakes live in many habitats from desertscrub to Mexican
pine-oak woodland. Salvadora hexalepsis probably lives near la Brisca today.

Thamnophis cf. cyrtopsis (Kennicott)— Black-necked Gartersnake

Material. —Vertebrae (2; 11141).

Comments. —The small natricine vertebrae are from a species of Thamnophis, and
came from individuals with SVLs of about 350 mm and 570 mm. The vertebrae (and

often the external morphology) of T. cyrtopsis and T. eques (Mexican Gartersnake) are
very similar, and apparently differ only in a more slender hypopophysis in T. cyrtopsis.
Thamnophis marcianus (Checkered Gartersnake) has shorter vertebrae, shorter acces-
sory processes, and broad hypopophyses. Both vertebrae compared best with T. cyr-
topsis. Thamnophis cyrtopsis is a snake of rocky canyons from the upper edge of the
desertscrub into pine forest in the Sierra Madre and southern Arizona. It is common
in the la Brisca area today (UAZ 42359). The only previous fossil record for T. cyrtopsis
is from Late Wisconsin and Early Holocene deposits in Howell's Ridge Cave, Hidalgo
County, New Mexico (Van Devender and Worthington 1977).

Family Crotalidae— Rattlesnakes
Crotalus atrox Baird and Girard— Western Diamondback Rattlesnake

Material. —Vertebrae (2; 1 1 140), centrum.

Comments.— 'WiQ vertebrae are from a very large rattlesnake with (1) a broad
zygosphene; (2) very large cotyle and condyle; (3) a high neural arch as viewed anteriorly.
Measurements of the largest vertebra are cl = 7.33 mm, naw = 8.64 mm, cl/naw =
0.85. Crotalus basiliscus (Mexican Green Rattlesnake) has a narrower zygosphene,
whereas C. molossus (Black-tailed Rattlesnake) has a flattened neural arch.

Late Wisconsin records for Crotalus atrox are from Friesenhahn and Miller's
Caves, central Texas (Holman \969a), and Dry Cave, southeastern New Mexico (Hol-
man 1970). Crotalus atrox was reported from Late Wisconsin/Early Holocene deposits
in Deadman Cave, Pima County, Arizona (Mead et al. 1984). It was found in an Early
Holocene packrat midden dated at 10 330 ± 330 B.P. in the Whipple Mountains,
southeastern California (Van Devender and Mead 1978). Crotalus atrox is widespread
in many habitats below woodland and forest from the Texas Gulf Coast west to south-
eastern California and south into Mexico. Crotalus molossus is the common rattlesnake
at la Brisca today, although C. atrox is probably not far away in more xeric habitats.

Class Aves— Birds

Order Anseriformes— Water Fowl

Family Anatidae— Ducks

Anas cf crecca Linnaeus— Green- winged Teal

Material. — Coracoid, missing the proximal head.

Comments. —On the basis of its very small size, the coracoid seems best referred
to the widespread small Green-winged Teal. Anas carolinensis is now considered to be
conspecific with the Old World A. crecca. The only previous record for the Pleistocene
of Mexico is from Jiminez Cave, Chihuahua (Brodkorb 1 964, Messing in press).

Order Falconiformes— Eagles, Hawks, and Vultures

Family Accipitridae— Hawks, Kites, Harriers, and Eagles

cf Spizaetos — Hawk-eagle

Material. —Distal half of metacarpal 2, lacking articular surface.

Comments. —This specimen was identified by R. McKenzie as being near the
Rancholabrean Spizaetos grinnelli (GvinnQVs Hawk-eagle), but somewhat smaller. Wing
elements of the two living New World tropical species (S. ornatus and S. tyrannus)
were not available for comparison. Spizaetos grinnelli has been reported from Carpin-
teria and Rancho la Brea in California, and San Josecito Cave in Nuevo Leon, Mexico
(Brodkorb 1964).

tSpecies indeterminate

Material. —Right digit 2, phalanx 2.

Comments. —The fossil is the size of an eagle (Aquila), but has some characters
different from that genus. A reference specimen of Haliaeetus leucocephalus (Bald Eagle)
was not available for comparison. It does not resemble Cathartes (Cathartid Vultures)
or Mycteria (Storks), which Ligon (1967) has shown to be more closely related to each

20i

- mm

Figure 1 1 . Owl left tarsometatarsi, dorsal aspect: modem Strix nebulosa (Great Gray Owl) on left; Rancho
la Brisca S. brea in center; holotype of Strix brea (La Brea Owl) from Rancho la Brea (LACM E9379) on
right.

Other than to true falconiforms. In the Pleistocene of North America there were nu-
merous eagles and eagle-like vultures (Howard 1932), but their distal-most wing ele-
ments are undescribed.

Order Galliformes— Gallinaceous Birds

Family Phasianidae— Pheasants, Quails, etc.

Meleagris gallopavo Linnaeus— Common Turkey

Material. —Distal end of ulna.

Comments. —The fossil was included as a female M. gallopavo in Rea's (1980)
summary of late Pleistocene and Holocene turkeys in the Southwest. The only other
late Pleistocene record of M. gallopavo from west of the Continental Divide is from
Arizpe, ca. 25 km SE of la Brisca. The extinct M. crassipes was widespread in the late
Quaternary of the Southwest. Historically, M. gallopavo probably lived near la Brisca,
although M. g. merriami (Merriam's Turkey) in Arizona and New Mexico appears to
represent feral introductions from prehistoric domestic animals (Rea 1980).

Order Strigiformes— Owls

Family Strigidae — Typical Owls

'\ Strix brea Howard— La Brea Owl

Material. —Left tarsometatarsus missing proximal end (10157, cast; Fig. 1 1).

Comments.— The tarsometatarsus is from an owl the size of a male Bubo virgi-
nianus (Great-homed Owl). Strix is distinguished from Bubo by ( 1 ) more parallel lateral
edges of the shaft; (2) the distal calcaneal ridge not converging with the internal ridge
of the shaft. The extinct Strix brea is distinguished from the living species S. nebulosa,
S. occidentalis, and S. varia by a more prominent tubercle for the attachment of the
M. tibialis anticus being placed higher on the shaft (see Howard 1933). The la Brisca
specimen was compared directly with the type and type series (n = 9) of S. brea at
LACM (Fig. 11). The living S. nebulosa (Great Gray Owl) of northern hemisphere
boreal forests has a shorter, stouter tarsometatarsus. Measurements of the la Brisca
fossil are: proximal end of trochlea for digit 3 to distal end of tubercle for M. tibialis

amicus = 37.9 mm; width across trochlea = 15.99 mm. Strix brea has been found
previously only in California at the Rancho la Brea (ibid.) and Carpinteria (R. Mc-
Kenzie, personal communication 1978) asphalt deposits.

Order Passeriformes— Perching Birds
Family Fringillidae, Emberizinae— New World Sparrows, Finches, etc.

Genus and species indeterminate

Material. —Right coracoid missing base (1 1 142).

Comments. —The coracoid is indistinguishable from Junco Ouncos) and Zono-
trichia (sparrows). Elsewhere, an indeterminant Emberizinae was reported from the
Late Wisconsin/Early Holocene deposits in Deadman Cave, Pima County, Arizona
(Mead et al. 1984). Several species in these genera occur in the la Brisca area as winter
migrants.

Family Icteridae— Meadowlarks, Blackbirds, Orioles
Agelaius phoeniceus Linnaeus— Red- winged Blackbird

Material. —Right humerus missing head and ectepicondylar process (11161, cast).

Comments. —The specimen was compared with Sturnella (Meadowlarks, 2 species),
Dolichonyx oryzivorus (Bobolink), Xanthocephalus xanthocephalus (Yellow-headed
Blackbird), Euphagus (Blackbirds, 2 species), Molothrus (Cowbirds, 3 species), Quis-
calus (Crackles, 2 species). Icterus (Orioles, 2 species), Cassiculus (Mexican Cacique),
Cacicus (Cacique), and Cardinalis cardinalis (Cardinal). This species is well-represented
in late Pleistocene sites (Brodkorb 1978), and occurs today in stream and cienega
habitats in the la Brisca area.

Class Mammalia— Mammals

Order Camivora— Carnivores

Family Procyonidae— Raccoons, Coatis and Ringtails

Bassaricus species— Ringtail

Material.— KV.

Comments. —The tooth is a premolariform incisor which closely resembles that
of the extant Bassariscus astutus in having the crown offset with the root to the
posterior, and the internal face spathulate. In Urocyon and Vulpes, the tooth is more
caniniform and not spathulate medially. The incisor of Must el a is similar, but blunter,
less spathulate, and with the crown centered over the root.

Bassariscus sonoitensis is an extinct Wisconsin Ringtail known only from Papago
Spring Cave, Arizona, and San Josecito Cave, Nuevo Leon, northeastern Mexico;
Bassariscus astutus is known from 1 4 Late Wisconsinin faunas from California, Nevada,
New Mexico, and Texas (Kurten and Anderson 1980). Several additional records from
Late Wisconsin/Early Holocene cave deposits in the Grand Canyon and Santa Catalina
Mountains of Arizona have been reported (Mead 1981, Mead et al. 1984).

Order Artiodactyla— Even-toed Ungulates

Family Camelidae— Camels and Llamas

"fCamelops species— Camel

Ma/er/a/.— Navicular (10153, cast; Fig. 12).

Comments. —The navicular is not fused with the cuboid and is from a large animal
(Fig. 1 1). The bone does not resemble those of Bison, Equus, or any of the large cervids.
The specimen is very similar to the navicular of a modem Camelus dromedarius
(Dromedary) from Pakistan. It appears to be close to Camelops hesternus (Yesterday's
Camel) in size, and larger than the extinct llamas (Hemiauchenia and Paleolama).
Camelops species was reported from Irvingtonian deposits at El Golfo, Sonora (Lindsay
1984). Camelops species is known from a number of Rancholabrean localities in Ar-
izona (Lindsay and Tessman 1974). Camelops hesternus was the common, widespread

0 20
I 1 1

Figure 12. Navicular of Camelops species (UALP 10153, cast).

camel in the late Pleistocene of the western United States. It has been reported from
several localities in Arizona, including a packrat midden dated at 13 820 ± 220 B.P.
from Vulture Cave in the western Grand Canyon (Mead and Phillips 1981).

Family Cervidae— Deer
Odocoileus hemionus Rafinesque— Mule Deer

Material. —Left antler (10444, cast; anterior half of RM, or RM2).

Comments.— This antler is referred to Odocoileus hemionus rather than O. vir-
ginianus (White-tailed Deer) because: (1) the shaft is only moderately curved anteriorly
and laterally; (2) the two tines at the first main fork are not greatly different in size
(anterior tine = 17.4 x 14.7 mm, posterior tine = 23.4 x 18.3 mm). The basal bur is
thickest to the anterior (37.3 x 32.1 mm). A small medial tine (38.0 mm long, 16.0 x
9.1 mm cross-section) is 37.4 mm above the bur. The base of the main fork is 134
mm above the bur. The antler is broken just above the main fork. The shaft below the
fork is flattened (17.8 x 16.6 mm). The shaft above the fork is also flattened, but may
be crushed. The molar fragment could be from O. hemionus as well.

Odocoileus is first recorded in North America and Arizona in the Blancan Land
Mammal Age (Lindsay and Tessman 1974). Odocoileus species was reported from
Irvingtonian deposits at El Golfo, Sonora (Lindsay 1984). Odocoileus hemionus has
been reported from 1 5 Irvingtonian and Rancholabrean sites from Arkansas to British
Columbia and California (Kurten and Anderson 1980). This is the first Pleistocene
record for Mule Deer from Mexico. Odocoileus virginianus presently lives in the la
Brisca area, while O. hemionus occurs at lower elevations to the south and west.

Family Antilocapridae— Pronghom Antelope
Capromeryx cf. minor Taylor— La Brea Pronghorn

Material. —hY*^ (15446, cast).

Comments.— Th\s tiny molariform premolar is similar in size to Capromeryx
minor {= Breameryx minor, Kurten and Anderson 1980) based on comparisons with
material in the LACM collections by George T. Jefferson. Capromeryx minor stood
only 560 mm at the shoulder and weighed about 1 0 kg. Previous Rancholabrean records
for C. minor arc from Ingleside on the Texas Gulf Coast, Blackwater Draw, New Mexico,

1-20

Figure 13. Molar of Bison species (UALP 10154, cast).

and McKittrick, Rancho La Brea, and Schuiling Cave, California (ibid.). Capromeryx
mexicana (Mexican Pronghom) from the late Pleistocene of the Mexican Plateau was
about the same size as C. minor. The only record of the genus for Arizona is Capromeryx
gidleyi from the Irvingtonian Curtis Ranch fauna in the San Pedro Valley, Cochise
County (Lindsay and Tessman 1974, Johnson et al. 1975).

^Tetrameryx species— Four-homed Antelope

Material. — LM' (1 1 162, cast).

Comments.— Tht molar fragment was compared to the LACM collections by
McKenzie and Jefferson and referred to Tetrameryx species on size and morphology.
The fossil is from an animal smaller than Oreamnos (Mountain Goat), Ovis canadensis
(Bighorn Sheep), and Odocoileus (Deer), but larger than Antilocapra americana (Prong-
hom), Stockoceros, and Capromeryx (extinct pronghoms). The enamel pattern of the
fossil was similar to that of the antilocaprids, but not to the other artiodactyls examined.
Tetrameryx has five Irvingtonian and Rancholabrean species known from Texas or
central Mexico (Kurten and Anderson 1980). Tetrameryx species was reported from
Irvingtonian deposits at El Golfo, Sonora (Lindsay 1984), and from Rancholabrean
deposits at Tule Springs, Nevada (Mawby 1967).

Family Bovidae— Bovids
"f Bison species— Bison

Material. —Lower molars (2, R, LM; or M2; 10154, cast; Fig. 13), ungual phalanx.

Comments. —These teeth are from a large Bison, but species determination is not
possible. Fossil Bison have been reported from a number of Rancholabrean sites in
Arizona including Papago Springs and Ventana Caves (Lindsay and Tessman 1974).
This is the first published report of Bison for Sonora, although it has been collected
from several other sites (R. S. White, personal communication).

Order Perissodactyla— Odd-toed Ungulates

Family Equidae — Horses

fEguus cf. tau Owen — Pygmy Onager

Material.— LV'~, LM'°^- (15447, cast), lower molar fragment (10155, cast),
RP3or4 (15447, cast), lower molar fragment, second phalanx, thoracic vertebra.

Comments. —These remains are from a very small species of horse. The upper
molar is worn nearly to the roots and was from a very old individual. The tooth is
shorter on the anterior-posterior axis than the transverse axis (21.3 x 25.4 mm). Equus
tau is characterized by a very short tooth row that was usually less than 1 20 mm in
length (Kurten and Anderson 1980). Measurements for the lower premolar from la
Brisca are 29.6 mm x 16.2 mm. Most of the la Brisca fossils could be from E. tau.
although some of them could be from the slightly larger E. conversidens (Mexican
Horse).

Equus tau was the smallest species of New World onagers, or stilt-legged horses
(subgenus Hemionus), as well as the smallest American Equus (ibid.). It is known from
Irvingtonian and Rancholabrean deposits from the Valley of Mexico to Oklahoma,
Florida, Texas, and Arizona (ibid.). Equus cf. conversidens was reported from Irving-
tonian deposits at El Golfo, Sonora (Lindsay 1984). Both E. tau and E. conversidens
were reported from Rancholabrean deposits in Papago Springs Cave, south-central
Arizona (Skinner 1942).

f Equus species— Horse

Material.— R. femur.

Comments. —The femur is apparently from an immature individual of a large
horse because it is similar in size to the femur of an adult E. asinus (Burro), but the
epiphyses on both ends are not fused. Remains of large horses have been reported in
a number of Rancholabrean deposits in Arizona (Lindsay and Tessman 1974). Equus
occidentalis (Western Horse) was common in the latest Rancholabrean deposits in
Ventana Cave on the Papago Indian Reservation, southwestern Arizona (Haury 1975).

Order Proboscidea— Elephants, Mastodons, Gomphotheres

Family Elephantidae— Mammoths and Elephants

fMammuthus species— Mammoth

Material.— R. pisiform, thoracic vertebra.

Comments. —The vertebra is identified as Mammuthus species on the basis of its
large size and its rounded, rather than sub-triangular shape as in Mammut. The pisiform
has the more elongate shape of Mammuthus (Olsen 1972). Additional proboscidean
remains not identifiable to genus include tusk and skull fragments, a fragment of a
humerus, and several partial ribs. Mammuthus remains have been reported from many
sites in Arizona (Saunders 1970) and are known from over 25 unpublished localities
in Sonora (R. S. White, personal communication 1975). Mammuthus imperator (Im-
perial Mammoth) was reported from Irvingtonian deposits at El Golfo, Sonora (Lindsay
1984). Mammuthus sonorensis (Sonoran Mammoth) was described from Irvingtonian
or Rancholabrean deposits from Arizpe, Sonora (Lindsay 1984), but has been consid-
ered a synonym of M. columbi (Columbian Mammoth; Kurten and Anderson 1980).
Mammuthus columbi was the common Rancholabrean elephant of the southwestern
United States, although there is some question of its distinctness from M. jeffersoni
(Jefferson's Mammoth; Kurten and Anderson 1980).

Order Rodentia— Rodents

Family Heteromyidae— Kangaroo Rats and Pocket Mice

Dipodomys species— Kangaroo Rat

Material. — LM2.

Comments. —The tooth is from a species of Dipodomys in the size range of D.
merriami (Merriam's Kangaroo Rat) and D. ordi (Ord's Kangaroo Rat). Teeth of Kan-

garoo rats are common in fossil packrat middens from the Mohave Desert (Van De-
vender et al. 1977). Dipodomys species and D. merriami were identified from three
Late Wisconsin and six Early Holocene packrat middens from the Sonoran Desert in
southwestern Arizona and adjacent California (Mead et al. 1983). Dipodomys species
and Dipodomys cf. ordi have been identified in Late Wisconsin sediments from Smith
Creek Cave, Snake Range, eastern Nevada (Mead et al. 1982). Dipodomys merriami
and D. ordi are widespread in desertscrub and desert-grassland habitats and probably
occur near la Brisca today.

Family Cricetidae— Mice, Rats, Lemmings, and Voles
Neotoma species— Packrat

Material. — LM2.

Comments. —This tooth is referred to Neotoma by being relatively large and high-
crowned among rodents. The lophs are rounded (as in A^. albigula, N. lepida, N. mi-
cropus) and not prismatic (as in A", cinerea, N. mexicana, N. stephensi; Harris 1984).
Neotoma albigula (White-throated Packrat) was reported from Late Wisconsin/Early
Holocene deposits in Deadman Cave, Pima County, Arizona (Mead et al. 1984). Teeth
of Neotoma are common late Pleistocene fossils in ancient packrat middens in Arizona
and California (Van Devender et al. 1977; Mead et al. 1983). Packrats live in virtually
all habitats from desertscrub at sea level to montane boreal forests over 3000 m ele-
vation. Neotoma albigula presently lives at la Brisca.

Onychomys species— Grasshopper Mouse

Material— KM ^.

Comments. —The teeth of Onychomys can be separated from those of similar-
sized Peromyscus (Deer Mouse) because they are higher crowned with more prominent
cusps. Onychomys cf. leucogastor was in the Rancholabrean fauna from Papago Springs
Cave, Santa Cruz County, Arizona (Skinner 1942). Onychomys species has been found
in two Late Wisconsin packrat middens from Arizona: Wolcott Peak #5, Pima County,
dated at 12 130 ± 500 B.P., and Brass Cap Point #1, Yuma County, dated at 1 1 450 ±
400 B.P. (Mead et al. 1983). Two species of Grasshopper Mice {O. leucogastor and O.
torridus) are widespread in grassland, desert-grassland and desertscrub habitats in the
southwestern United States and northern Mexico. Both species live near the fossil site
today.

Sigmodon species— Cotton Rat

Material. -Maxilla with RM'-^ RM' (1 1 144), LM' (1 1 143), dentary with RMi_3.

Comments.— ThQSQ specimens are from a medium-sized cricetid rodent and are
referred to the genus Sigmodon because of the distinctive tooth morphology. Sigmodon
hispidus (Hispid Cotton Rat), S". ochrognathus (Yellow-nosed Cotton Rat), and S.
minimus (Red-bellied Cotton Rat) are present in southern Arizona and northern Sonora
today. Sigmodon hispidus is now considered to be three species: S. hispidus, S. mas-
cotensis, and S. arizonae based on different numbers of chromosomes (Zimmerman
1970); the form in northern Sonora is S. arizonae.

Sigmodon species was reported in Arizona from the late Pleistocene Rancholabrean
Murray Springs Arroyo Fauna, Cochise County (Lindsay and Tessman 1974), from
the Late Wisconsin/Early Holocene Deadman Cave, Pima County (Mead et al. 1984),
and in the Early Holocene Wellton Hills #2 packrat midden, Yuma County (Mead,
et al. 1983). Sigmodon ochrognathus and Sigmodon species were found in Wolcott
Peak #2 packrat midden, a mixed Middle Holocene and Late Wisconsin sample from
Pima County, Arizona (Mead et al. 1983).

Table 1. Vertebrates of the Rancho la Brisca local fauna (Late Pleistocene: Rancholabrean Land Mammal
Age; Sangamon Interglacial) of Sonora, Mexico, t = Extinct.

Fish

Castostomus wigginsi—OpaXa Sucker
Agosia chrysogaster—Longfin Dace
Indeterminate cyprinid
Poeciliopsis occidentalis— Gila Topminnow
Poeciliopsis monacha-occidentalis—A\\-{emale
Topminnow

Amphibians

Bufo alvarius—ColoaTdo River Toad
Bufo cf cognatus— Great Plains Toad
Bufo cf kelloggi—LiXl\e Mexican Toad
Bufo mazatlanensis —SinaXoa Toad
Bufo punctatus—Red-spolted Toad
Bufo species— Toad
Hyla arenicolor— Canyon Treefrog
Hyla species— Treefrog
Pternohyla fodiens— Burrowing Treefrog
Hylactophryne august i—BarVing Frog
Leptodactylus melanonotus—Sahinal Frog
Gastrophtyne cf. olivacea—GvtaX Plains Narrow-
mouth Toad
Scaphiopus cowc/zz— Couch's Spadefoot Toad
Scophiopus species— Spadefoot Toad
Rana ""pipiens'" Complex — Leopard Frog

Reptiles

tcf Terrapene— Box Turtle
Pseudemys scripta—Yaqui Slider
Kinosternon flavescens—YeWov/ Mud Turtle
Kinosternon sonoriense—Sonoran Mud Turtle
cf Callisaurus draconoldes—Zebra-\ai\ed Lizard
Sceloporus cf c/arA:// — Clark's Spiny Lizard
Hypsiglena torquata—NighX Snake
Masticophis cf. mentovarius— Tropical Whipsnake
Salvadora species— Patch-nosed Snake
Thamnophis cf c.vr/op5/5— Black-necked Garter-
snake
Crotalus a/rox— Western Diamondback Rattlesnake

Birds

Anas cf cr^'cca- Green-winged Teal

fcf Spizaetos—WavjlL-eaglc
Indeterminate falconiform— ?Eagle
Meleagris gallopavo— Common Turkey

fStrix hrea—La Brea Owl
Indeterminate Emberizinae— Junco or Sparrow
Agelaius phoeniceus—Kcd-V<ingQd Blackbird

Mammals

Bassariscus species— Ringtail
fCamelops species— Camel

Odocoileus hemionus— Mule Deer
"fCapromeryx c{. minor— La Brea Pronghom
fTetrameryx species— Four-homed Antelope
^ Bison species— Bison
fEquus cf tau— Pygmy Onager
fEquus species— Horse
^Mammuthus species— Mammoth

Dipodomys species— Kangaroo Rat

Neotoma species— Packrat

Onychomys species— Grasshopper Mouse

Sigmodon species— Cotton Rat

Faunal Analysis

A total of 493 bones representing 51 taxa of vertebrates from 29 families are
identified from the Rancho la Brisca local fauna. The fauna includes fishes (5), anurans
(12), reptiles (11), birds (7), and mammals (13). The fish, amphibians, and reptiles
represent 60.8% of the species and 92.9% of the identified specimens, while birds were
13.7% and 1.8%, and mammals were 25.5% and 5.3%, respectively. These percentages
are unusually low for mammals in late Pleistocene sites, but may be explained by the
ancient sedimentary environment at la Brisca (see below).

Percentages of the total number of identified elements were used in the analyses
because minimum number of individuals (MNI) does not reflect the abundance of some
groups (e.g., snakes) very well, and it was not possible to compare fossils collected over
a six-year period and deposited regularly into the collection in Mexico City. Most bones
appear to represent separate individuals, with a few exceptions (e.g., the 20 vertebrae
from Masticophis cf. mentovarius).

The fauna is strongly biased toward medium- and small-sized animals (i.e., less
than 0.5 kg). The bones o^ Leptodactylus melanonotus, Gastrophryne cf olivacea, and
all of the fish are very small. There were only ten species of large animals, all except
the eagle and hawk-eagle being mammals. These bones represent 19.6% of the species,
but only 3.0% of the identified bones.

Nine (or ten, if the cf. Terrapene represents an extinct form) of the species (or
17.6-19.6% of the fauna) are extinct. Twenty bones from extinct animals account for
4.1% of the total. Warm blooded animals account for most of the extinction: birds,
28.6% of species and identified bones; mammals, 53.8% of species and 61.7% of iden-
tified bones. By contrast, 2.6% of the species and 1.0% of the bones of cold blooded
animals are from extinct animals. None of the fish or amphibians, and perhaps only
cf Terrapene among the reptiles, were affected by the extinction at the end of the Late
Wisconsin about 1 1 000 years ago (Martin 1973).

There is a strong bias in the fauna towards aquatic animals: 10 (19.6%) species
and 69.9% of the identified bones. Besides fishes these include Hyla arenicolor, Lep-
todactylus melanonotus, Rana "p/p/^«5 "-complex, Pseudemys scripta, Kinosternon fla-
vescens, K. sonoriense, Thamnophis cf cyrtopsis, and Anas cf crecca. The remainder
of the anurans and the Red- winged Blackbird are considered semiaquatic because some
period of their life history is associated with water. Mud Turtles and Leopard Frogs
dominate the fauna, with 55.9% of the identified bones. The totals for the aquatic and
semiaquatic animals combined are 49.0% of the species, and 87.2% of the identified
bones. The terrestrial animals in the fauna represent 5 1 .0% of the species, but only
12.8% of the bones.

Paleoen vironments

The Rancho la Brisca fauna is dominated by small, aquatic and semiaquatic an-
imals that are found in permanent stream or cienega habitats. At least locally, the water
was deep enough to support Pseudemys scripta. Catostomus wigginsi lives in stream
pools with moderate current. The most abundant species, Rana "'pipiens'" -complex
and Kinosternon sonoriense, also require fresh water. The association of the fauna and
the fine-grained clay matrix of the la Brisca sediments suggest that the fossils were
preserved in a well-developed cienega habitat (Hendrickson and Minckley 1984), sim-
ilar to the nearby Saracachi Cienega with its stream inlet, open pools, and marsh located
in the center of a relatively open stream valley (Fig. 2). The riparian gallery forest near
the inlet pools of the Rancho la Brisca paleocienega provided roosts for raptorial birds
whose pellets would have been a source for the bones of smaller vertebrates preserved
in the sediments. The permanent water probably attracted the large mammals and their
predators. Occasional floods probably account for the minor gravel component in the
otherwise fine-grained sediments. The la Brisca sediments, perched 15 m above the
modem streambed, indicate the former base level of the Rio Santo Domingo which
has incised into the soft indurated stream gravels subsequent to the deposition of the
la Brisca fauna.

Zoogeography

Many fishes of the Magdalena, Sonora, and Yaqui systems are closely related to
or conspecific with species in the Gila River of Arizona and New Mexico (Miller 1958,
Minckley 1973, Hendrickson et al. 1980). Catostomus bernardini of the Rio Yaqui is
allied to C. insignis of the Gila River. The distributions o{ Agosia and Poeciliopsis also
indicate former connections between the rivers of Sonora and southern Arizona and
New Mexico. Kinosternon sonoriense is common in most of the rivers of southeastern
Arizona, northwestern Chihuahua and Sonora, further suggesting stream connections
in the past.

By the late Pliocene, Kinosternon flavescens apparently reached the Gila River
drainage in southeastern Arizona from the central United States. The Blancan fossils
from the San Pedro River Valley were already differentiated into the Sonoran subspecies
K. f. arizonense by about three million years ago (Iverson 1979^). This turtle has
adapted its breeding activities to coincide with the intense summer rainy season rather
than spring rains. Today it is found from south-central Arizona on the Papago Indian
Reservation through central Sonora as far south as the Rio Yaqui south of Guaymas
(Iverson 1919 b, Seidel 1978). The western drainages occupied by K.f. arizonense drain

southward and are isolated from the Gila-Colorado system (including the San Pedro
River) to the north. The only permanent aquatic habitats in these areas are artificial
stock ponds. Kinosternon f. arizonense probably evolved in southeastern Arizona and
dispersed south into Sonora at a time when the San Pedro River and Sonoran systems
were connected. The present, isolated populations in Arizona probably dispersed from
Sonora during a warm, wet interstadial period, rather than directly from southeastern
Arizona.

Pseudemys scripta is a large aquatic turtle found from the southeastern United
States to western Texas, south to Central America, and up the western coast of Mexico
into central Sonora and southern Baja California. It has a rich fossil record east of the
Continental Divide, but has not been recorded in Pliocene or Pleistocene deposits in
Arizona, although it has now been found in Irvingtonian and Rancholabrean deposits
in Sonora. Apparently, P. scripta never dispersed from Mexico into Arizona, suggesting
that the connections between river systems were short-lived, shallow streams. Consid-
ering the fossil record of the cold-blooded groups represented, the past stream con-
nections probably began in the Late Pliocene providing multiple opportunities for
dispersals of some animals.

Paleoclimates and Age of Fauna

Five animals in the fauna {Bufo cf kelloggi, B. mazatlanensis, Leptodactylus mel-
anonotus, Pternohyla fodiens and Masticophis cf. mentovarius) no longer live in the la
Brisca area, but are present to the southwest and southeast in Sonoran desertscrub and
Sinaloan thomscrub communities. Bufo alvarius, cf. Callisaurus draconoides, and Sce-
loporus cf clarkii are other Sonoran elements in the fauna that live in desertscrub,
thomscrub, or oak woodland/desert-grassland communities which are found in the
Rancho la Brisca area today. Hylactophryne augusti is another animal that just reaches
Arizona, but is widespread in central and eastern Mexico. The area where most of the
species in the la Brisca fauna occur together today would be along the Rio Yaqui near
El Novillo east of Hermosillo (Figs. 1 and 14), about 240 km SSE of la Brisca.

The biota of the Sonoran Desert becomes more subtropical to the south and east
as the number of freezes per winter decreases, and the total annual precipitation and
the percentage of summer rainfall increase (Hastings and Turner 1965). The presence
of subtropical Sonoran animals suggests that the la Brisca fauna lived in a climate with
fewer winter freezes and substantially greater summer rainfall than occurs in the area
today.

Fossil packrat middens provide detailed chronologies of vegetation and climate
for the last 30 000 years for many desert areas in the southwestern United States (Van
Devender and Spaulding 1979). The general Middle and Late Wisconsin (35 000-1 1 000
B.P.) paleoclimatic reconstruction from the midden record for the area between 32-
36°N latitude includes mild winters with greatly increased rainfall and cool summers
with greatly decreased rainfall. There was little summer rainfall in the present Sonoran
Desert in western Arizona. A Middle Wisconsin packrat midden from west of Her-
mosillo, Sonora, recorded the expansion of some woodland trees into low areas in
central Sonora during the last glacial period (Wells and Hunziker 1976). The la Brisca
fauna, however, is more likely to reflect a thermal maximum during an interglacial
with increased summer monsoons and an expansion of subtropical communities into
north-central Sonora. The climate of the Late Holocene (4000 B.P.-present) was prob-
ably similar to the paleoclimate of the la Brisca fauna.

The Rancholabrean Land Mammal Age began at the end of the Yarmouthian
Interglacial and the beginning of the Illinoian Glacial. Previously, an interstadial Ran-
cholabrean fauna like that of la Brisca would have been placed in the Sangamon
interglacial period between 125 000 and 70 000 years ago. At least ten Rancholabrean
faunas in Florida have been assigned to the Sangamon interglacial, although few faunas
in the western United States have been correlated with that period (Kurten and An-
derson 1980). However, the beginning of the Rancholabrean was recently correlated
with the Brunhes normal magnetic polarity zone at about 690 000 B.P. (Kurten and

Figure 14. Three miles above Soyopa on Rio Yaqui between El Novillo and Tonichi in July 1983. Lep-
todactylus melanonotus (Sabinal Frog) live in moist side of river, Pseudemys scripta (Yaqui Slider) sun on
exposed bank on far side of river. Masticophis mentovarius striolatus (Tropical Whipsnake) was observed
on the slopes. Slope vegetation is mostly tropical deciduous forest with Sinaloan thomscrub on drier aspects
and inland away from river. This area is 240 km SSE of la Brisca.

Anderson 1980, Lindsay et al. 1975). With the inferred length of the Illinoian Glacial,
the correlation of the Rancholabrean with glacial/interglacial sequences is no longer
clear. Sangamon faunas could actually correlate with any of the five or so earlier warm
periods recorded in oxygen isotope sequences from deep-sea cores (Imbrie and Imbrie
1979). However, the arrival of Bison south of the continental ice sheets now appears
to have been between 1 70 000 and 1 50 000 years ago (C. A. Repenning, personal
communication 1984). The presence of Bison species places the fauna in the last in-
terglacial, the traditional Sangamon.

Acknowledgments

Richard S. White and Dr. Arturo Oliveras, Centro Regional Noroeste, Hermosillo,
discovered the site and encouraged this study. Ismael Ferrusquia V. and Oscar Carranza
C, Instituto de Geologia, Ciudad de Mexico, arranged for a collection permit and have
accepted the fossils for the Mexican government. John B. Iverson, Earlham College,
identified the Kinosternon material. Jim Honey, University of Arizona, identified the
Camelops species navicular. David W. Steadman, Smithsonian Institution, identified
the turkey. Rob McKenzie and George T. Jefferson, Los Angeles County Museum of
Natural History, examined the antilocaprids and the eagle. Christopher A. Shaw, George
C. Page Museum, provided information about the El Golfo, Sonora, fauna. Kevin B.
Moodie, Louis H. Taylor, Louis L. Jacobs, and Everett H. Lindsay, University of
Arizona Laboratory of Paleontology, curated and made casts of the la Brisca fossils.
Kenneth L. Petersen, Robert S. Thompson, and Vera Markgraf, University of Arizona,
processed the pollen samples. Charles H. Lowe, Jr., John K. Cross and Cecil Schwalbe
provided unpublished locality records for Sonoran amphibians and reptiles in the
University of Arizona herpetological collection. Howard Lawler, Arizona-Sonora Des-
ert Museum, provided common names and observations for Sonoran amphibians and

reptiles. Jim I. Mead, Kevin B. Moodie, Stephen F. Hale, Owen K. Davis, and Paul
S. Martin (University of Arizona), Ellie Baker Koon (University of Michigan), Edie
Marsh (University of Texas), and R. Wayne Van Devender (Appalachian State Uni-
versity) helped in the field work. Paul S. Martin, Larry Marshall, Jim Mead, Kevin
Moodie and Bob McCord (University of Arizona), Gregory K. Pregill (San Diego
Natural History Museum), and Robert R. Miller (University of Michigan) commented
on the manuscript. We especially thank the Don Crescentio Palafox family of Rancho
la Brisca for their hospitality.

Financial support was provided by National Science Foundation grants DEB #76-
19784 and DEB #80-22773 to Thomas R. Van Devender and DEB #75-13944 to Paul
S. Martin, Department of Geosciences, University of Arizona. Drafts of this manuscript
were prepared by Margaret Madouse, Deborah Gaines, Betty Fink and Jean Morgan.
Julio Betancourt translated the abstract into Spanish.

Literature Cited

Alvarez, J., and F. Aguilar. 1957. Contribucion
al estudio de la suspension gonopodica del gen-
ero Poeciliopsis con descripcion de una nueva
especie fosil procedente de El Salvador, Centro
America. Revista Societie Mexicana Historia
Natural 18:153-172.

Auffenberg, W. A. 1963. The fossil snakes of Flor-
ida. Tulane Studies in Zoology 10:131-216.

Bezy, R. L., W. C. Sherbrooke, and C. H. Lowe,
Jr. 1966. Rediscovery of Eleutherodactylus
augusti in Arizona. Herpetologica 22:22 1-225.

Branson, B. A., C. J. McCoy. Jr., and M. E. Sisk.
1 960. Notes on the freshwater fishes of Sonora
with an addition to the known fauna. Copeia
1960:217-220.

Brattstrom, B. H. 1954. Amphibians and reptiles
from Gypsum Cave, Nevada. Southern Cali-
fornia Academy of Science Bulletin 53:8-12.

. 1958. Additions to the herpetofauna of

Nevada. Herpetologica 14:36.

1 964. Amphibians and reptiles from cave

deposits in south-central New Mexico. South-
em California Academy of Science Bulletin 63:
93-103.

Brodkorb, P. 1964. Catalogue of fossil birds: Part
2 (Anseriformes through Galliformes). Bulletin
Florida State Museum Biological Sciences
8:195-335.

. 1978. Catalogue of fossil birds: Part 5

(Passeriformes). Ibid. 23:139-228.

Brown, D. E., and C. H. Lowe, Jr. 1977. Biotic
communities of the southwest. U.S.D.A. For-
est Service, General Technical Report RM-4 1 ,
Fort Collins, Colorado.

Ferguson, J. H., and C. H. Lowe, Jr. 1969. Evo-
lutionary relationships in the Bufo punctatus
group. American Midland Naturalist 81:435-
466.

Fichter, L. S. 1969. Geographic distribution and
osteological variation in fossil and recent spec-
imens of two species of Kinosternon (Testu-
dines). Journal of Herpetology 3:1 13-1 19.

Fouquette, M. J., Jr. 1970. Bufo aharius. Cata-
logue of American Amphibians and Reptiles
93:1-4.

Gaup, E. 1896. Lehre vom skelet und vom muskel
system. Vol. 1, 97. Pp. in A. Ecker and R.
Wiedersheim (eds.). Anatomic de Frosches,
Friedrich Vieweg and Sohn, Braunschweig.

Gilmore, C. W. 1922. A new fossil turtle, Kino-
sternon arizonense, from Arizona. Proceedings
United States National Museum 62:1-8.

Harris, A. H. 1984. Neotoma in the late Pleisto-
cene of New Mexico and Chihuahua. Pp. 164-
178 in H. H. Genoways and M. R. Dawson
(eds.). Contributions in Quaternary Vertebrate
Paleontology: A Volume in Memorial to John
E. Guilday. Carnegie Museum of Natural His-
tory Special Publication No. 8, Pittsburgh,
Pennsylvania.

Haury, E. W. 1975. The stratigraphy and archeol-
ogy of Ventana Cave. 2nd ed.. University of
Arizona Press, Tucson, Arizona.

Hastings, J. R., and R. R. Humphrey. 1969. Cli-
matological data for Sonora and northern Si-
naloa. University of Arizona Institute of At-
mospheric Physics Technical Report No. 19.

, and R. M. Turner. 1965. The changing

mile. University of Arizona Press, Tucson.

Hendrickson, D. A., W. L. Minckley, R. R. Miller,
D.J. Siebert,andP. H.Minckley. 1980. Fish-
es of the Rio Yaqui Basin, Mexico and United
States. Journal of the Arizona-Nevada Acad-
emy of Science 15:65-106.

, and . 1984[1985]. Cienegas-van-

ishing climax communities of the American
Southwest. Desert Plants 6:131-175.

Hill, W. H. 1971. Pleistocene snakes from a cave
in Kendall County, Texas. Texas Journal of
Science 22:209-216.

Holman, J. A. 1969a. The Pleistocene amphibi-
ans and reptiles of Texas. Michigan State Uni-
versity Publications of the Museum Biological
Series 4:163-192.

. 1969^. Pleistocene amphibians from a

cave in Edwards County, Texas. Texas Journal
of Science 21:63-67.

. 1969<:'. A small Pleistocene herpetofauna

from Tamaulipas. Quarterly Journal of the
Florida Academy of Science 32:153-158.

. 1970. A Pleistocene herpetofauna from

Eddy County, New Mexico. Texas Journal of
Science 22:29-39.

. 1972. Amphibians and reptiles. Pp. 55-

71 in M. F. Skinner and C. W. Hibbard (eds.).
Early Pleistocene Preglacial Rocks and Faunas
of North-Central Nebraska. Bulletin of the
American Museum of Natural History 148.

Howard, H. 1932. Eagles and eagle-like vultures
of the Pleistocene of Rancho la Brea. Contri-
butions in Paleontology Carnegie Institute of
Washington Publication No. 429:1-82.

. 1933. A new species of owl from the Pleis-
tocene of Rancho la Brea, California. Condor
35:66-69.

Hulse, A. C. 1977. Bufo kelloggi. Catalogue of
American Amphibians and Reptiles 200:1-2.

. 1978. Bufo retiformis. Catalogue of

American Amphibians and Reptiles 207:1-2.

Imbrie, J. J., and K. P. Imbrie. 1979. Ice ages.
Solving the Mystery. Enslow Publishers, Hill-
side, New Jersey.

Iverson, J. B. 1976. Kinosternon sonoriense. Cat-
alogue of American Amphibians and Reptiles
176:1-2.

. 1979a. On the validity of Kinosternon

arizonense GWmorc. Copeia 1979:175-177.
1979Z>. A taxonomic reappraisal of the

yellow mud turtle, Kinosternon flavescens
(Testudines: Kinostemidae). Copeia 1979:212-
225.

Johnson, E. 1974. Zooarcheology and the Lub-
bock Lake Site. Pp. 107-122 in C. C. Black
(ed.). History and Prehistory of the Lubbock
Lake Site. West Texas Museum Association,
the Museum Journal XV.

Johnson, J. D. 1977. The taxonomy and distri-
bution of the neotropical whipsnake Mastico-
phis mentovarius (Reptilia, Serpentes, Colu-
bridae). Journal of Herpetology 1 1:287-309.

. 1982. Masticophis mentovarius {DnmQnl,

Bibron, and Dumeril) Neotropical whipsnake.
Catalogue of American Amphibians and Rep-
tiles 295:1-4.

Johnson, N. M., N. D. Opdyke, and E. H. Lindsay.
1975. Magnetic polarity stratigraphy of Plio-
Pleistocene terrestrial deposits and vertebrate
faunas, San Pedro Valley, Arizona. Geological
Society of America Bulletin 86:5-12.

Kurten, B., and E. Anderson. 1980. Pleistocene
Mammals of North America. Columbia Uni-
versity Press, New York.

Langebartel, D. A. 1953. Faunal and archaeolog-
ical researches in Yucatan caves. Part 4. The
reptiles and amphibians. Bulletin of the Cran-
brook Institute of Science (33):9 1-108.

Ligon, J. D. 1967. Relationships of the cathartid
vultures. Occasional Papers of the Museum of
Zoology University of Michigan No. 65 1 : 1-26.

Lindsay, E. H., and N. T. Tessman. 1974. Ce-
nozoic vertebrate localities and faunas in Ar-
izona. Journal of the Arizona Academy of Sci-
ence 9:3-24.

, N. M. Johnson, and N. D. Opdyke. 1975.

Preliminary correlation of North American
Land Mammal Ages and geomagnetic chro-
nology. Pp. 1 1 1-1 19 m G. R. Smith and N. E.
Friedland (eds.). Studies on Cenozoic Paleon-
tology and Stratigraphy in Honor of Claude W.
Hibbard. University of Michigan Papers in Pa-
leontology No. 12.

. 1984. Late Cenozoic mammals from

Springs Site, Nevada. Pp. 125-128 in H. M.
Wormington and D. Ellis (eds.). Pleistocene
Studies in Southern Nevada. Nevada State
Museum Anthropological Papers No. 13.

Mead, J.I. 1981. The last 30,000 years of faunal
history within the Grand Canyon, Arizona.
Quaternary Research 15:311-326.

, and A. M. Phillips. 1981. The late Pleis-
tocene and Holocene fauna and flora of Vulture
Cave, Grand Canyon, Arizona. Southwestern
Naturalist 26:257-288.

, R. S. Thompson, and T. R. Van Devender.

1982. Late Wisconsin and Holocene fauna
from Smith Creek Canyon. Snake Range, Ne-
vada. Transactions of the San Diego Society of
Natural History 20:1-26.

, T. R. Van Devender, and K. L. Cole. 1 983.

Late Quartemary small mammals from So-
noran Desert packrat middens, Arizona and
California. Journal of Mammalogy 64: 1 73-1 80.

, E. L. Roth, T. R. Van Devender, and D.

W. Steadman. 1984. The late Wisconsin ver-
tebrate fauna from Deadman Cave, southern
Arizona. Transactions of the San Diego Society
of Natural History 20:247-276.

Mecham, J. S. 1959. Some Pleistocene amphib-
ians and reptiles from Friesenhahn Cave, Tex-
as. Southwestern Naturalist 3:17-27.

Messing, H. J. in press. A late Pleistocene-Ho-
locene fauna from Chihuahua, Mexico. South-
western Naturalist.

Miller, R. R. 1958. Origin and affinities of the
freshwater fish fauna of western North Amer-
ica. Pp. 187-222 in C. L. Hubbs (ed.). Zoo-
geography. American Association Advance-
ment of Science Publication 5 1 .

Milstead, W. W. 1967. Fossil box turtles {Ter-
rapene) from central North America, and box
turtles of eastern Mexico. Copeia 1967:168-
179.

. 1969. Studies on the evolution of box

turtles (genus Terrapene). Bulletin of the Flor-
ida State Museum, Biological Science 14: 1-1 1 3.
-, and D. W. Tinkle. 1978. Terrapene of

northwestern Mexico. Journal of Vertebrate

Paleontology 4:208-215.
Martin, P. S. 1973. The discovery of America.

Science 179:969-974.
Mawby, J. E. 1967. Fossil vertebrates of the Tule

western Mexico, with comments on the species
groups in the genus. Copeia 1967:180-187.

Minckley, W. L. 1973. Fishes of Arizona. Arizona
Game and Fish Department, Phoenix, Arizo-
na.

Moodie, K. B., and T. R. Van Devender. 1978.
Fossil box turtles (genus Terrapene) from
southern Arizona. Herpetologica 34:172-174.

Moore, W. S., R. R. Miller, and R. J. Schultz. 1 970.
Distribution, adaptation, and probable origin
of an all-female form of Poeciliopsis (Pisces:
Poeciliidae) in northwestern Mexico. Evolu-
tion 23:789-795.

Nelson, C. E. 1972. Gastrophryne olivacea. Cat-
alogue of American Amphibians and Reptiles
122:1-4.

Olsen, S. J. 1972. The American mastodon and
the woolly mammoth. Papers of the Peabody
Museum of Archaeology and Ethnology, Har-
vard University 56:1-47.

Platz, J. E., and J. S. Frost. 1984. Rana yava-
paiensis, a new species of leopard frog (Rana
pipiens complex). Copeia 1984:940-948.

Rea, A. M. 1980. Late Pleistocene and Holocene

turkeys in the southwest. Contributions in Sci-
ence of the Natural History Museum of Los
Angeles County 330:209-224.

Rogers, K. L. 1976. Herpetofauna of the Beck
Ranch Local Fauna (Upper Pliocene: Blancan)
of Texas. Michigan State University Publica-
tions of the Museum Paleontology Series
1:167-200.

Rosen, D. E., and R. M. Bailey. 1963. The poe-
ciliid fishes (Cyprinodontiformes), their struc-
ture, zoogeography, and systematics. Bulletin
of the American Museum of Natural History
126:1-176.

Sanders. O. 1953. A new species of toad with a
discussion of the morphology of the bufonid
skull. Herpetologica 9:25-47.

Saunders, J. J. 1970. The distribution and tax-
onomy of Mammuthus in Arizona. Unpub-
lished M.S. Thesis, University of Arizona,
Tucson.

Seidel, M. E. 1978. Kinosternon flavescens. Cat-
alogue of American Amphibians and Reptiles
216:1-4.

Shreve, F. 1964. Vegetation of the Sonoran Des-
ert. Pp. 6-186 in F. Shreve and L L. Wiggins
(eds.). Vegetation and Flora of the Sonoran
Desert. Stanford University Press, Stanford,
California.

Skinner, M. F. 1 942. The fauna of Papago Springs
Cave, Arizona. Bulletin of the American Mu-
seum of Natural History 80:143-220.

Tihen, J. A. 1962a. Osteological observations on
New World Bufo. American Midland Natu-
ralist 67:157-183.

. 1 962b. A review of New World fossil bu-

fonids. Ibid. 68:1-50.

Trueb, L. 1969. Pternohyla, P. dentata, P.fodiens.
Catalogue of American Amphibians and Rep-
tiles 77:1-4.

Van Devender, T. R., and C. H. Lowe, Jr. 1977.
Amphibians and reptiles of Yepomera, Chi-

huahua, Mexico. Journal of Herpetology 11:
41-50.

, and J. L Mead. 1978. Eariy Holocene and

late Pleistocene amphibians and reptiles in So-
noran Desert packrat middens. Copeia 1978:
464-475.

, A.M. Phillips, and J. L Mead. 1977. Late

Pleistocene reptiles and small mammals from
the lower Grand Canyon of Arizona. South-
western Naturalist 22:49-66.

, and W. G.Spaulding. 1979. Development

of vegetation and climate in the southwestern
United States. Science 204:701-710.

, and R. D. Worthington. 1977. The her-
petofauna of Howell's Ridge Cave and the pa-
leoecology of the northwestern Chihuahuan
Desert. Pp. 85-106 in R. H. Wauer and D. H.
Riskind (eds.). Transactions of the Symposium
on the Biological Resources of the Chihuahuan
Desert, United States and Mexico. National
Park Service Transactions and Proceedings Se-
ries No. 13, Washington, D.C.

Wasserman, A. O. 1970. Scaphiopus couchi. Cat-
alogue of American Amphibians and Reptiles
85:1-4.

Wells, P. v., and J. H. Hunziker. 1976. Origin of
the creosote bush (Larrea) deserts of south-
western North America. Annals of the Mis-
souri Botanical Garden 63:843-861.

Wilson. L. D. 1970. The coachwhip snake, Mas-
ticophis flagellum (Shaw): taxonomy and dis-
tribution. Tulane Studies in Zoology and Bot-
any 16:31-99.

Zimmerman, E. G. 1970. Karyology, systematics,
and chromosomal evolution in the rodent ge-
nus Sigmodon. Michigan State University
Publications of the Museum Biological Series
4:389-454.

Zweifel, R. 1967. Eleutherodactylus augusti. Cat-
alogue of American Amphibians and Reptiles
41:1-4.

1,^^ TRANSACTIONS

^ OF THE SAN DIEGO

SOCIETY OF
NATURAL HISTORY

Volume 21 Number 3 pp. 57-70 29 October 1985

L/eRARy

Floral morphology, nectar production, and breeding systems in
Dudleya subgenus Dudleya (Crassulaceae)

Geoffrey A. Levin L* - -

Department of Botany, San Diego Hatuml Historv Kf^eum, San Diego, California 92112 USA

Thomas W. Mulroy

URS Company, HI W. Micheltorena, 3rd Floor, Santa Barbara, California 93101 USA

Abstract. Floral morphology, nectar production, and breeding systems of 2 1 taxa in Dudleya
subgenus Dudleya suggest three reproductive strategies. Most species— 13 of those examined — have 1-
1 5% auto-fertility (defined as the proportion of seed set by self-pollination in the absence of pollinators)
and produce nectar with about 2-5 mg sugar per flower. These species, which are predominantly coastal
in distribution, have dense inflorescences of yellow flowers and appear to be pollinated primarily by
bees and long-tongued flies. Increased seed set and seedling vigor with cross-pollination select for
outcrossing in these species. A second group of three species has long-tubed, frequently pendent, red
flowers in very open cymes, high auto-fertility (about 40-60%), and abundant nectar— yielding 5-12
mg sugar/flower. Ranging from hills near the coast to desert mountains, these species are hummingbird-
pollinated. The remaining three species (one with three subspecies) have short-tubed flowers in dense
cymes, high auto-fertility (25-50%), and nectar production of less than 2.5 mg sugar/flower. These
species are typically montane and occupy habitats with shorter and less reliable growing seasons than
are usual for the genus. Environmental unpredictability and pollinator unreliability may explain the
apparent trend toward autogamy in the third group and the high auto-fertility of the hummingbird-
pollinated species. Because flowers are protandrous, even species with high auto-fertility maintain the
ability to outcross if pollinators are available.

Introduction

The genus Dudleya (Crassulaceae) consists of about 40 species of succulent rosette
perennials of western North America (Moran 1951, 1959). Subgenus Dudleya is the
most diverse (about 25 species) and most widespread of the three subgenera. The
greatest diversity is in coastal and insular southern California and Baja California,
although the subgenus extends from the Cape Region of Baja California to coastal
southern Oregon and inland to southern Nevada and central Arizona, spanning an
altitudinal range from sea level to 2750 m. Habitats include coastal bluffs, montane
canyons, and slopes of desert mountains. About half the species are narrow endemics,
many of them insular; the remainder are widespread. Except in a few species of coastal
northern Baja California, distributions are mostly patchy, with populations commonly
small and well isolated.

Given the great diversity of habitat and population structure of its species, Dudleya
might be expected to vary in 1) breeding systems, 2) pollination syndromes, and 3)
reproductive strategies. Some aspects of pollination biology have been shown to vary
within groups of related plants, e.g., at the family level in Polemoniaceae (Grant and
Grant 1965) and Bignoniaceae (Gentry 1 974), and at the generic level in Agave (Schaffer
and Schaffer 1977), Leavenworthia (Lloyd 1965, Solbrig 1976, Solbrig and Rollins
1977), Pedicularis (Sprague 1962, Macior 1968, 1970), Rhododendron (Stevens 1976)
and Trichostema (Spira 1980). Yet, except in Spira's study, variation in all three aspects
has not been examined in a single genus.

Methods

We studied floral morphology, nectar production, and breeding systems in field-
collected plants grown in a glass-topped screenhouse at Rancho Santa Ana Botanic
Garden, Claremont, California. Localities of the populations studied are listed in the
Appendix. As noted below, we also made some field measurements of nectar production.
We also observed pollinators on several species, although most observation periods
were relatively short.

We determined nectar volume by extracting all nectar from a flower with a vol-
umetric (5-Ail or 10-/ul) capillary tube. Upon sampling, we immediately measured the
concentration (in mg sucrose equivalent/mg solute) of sugar in the extracted nectar with
a hand-held Bausch & Lomb sucrose refractometer. We converted concentrations to
mg sucrose equivalent/ml solution using Table 88 in the 59th edition of the Handbook
of Chemistry and Physics (1978-1979:D-308) and then calculated total sugar by mul-
tiplying concentration by nectar volume (Bolten et al. 1979).

To determine phenology of nectar production and variation in nectar concentration
and volume with flower age, we sampled flowers at different stages of anthesis. The
first season, we recorded the relative age of each flower. The second season, in order
to obtain measurements on the basis of absolute time, we sampled flowers at daily
intervals after they opened. Because sampling often damaged the flower, we could not
reliably resample the same flower. Instead, for each time period, we sampled 1 0 flowers,
chosen from several plants.

On each flower sampled for nectar, we measured the length of the corolla tube,
that portion of the corolla in which adjacent petals are fused; sample sizes ranged from
50-80 flowers. We also recorded flower color and positions of anthers and stigmas.

To determine the breeding systems of the different species, we mechanically self-
pollinated some flowers, mechanically cross-pollinated others, emasculated others in
bud, and left others untouched. We allowed fruits to mature on the plants but removed
them before dehiscence. Percentage seed set was determined by dividing the number
of developed seeds by the total number of ovules. Unfertilized ovules were small and
withered, making them easy to distinguish from the larger plump seeds. Typically, three
flowers from three diflerent plants were included in each treatment.

For six species, we compared viability and seedling vigor of seeds from self-
pollinated and cross-pollinated flowers by planting 30 seeds from each treatment and
counting the number of seedlings at three and seven weeks after sowing.

Pollinators

Floral morphology suggests that there are two different groups of pollinators. In
aU species of subgenus Dudleya, the petals are essentially erect, with the overlapping
edges usually closely appressed above the corolla tube (Fig. 1). In the relatively small
flowers of most species (7-15 mm long), nectar is available to small bees and flies that
can crawl into the corollas, and to larger insects with moderately long tongues. These
species primarily have yellow to orange flowers, many with ultraviolet reflectance
patterns (T. W. Mulroy, pers. obs.), borne erect in more or less flat-topped inflorescences
that would serve well as insect landing platforms (Figs. 1 and 2A). Apparently the genus
has little ability to produce a floral scent: only three species, none of them in subgenus
Dudleya, produce any aroma (Moran 1951, 1959; pers. obs.)} We have observed bees
of eight genera and occasional butterflies visiting Dudleya flowers (G. A. Levin in prep.);
Moldenke (1976) listed bees in the genera Bombus and Anthophora as important pol-
linators of Dudleya.

Three closely related species, D. arizonica, D. anthonyi, and D. pulverulenta (Fig.
2B, C), appear to be hummingbird pollinated. The latter two, in particular, possess a

' Although Johansen (1935) reported that flowers of Z). echeverioides. now regarded as a synonym of D.
greenei, have an odor resembling woodland violets, neither we nor Moran (1951) has been able to detect
any floral fragrance in D. greenei.

Figure 1. Inflorescence of Dudleya greenei. Arrows labeled A indicate young flowers (1-2 days old); the
anthers have dehisced and are positioned toward the center of the corolla. Arrows labeled B indicate older
flowers (3-5 days old); the styles have elongated, positioning the now receptive stigmas near the mouth of
the corolla, and the anthers are positioned near the edge of the corolla. As the flowers age further, the anthers
will again move toward the center. (Photo by Reid Moran.)

suite of characteristics associated with hummingbird pollination (Faegri and van der
Pijl 1979, Grant and Grant 1968). Their corollas are 1.5-2 cm long, fused about 1 cm,
and colored deep red. The flowers are pendent on long, slender pedicels, becoming
erect in fruit. The inflorescences of these species are typically more open than in the
remainder of the species. Dudleya arizonica also has red flowers, but they are somewhat
smaller (1.2-1.4 cm long) and erect in more dense inflorescences. By probing flowers
with a dead hummingbird (sp. indet.), we found that hummingbirds could effect pol-
lination while feeding, and we have observed them foraging on D. piilverulenta and D.
arizonica. We also observed hummingbirds visiting D. hhttonii, D. cymosa cymosa,
and D. ingens, species that are better adapted for bee pollination (G. A. Levin in prep.).
Grant and Grant (1966) reported hummingbirds visiting D. cymosa minor and D.
lanceolata, and Moldenke (1976) considered hummingbirds to be the principal polli-
nators of Dudleya, although he did not indicate which species he observed.

Nectar Production

Phenology^ —In Dudleya, the nectaries are located at the base of the gynoecium.
The flowers are strongly protandrous (Fig. 1), and nectar volume and concentration
are correlated with the age of the flower (Fig. 3). No nectar is produced before the
anthers release pollen. Following anther dehiscence, nectar is secreted rapidly and

Figure 2. A— Flowering plant oi Dudleya greenei, typical of bee-pollinated Dudleya species (photo by Reid
Moran). B, C— Flowering plant and inflorescence, respectively, of Dudleya pulverulenta, typical of hum-
mingbird-pollinated Dudleya species.

o) 2

h-"

z
o
o

LU
CO

I - T
®

1 1 1

QC 1
O

(

1 1

1 1 1

1 1

1 1 1

NECTAR CONCENTRATION

>ft.^

^<^^^

D
_l

>
<

■

^"^-^^^

" 2^

NECTAR VOLUME

(
1

(

o »

1 1

1 1 1

-40 Q

111
30 O

O
O

- 20

- 10

0 1 2 3 4 5 6 7

DAYS AFTER OPENING

Figure 3. Phenology of nectar production in Dudleya nuhigena. representative of the typical pattern in
subgenus Dudleya. Points indicate mean values. Concentration is in g sugar/ 1 00 g solution. Flowers are
protandrous; stigmas become receptive on day 2.

Table 1 . Characteristics of nectar production and corolla tube length in Dudleya subgenus Dudleya. "Max-
imum" denotes the mean of the three highest measurements of that characteristic. Concentration is in g
sucrose equivalent/ 100 g solution. Energy content is based on 4 cal/mg sugar (Heinrich 1975).

Maximum

Minimum

Cone, at

sucrose

energy

Corolla

volume

cone.

max. vol.

content

tube length

Dudleya species

cal

abramsii

trace

—

1.4

acuminata

4.8

3.4

13.6

4.2

albiflora

4.2

2.1

8.4

4.3

(2 populations)

5.6

—

4.1

16.4

5.0

anthonyi

14.0

9.5

38.0

6.0

arizonica

9.2

—

4.8

19.2

5.7

(3 populations)

5.6

2.9

11.6

6.2

16.0

7.8

31.2

7.0

bettinae

1.8

1.1

4.4

1.0

brittonii

glaucous form

3.4

2.3

9.2

2.9

(2 populations)

7.4

—

4.7

18.8

3.2

green x glaucous

6.8

—

4.1

16.4

3.8

caespitosa

11.5

—

7.2

28.8

2.4

(2 populations)

11.5

—

4.6

18.4

2.4

cultrata

3.1

1.6

6.4

1.9

(2 populations)

8.9

—

4.8

19.2

3.7

cymosa cymosa

2.8

1.1

4.4

1.1

c. marcescens

3.7

2.0

8.0

1.1

c. ovatifolia

4.8

2.4

9.6

1.6

gatesii

13.5

6.8

27.2

6.1

greenei

4.7

3.5

14.0

1.3

ingens

coastal form

4.0

2.3

9.2

2.0

(2 populations)

12.0

—

5.9

23.6

5.0

inland form

7.3

—

4.8

19.2

5.0

lanceolata

9.0

4.4

17.6

2.3

linearis

2.3

1.3

5.2

2.0

nubigena

5.0

2.2

8.8

3.2

parva

trace

—

1.9

pulverulenta

44.0

14.3

57.2

7.7

(2 populations)

32.1

12.5

50.0

8.0

saxosa saxosa

5.7

2.5

10.0

1.8

collects in the base of the corolla tube. Volume and concentration increase throughout
the male phase of anthesis, reaching maximum volume soon after the stigmas become
receptive. Thereafter, nectar volume tends to decrease and concentration continues to
increase, probably because of a cessation or attenuation of nectar secretion and evap-
oration of water from the nectar.

Sugar content, like nectar volume, increases rapidly through the male phase and
reaches a maximum after the stigmas become receptive (Fig. 3). Thereafter sugar content
remains essentially constant, again suggesting that nectar secretion had ceased. Other
genera have similar patterns of age-related nectar production (Anderson 1976, Car-
penter 1976, Feinsinger 1978, Pyke 1978, Cruden et al. 1983).

The phenology of nectar production in Dudleya is highly economical. During the
male phase of anthesis, visiting foragers pick up pollen on their bodies and may carry
it to other flowers. Pollinators continue to be attracted to a flower until stigmas are
receptive, but soon thereafter no more nectar is produced to reward their visits. The
flower will probably have been pollinated by this time, so further visits are unnecessary.
Within 24 h following pollination (provided the stigmas are receptive), the flower closes.
However, unpollinated flowers remain open for up to five days after the stigmas become
receptive, and because no morphological changes are associated with the cessation of
nectar production, it is likely that pollinators will continue to be attracted to unpolli-
nated flowers by previously accumulated nectar.

_ 16

r = 0.71
p< 0.001

LENGTH OF COROLLA TUBE, mm

Figure 4. Relationship between maximum nectar volume and corolla tube length in Dudleya subgenus
Dudleya. Each point represents one population. Linear correlation of r = .71 is significant (f < .001).

Environmental factors affect nectar production in Dudleya. Cool, cloudy weather
reduces the rate of secretion: in some cases only a trace of nectar accumulated in flowers
open for three rainy days. Similar meteorological effects on nectar production have
been observed in alfalfa (Pederson 1953, Walker et al. 1974) and Ipomopsis (Pleasants

•

—

•

—

•

^^ •

—

% ^^

•

—

••

•

15
10

•
•

•

• •

•
•

•

r= 0.77

•
1

P<0.001

1 <

0 1 2345678

LENGTH OF COROLLA TUBE, mm

Figure 5. Relationship between maximum energy content of nectar and corolla tube length in Dudleya
subgenus Dudleya. Each point represents one population. Linear correlation of /■ = .77 is significant (P <
.001).

1983) and have been attributed to low temperature and low sunlight. Understandably,
the volume of accumulated nectar remains higher and the concentration lower when
the weather is cool and humid than when it is warm and dry. The loose fit of the points
to the curves in Figure 3 probably results in part from changes in light, temperature,
and humidity during our study.

Quantity. —Nectar volume, maximum sugar content, and maximum caloric con-
tent vary considerably among species and even among populations in some species.
Nectar concentration varies to a lesser extent (Table 1). Field measurements with D.
cymosa cymosa and D. brittonii agree with our greenhouse results.

We find strong positive correlations between maximum nectar volume and corolla
tube length (r = .71; Fig. 4) and between maximum caloric content and corolla tube
length (r = .77; Fig. 5). These results suggest that the degree of petal fusion, an important
taxonomic character in this genus, has a functional significance. Larger flowers with
longer corolla tubes might be expected to require larger pollinators, which require more
energy and thus more nectar (Heinrich and Raven 1972) than smaller flowers could
hold.

The quantities of sugar offered by the flowers support the hypothesis that most

Table 2. Number of living seedlings from self-pollinated flowers and cross-pollinated flowers of Dudleya.
Thirty seeds from each treatment were sown.

Time

after

sowing

3 weeks

7 weeks

Dudleya species

Selfed

Crossed

Selfed

Crossed

brittonii
cult rat a

14
29

23
26

8
4

cymosa marcescens
c. ovatifolia
ingens

2 plants
linearis

4
6
9
4

4
2
3
5
9

2
7
8
3

Species of Dudleya are pollinated by bees and flies, but that some have evolved for
pollination by hummingbirds. Nectar accumulates over about three days, with a daily
energy production of 2-3 cal/flower/day for most species. These values are similar to
some temperate bee-pollinated flowers (Heinrich 1975, 1976, Reader 1977, Rust 1977,
Schaffer and Schaffer 1977). Unless insects were excluded from the flowers, the nectar
energy would be too small for temperate hummingbirds, which require an intake of
5.5-7.5 kcal/day (Pearson 1954, Stiles 1971), or about 1.5-2.0 g sugar/day (Heinrich
1975). In species that produce large quantities of nectar (up to 7-8 cal/flower/day), the
longer corolla tubes, red corolla color, and pendent flower position probably all help
prevent feeding by most bees and flies. Although 1000-1 500 flowers would be required
to support one hummingbird for a day, this number is not inconsistent with some
observations (Pearson 1954). Clearly nectar quantities are small enough not to satiate
pollinators, and thus small enough to encourage outcrossing, even if several flowers
are open simultaneously on each plant (Heinrich and Raven 1972). Nectar concentra-
tions are all within the range typical of both bee- and hummingbird-pollinated species
(Hainsworth 1973, Heinrich 1975).

Breeding Systems

Phenology of ant hesis.— As noted above, Dudleya flowers are protandrous (Fig.
1). Anthers and stigmas are initially separated by a few millimeters. About two days
after the anthers dehisce, the styles elongate and the stigmas become receptive. As a
flower ages, the filaments of its stamens shrivel and the anthers may then contact the
stigmas, transferring any remaining pollen. Contact typically occurs four to six days
after the flower opens.

Seed set. —All species examined are self-compatible and capable of some auto-
fertilization (self-pollination in the absence of pollinators) (Fig. 6). Compared to the
other species we investigated, D. cymosa, D. nubigena, D. pulverulenta and one pop-
ulation of i). brittonii had high auto-fertility. D. cymosa in particular departs from the
general morphological pattern in that its stamens form a tight ring around the stigmas
deep within the corolla tube, thereby facilitating transfer of pollen as the flowers age.

Except in highly auto-fertile subspecies of D. cymosa and in D. pulverulenta, me-
chanical self-pollination produced significantly higher seed set than did auto-fertiliza-
tion, in most cases by a factor of two or more. Cross-pollinated flowers usually produced
nearly twice as many seeds as self-pollinated flowers. Thus, for most species, there is
clearly an advantage to attracting pollinators. The increased seed set of outcrossed
flowers may be the result of fewer homozygous combinations of deleterious genes (D.
A. Levin 1971), or faster pollen tube growth of cross-pollen, resulting in more successful
fertilization (Bateman 1956, Smith and Clarkson 1956, Weller and Ornduff" 1977).

Seed viability and seedling vigor. —Table 2 shows the number of seedlings present
three and seven weeks after sowing 30 seeds each from self- and cross-pollinated flowers
of six taxa. There is no significant diflerence between the number of seedlings from

DUDLEYA SPECIES:

CYMOSA CYMOSA

CYMOSA MARCESCENS

GREENEI

ABRAMSM

CYMOSA OVATIFOLIA

SAXOSA SAXOSA

LINEARIS

LANCEOLATA

CAESPITOSA

NUBIGENA

BRITTONII

CULTRATA

ACUMINATA

ALBIFLORA

INGENS (INLAND FORM)

GATESII

ARIZONICA

PULVERULENTA

AVERAGE PERCENT SEED SET BY:

UNTREATED
(AUTO-FERTILIZATION)

MECHANICAL
SELF-POLLINATION

MECHANICAL
CROSS-POLLINATION

to
O

a>
o

no data

— r-

no data

Figure 6. Seed set under different treatments in Dudleya subgenus Dudleya. Species are arranged in order
of increasing corolla tube length. Values are means, typically of three flowers each from three different plants.

self-pollinated flowers and cross-pollinated flowers three weeks after sowing (Wilcoxen
paired-sample test; P > .20). Thus, there appears to be no difference in seed viability.
After seven weeks, however, significantly more seedlings survived from cross-pollinated
flowers than from self-pollinated flowers (P < .05). In contrast, D. cymosa showed
approximately equal survivorship from the two treatments, suggesting that, like ha-
bitually self-pollinating plants, it suffers less inbreeding depression than habitually cross-
pollinating species (Grant 1975).

Reproductive Strategies

When maximum energy content is plotted against auto-fertility, the species fall
into three groups (Fig. 7). First, there is a large group with relatively low auto-fertility
(<20%) and moderate to high nectar production. This group contains D. acuminata,
D. albijlora, D. brittonii, D. caespitosa, D. cultrata, D. gatesii, D. greenei, D. ingens,
D. lanceolata, and D. saxosa; D. bettinae, a species whose breeding systems we did not
examine, probably also belongs to this group, as do D. abramsii and D. parva, species
in which we had difficulty measuring nectar production. The second group comprises
species with relatively high auto-fertility (25-50%) and little nectar (three subspecies
of Z). cymosa, D. linearis, and D. nubigena), a combination of characters suggesting at
least incipient autogamy (Faegri and van der Pijl 1979, Omduff" 1969). Differences
between the two groups in both nectar production and auto-fertility are significant
(Mann-Whitney test; P < .001). The third group consists of the putatively humming-
bird-pollinated species {D. arizonica, D. pulverulenta, and probably D. anthonyi, al-
though we did not determine its breeding system).

Our data demonstrate that it is advantageous for most Dudleya species to attract

_i
<

o
o

•

SEED SET BY AUTO-FERTILIZATION

Figure 7. Relationship between maximum energy content of nectar and auto-fertility in Dudleya subgenus
Dudleya. Each point represents one population. Species with high auto-fertility produce little nectar (Group
I), whereas species with low auto-fertility produce moderate amounts of nectar (Group II). The three pop-
ulations that do not fit this pattern are hummingbird pollinated (Group III).

pollinators: plants that do so set more seed, whether by self- or cross-pollination.
Moreover, there are the immediate advantages to outcrossing of increased seed set and
increased seedling vigor, in addition to probable long-term advantages of increased
genetic variability (Williams 1975, Solbrig 1976, Gottlieb 1977, Hancock 1977, Solbrig
and Rollins 1977).

What then might account for the apparent autogamous tendencies of D. cymosa
and other members of the group showing high auto-fertility and low nectar production?
Unlike the majority of Dudleya species, those with this quasi-autogamous syndrome
are comparatively short-lived perennial plants growing in habitats with short growing
seasons and with great seasonal variation in environmental conditions. D. cymosa, for
example, is widespread in the Sierra Nevada, Coast Ranges, and Transverse Ranges
of California. Conditions that favor autogamy, such as a short and unpredictable re-
productive season, small population size, high population turnover, and pollinator
unreliability (Grant and Grant 1965, Vasek 1971, Hinton 1976, Hurka et al. 1976,

Solbrig 1976, Solbrig and Rollins 1977) could be expected to be more prevalent in
these environments than in the coastal environment typical of most Dudleya species.
Although we have not tested the relative importance of these factors, unreliable pol-
lination does appear to be involved (G. A. Levin in prep.)-

The high auto-fertility of those species pollinated by hummingbirds is, on face
value, unexpected. However, preliminary evidence suggests that hummingbirds are
unreliable pollinators of Dudleya, varying considerably in abundance both temporally
and spatially (G. A. Levin in prep.). Increased specialization for hummingbird polli-
nation may concomitantly select for increased ability to set seed in the absence of
pollinators.

Even the species with the strongest propensity toward autogamy are protandrous
and produce sufficient nectar to attract pollinators. The actual amount of auto-fertil-
ization that occurs in nature depends on the quantity of pollen removed from the
anthers before they contact the stigmas, in addition to the auto-fertility of the species
(Arroyo 1975). In Lupinus nanus, a species with synchronous maturation of anthers
and stigma, plants having more than 30% auto-fertility are predominately autogamous
(Harding et al. 1 974). Field observations indicate that, because of protandry, only about
50% of seed set in D. cymosa cymosa results from auto-fertilization in spite of high
auto-fertility (G. A. Levin in prep.). Dudleya thus has a breeding system that promotes
outcrossing while maintaining the possibility of auto-fertilization, the balance being
selected according to the particular environment of the species.

In conclusion, this study demonstrates the interdependence of breeding system,
pollination syndrome, and reproductive strategy. A short and uncertain growing season
and/or pollinator unreliability may make it important to shift the reproductive strategy
toward assurance of high seed set. In response, the breeding system is shifted toward
greater auto-fertilization, which in turn requires a change in floral morphology and
allows lower nectar production— a shift in the pollination syndrome. Thus natural
selection does not modify one characteristic of the reproductive system without mod-
ifying various other characteristics.

Acknowledgments

We wish to thank G. K. Pregill, R. V. Moran, M. O'Brien, E. A. PhiUips, R. W.
Thorp, G. L. Webster, and an anonymous reviewer for their constructive criticism of
earlier drafts, and F. L. Carpenter for her valuable suggestions. We appreciate R.
Moran's permission to use his photographs for Figures 1 and 2A. Greenhouse space
was generously provided by Rancho Santa Ana Botanical Garden, Claremont, Cali-
fornia. Financial support from the Educational Foundation of America and the Egbert
Schenk Botanical Fund, Pomona College, Claremont, is gratefully acknowledged.

Literature Cited

Anderson, G. L. 1976. The pollination biology of
Tilia. American Journal of Botany 63:1203-
1212.

Arroyo, M. T. K. 1975. Electrophoretic studies
of genetic variation in natural populations of
allogamous Limnanthes alba and autogamous
Limnanthes flocossa (Limnanthaceae). Hered-
ity 35:153-164.

Bateman,A. J. 1956. Cryptic self-incompatibility
in the wallflower: Cheiranthus cheiri L. Hered-
ity 10:257-261.

Bolten, A. B., P. Feinsinger, H. G. Baker, and I.
Baker. 1979. On the calculation of sugar con-
centration of flower nectar. Oecologia 4 1 :30 1-
304.

Carpenter, F. L. 1976. Plant-pollinator interac-
tions in Hawaii: Pollination energetics of Me-
trosideros collina (Myrtaceae). Ecology 57:
1125-1144.

Cruden, R. W., S. M. Hermann, and S. Peterson.
1 983. Patterns of nectar production and plant-
pollinator coevolution. Pp. 80-125 in B. A.
Bentley and T. S. Elias (eds.). Biology of Nec-
taries. Columbia Univ. Press, New York.

Faegri, K., and L. van der Pijl. 1979. The Prin-
ciples of Pollination Ecology, 3rd ed. Perga-
mon Press, New York.

Feinsinger, P. 1978. Ecological interactions be-
tween plants and hummingbirds in a succes-
sional tropical community. Ecological Mono-
graphs 48:269-287.

Gentry, A. H. 1974. Coevolutionary patterns in
Central American Bignoniaceae. Annals of the
Missouri Botanical Garden 61:728-759.

Gottlieb, L. D. 1977. Electrophoretic evidence
and plant systematics. Annals of the Missouri
Botanical Garden 64:161-180.

Grant, K. A., and V. Grant. 1 968. Hummingbirds

and their Flowers. Columbia Univ. Press, New
York.

Grant, V. 1975. Genetics of Flowering Plants. Co-
lumbia Univ. Press, New York.

, and K. A. Grant. 1965. Flower Pollina-
tion in the Phlox Family. Columbia Univ. Press,
New York.
-, and . 1966. Records of humming-

bird pollination in the western American flora.
I. Some California plant species. Aliso 6(2):5 1-
66.

Hainsworth, F. R. 1973. On the tongue of a hum-
mingbird: its role in the rate and energetics of
feeding. Comparative Biochemistry and Phys-
iology A 46:65-78.

Hancock, J. F., Jr. 1977. The relationship of ge-
netic polymorphism and ecological amplitude
in successional species of Erigeron. Bulletin of
the Torrey Botanical Club 104:279-281.

Handbook of Chemistry and Physics, 59th ed.
1978-1979. Chemical RubberCo., West Palm
Beach, Florida.

Harding, J., L. B. Mankinen, and M. H. Elliot. 1 974.
Genetics of Lupinus. VII. Outcrossing, auto-
fertility, and variability in natural populations
of the nanus group. Taxon 23:729-738.

Heinrich, B. 1975. The energetics of pollination.
Annual Review of Ecology and Systematics 6:
139-170.

. 1976. Resource partitioning among some

eusocial insects: Bumblebees. Ecology 57:874-
889.
-, and P. H. Raven. 1972. Energetics and

pollination ecology. Science 176:597-602.

Hinton, W. F. 1976. The evolution of insect-me-
diated self-pollination from an outcrossing sys-
tem in Calyptridium (Portulacaceae). Ameri-
can Journal of Botany 63:979-986.

Hurka, H., R. Krauss, T. Reiner, and K. Wohr-
mann. 1976. The flowering behavior of Cap-
sella bursa-pastoris (Brassicaceae). Plant Sys-
tematics and Evolution 125:87-95.

Johansen, D. A. 1935. Contributions toward a
monograph of the genus Dudleya—Yl. Cactus
and Succulent Journal 6:122-123.

Levin, D. A. 1971. The origin of reproductive
isolating mechanisms in flowering plants. Tax-
on 20:91-113.

Levin, G. A. Pollination biology of Dudleya cy-
mosa ssp. cymosa (Crassulaceae). (in prep.)

Lloyd, D. G. 1965. Evolution of self-compatibil-
ity and racial diflerentiation in Leavenworthia
(Cruciferae). Contributions of the Gray Her-
barium 195:3-134.

Macior, L. W. 1968. Pollination adaptation in
Pedicularis groenlandica. American Journal of
Botany 55:927-932.

. 1970. The pollination ecology of P£'<^/c-

ularis in Colorado. American Journal of Bot-
any 57:716-728.

Moldenke, A. R. 1976. California pollination
ecology and vegetation types. Phytologia 34:
305-361.

Moran, R. V. 1951. A revision of Dudleya (Cras-
sulaceae). Doctoral dissertation. University of
California, Berkeley.

. 1959. Dudleya. Pp. 344-359 in H. Jacob-
sen (ed.). A Handbook of Succulent Plants, Vol.
I. Blandford Press, London.

Omdufi", R. 1969. Reproductive biology in rela-
tion to systematics. Taxon 18:121-133.

Pearson, O. P. 1954. The daily energy require-
ments of a wild Anna hummingbird. Condor
56:317-322.

Pederson, M. W. 1953. Environmental factors af-
fecting nectar secretion and seed production in
alfalfa. Agronomy Journal 45:359-361.

Pleasants, J. M. 1983. Nectar production patterns
in Ipomopsis aggregata (Polemoniaceae).
American Journal of Botany 70:1468-1475.

Pyke, G. H. 1978. Optimal foraging in bumble-
bees and coevolution with their plants. Oeco-
logia 36:281-293.

Reader, R. J. 1977. Bog ericad flowers: self-com-
patibility and relative attractiveness to bees.
Canadian Journal of Botany 55:2279-2287.

Rust, R. W. 1977. Pollination in Impatiens ca-
pensis and Impatiens pallida (Balsaminaceae).
Bulletin of the Torrey Botanical Club 1 04:36 1-
367.

Schaffer, W. M ., and K. Schaffer. 1977. There-
productive biology of Agavaceae: I. Pollen and
nectar production in four Arizona agaves.
Southwestern Naturalist 22:157-168.

Smith, F. H., and O. D. Clarkson. 1956. Cyto-
logical studies of interspecific hybridization in
Iris, subsection Californicae. American Jour-
nal of Botany 43:582-588.

Solbrig, O. T. 1976. On the relative advantages
of cross- and self-fertilization. Annals of the
Missouri Botanical Garden 63:262-276.

, and R. C. Rollins. 1977. The evolution

of autogamy in species of the mustard genus
Leavenworthia. Evolution 31:265-281.

Spira, T. P. 1 980. Floral parameters, breeding sys-
tem and pollinator type in Trichostema (La-
biatae). American Journal of Botany 67:278-
284.

Sprague, E. F. 1962. Pollination and evolution in
Pedicularis (Scrophulariaceae). Aliso 5:181-
209.

Stevens, P. F. 1976. The altitudinal and geograph-
ical distributions of flower types in Rhodo-
dendron section Vireya, especially in the Pap-
uasian species, and their significance. Journal
of the Linnean Society, Botany 72:1-33.

Stiles, F. G. 1971. Time, energy, and territoriality
of the Anna hummingbird {Calypte anna). Sci-
ence 173:818-821.

Vasek, F. C. 1971. Variation in marginal popu-
lations of C/arAr/a. Ecology 52:1046-1051.

Walker, A. K., D. K. Barnes, and B. Furgula. 1 974.
Genetic and environmental effects on quantity
and quality of alfalfa nectar. Crop Science 14:
235-238.

Weller, S. G., and R. Omduff". 1977. Cryptic self-
incompatibility in Amsinckia grandiflora.
Evolution 31:47-51.

Williams, G. C. 1975. Sex and Evolution. Prince-
ton Univ. Press, Princeton, New Jersey.

Appendix

Localities of Dudleya populations studied

Populations are listed taxonomically in same order as Table 1 .

D. abramsii Rose. California, San Diego Co.: Highway 94 5.4 km W of Campo. D. acuminata Rose.
Mexico, Baja California (Norte): Millers Landing. D. albiflora Rose. Mexico, Baja California (Norte): Cedros
Island; Highway 1 near Rosarito. D. anthonyi Rose. Mexico, Baja California (Norte): Cabo San Quintin. D.
arizonica Rose. Mexico, Baja California (Norte): Rio Santo Tomas ca. 16 km E of coast; California, San
Diego Co.: Campbell Grade, Highway 52 ca. 22 km S of Highway 78; Highway 94 4.8 km W of Campo. D.
bettinae Hoover. California, San Luis Obispo Co.: Cuyucos. D. brittonii Johansen. Glaucous form. Mexico,
Baja California (Norte): near La Mision; Playa de Punta Banda. Green x glaucous form. Mexico, Baja
California (Norte): Playa de Punta Banda. D. caespitosa (Haworth) Britton & Rose. California, Los Angeles
Co.: Topanga Canyon ca. 5 km N of Pacific Ocean; Ventura Co.: Pt. Mugu. D. cultrata Rose. Mexico, Baja
California (Norte): San Martin Island; Cabo San Quintin. D. cymosa (Lemaire) Britton & Rose ssp. cymosa.
California, Tulare Co.: Hospital Rock, Sequoia National Park. D. cymosa ssp. marcescens Moran. California,
Ventura Co.: Little Sycamore Canyon, Santa Monica Mts. D. cymosa ssp. ovatifolia (Britton) Moran. Cali-
fornia, Los Angeles Co.: Topanga Canyon. D. gatesii Johansen. Mexico, Baja California (Norte): Millers
Landing. D. greenei Rose. California, Santa Barbara Co.: Prisoners' Harbor, Santa Cruz Island. D. ingens
Rose. Coastal form. Mexico, Baja California (Norte): San Juan de las Pulgas; Punta Cabras. Inland form.
Mexico, Baja California (Norte): specific locality unknown. D. lanceolata (Nutt.) Britton & Rose. California,
Orange Co.: Modjeska Canyon. D. linearis (Greene) Britton & Rose. Mexico, Baja California (Norte): West
San Benito Island. D. nubigena (Brand.) Britton & Rose. Mexico, Baja California Sur: Cabo San Lucas. D.
parva Rose & Davidson. California, Ventura Co.: Arroyo Santa Rosa. D. pulverulenta (Nutt.) Britton & Rose.
Mexico, Baja California (Norte): Rancho Arenoso, ca. 50 km E of El Rosario on Highway 1 ; California,
Orange Co.: Laguna Beach. D. saxosa (M. E. Jones) Britton & Rose ssp. saxosa. California, Inyo Co.:
Aguerberry Point, Panamint Mts.

TRANSACTIONS
MCZ OF THE SAN DIEGO

LIBRA^RY SOCIETY OF

NATURAL HISTORY

W/IR 26

1986

Volume 21 Number 4 pp. 71-79 24 February 1986

Fishes living in deepsea thermal vents in the tropical eastern
Pacific, with descriptions of a new genus and two
new species of eelpouts (Zoarcidae)

Richard H. Rosenblatt

Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093 USA

Daniel M. Cohen

Natural History Museum of Los Angeles County, Exposition Park, Los Angeles, CA 90007 USA

Abstract. A new genus and two new species of zoarcid fishes are described from deep sea hydro-
thermal vent systems in the eastern Pacific. The new genus Thermarces is distinguished from other
zoarcids by reduction of suborbital bones to one or two, unossified pectoral radials, and lack of fourth
infrapharyngobranchial bone, postcleithrum, scales and pelvic fins. One species of the genus has been
taken at 21''N, 109°W, and near the Galapagos Islands, the other at 12°48'N, 104°W. The new species
are diagnosed and described. The otoliths examined show clear growth rings.

The objectives of this paper are to distinguish so far as possible the various fishes
known to hve in warm water vented from deepsea springs in the tropical eastern Pacific.
Two species of eelpouts appear to be heretofore unknown, and we describe them here.

One so-called vent fish that has been observed and photographed from the sub-
mersible ALVIN in and near vents along the Galapagos Rift was referred by Cohen
and Haedrich (1983) to the genus Diplacanthopoma of the ophidiiform family Bythi-
tidae (Cohen and Nielsen 1978). Photographs of the same or a similar form taken by
Harmon Craig, Scripps Institution of Oceanography (SIO) from ALVIN at a vent system
at 10°57'N, 103°41'W have been seen by us, and Robert R. Hessler, SIO, has seen
small individuals at 13°N from CYAN A. No bythitid fish has yet been seen at 2rN
despite extensive observations. As of this writing specimens have not been captured,
and the species is not further discussed in the present paper.

The Zoarcidae, or eelpout family, also includes species of vent-associated fishes.
At the Galapagos Rift vent area, eelpouts are cryptic and have been questionably
identified from ALVIN only twice; however, two species are common in time-lapse
photographs (Cohen and Haedrich 1983). Two specimens have been captured, one a
relatively large, light-brown individual taken in a trap; the other, a smaller, pale fish,
was washed from ALVIN after the submersible surfaced. The two specimens have very
similar counts and head pore patterns. At 21°N a pale zoarcid was observed to be
common in warm water. Several specimens were captured incidentally, and enzyme
activities were described by Hand and Somcro (1983). We have also examined two
pale specimens trapped among pogonophorans by a French expedition working at vents
near 13°N, where eelpouts were common.

Recently a sulfide-rich area with a community having many features of the Pacific
vent communities has been discovered off the Florida escarpment (Paull et al. 1984).
Color photographs seen by us show an elongate, pale fish on the bottom, certainly a
zoarcid, and with a considerable general resemblance to our new genus. However,
neither specimens nor close-up pictures are available.

SUPRAORBITAL
PORES 12

NOSTRIL

POSTORBITAL PORE 1

SUBORBITAL CANAL
PORES 1-6

SUBORBITAL
OSSIFICATIONS

1 mm

Figure 1 . Thermarces cerberus new species (SI082-46). Lateral view of left side of head showing suborbital
canal and ossifications (posterior ossification actually present on right side only), suborbital pores, and first
preorbital pore.

We have been unable to place our zoarcid material in a genus or species. The
specimens cannot be included in any genus as presently defined. We have had more
success in referring our material with the aid of a Ph.D. dissertation by Eric Anderson
(1984).

Although all eight of our specimens have approximately similar counts, one is
notably different from the others in its light-brown color, and in having scales, vestigial
pelvic fins, and a long tail (62% SL). This specimen was captured in a baited trap and
photographed in the general area of one of the Galapagos vents where, although cryptic
in habit, the species is apparently abundant (Cohen and Haedrich 1983). It may rep-
resent an undescribed species of Pachycara Zugmayer, 1911 (M. E. Anderson personal
communication). Because this species is not known to occur in warm water and because
our single example is in poor condition, we are not able to comment further upon it.

Our other seven specimens, all directly or indirectly associated with warm water,
are pale, lack scales and pelvic fins, and have short tails (48.9 to 54.8% SL). These
fishes do not fall within the bounds of any zoarcid genus as defined by Anderson ( 1 984),
and we place them in a new genus that agrees in part with Pachycara. The measurements
as given in Table I are self-explanatory. Head-pore terminology is that of Gosztonyi
( 1 977). Fin rays and vertebrae were determined from radiographs. Description of cranial
osteology is based on a trypsin-cleared preparation stained for cartilage and bone.

Thermarces new genus

Type species. — Thermarces cerberus, new species.

Diagnosis. —Lycodine zoarcids with precaudal vertebrae 29-31, total vertebrae.

HYOIVIANDIBULAR

MESOPTERYGOID

SYMPLECTIC

ECTOPTERYGOID

QUADRATE

1 mm

Figure 2. Thermarces cerberus new species (SI082-46). Lateral view of right suspensorium.

94-97; suborbital bones 1 or 2; ectopterygoid in contact with a small area of the
quadrate, and mesopterygoid with no contact; pectoral radials 4, unossified; postcleith-
rum lacking; infrapharyngobranchials 2; pelvic bone and fin rays lacking; no scales, no
body lateral line.

Description. — Body relatively deep, 9.8-1 3.4% standard length; tail relatively short,
48.9-55% standard length; snout blunt and rounded, with subterminal jaws. Scales
lacking.

Ventral face of dentary lacking cartilaginous ridges (mental crests of Anderson
1984). Pseudobranch reduced to a continuous membrane with several small nubbins.
Infrapharyngobranchials with ossified tooth plates on arches two and three only.

Suborbital bones one or two (Fig. 1), no cartilaginous elements; a slight, irregular
ossification roofs the sensory canal dorsal to pore number 2. There is also a slight
ossification on the medial wall of the canal midway between pores 3 and 4 on the right
side of the specimen but not on the left (shown on the left in Fig. 1 ).

Abdominal vertebrae 29-32; total vertebrae 94-97.

PARIETAL

FRONTAL

MESETHMOID

SUPRAOCCIPITAL
EPIOTIC

PTEROTIC
EXOCCIPITAL

BASIOCCIPITAL

VOMER

LATERAL
ETHMOID

TRIGEMINOFACIALIS
FORAMEN

1 mm

Figure 3. Thermarces cerberus new species (SI082-46). Lateral view of left side of cranium. Ossification
is thin, location of sutures approximate and based on a single specimen.

Figure 4. Thermarces cerberus new species, holotype.

Ectopterygoid a slender splint anteriorly, expanded posterioriy but in contact with
no more than the dorsal section of the leading edge of the quadrate (Fig. 2). Meso-
pterygoid represented by a long, tissue-thin ossification in a band of cartilage, narrowly
connected with metapterygoid posteriorly. Nearly all of dorsal margin of quadrate
bordered by cartilage, except at the extreme anterior end where a narrow, ossified lappet
extends posteriorly from the ectopterygoid.

Pectoral girdle with cleithrum well-ossified, scapula and coracoid poorly ossified
and tissue-thin, radials unossified and scarcely visible; postcleithrum lacking.

Pelvic fin rays and pelvic bone lacking.

Ascending wing of parasphenoid not reaching mid-height of trigeminofacialis fo-
ramen, pterosphenoid not separating frontal and parasphenoid (Fig. 3).

Etymology. —The name Thermarces is derived from the Greek thermos, heat, and
the generic name Zoarces, the type genus of the family.

Discussion. —y\.osX of the diagnostic characters presented above are reductional.
Thermarces could be a derivative of a Pachycara-\\\iQ fish. It shares with Pachycara
the following characters: body robust; tail short; mental crests absent; parasphenoid
wing below mid-height of trigeminofacialis foramen; abdominal vertebrae 26-32; pseu-
dobranch filaments 0-6; head blunt and rounded (characters for Pachycara from An-
derson 1984).

Thermarces cerberus new species
Figures 4, 5

Description. —CounXs and measurements are given in Table I. Head and body
laterally compressed, body width contained about twice in depth at mid-trunk, about
7 in depth just before caudal fin. Head and trunk slightly shorter than tail. Head 1.8
in trunk (1.4 in small Galapagos specimen). Eye small, covered by skin, 4.5-5 in snout
(4 in smallest specimen). Mouth terminal, moderately oblique, anterior tip of mandible
well above mandibular symphysis; jaws subequal. Lips distinct, thick and fleshy, con-
tinuous and smooth. Oral valves obsolete. Nostril in a short tube, which does not reach
upper lip. Head pores large and conspicuous. Occipital pores absent, suborbital 6,
supraorbital 2, postorbital 2, preopercular 4, mandibular 4 (symphysial pores closely
opposed).

Teeth in both jaws stout, conical and pointed. Dentary teeth in a triserial patch

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Figure 5. Otoliths of Thermarces cerberus new species, from a 244 mm paratype, SI08 1-155. Upper, right
otolith, inner face; lower, left otolith, outer face.

Figure 7. Thermarces cerberus in situ near the type locality. In the foreground the vestimentiferan worm
Riftia and part of the submersible ALVIN.

Figure 8. Otolith of Thermarces cerberus, same data as Figure 5, viewed in transmitted light.

anteriorly and a single posterior row. Teeth of upper jaw uniserial except for a few
slightly enlarged teeth in outer row at symphysis. Vomer with patch of about 15 teeth,
autopalatines with a row of about a dozen teeth. Teeth in roof of mouth about as large
as largest jaw teeth. Gill openings relatively unrestricted, ending about at level of lower

Figure 6. Thermarces andersoni new species, holotype.

end of pectoral base, about 3 in head. Isthmus width shghtly less than gill-opening
length. Gill rakers 1-1-14 on first arch, rakers short but flattened, some on ceratobran-
chial with pair of teeth at tip. Gill filaments well-developed, about 3 in snout. Pectoral
fin small, rounded, its base about 2.2 in gill opening, its length about 0.8 in snout.
Pectoral rays covered by thick skin. Vertical fins relatively well-developed, covered by
skin. Dorsal origin obscure, on radiographs seen to be between sixth and seventh
vertebrae. Caudal pointed, with 6 + 5 rays. Dorsal and anal rays mostly unbranched.
Color in situ pale. Freshly dead individuals white with pink suffusion, dark peritoneum
showing through body wall. Holotype with a series of dark flecks along dorsum, be-
ginning just behind head. Paratypes from SI08 1-155 with a few melanophores scattered
on the dorsum. Body otherwise immaculate. Peritoneum dusky.

£'?vmo/o^.— Cerberus is the dog-like monster which in Greek mythology guards
the gates of Hades.

Holotype. —S\0^\-\55, a 259 mm SL 9 with ripening eggs. Taken off" Mexico at
20°5rN, 109°04'W, at a hydrothermal vent site in 2600 m by Expedition 'Tluto," leg
4, ALVIN Dive 1157 on 21 November 1981. The specimen was found accidentally
trapped in the conning tower of the submersible ALVIN, and returned to Scripps
Institution of Oceanography by Harmon Craig.

Paratypes. —S\0^\-\55, collected with, and bearing the same data as the holotype
2(181-244). Natural History Museum of Los Angeles County, LACM43719-1, formerly
SI082-45, off'Mexico at 20°49.05'N, 109°06.40'W at a hydrothermal vent site, at 2600
m on 20 April 1982 by Expedition "Oasis," station 1214-4. Found in the conning
tower of the submersible ALVIN and returned to SIO by Robert R. Hessler.

Additional material. —SIOS2-46. Same data as S1082-45, but taken on 14 May
1982 from a pipe draining sail of ALVIN. 1, head and part of trunk. Cleared and

stained. LACM43531-1, Galapagos Rift zone, from conning tower of ALVIN, 22 Au-
gust 1977.1(127).

Thermarces andersoni new species
Figure 6

Description.— CownXs and measurements are given in Table 1. Thermarces an-
dersoni is similar to T. cerberus in most respects, and characters in agreement are not
repeated here. Head and body compressed, but robust, head 1.4 in trunk. Eye small
3.3-3.5 in snout. Gill opening 2.75 in head in holotype, 3.0 in paratype. Isthmus width
equal to gill opening. Most dorsal and anal rays branched, dorsal rays branched for
about one-half their length, anal rays branched for one-third to one-half their length.

Color of freshly dead individuals pale, belly dark. Body, fins and dorsal part of
head flecked and mottled with brown. Peritoneum of holotype pale, that of paratype
blotched with pigment, mostly dorsally. Photographs of three fresh individuals supplied
by R. R. Hessler show a dark belly, indicating a dark peritoneum.

Holotype.— MusQum. National d'Histoire Naturelle, MNHN 1985-400, CENTOB,
BIOCYATHERM, DIVE 82-35. A 272 mm $ taken in an amphipod trap at 1 2°48.85'N,
103°56.60'W on 12 March 1982 at 2620 m depth, by the submersible CYANA.

Paratype.— MNWN 1985-401, a 249 mm 6 taken with the holotype.

Etymology. — Earned for M. Eric Anderson, student of zoarcids, who freely shared
his knowledge with us.

Comparison. — Thermarces andersoni is similar to T. cerberus in many respects,
including meristics. It differs most notably in the more robust head and body, a larger
eye, and in coloration. Also, there appears to be a difference in number of anal, and
possibly caudal, rays (Table 1).

Due to the small number of available specimens, the morphological differences,
though readily apparent, are difficult to establish and validate through measurement.
However, Table 1 shows that the values for Body Width and Head Depth for the
Thermarces andersoni specimens are higher, and well outside the range for the five
specimens of T. cerberus. The eye of the types of T. andersoni is proportionately larger
than in the comparably sized specimens of T. cerberus. The smallest specimen of T.
cerberus (127 mm) does have an eye which is proportionately as large as that of the
much larger type specimens of T. andersoni, but typically the eye exhibits negative
allometry.

The specimens of Thermarces andersoni are much more heavily pigmented, es-
pecially about the head, body and fins, than are those of T. cerberus, which are almost
completely colorless, with at most a few flecks of pigment on the dorsum.

The differences in coloration and body shape are not sexual, as males and females
are represented in both species. Nor is it likely that the andersoni types represent the
chance capture of two rare variants. Color slides of three additional Thermarces an-
dersoni from 1 3°N supplied by Robert Hessler show individuals closely resembling the
types in having a robust body and being relatively heavily pigmented. It thus appears
that the type material of T. andersoni fairly represents the population at 1 3°N.

The two nominal species will probably be found to differ also in number of anal
rays. The range for Thermarces cerberus is 66-69, x 67.6, SD 1.3. The holotype of T.
andersoni has 64 and the paratype 65. The available material also differs in number
of caudal rays, 10 in T. andersoni and 1 1 in 7". cerberus.

Natural History

Individuals of Thermarces cerberus are commonly seen near vents, either in the
open, or nestled among mussels or clams. Their relative abundance in some places is
shown in Figure 7. Hand and Somero (1983) have noted that the activity of the enzymes
lactate dehydrogenase and pyruvate kinase in white muscle of T. cerberus is the highest
thus far measured for a deepsea fish, and "within the range noted for many shallow-

living demersal species." The ability to sustain a high metabolic activity was attributed
to the food-rich environment of the vents.

We examined the stomach contents of two Thermarces cerberus. One contained
5 white trochiform snails (undescribed) about 7 mm diameter. The other contained
two lysionassid amphipods (undescribed), and a moss-green material with a strong
sulfurous smell that proved to be from the trophosome of the pogonophoran Riftia
pachyptila. The trophosome contains a large number of symbiotic sulfur-oxidizing
bacteria (Cavanaugh 1983). A radiograph of the holotype shows that there are two
snails in the intestine and another in the pharynx.

The pogonophoran is in a stout tube which should deny small fishes access to its
soft parts. However, the submersible ALVIN had been lying on the bottom while an
experiment was being performed and had undoubtedly crushed numerous worm tubes
making an otherwise inaccessible food available. That a probably unaccustomed prey
was taken indicates a generalized feeding habit. Moreover the fact that Riftia, which
may have concentrations of up to 1.1 mM hydrogen sulfide in the blood (Arp and
Childress 1983) was eaten, indicates a considerable tolerance for this poison by Ther-
marces cerberus.

There is less information available concerning Thermarces andersoni. The types
were trap-caught, and the stomach of the paratype proved to be empty. The trap entered
was baited with fish, which may also indicate a generalized food habit for this species.

Otoliths were removed from four specimens of Thermarces cerberus. All show
clear and opaque bands (Fig. 8). Given the limited nature of the material it would be
premature to ascribe significance to the banding, but it is suggestive that otoliths from
the three large specimens (250, 244, 239 mm) have two clear zones and that of a smaller
one (181 mm) has but one.

Acknowledgments

The following individuals provided information, specimens, or both: Eric Anderson,
California Academy of Sciences; Roberta Baldwin, SIO; John Corliss, Oregon State
University; Harmon Craig, SIO; Daniel Desbruyeres, IFREMER, CENTOB, Brest;
John Edmond, Massachusetts Institute of Technology; Richard Haedrich, Memorial
University of Newfoundland; Robert Hessler, SIO; Emory Kristof, National Geographic
Society; Charles Paull, SIO; John Porteus, Woods Hole Oceanographic Institution;
Michel Segonzac, CENTOB, Brest; F. N. Spiess, SIO. We thank them all.

Material of Thermarces andersoni was supplied by the Centre National de Tri
d'Oceanographie Biologique (CENTOB, Brest) and came from mission BIOACYTHERM,
organized by the IFREMER (Centre de Brest).

Literature Cited

Anderson, M. E. 1984. On the anatomy and phy-
logeny of Zoarcidae (Teleostei: Perciformes).
Ph.D. Dissertation. School of Marine Science,
The College of William and Mary in Virginia.

Arp, A. J., and J. J.Childress. 1983. Sulfide bind-
ing by the blood of the hydrothermal vent tube
worm Riftia pachyptila. Science 213:342-344.

Cavanaugh, C. M. 1983. Symbiotic chemauto-
trophic bacteria in marine invertebrates. Na-
ture 320:58-61.

Cohen, D. M., and R. L. Haedrich. 1983. The fish
fauna of the Galapagos thermal vent system.
Deep-Sea Research. 30(4A):37 1-379.

, and J. G. Nielsen. 1978. Guide to the iden-
tification of genera of the fish order Ophidi-
iformes with a tentative classification of the
order. National Oceanic and Atmospheric
Administration Tech. Rept., National Marine
Fisheries Service Circular 417:1-72.

Gosztonyi, A. E. 1977. Results of the research
cruise of the FRV "Walter Herwig" to South
America XLVIII. Revision of the South Amer-
ican Zoarcidae (Osteichthys, Blennioidei), with
the description of three new genera and five
new species. Arch. Fisch.-Wiss. 27(3): 19 1-249.

Hand, S. C, and G. N. Somero. 1983. Energy
metabolism pathways of hydrothermal vent
animals: adaptations to a food-rich and sulfide-
rich deep-sea environment. Biological Bulletin
165:167-181.

Paull, C. K., B. Hecker, R. Commeau, R. P. Free-
man-Lynde, C. Neumann, W. P. Corso, S. Go-
lubic, J. E. Hook, E. Sikes, and J. Curray. 1 984.
Biological communities at the Florida escarp-
ment resemble hydrothermal vent taxa. Sci-
ence 226(4677):965-967.

TRANSACTIONS
-, OF THE SAN DIEGO

.^RARY SOCIETY OF

^' "^^ NATURAL HISTORY

MAR ^ 6 1986

li ARX/AvRD
J ,y Volume 21 Number 5 pp. 81-87 24 February 1986

A lectotype for Dinapate wrightii Horn, the giant palm-borer, and
description of a new species of Dinapate from eastern Mexico
(Coleoptera: Bostrichidae)

Kenneth W. Cooper

Department of Biology, University of California, Riverside, California 92521 USA

Abstract. A lectotype is designated for Dinapate wrightii Horn. It is emphasized that Horn's type
series consists entirely of fragmentary, disarticulated specimens from which Horn drew a composite
description. Only three of these very imperfect syntypes appear to have been preserved. A second
species (Dinapate hughleechi new species) has been found infesting palms [Sabal texanum (Cook) Becc]
in east-central Mexico. Its description, secondary sexual characteristics, and taxonomic separation from
D. wrightii are presented.

Resumen. Un lectotipo para Dinapate wrightii Horn, el baranillo gigante de las palmeras y una
descripcion de una nueva especie de Dinapate del este de Mexico (Coleoptera: Bostrichidae). Un
lectotipo esta designado por Dinapate wrightii Horn. Se nota que el tipo Horn consiste solamente de
especimenes fragmentarios y desarticulados de los cuales Horn inferio una descripcion compuesta.
Parece que solamente tres de estos sintipos se han preservados. Un segunda especies {Dinapate hugh-
leechi new species) se ha encontrado infestando palmas [Sabal texanum (Cook) Becc] en el este-central
de Mexico. Su descripcion, sus rasgos sexuales secundarios y la separacion taxonomica de D. wrightii
se exponen en el texto.

Introduction

Dinapate (Horn 1 886a) until now has been a monotypic genus, with its sole species
a subject of unusual interest and speculation ever since its discovery. It was set apart
on morphological grounds from other bostrichids within a tribe Dinapatinae (Lesne
1910), later the subtribe Dinapatina (Lesne 1938), of which it has remained the sole
representative. Generic diagnoses are to be found in Horn (1886), Lesne (1909) and
Fisher (1950).

In keeping with its taxonomic isolation, there are distinctive aspects of its biology.
Almost all bostrichids are polyphagous, feeding upon ligneous tissues of a wide range
of plants (Lesne 1911). Few bostrichids attack living plant tissue, and only 5 other
species among the 400-500 known Bostrichinae include palms or their parts among
the beetles' ordinarily diverse sources of food (Lepesme 1947). Dinapate wrightii is,
therefore, markedly unusual among bostrichids. Not only does it regularly attack living
palms, but it would appear unique by being restricted in its development to but one
species, the California Fan Palm, Washingtonia filifera Wendl. (Baker 1971). The
known distribution of D. wrightii, southern California to Catavina in Baja California
Norte (Michelbacher and Ross 1 939), lies entirely within the natural range of W. filifera.
Dinapate is also the giant among bostrichids, by far the largest known, up to 60 mm +
in length from the anterior margin of the pronotum to the apices of the elytra. It thus
reaches nearly twice the length and 6.6 times the volume of the second largest bostrichid,
Apate terebrans Pallas (to 32 mm, Lesne 1909), a native of tropical Africa and a miner
oi Acacia and its relatives (Lesne 1924).

The purpose of this paper is to designate a lectotype for Dinapate wrightii Horn

and to describe a new species of Dinapate from eastern mainland Mexico that is also
a palm miner. A second study will provide information and new findings on the general
biology, host range, and distribution of Dinapate species, as well as critical comment
on the early history surrounding William Greenwood Wright's discovery of the beetle
bearing his name— a paradoxical record.

Designation of a Lectotype

The George H. Horn collection, Museum of Comparative Zoology, Harvard Uni-
versity, contains three articulated female specimens labelled as follows:

(1) Lectotype 3560/ Dinapate wrightii Horn. Moj. Des.;

(2) Cal./Para-type 3560-2;

(3) N.J./Hom Coll. H 10, 1 59 [the catalog number in Henshaw's third supplement
(1895)].

In addition there is a fourth "mock-up" of Dinapate wrightii made from fragments of
a male, blackened cork and beeswax, labelled: Para-type 3560-3.

When Horn (1886a) described D. wrightii he thanked Wright, the collector, "For
the fragments in my possession," and his descriptions and illustrations (plate I) were
prepared from fragments of "several specimens" (Horn 1885, 1886a; see also Schwarz
1899). Among these there were at least more than one representation of the female sex,
for he stated ". . . the smaller specimens are females" (Horn 1886a). Where are the
remaining fragments to be found of two or more females that Horn possessed?

There are four additional specimens of Z). wrightii in the John L. Leconte collection
at the Museum of Comparative Zoology, necessarily placed there after Leconte's death
in 1883 (and most certainly by Horn). Two of these are fragmented. One is a female
without labels, consisting of an elytron, abdominal venter, meso- and metastema, and
legs; the other is represented by a pair of male elytra mounted on a beetle-shaped piece
of wood on a pin, and is also without labels. Very likely these two are from the sets of
fragments from which Horn drew his descriptions and illustrations. I have been unable
to discover whether a fourth disarticulated specimen, or still more, attributable to
Horn's original series now exists. If so, the specimen or specimens are neither at Harvard
nor at the Academy of Natural Sciences in Philadelphia in which Horn's collection was
originally housed.

Horn's article appeared in the January 1886 issue of the Transactions of the
American Entomological Society, but that issue almost certainly was published at some
unrecorded later month. It was in fact first approved for publication on Jan. 28, 1886
as stated in the publication register of the American Entomological Society. It is thus
possible that Horn studied, but did not mount, keep, or explicitly mention, additional
fragments of the beetle possibly received along with "... the fragment of tree trunk
sent several months ago [early in June?] by W. G. Wright" (Horn 1886^). Later, in
early September of 1 886 and certainly after publication of Horn's description (for Horn
makes no mention there of having seen an intact specimen), an unspecified number of
Dinapate emerged from the fragment of trunk. With one possible exception, they were
females, no more than five or six in number, and assuredly are the only complete
specimens mentioned by Horn in his writings. Some of them at least are among the
intact specimens in the Horn and Leconte collections. Their possession made it un-
necessary for Horn to retain in his collection any fragmented specimens. Why then did
he keep "Para-type 3560-3"? Almost certainly that specimen, a male, was the best of
those used by Horn when describing Dinapate wrightii, and had value to him for that
reason.

In any case, the three fragmented specimens mentioned above certainly served as
pari of Horn's descriptive material and are syntypes, whereas none of the intact spec-
imens in the Horn and Leconte collections so served, nor did the female possessed by
the M seum National d'Histoire Naturelle, Paris, a gift from Horn in 1888. So what
is to be Tiade of the specimen in the Horn collection that is in fact labelled: "Lectotype
3560"?

Horn never formally designated a type, and I have been informed (by Mr. P. J.
Johnson and through Dr. A. F. Newton, ]r.— personal communication) that "When
the Horn collection was still in Philadelphia all the unique or first-specimen-of-the-
series specimens were labelled with cataloging numbers. Unfortunately the labels used
were printed as lectotype labels, and to date no lectotype has been designated."

For the reasons given, the only specimen of the series now in the Horn collection
that contributed to the description of Dinapate is the male mock-up bearing the sole
label: Para-type 3560-3. That specimen is designated here as the lectotype; the frag-
mented female and mounted male elytra in the Leconte collection are, accordingly,
paralectotypes.

A New Species of Dinapate

Mr. Hugh B. Leech, commenting in June 1984 on a draft of a manuscript devoted
to the biology and history o^ Dinapate wrightii, stated that Dinapate is also to be found
in eastern, mainland Mexico, about 1040 km E of Baja California, where he and Dr.
E. S. Ross had dug a partially disarticulated female from a palm log. That specimen
appears very similar to the female of D. wrightii insofar as the remains are concerned,
but differs noticeably by having an unusual amount of long hair on the frons. Then,
on Dec. 6, 1984, Dr. Ross Amett informed me that specimens of Dinapate, collected
in 1965 from eastern Mexico and thought to be a new species, are in the Florida State
Collection of Arthropods, Gainesville. Through his kindness, and the generosity of
Drs. Robert Woodruff and Eugene J. Gerberg, I have been permitted to examine and
study the three female specimens. Finally, and most fortunately, the California Academy
of Sciences possesses a male, collected by Dr. E. S. Ross in 1946, that I have been
permitted to include in this study. The five specimens do indeed represent a species
markedly similar in size and general appearance to smaller specimens of D. wrightii,
yet differ notably in many features that become striking only in aggregate.

The color names having a numerical notation in the following description are
represented by color swatches portrayed and described in Smithe (1974-1981).

Dinapate hughleechi new species
(Figures lA, IC, IE, II, IJ)

Description. —Length (anterior pronotal margin to elytral apex) 35-40 mm; width
at humeral umbone 12.7-14.4 mm. Head, body above, legs, palps, scape and funicular
joints of antennae dark, blackish to warm sepia (221 A); expanded portions of antennal
club warm sepia to burnt umber (22); pubescence long and abundant on head, mouth-
parts, tibiae, sternum and abdomen, ferrugino-testaceous to buff (24).

Head, including frontal furrow and clypeal suture, similar to D. wrightii, except
sides of clypeus, frons (especially bordering eyes), and upper occiput with abundant
long pubescence (may be diminished or lost with age). Antennae with 8th joint forming
a wide angle (80°±) above, length 10th joint about 1.8 x greatest breadth (Fig. IE).

Pronotum slightly wider than long (m w/1 = 1.9, range 1.07-1.10), similar to D.
wrightii with sparse, long pubescence along margins and flanks, strong, rasp-like pro-
jections anteriorly and laterally.

Scutellum concave above.

Elytra at humeral umbone broader than pronotum at widest (mean humeral width/
pronot. w. = 1.18, range 1 .06-1 .27); humeral umbone coarsely, deeply wrinkled, incised
and reticulated; sides subparallel; surface with 6 low, broad costae, crenulated along
lengths by angular, marginal punctures, disposed as in D. wrightii (Figs. IG, IH),
corresponding with the customary main longitudinal tracheae of the coleopterous wing
pad: costa 1 (Sc?) subparallel to fluted marginal bead, 2 and 3 (R and M?) arising from
below and behind the umbone, 3 very weak, obsolescent along most of length, 4 (Cu?),
5 (PCu?), and 6 ("A"), the sutural costa; costa 2 terminates below the outer broad
tumidity ("outer tubercle") above the declivity, and 3 and 4 terminate on that eminence
(Figs. IG, IH); 1 and 2 contact and then diverge in apical third (Fig. IH), basally

■ ■ III

- w» try -r w.«f-».f .V." r.*'.*".««.'"T~^''^"v^;a^ v\.

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3
2

5
4
3
2

Figure 1. Profile of elytral tubercles and declivities of (A) D. hughleechi male, (B) D. whghtii male, (C) Z).
hughleechi female, (D) D. whghtii female, with 10 mm scale for Figs. A-D. Fig. (E) antenna of Z). hughleechi,
with 3 mm scale, (F) of D. whghtii, to same scale as E. Fig. (G) left elytron of D. whghtii from above, (H)
same, obliquely from side (numbers to right of both figures designate costae), scale equals 10 mm. Fig. (I)
anterior face of hind tibia of female D. hughleechi and (J) male; (K) same, of D. whghtii female and (L)
male, with 5 mm scale for Figs. I-L.

enclosing a long subcostal cell; 5 terminates on the narrow, raised inner tubercle above
the declivity (Figs. 1 G, 1 H); 6 extends forward along the suture, diverging anteriorly
somewhat before the apex of the scutellum, margins raised and somewhat widened
along declivity. Dorsal intervals closely, coarsely punctate, the raised polished interstic-

es giving the appearance of being irregularly linked; elylral apices triangularly divergent,
more or less sinuate laterally.

Legs subequal in length; fore-tarsus (not including claws) shorter than tibia; mid-
and hind-tarsi subequal to their tibiae; tibiae flattened, with 8-12 blunt, subtriangular
teeth on outer margin (Figs. II, IJ); posterior surface of anterior tibia with 2-4 broadly-
based, small denticles (m = 2.8); anterior surface of mid-tibia with 6-13 (m = 8.8), of
hind-tibia with 0-10 (m = 5.3) blunt, low-lying tubercles, more or less in lines, 1-3
tubercles in breadth along apical 4/5ths of tibiae (Figs, II, IJ); asymmetry in numbers
and disposition of tubercles and marginal teeth of right and left tibiae the rule; a
conspicuous, smooth, polished area behind anterior apical spine and outer apical tooth
of hind-tibia (Figs. II, IJ), a smaller, more irregular area on mid-tibia; posterior surfaces
of mid- and hind-tibiae with abundant, long recumbent hair directed apically.

Pro-, meso-, metastemum and abdominal stemites finely asperate at bases of hairs;
metastemum appears strigate in part, metepistemum finely shagreened. Fifth visible
abdominal sternum truncate or slightly concave on apical margin, marginate, with the
margin broadened and polished along medial fourth.

Secondary sexual characteristics. —Male similar in size and overall morphology to
female but differing as follows: clypeus and front of head coarsely punctate, punctures
separated by a diameter or more (clypeus and frons of female closely and conspicuously
asperate); pronotal rasp-like tubercles on flanks and anterior dorsum of male more
strongly developed; inner ("sutural") posterior tubercle of elytron pointed, noticeably
projecting above elytral declivity but blunt, not or barely projecting in female {cf. Figs.
lA, IC); declivity shining, sparsely punctate (in female dull, densely rugose and as-
perate); tibiae broader apically (cf. Figs. II, IJ), with dense long hairs on posterior
surfaces of mid- and hind-tibiae, those of hind-tibiae very dense (inner surfaces of mid-
and hind-tibiae of female alike, hairs abundant but not dense); posterior surfaces of
joints 2-4 of mid-tarsi (and probably also of hind-tarsi, as is the case in D. wrightii)
with posteriorly-directed fans of long, stiff, hairs (female with relatively sparse, very
short hairs); hairs on disc of the 5th visible abdominal stemite not abruptly longer and
nearly erect (abruptly longer and erect or suberect in female). It is to be noted that a
hairy frons, while common among female Bostrichinae, is an uncommon attribute of
males (Lesne 1924).

Etymology.— The specific epithet hughleechi is in honor of Mr. Hugh B. Leech,
now Curator Emeritus of Coleoptera at the California Academy of Sciences who,
over very many years, has generously helped, counseled, and befriended countless
coleopterists, among whom I have had the great good fortune to be one.

Holotype. —Male, 37.5 mm long, from Mexico, State of Tamaulipas, 1 5 miles west
of Antigua Morelos [hence, near Nuevo Morelos— see below] ex palm log, Nov. 10,
1946, E. S. Ross collector. Collection of the California Academy of Sciences, San
Francisco, type number 15290. The type was evidently taken from the log as a dead
specimen; it is nevertheless the individual in best condition of all 5 specimens available.
It lacks palpi, joints 9-10 of both antennae, the right mid-tibia and tarsus, and both
hind tarsi.

Allotype. —Female, 35.4 mm long; from Mexico, State of San Luis Potosi, El Salto
Falls [Salto de Agua], elevation 402 m (1320 ft), April 22, 1965, E. M. Collins, Jr.,
collector. Florida State Collection of Arthropods, Gainesville. The allotype lacks the
right maxillary palp, both antennae beyond joints 2, right anterior tarsal joints 4-5,
and the left posterior tarsus.

Paratypes. —One female, Mexico, State of Tamaulipas, near Nuevo Morelos, dead
when collected, in poor condition, ex log of Sabal texana (Cook) Becc. (determined as
S. mexicana Cook, a junior synonym [Bailey 1961], by J. F. Hart of Ciudad Valles,
San Luis Potosi, Mexico), Nov. 18, 1948, Hugh B. Leech and E. S. Ross collectors,
California Academy of Sciences.

Two additional females, of same label data as the allotype, Florida State Collection
of Arthropods, Gainesville, lacking antennae, one or more palps and legs.

Comment. —The three specimens from the Florida State Collection of Arthropods

came loose during shipment to me. The broken palps, antennae, legs, and parts of legs
were recovered; though suitable for study, they cannot with certainty be matched to
individual specimens. They are now collectively preserved in a gelatin capsule accom-
panying the specimens, labelled and mounted on a pin.

Recognition ofD. hughleechi.— Though not easily distinguished from all specimens
of/), wrightii without the use of a lens, D. hughleechi is nevertheless strikingly different.
In descending order of ease in determination, it may be separated by (1) the concavity
of its scutellar disc (convex in D. wrightii), (2) the large, subrectangular, slightly convex,
polished apical area on the anterior face of the hind tibia (a lesser one on the mid-
tibia) {cf. Figs. II, IJ, with IK, IL), (3) the abundant long hairs on clypeus, frons and
occiput, recognizable by their stumps when abraded (in D. wrightii there are few long
hairs on the clypeus or supraorbitally, and the hairs of the occiput, which are rarely
lost, are numerous but inconspicuous, very short, fine and decumbent), (4) the strongly
wrinkled and deeply incised reticulation of the humeral umbone, (5) the inner and
outer elytral tubercles above the declivity are less well-developed {cf. Figs. 1 A, 1 C with
IB, ID, IG, IH), (6) first joint of the antennal club (joint 8) has its superior dorsal
angle >78° (in D. wrightii ca. 65°, cf. Figs. IE, IF), (7) the outer marginal teeth of the
tibiae are broader, blunter (m angle = 41°, range 31°-51°, Figs. II, IJ; in D. wrightii
m = 29°, range 25°-37°, Figs. IK, IL; also Lesne, 1909, pi. 14, figs. 3, 4), and (8) the
tubercles on the anterior face of the mid- and hind-tibiae, and posterior face of the
anterior tibia, are decumbent and blunt (spinulose and suberect in D. wrightii; cf Figs.
11, IJ with IK, IL).

The costae on the flanks (especially costa 3) of the elytra in D. hughleechi are not so
strongly defined, although I would expect some individuals in a larger sample to have
them equally developed to those of £>. wrightii. Horn (1886) overlooked costae 2, 3
and 6 when describing D. wrightii, and Fisher (1950) noted only "four or five obtusely
rounded, longitudinal costae." Admittedly all six costae are not definable at a glance.
But if an elytron is removed from a specimen, and a fine pin is passed through each
of the six tracheae running lengthwise and close to the inner surface, the resulting six
(pin-) holes on the outer surface of the elytron immediately flag the costae. Once seen
in this manner, they can be made out in all specimens of both species seen by me {n =
5 and 76 respectively) and correspond precisely with those figured by Lesne (1898:446,
fig. 49) for Bostrichus capucinus Linn.

Diagnosis of the genus Dinapate.— Fisher's (1950, pp. 51-52) fine diagnosis re-
quires only three emendations now that a second species is known: (1) "Scutellum
small, quadrate, strongly elevated:— delete "strongly elevated"; (2) "tibiae . . . armed
on exterior margins with a few large, triangular teeth "—delete "few"; (3) ""posterior
tarsi as long as tibiae"— replace with: mid and posterior tarsi subequal to tibiae.

Acknowledgments

Special gratitude is extended to Mr. Hugh B. Leech who first called my attention to
the occurrence of Dinapate in mainland Mexico. I am indebted to Drs. David Kav-
enaugh and Paul Amaud for loan of the holotypic male and for information concerning
W. G. Wright's specimens and collecting records; to Mr. Saul Frommer, of the Uni-
versity of California at Riverside, for use of the specimens in his custody; to Drs. Ross
Amett and Robert Woodruff'of the Florida State Collection of Arthropods, Gainesville,
and to their colleague Dr. Eugene F. Gerberg, for their generous suggestion that I describe
the specimens in their care. To Dr. Alfred F. Newton, Jr., Curatorial Associate in
Entomology at Harvard University, and to Mr. Paul J. Johnson (now at the University
of Idaho), I am greatly indebted for their detailed and cordial responses to my many
questions concerning specimens of Dinapate in the collections of the Museum of Com-
parative Zoology. Dr. Jean J. Menier, of the Museum Natural d'Histoire Naturelle,
Paris, obligingly sent me accession records of the specimen of Dinapate used by Lesne
in erecting the tribe Dinapatinae. I thank Ms. Carol M. Spawn, Manuscript and Archives
Librarian of the Academy of Natural Sciences, Philadelphia, who searched for possible

records that would establish the issue-dates of the Transactions of the American En-
tomological Society for 1886, and for correspondence between Wright and Horn (of
which none seems to remain), as well as Mr. Donald Azuma, at the same institution,
who searched for additional fragments of Dinapate upon which Horn based his new
genus and species. Professor R. Ruibal and Mrs. G. Gordh kindly rendered the title
and abstract in Spanish.

Literature Cited

Bailey, L. H. 1961. Palmaceae. In C. L. Lundell.
Flora of Texas 3:197-199 (issued 1944). Texas
Research Foundation, Rennev.

Baker, N. W. 1971. Observations on the biology
of the giant palm-boring beetle, Dinapate
wrighti [sic] Horn. (Coleoptera: Bostrichidae).
Journal of the New York Entomological So-
ciety 79:31-42.

Fisher, W. S. 1 950. A revision of the North Amer-
ican species of beetles belonging to the family
Bostrichidae. U.S. Department Agriculture
Miscellaneous Publications 698.

Henshaw, S. 1895. Third supplement to the list
of Coleoptera of America, North of Mexico.
American Entomological Society, Philadel-
phia.

Horn, G. H. 1885. (Proceedings, Month. Mtg.
Entomol. Sect. Acad. Nat. Sci., Philadelphia,
Dec. 14, 1885.) Transactions American En-
tomological Society 12:xxiv.

. 1886a. Dinapate wrightii and its larva.

Transactions of the American Entomological
Society (Philadelphia) 13:1-4.

1886Zj. (Proceedings, Month. Mtg. Ento-

mol. Sect. Acad. Nat. Sci., Philadelphia, Sep.
23, 1 886.) Transactions American Entomolog-
ical Society, Philadelphia 13:xix.
Lepesme, P. 1947. Les insectes des palmiers.
Lechevalier, Paris.

Lesne, P. 1898. Revision des coleopteres de la
famille des bostrychides. 3' Memoire. Annales
Societe Entomologique France 67:438-621.

. 1910. Revision des coleopteres de la fa-
mille des bostrychides. 6*" Memoire: Dinapa-
tinae et Apatinae. Annales Societe Entomo-
logique France (1909) 78:471-574.

. 1911. Le regime alimentaire des bostry-
chides. Bulletin Societe Entomologique France
16:135-138.

. 1924. Les coleopteres bostrychides de

TAfrique tropicale Franfaise. Encyclopedie
Entomologique 3. Lechevalier, Paris.

. 1938. Coleopterorum Catalogus. Pars 1 6 1 .

Bostrychidae. W. Junk, s'-Gravenhage.

Michelbacher, A. E., and E. Ross. 1 939. The giant
palm borer (Coleoptera: Bostrichidae), an eco-
nomic pest in lower California. California State
Department of Agriculture Bulletin 28:166-
169.

Schwarz, E. A. 1899. (Proceedings, Mtg Dec. 2,
1897.) Proceedings of the Entomological So-
ciety of Washington 4:230.

Smithe, F. B. 1974-1981. Naturalist's Color
Guide, Part 1(1975); Color Guide Supplement,
Part 11 (1974); Supplement, Part 111 (1981).
American Museum of Natural History, N.Y.

ivy

TRANSACTIONS
OF THE SAN DIEGO
SOCIETY OF
NATURAL HISTORY

Volume 21 Number 6 pp. 89-110 5 December 1986

Holocene terrestrial gastropod faunas from Isla Santa Cruz and Isla
Floreana, Galapagos: evidence for late Holocene declines

Steven M. Chambers '-^Sf^/\p^

Office of Endangered Species, U.S. Fish and Wildlife Service, Washington, D.C. 20240 USA and
Department of Biology, George Mason University, Fairfax, Virginia 22030 USA i _

-'^ 7986

David W. Steadman'

Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution,
Washington, D.C. 20560 USA ^N:

Abstract. We report 1 6 species of land snails from late Holocene cave deposits and nearby surface
areas on Isla Santa Cruz and Isla Roreana, Galapagos Islands. These snails are associated with vertebrate
fossils that accumulated in lava tubes or fissures largely as the regurgitated items of bam owls (Tyto
punctatissima). Most or possibly all of the snails, however, probably do not represent prey remains,
but entered the cave mainly with infilling sediment. The fossil snails represent a much less complete
sample of each island's historic fauna than do the vertebrate fossils from the same deposits. Radiocarbon
ages on these faunas range from 2420 ± 25 years BP to Modem. Lectotypes and paralectotypes are
designated for Naesiotus nesioticus and Naesiotus reibischi. Naesiotus galapaganus, which is rare in
historic collections, occurred abundantly in the fossil deposits on Floreana. Five species from these
collections on Santa Cruz had not been previously reported from this island (Gastrocopta duncana,
Succinea corbis, Guppya bauri, and two species of Naesiotus that have recently been described else-
where). As with vertebrates, certain species of snails have suffered considerable late Holocene declines
in range and abundance, and possibly have become extinct in Galapagos. The causes of gastropod
declines are not clear, but are likely related to human impact of the past century. The most likely cause
is habitat destruction by introduced goats, donkeys, and pigs, although predation by introduced rodents
may also be important.

Introduction

Fossils have traditionally played a minor role in studies of the evolution and
biogeography in the Galapagos Islands. This is largely because few scientists have looked
for them and have regarded the volcanic terrain of Galapagos (Fig. 1 ) to be a poor
environment for the deposition and preservation of fossils. Invertebrate fossils have
been reported from localized marine sedimentary rocks in Galapagos (Hertlein 1972
and references therein), but these studies were based upon field work done decades
before absolute dating of volcanic rocks was possible through potassium-argon and
paleomagnetic determinations. Renewed interest in the Quaternary marine fossils of
Galapagos (James 1984, Hickman and Lipps 1985) has resulted from new collections
from deposits stratigraphically related to lava flows whose ages are fairly well known.

Until the past several years, the paleontology of terrestrial organisms in Galapagos
had received even less attention than that of marine organisms. Again, much of this
lack of attention was due to the axiom of geology that states the rarity or lack of fossils
in volcanic rocks. Biologists (e.g.. Lack 1960) lamented that Galapagos was, unfortu-
nately, an area that had yielded no paleontological clues about the history of the birds

' Present address: Biological Survey, New York State Museum, The State Education Department, Albany,
New York 12230 USA.

91«00

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I I I I I I I

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SEYMOUR NORTE

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SAN CRISTOBAL

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Figure 1 . Galapagos Islands, Ecuador. Dots indicate the approximate locations of the fossil sites on Floreana
and Santa Cruz.

or other terrestrial organisms for which these islands are so well known. This situation
has now changed.

In 1978 and 1980, DWS collected large samples of fossil vertebrates from Isla
Santa Cruz and Isla Floreana (Fig. 1), and a smaller sample from Isabela. In 1984,
large collections were made on San Cristobal, Rabida, and Isabela. Only the collections
from Santa Cruz and Floreana yielded large samples of gastropods. The fossil vertebrates
from Santa Cruz and Floreana, and to some extent those from Isabela, have been
reported (Steadman 1981, 1982, 1985, 1986; Steadman and Ray 1982); from these
reports we have abstracted the stratigraphic and chronological context of the fossil snail
faunas, supplemented for Santa Cruz by data previously unpublished. Although none
of the fossil deposits has been shown to pre-date even the Holocene, the paleofaunas
nevertheless shed new light on the natural (=before human contact) distributions of
species, and have helped to resolve problems in the systematics of living or recently
extinct species.

Late Holocene vertebrate paleofaunas have shown that human-caused predation
and habitat degradation have altered natural patterns of distribution and diversity on
islands (Pregill and Olson 1981, Olson and James 1 982^, b, Olson and Hilgartner 1 982,
Steadman et al. 1984). In Galapagos as well, analyses of vertebrate paleofaunas have
revealed much extinction that is related to human impact (Steadman and Ray 1982,
Steadman 1986). The present analysis of gastropods from the same fossil sites
provides a comparison from an entirely different element of the Galapagos paleofauna.

Site Descriptions and Sampling Methods

The fossil snail collections are mainly from lava tubes or fissures in the arid
lowlands. Lava tubes are especially effective repositories for terrestrial sedimentation
in Galapagos.

Floreana. —The fossil fauna of Floreana was collected from four caves in the Post
Office Bay region in the north-central coast of the island (see figs. 2-3 of Steadman
1986). The elevations of the caves range from 20 to 50 m above modem sea level. No
cave is more than 500 m from the present seashore. Access to each cave is through a
vertical collapse in the roof created by weathering processes such as pedogenesis, growth
of tree roots, and percolation of water. Two of the caves, Cueva de Post Office (Inferior)
and Cueva de Post Office (Superior), had been mapped previously by Montoriol-Pous
and Escola (1975), who also described various physical and chemical features of the
caves. The other two caves, Finch Cave and Bam Owl Cave, had not been mapped or
described before our explorations. Fossils were collected from the surface of the floor
of each cave, and except in Finch Cave, sediments were also excavated using standard
techniques and washed through screens of V^ inch and '/k, inch mesh. The species
composition of the faunas from excavations did not differ from that of the floor's
surface, although, as one would expect, a higher percentage of small species (both of
mollusks and vertebrates) was recovered from the screened sediments. Fossils were
typically most common near the roof collapse. The sediments from all excavations
were generally similar to each other in physical characteristics, consisting of combi-
nations of clays, silts, sands, and gravels that were usually poorly sorted and rather
angular. Water and gravity sliding seem to have deposited the sediments, but the poor
sorting, poor rounding, and lack of laminations suggest a short distance of transport.

The 20 000 vertebrate fossils from Floreana consist of nearly every resident species
of bird, reptile, and mammal, including six species that no longer occur on Floreana:
Geochelone elephantopus (tortoise), Alsophis biserialis (snake), Tyto punctatissima (bam
owl), Mimus trifasciatus (Floreana mockingbird), Geospiza nebulosa (sharp-beaked
ground-finch), and G. magnirostris (large ground-finch). The above species, except Tyto
punctatissima, are known on Floreana from early 1 9th century specimens. The loss of
each of these species can be related to human activities, especially the settlement of
the island in 1832 by several hundred people (Steadman 1986).

Six radiocarbon ages from the Floreana sites (table 2 of Steadman 1986) range
from 2420 ± 25 years BP to Modem. Each determination is based upon material from
the surface of the floor, as no organic material other than bone and gastropod shells
was recovered from the sub-surface. The radiocarbon data indicate that organic material
has been accumulating in the Floreana caves for at least the past several thousand
years. We cannot say how much older certain of the underlying sediments are, but
based upon similarities in faunal composition and in preservation of the bone itself,
all excavated materials are probably also late Holocene in age.

Santa Cruz.—Ks with the paleofaunas of Floreana, the fossil vertebrate faunas
from Santa Cruz are derived mainly from regurgitated prey remains of bam owls {Tyto
punctatissima), and represent a thorough sampling of the vertebrate life of the island
before human disruption (Steadman 1986). Fossils were collected from two sites in the
arid lowlands of southem Santa Cruz {see fig. 2 of Steadman and Ray 1982). The
first is Cueva de Iguana, a fissure ca. 10m deep that trends east-west for at least several
hundred meters, parallel to and seaward from the conspicuous fault scarp 400 m north
of the Charles Darwin Research Station. The elevation of Cueva de Iguana is only ca.
10 m, and brackish water flows through its bottom. Vertebrate fossils have accumulated
in Cueva de Iguana in thin, unstratified pockets of sediment perched on small, horizontal
ledges of the roughly vertical walls. Eight such accumulations included land snails.

The second fossil site on Santa Cruz is Cueva de Kubler, a large lava tube 1.5 km
north of Puerto Ayora, at ca. 75 m elevation. Cueva de Kubler has been mapped and
described by Stoops (1967), Balasz (1972), and Montoriol-Pous and de Mier (1977),
none of whom, however, noted the abundance of fossils within the cave. Five exca-

vations were made in the loose, powdery, unstratified sediments of Cueva de Kubler,
and fossils were collected from the floor's surface as well. Excavations IIB, IIC, IID,
and HE were in sediments that had been redeposited within the cave. Excavation IIA,
whose sediments were the source of those in Exs. IIB-IIE, had not been redeposited.
Therefore, unlike in Exs. IIB-IIE, the sediments of Ex. IIA contained fossils only of
native fauna, uncontaminated by the remains of two murine rodents {Rattus rattus and
Mus musculus) introduced onto Santa Cruz in historic times. Bones of the introduced
rodents occurred on the surface of Ex. IIA, but not within the sediments. Excavation
IIA (1.0 m X 3.0 m x 0.8 m deep) was spectacularly fossiliferous, especially in the
upper half, whereas Exs. IIB-IIE, which were smaller in volume than Ex. IIA, were
very fossiliferous throughout. A very crude estimate of the number of vertebrate fossils
from these excavations is several hundred thousands. The sediments of both Cueva de
Iguana and Cueva de Kubler are rather poorly sorted silts, clays, and pebbles. Deposition
was probably through a combination of water, wind, and gravity sliding.

The vertebrate faunas of Cueva de Iguana and Cueva de Kubler are similar, both
being dominated by an extinct rice rat {Nesoryzomys indefessus). Two other extinct
rodents occur in fair numbers (the smaller rice rat A'^. darwini and the giant thoma-
somyine rat Megaoryzomys curioi). Both species of Nesoryzomys became extinct on
Santa Cruz in the 20th century, whereas Megaoryzomys has never been recorded his-
torically. Each species of terrestrial reptile ever reported from Santa Cruz, including
the historically extinct land iguana {Conolophus subcristatus), occurs in the sites, as
does nearly every species of resident bird.

No radiocarbon ages have been determined for the paleofauna of Cueva de Iguana,
but these fossils are undoubtedly late Holocene in age, based upon the loose nature of
the sediments and the low level of mineralization of the fossils, some of which are
entirely modem in appearance. Several radiocarbon ages have been determined for the
Cueva de Kubler paleofauna, but these samples (wood) were badly contaminated with
modem radioactive carbon, probably from surface testing of nuclear weapons in the
Pacific (R. Stuckenrath in litt.). Unfortunately, therefore, the ages for the Cueva de
Kubler samples vary from 1755 ± 335 years BP to 1 17.5% of Modem. Even the older
date probably is contaminated by bomb-produced radiocarbon. Because bones and
snails may be less prone to radioactive contamination than plant material, there is still
hope of obtaining future determinations that have minimal contamination. Resolution
of the chronology of Cueva de Kubler and Cueva de Iguana will depend either upon
species-specific radiocarbon dating of bone itself, using tandem accelerator mass spec-
trometry (such as done recently for plants by Betancourt et al. 1984), or the dating of
large quantities of land snails through fairly standard counting techniques, as outlined
by Goodfriend and Hood (1983) and Goodfriend and Stipp (1983).

A surface sample of empty snail shells was collected for camparison with the cave
samples along the trail to Tortuga Bay on Santa Cmz, ca. 1.5 km south of Cueva de
Kubler at ca. 30 m elevation. This locality represents shells that were lying beneath
and between large basaltic boulders along the trail.

Systematics

The Galapagos land snail fauna was reviewed by Dall (1 896) and Dall and Ochsner
(1928). Additional contributions include those of Pilsbry (1897-1898, 1916-1918,
1927-1935), Odhner (1950), A. G. Smith (1966, 1971, 1972, 1974), and Vagvolgyi
(1974, 1977). Breure and Coppois (1978) analyzed shell and anatomical features
of most of the Galapagos bulimulid species and rejected the subgeneric classification
of Dall (1920). These authors also reported on the locations of type material of many
Galapagos species and designated lectotypes for some. Breure (1979) gave additional
information on the locations of type material in his review of the Bulimulinae. Coppois
and Glowacki (1983) used factor analysis to study shell variation among species from
Isla Santa Cruz.

This report is based on over 1 0 000 fossil shells, which have been deposited in the

Figure 2. Shells of some Galapagos land snails. All except F and I are fossil shells from Isla Santa Cruz
or Isla Floreana. A, Succinea corbis (USNM 861456) from Cueva de Kubler, Santa Cruz; B, Naesiotus
galapaganus (USNM 861559) from Bam Owl Cave, Floreana; C, Naesiotus cymatias (USNM 86 1 490) from
Cueva de Iguana, Santa Cruz; D, Naesiotus blombergi (USNM 86 1 505) from Cueva de Kubler; E, Naesiotus
ochsneri (USNM 86 1 502) from Cueva de Kubler; F, Naesiotus reibischi lectotype; G-H, A', reibischi (USNM
86 1532) from entrance to Cueva de Kubler; I, Naesiotus nesioticus lectotype; J-K, Naesiotus nesioticus from
Cueva de Kubler (USNM 86 1 509); L, Naesiotus kublerensis holotype from Cueva de Kubler (USNM 842298).
Scale bar is 10 mm.

Division of Mollusks, National Museum of Natural History, Smithsonian Institution,
Washington, D.C. Species were identified mainly by examination of the published
literature and by comparison with the collections of Galapagos gastropods in the Di-
vision of Mollusks of the National Museum of Natural History, Washington, D.C.

(specimen catalog numbers indicated by the prefix USNM); the California Academy
of Sciences in San Francisco (CAS); the Academy of Natural Sciences of Philadelphia
(ANSP); and the Museum of Comparative Zoology of Harvard University (MCZ). Type
material was examined for all but three of the species identified from fossils. No attempt
was made to revise classification at the generic or familial levels.

Unfortunately, no detailed, comprehensive account has been published on the land
snails collected in 1964 during the Galapagos International Scientific Project, now
housed mainly at the California Academy of Sciences. A. G. Smith (1966) provided
an informative summary, but these collections have not yet been described in detail.
A thorough review of this collection and associated field notes would improve our
understanding of the habitats occupied by the various species of land snails. The habitat
data available in Ochsner's (1905-1906) field notes, R. P. Smith's (1971) unpubHshed
study, and Coppois' (1984) transect study of the northern slope of Santa Cruz are useful
but are inadequate to make definitive statements about the range of habitats of land
snails, thus limiting our interpretations of the fossil fauna.

Class Gastropoda Cuvier, 1797
Subclass Prosobranchia Milne Edwards, 1848 (=Streptoneura Spengel, 1881)

Order Archaeogastropoda Thiele, 1925

Family Helicinidae Latreille, 1825

Genus Helicina Lamarck, 1799

Helicina nesiotica Dall, 1892

Helicina (Idesa) nesiotica DALL, 1892, p. 97.
Sturanva nesiotica (Dall). WAGNER 1905-191 1, p. 45.
Helicina nesiotica Dall. A. G. SMITH 1971, p. 7.

Typ^.-Holotype: USNM 107324. PI. XV, figs. 1-2, in Dall (1896). Type locality
is Chatham (San Cristobal) Island at 1600 feet (488 m) above sea level (Dall 1892).

Material. -U^'NM 861375-861395 (Santa Cruz), USNM 861396 (Floreana).

Remarks. —Two species oi Helicina have been described from Galapagos, both by
Dall (1892, 1917). Helicina nesiotica is based on a specimen from Isla San Cristobal
(Chatham). Dall's descriptions (1892, 1896) of this species refer to its "bright reddish
chestnut epidermis" or periostracum. Dall described Helicina ochsneri Dall, 1917 from
material (type: USNM 2 1 602 1) from Isla Isabela (Albemarle). He described this species'
periostracum as "blackish," but noted that removal of the periostracum of//, ochsneri
exposed a shell with a surface and color similar to //. nesiotica.

All the fossil Helicina lack the periostracum, so their identification as //. nesiotica
is based on the sizes of the fossil specimens. Shell height/diameter for //. nesiotica is
3.3 mm/2.3 mm (Dall 1892) and for //. ochsneri is 4.7 mm/3.5 mm (Dall 1917). Some
fossil individuals approach the measurements stated for //. ochsneri and may belong
to that species.

Dall and Ochsner (1928) reported H. nesiotica from Roreana. Based on exami-
nation of CAS material and the holotype, the Helicina reported from Santa Cruz by
A. G. Smith (1966) is //. nesiotica.

Subclass Pulmonata Cuvier, 1817 (=Euthyneura Spengel, 1881, in part)

Order Stylommatophora A. Schmidt, 1856

Family Achatinellidae Gulick, 1873

Subfamily Tomatellininae Pilsbry, 1910

Genus Tornatellides Pilsbry, 1910
Tornatellides chathamensis (Dall, 1892)

Leptinaria chathamensis DALL, 1892, p. 98.
Tornatellina chathamensis (Dall). DALL 1900, p. 95.
Tornatellides chathamensis (Dall). ODHNER 1950, p. 254.

Types. -\J%'\<iM 107322 (6 syntypes). One specimen in PI. XVI, fig. 9, of Dall

(1896). Type material was taken on ferns at 1600-2000 feet (488-610 m) above sea
level on Chatham (San Cristobal) Island.

Material. -VSNM 861397-861403 (Santa Cruz).

Remarks. —Placement of this species in Tornatellides and the subfamily Toma-
tellininae of the family Achatinellidae follows Cooke and Kondo (1960). Vagvolgyi
(1974) noted that Tornatellides chathamensis and Nesopupa galapaganus Vagvolgyi,
1974 represent the only Indo-Pacific elements in the Galapagos land snail fauna, which
is otherwise Neotropical in origin.

Cooke and Kondo (1960:246) observed that individuals in two lots in the Bishop
Museum (BPBM 115299 from Chatham [San Cristobal] Island and BPBM 115300
from Albemarle [Isabela] Island) are not as sharply conical as the specimen figured by
Dall ( 1 896, PI. 1 6, fig. 9). SMC compared the fossil specimens with the syntypes (USNM
107322), finding that the fossils likewise are less conical than the figure and syntypes.

Dall (1896) included Bulimulus (Pelecostoma) cymatoferus Reibisch, 1892 in his
synonymy for this species. Dall's name was published earlier in 1892 and therefore
has priority. Our examination of Reibisch's (1892) description and figure suggest that
Dall's assessment was correct, although we have not seen Reibisch's type material (see
comments below on types of Gastrocopta clausa).

Smith (1966) first reported Tornatellides from Santa Cruz.

Family Pupillidae Turton, 1831

Genus Gastrocopta WoUaston, 1898

Gastrocopta duncana Pilsbry, 1931

Gastrocopta duncana PILSBRY, 1931, p. 65-66, PI. 17, figs. 1-2.

Types.— M^^V 152689 includes the lectotype designated by Baker (1963) and 3
paralectotypes. Additional paralectotypes: ANSP 152690 (8 shells) and ANSP 152691
(5 shells). Pilsbry (1931) reported that the 17 specimens of the type m.aterial were
collected with Gastrocopta clausa on the south side of Duncan (Pinzon) Island. He
stated that these localities were from 500 feet (152 m) elevation to the summit (457
m), with G. duncana being more abundant at the summit.

Material. -US'HM 861404 (Santa Cruz).

Remarks.—^ single specimen from the trail near Cueva de Kubler, Santa Cruz,
represents the first record of this species outside of Isia Pinzon.

Gastrocopta clausa (Reibisch, 1892)

Pupa (Leucochila) clausa REIBISCH, 1892, p. 15.
Gastrocopta clausa (Reibisch). PILSBRY 1916, p. 99.

Types.— The location of Reibisch's type material for this species is not known to
us, although Breure (1979) reported that some of Reibisch's bulimulid type material
is in the British Museum (Natural History) and the Zoologisches Museum der Hum-
boldt-Universitat in Berlin. Reibisch's (1892) description includes a figure (PI. II, fig.
10) and a description of the type locality as shrubs near the sea. Indefatigable (Santa
Cruz) Island.

Material. -VSNM 861405-861426 (Santa Cruz), USNM 861427-861440 (Flo-
reana).

Remarks. —Pilshry (1931:69) considered Gastrocopta clausa to be very similar to
but distinct from Gastrocopta munita (Reibisch, 1892), the former having a well de-
veloped subcolumellar tooth that is either absent in G. munita or very weakly tuber-
culate, consisting only of a sloping callus. Later, Pilsbry (1931:71 and pi. 17) referred
to specimens of G. clausa from Chatham (San Cristobal) Island that lacked this sub-
columellar tooth. These observations plus LaRochelle's (1983) report of apparent in-
traspecific variation in tooth number among some North American pupillids lead us
to question the reliability of this character for separating these two species. The other
character that Pilsbry used to separate these species, the presence of a nodule associated

with the parietal lamella that is present in his "typical" G. clausa, but absent in G.
munita, also seems deficient as a diagnostic character. The fossils are identified as G.
clausa because of the presence of a subcolumellar lamella, expressed to varying extents,
and the lack of any other apparent and consistent variation among them. A revision
of the Galapagos Gastwcopta, a preliminary version of which was very briefly described
in an abstract by Vagvolgyi (1979), could resolve some of the confusion concerning
these forms.

Family Succineidae Beck, 1837

Genus Succinea Drapamaud, 1801

Succinea corbis Dall, 1893

Figure 2A

Succinea corbis DALL, 1893, p. 55.

7>j^£'5.-USNM 107321 (13 syntypes). PI. XV, fig. 5, of Dall (1896). The type
locality is Albemarle (Isabela) Island.

Material. -US^M 861441-861465 (Santa Cruz).

Remarks. —Species identifications based on shell material alone must be considered
tentative in this difficult family. The fossil Succinea are referred to S. corbis because
they possess the fine microsculpture that Dall (1893) described as "an excessively fine
network of closely reticulated fine incised lines." Dall and Ochsner (1928) later stated
that the "lattice-like corrugation" had disappeared from the type material owing to
contraction of the periostracum. SMC has examined the syntypes and found this mi-
crosculpture to be seen easily under 30 x magnification.

Expression of the fine microsculpture ranges from strong to faint. The fine micro-
sculpture was not visible on some of the smaller or more eroded shells. These were
identified as S. corbis because they differed in no other way from the microsculptured
shells in the same lots, although it cannot be ruled out that some or all of these are
Succinea bettii Edgar Smith, 1877. The specimen (USNM 107318) that Dall (1896, PI.
XV, fig. 6) apparently portrayed as an example of S. bettii shows the S. corZjz^-like
microsculpture on unworn outer surfaces of the shell and is considered here to be S.
corbis. We have not examined the type material of S. bettii; it is probably in the British
Museum (Natural History) [BM(NH)], where Edgar Smith was keeper of mollusks.
Examination of this material for microsculptural features would aid in determining
whether S. bettii and S. corbis are synonyms.

A similar pattern of microsculpture is present in two shells (USNM 163056 and
USNM 216030) from Cocos Island, Costa Rica, although the overall shell form of
these individuals is very short-spired and therefore distinct from S. corbis. Another
example may be that referred to as "crisscross" sculpture by Solem (1959) in his
discussion of Quick's (1939, 1951) work on some Austromalayan Succinea.

This is the first record for Succinea corbis on Santa Cruz.

Family Bulimulidae Tryon, 1867
Genus Naesiotus Albers, 1850

Remarks.— Tho, full generic status of Naesiotus, including the Galapagos species,
has been recognized by A. G. Smith (1971, 1972, 1974), Vagvolgyi (1977), Breure and
Coppois (1978), and Breure (1979), although Coppois and Glowacki (1983) recognized
Naesiotus as a subgenus of Bulimulus.

Naesiotus galapaganus (Pfeiffer, 1854)
Figure 2B

Bulimus galapaganus PFEIFFER, 1854, p. 58.

Bulimulus (Naesiotus) galapaganus (PfeifTer). DALL 1896, p. 435 [synonymy].

Naesiotus galapaganus (Pfeiffer). BREURE AND COPPOIS 1978, p. 176.

rj/7^5. -Lectotype [BM(NH) 1975 146] and paralectotype [BM(NH) 1975 147] des-
ignated by Breure and Coppois (1978) (not seen). Pfeiffer (1854) listed the type locality
only as the "Galapagos Islands."

Table 1 . Measurements of shells of some adult Naesiotus. Ranges are within parentheses. Specimens are
from Santa Cruz unless otherwise indicated.

Sample

Shell height

Terminal apical

Specimens

size

in mm

angle in degrees

Naesiotus nesioticus:

Lectotype

13.2

Paralectotypes

12.8

26.7

(11.6-14.7)

(22-31)

USNM 215982

13.0

(11.6-13.7)

(22-26)

Trail to Tortuga Bay

12.6

23.8

(11.6-13.1)

(22-26)

Cueva de Kubler surface

12.6

21.5

(12.3-12.8)

(20-23)

Cueva de Kubler Excavation IIA

13.2

23.3

(12.3-17.3)

(20-27)

Cueva de Kubler Excavation IIB

12.9

23.1

(11.5-14.0)

(18-26)

Cueva de Kubler Excavation IIC

13.2

(12.8-13.5)

(22-44)

For all N. nesioticus above

13.0

23.5

(11.5-17.3)

(18-31)

Naesiotus reibischi:

Lectotype

10.9

Paralectotype

9.6

USNM 534106 (James Island)

11.4

15.3

(10.9-11.9)

(15-16)

Cueva de Iguana

11.8

16.2

(10.9-13.1)

(14-17)

Cueva de Kubler surface

11.8

16.2

(10.5-13.3)

(13-18)

Cueva de Kubler Excavation IIA

12.4

17.5

(12.2-12.6)

(17-18)

For all A^. reibischi above

11.7

16.2

(9.6-13.3)

(13-18)

Naesiotus kublerensis:

Holotype

10.9

Paratypes:

Cueva de Kubler surface

11.0

34.3

(10.1-12.2)

(30-40)

Cueva de Kubler Excavation IIA

11.4

Naesiotus duncanus holotype

18.9

Naesiotus hirsutus holotype

9.9

Naesiotus cavagnaroi MCZ paratypes

21.6

(19.8-23.2)

(51-62)

Material. -USNM 861551-861613 (Roreana).

Remarks.— Wq are not aware of any published records of this species since Dall
(1896) reported it among the collections made by G. Baur in 1890. This species was
found in large numbers in all fossil deposits sampled on Floreana.

Naesiotus cymatias (Dall, 1917)
Figure 2C

Bulimulus (Naesiotus) cymatias DALL, 1917, p. 380.
Naesiotus cymatias (Dall). BREURE 1979, p. 69.

Type. -CAS 1667 (not seen). Photograph in Dall and Ochsner (1928: fig. 19). The
type locality is described by Dall (1917) as "Indefatigable [Santa Cruz] Island, under
lava blocks in a moist area between 400 and 600 feet [122 and 183 m] elevation."

Material. -VSNM 861474-861498 (Santa Cruz).

Naesiotus ochsneri (Dall, 1917)
Figure 2E

Bulimulus (Naesiotus) ochsneri DALL, 1917, p. 38.
Naesiotus ochsneri (Dall). A. G. SMITH 1972, p. 12.

7-y;,^5._Holotype: CAS 1668; fig. 20 in Dall and Ochsner (1928). Paratypes: CAS
1490 (3 shells); CAS 1669 and 1670 (one shell each) are labeled as "syntypes"; USNM
215932 (ten shells) labeled as paratypes and with collection data identical to that
accompanying Dall's description. The type locality is described as "Indefatigable Island,
under lava blocks at 200 to 650 feet [61 to 198 m]" (Dall 1917).

Material. -VSNM 861449-861504 (Santa Cruz).

Naesiotus nesioticus (Dall, 1896)
Figure 2I-K

Bulimulus (Naesiotus) nesioticus DALL, 1896, p. 443.
Bulimulus (Naesiotus) naesioticus [sic] Dall, DALL 1920, p. 121.
Naesiotus nesioticus (Dall). BREURE 1979, p. 70.

Types.— US'NM 107277 (Fig. 21) is here designated the lectotype. This specimen
was figured by Dall (1896, PI. XVI, fig. 1) with the original description. A printed label
with the specimen indicates that it is the figured "type." The protoconch is mostly
missing. Measurements of the four specimens of USNM 107277a, here designated
paralectotypes, are presented in Table 1 . The type locality is James Island (Isla Santiago).

Material. -US^M 861506-861529 (Santa Cruz).

Remarks.— This species is further discussed below with Naesiotus kublerensis.

Naesiotus reibischi (Dall, 1895)
Figure 2F-H

Bulimulus (Naesiotus) Reibischii DALL, 1895, p. 26.

Bulimulus (Naesiotus) Reibischi Dall. DALL 1896, p. 444 [emendation].

Naesiotus reibischi (Dall). BREURE AND COPPOIS 1978, p. 183.

Types. -The shell (USNM 107279) depicted in PI. XVI, fig. 4, of Dall (1896) and
Figure 2F of this paper is here designated the lectotype. This specimen's label indicates
that it is the figured "type." USNM 107279a, apparently the second specimen men-
tioned by Dall (1895:127) in the type lot, is here designated a paralectotype. Some
measurements of these specimens are presented in Table 1 . The type locality is Inde-
fatigable Island (Isla Santa Cruz).

Material. -VSNM 861530-861550 (Santa Cruz).

Remarks.— The long, slender fossil bulimulids are identified here as either A^.
nesioticus or A^. reibischi (Fig. 2F-K). Coppois and Glowacki (1983) reported two
additional slender species, which they referred to as unidentified, from Santa Cruz (see
remarlcs on Naesiotus kublerensis). Another long, slender species, Naesiotus rugiferus
(Sowerby, 1833), has been reported from Santa Cruz by R. P. Smith (1971) and Breure
and Coppois (1978). Coppois and Glowacki described the apical sculpture of their two
unidentified species and A^. nesioticus as undulating riblets. Breure and Coppois (1978)
described the protoconchal sculpture of A^. rugiferus as undulating and A^. reibischi as
straight. Examination of the protoconchs of our material and the USNM types revealed
that the riblets are straight in the type material of both A^. reibischi and A^. nesioticus.
This feature could not be discerned reliably in most of our fossil material; the riblets
were mostly straight when visible, with some waviness in a few individuals, especially
material here referred to N. reibischi. The slight variation observed in this feature in
the fossil shells provides no basis for referring them to species other than A^. reibischi
and N. nesioticus. Naesiotus reibischi is further discussed in the comments below on
Naesiotus kublerensis.

Naesiotus blombergi (Odhner, 1950)
Figure 2D

Bulimulus blombergi ODHNER, 1950, p. 255.

Naesiotus deroyi A. G. SMITH, 1972, p. 9.

Naesiotus blombergi (Odhner). A. G. SMITH 1974, p. 67.

7>/7^5.— Breure (1979:68) indicated that a holotype was in the Swedish State Mu-
seum of Natural History (Naturhistoriska Riksmuseet) in Stockholm. We are not aware
of any published designation of a lectotype for this species. In the original description,
Odhner (1950) indicated that 12 specimens constituted the type material and described
the type locality as being ''200-300 m above sea level on plants, bushes, and trees" on
Isla Santa Cruz. That description included figures (Figs. 1, 3-5) of an apertural view
of the shell of a single specimen and of apical sculpture, jaw, and radula.

A. G. Smith (1972) designated CAS 13730 as the holotype of TV. deroyi. He also
designated 72 paratypes, which he indicated that he had distributed to various museums
and private collections. These paratypes include the 4 alcohol-preserved specimens of
MCZ 280009 and 4 dry specimens of USNM 735981, all of which were examined in
the present study. Smith's type material was taken on a thorny bush at 264 m elevation
on the northwest side of Isla Santa Cruz.

Material -\JSHM 861505 (Santa Cruz).

Naesiotus kublerensis Chambers, 1986
Figure 2L

Naesiotus kublerensis CHAMBERS, 1986, p. 289.

Types. -Uo\o\y^Q (USNM 842298) and paratypes (USNM 842299, 7 shells; USNM
842300, 1 shell; USNM 842301, 7 shells; USNM 842302, 5 shells; USNM 842303,
25 shells) from the entrance of or within Cueva de Kubler, Santa Cruz (Chambers
1986). Figure 2L is of the holotype. Paratypes in figure 3 of Chambers (1986) include
two shells from USNM 842299 and three shells from USNM 842301.

Material. -USNM 842298-842304 (Santa Cruz).

Remarks. —Among the several, high-spired Naesiotus species reported from Santa
Cruz are two "unidentified" species reported by Coppois and Glowacki (1983), whose
work represents an important quantitative comparative study of Santa Cruz bulimulids.
Assigning names to our three elongate species of fossil Naesiotus (N. reibischi, N.
nesioticus, and A'^. kublerensis) and comparison with the available data on Coppois and
Glowacki's unidentified species necessitated a more detailed analysis (described below)
using the method developed by those authors. In this analysis, the elongate species are
compared with respect to two measurements: shell height and terminal apical angle.
Coppois and Glowacki (1983) concluded from factor analysis of seven measurements
that these two measurements defined intraspecific variation well enough that in most
cases an individual bulimulid shell from Santa Cruz could be assigned to a species
simply by taking these two measurements and comparing them to those of known
samples of only five shells per species, as portrayed in their Figure 3.

In the present study, these two characters were determined (to the nearest . 1 mm
or the nearest whole degree) for shells of A^. nesioticus, N. reibischi, N. kublerensis, and
to available type material for these and other species, following the methods of Coppois
and Glowacki. These data are summarized in Table 1 and Figure 3.

Three major clusters (represented by triangles, circles, and squares, respectively)
of points are discemable in Figure 3. The most discrete of these consists of shells here
considered as representing A^. reibischi (squares) and including the type material for
that species. This cluster overlaps the coordinates representing Coppois and Glowacki's
unidentified species "22" and "56" and is disjunct from their values for A^. reibischi.
In the absence of further information on species "22" and "56," and based on the
coordinates of the type material, we refer these very slender shells to A^. reibischi.

The cluster representing our material of A^. nesioticus (circles) overlaps Coppois

100

^25

<
Z 20

10-

AA A A;

A 68 !

\^ 1

Aa!

A
A

A
O

o®

. ^ ^A

-^ 81 ^~~^^-i

0 O 00 o
OO 0 ® (KD OO O
0 0 ® O O
9-0 00 (DO 0

kT 7 "--. 000 0

D 0 ~~"~~--"o

■oa

wmm

■ ■ ^C D

56 /-^ ■

10 II 12 13 14

SHELL HEIGHT (mm)

N. reibischi

nesioticus

N.k

ubierensis N. hirsutus

KUBLER

IGUANA

■

TRAIL

USNM

LECTOTYPE

HOLOTYPE 0

PARALECTOTYPE

Figure 3. Variation in two characters in some elongate Naesiotus. Each symbol may represent more than
one individual. Numbered areas enclosed by dashed lines were drawn after fig. 3 of Coppois and Glowacki
(1983) and delimit their ranges of these measurements for A", reibischi (7), A^. hirsutus (18), A^. jacobi (68),
TV. nesioticus (81), and two unidentified species of Naesiotus (22 and 56). Shells are from Isla Santa Cruz,
except the type and "USNM" material of A', nesioticus.

101

and Glowacki's coordinates for both N. reibischi and N. nesioticus. These are identified
here as N. nesioticus because this cluster includes the lectotype of TV. nesioticus and is
disjunct from the N. reibischi type material. Most shells in this cluster are more slender
than the lectotype. We do not believe that this cluster represents common ancestors
of A^. reibischi and A^. nesioticus because it includes non-fossil material. In addition,
neither character is correlated with depth in fossil deposits. As discussed above in the
remarks on A^. reibischi, the differences between N. reibischi and N. nesioticus in apical
sculpture of the shell cited by Coppois and Glowacki (1983) are not supported by the
type material.

The third cluster (triangles) represents Naesiotus kublerensis and includes a wider
range of values for terminal apical angle, but a narrower range for shell height, than
the other two clusters. A lectotype of TV. nesioticus is found near the edge of this cluster,
which also overlaps Coppois and Glowacki's (1983) coordinates for Naesiotus hirsutus
Vagvolgyi, 1977 and Naesiotus jacobi (So-werhy, 1883). Naesiotus kublerensis, however,
possesses axial sculpture that becomes rugose on the body whorl, which is not found
on either A^. Jacobi or A^. hirsutus (Chambers 1986).

The failure of some type material to fall within Coppois and Glowacki's circum-
scribed boundaries for the corresponding species led us to measure these two characters
in additional available Naesiotus type material. Coordinates representing the type of
Naesiotus duncanus (Dall, 1893), the paralectotype of A^. reibischi, and some MCZ
paratypes of Naesiotus cavagnaroi A. G. Smith, 1972, fall outside the limits circum-
scribed for these species by Coppois and Glowacki (1983). The lectotypes of A^. nesi-
oticus and A^. reibischi fall within the limits set by Coppois and Glowacki, but the two
paralectotypes of A^. nesioticus fall outside. Although Coppois and Glowacki (1983:
2 1 5-2 1 6) found that five specimens for each species adequately described the range of
variation of larger samples for the species that they studied, their samples did not
encompass the variation in all type material and in our material of A^. nesioticus and
A^. reibischi.

Naesiotus steadmani Chambers, 1986
Naesiotus steadmani CHMA^ERS, 1986, p. 287.

Types. -ThQ holotype (CAS 059358) and 67 paratypes (CAS 038052) are shells
collected under lava rocks on a cliff above Academy Bay, Santa Cruz. Figure 1 of
Chambers (1986) portrays the holotype and three paratypes.

Material. -\JS\^M 842297 (Santa Cruz).

Remarks.— ThQ single fossil specimen {see fig. 1 of Chambers 1986) resembles A^".
cymatias, but has a higher spire than that species. It is more weathered in appearance
than most of the other fossil shells. The type material was collected on Santa Cruz, but
not identified, by A. G. Smith in 1964.

Family Helicarionidae Godwin-Austen, 1888

Genus Guppya Morch, 1867

Guppya bauri (Dall, 1892)

Zonites {Hyalinia) Baueri DALL, 1892, p. 98.
Trochomorpha bauri (Dall). DALL 1896, p. 447 [emendation].
Guppya bauri (Dall). DALL 1900, p. 92.

Typ^.-USNM 107317. PI. XV, figs. 8-9 in Dall (1896). The type, which for many
years was the only known specimen, was found on ''South Albemarle [Isabela] Island
on weathered bones of tortoises" (Dall 1892).

Material. -US^M 861466-861467 (Santa Cruz).

Remarks. —B^ktv (1941:223) suggested that this species may belong in the genus
Habroconus Fischer and Crosse. This species has been reported from Espaiiola, Pinzon,
Isabela, and Pinta (Dall and Ochsner 1928), but not previously from Santa Cruz.

102

Genus Habroconus Fischer and Crosse, 1872
Habroconusl galapaganus (Dall, 1893)

Conulus galapaganus DALL, 1893, p. 55.

Euconulus galapaganus (Dall). DALL AND OCHSNER 1928, p. 175.

Habroconusl galapaganus (Dall). A. G. SMITH 1971, p. 7.

Types.-US^M 107315 (three syntypes), PI. XV, fig. 11 in Dall (1896). Type
locality is described on the label of the syntypes as the southwestern end of Chatham
Island (San Cristobal) at 1600 feet (488 m).

Material. -VSl^M 861468 (Santa Cruz).

Remarks.— BakQV (1941:223) commented that this species may also belong in
Habroconus, a suggestion apparently followed by Vagvolgyi (1975, Table 4). A. G.
Smith (1966) reported Euconulus (= Habroconus?), probably this species, from Isla
Santa Cruz.

Family Zonitidae Morch, 1864

Genus Retinella Fischer in Shuttleworth, 1877

Retinella? chathamensis (Dall, 1893)

Hyalinia chathamensis DALL, 1893, p. 54.
Vitrea chathamensis (Dall). DALL 1896, p. 448.
Retinella? chathamensis (Dall). A. G. SMITH 1971, p. 7.

Type. -USNM 107316. PI. XV, figs. 3, 10 in Dall (1896) appear to be illustrations
of the type. Dall (1893) described the type locality as 1600 feet (488 m) on Chatham
(San Cristobal) Island.

Material. -IJSNM 861469-861473 (Santa Cruz).

Remarks.— Although reported from a number of islands in Galapagos (Dall and
Ochsner 1928), this species had not been recorded on Santa Cruz until A. G. Smith's
1966 report.

Discussion

Distribution of species in fossil deposits.— Only three species were found as fossils
at the Floreana localities (Table 2). Two of these, Helicina nesiotica and Gastrocopta
clausa, are small species more commonly recorded from screened excavations than
from hand-picked surface remains. Naesiotus galapaganus is extremely abundant in

Table 2. Fossil land snails from Floreana. X indicates the presence of the species.

Helicina

Gastrocopta

Naesiotus

nesiotica

clausa

galapaganus

Cueva de Post Office (Superior)

Surface

Excavation 1

Excavation 2

Excavation 3

Excavation 4

Cueva de Post Office (Inferior)

Surface

Excavation 1

Excavation 2

Excavation 3

Bam Owl Cave

Surface

Excavation

Finch Cave

Surface

103

Table 3. Land snails from Cueva de Iguana, Santa Cruz. Numbers in Tables 3-6 indicate the minimum
number of individuals represented by the fossil material.

Site

Site 4E

Site 4W

Site 5E

Site 5W

Area

Ledge

Area

Ledge

Site

Helicina nesiotica

Tornatellides chathamensis

Gastrocopta duncana

Gastrocopta clausa

Succinea cordis

Naesiotus cvmatias

Naesiotus ochsneri

Naesiotus nesioticus

Naesiotus reihischi

Naesiotus blombergi

Naesiotus kublerensis

Naesiotus steadmani

Guppya bauri

Habroconusl galapaganus

Retinellal chathamensis

all Floreana samples, although this Floreana endemic has only rarely been collected
before.

On Santa Cruz, Naesiotus cymatias was by far the most common species found
in excavations. Thousands of shells of this species were recovered from the excavations
in Cueva de Kubler and Cueva de Iguana. Tornatellides chathamensis, Succinea cordis,
and Naesiotus reibischi were also found at all sites, but in lesser numbers.

Only four species were recovered from Cueva de Iguana (Table 3). In contrast to
the Kubler excavations, Naesiotus reibischi was found in Cueva de Iguana in the absence
of A^. nesioticus. Species composition was similar for all sites within Cueva de Iguana,
except that Helicina nesiotica was recovered only from Site 4W.

All 14 species from excavations on Santa Cruz were found in Cueva de Kubler
(Tables 4-6). A notable feature of the Kubler fauna is the abundance of A^. nesioticus,
which was not found at Cueva de Iguana. The similar, high-spired species A^. reibischi
was also present, but in smaller numbers. Samples of shells taken from the surface of
soil deposits among boulders both just outside and within the cave entrance also

Table 4. Land snails from entrance and Excavation IIA in Cueva de Kubler (except column under "Trail"),
Santa Cruz. The Trail site represents a surface collection of shells from beneath boulders.

Surface:

Excavation IIA

near

Entrance

0-20

20-40

40-60

60-80

Trail

entrance

rubble

Helicina nesiotica

111

Tornatellides chathamensis

Gastrocopta duncana
Gastrocopta clausa
Succinea corbis

1
3

38
26

48
21

Naesiotus cvmatias

171

-1000

159

-2200

246

Naesiotus ochsneri

Naesiotus nesioticus

107

Naesiotus reibischi

Naesiotus blombergi
Naesiotus kublerensis

Naesiotus steadmani

Guppya bauri
Habroconusl galapaganus
Retinella? chathamensis

1
1

104

Table 5. Land snails from Cueva de Kubler, Excavation IIB, Santa Cruz.

Surface

0-6

6-12

12-18

18-24

24-30

30-36

Helicina nesiotica 3 399 3 3 1 7

Tornatellides chathamensis

Gastrocopta duncana

Gastrocopta clausa 4 6 2 11

Succinea corbis 10 2 2

Naesiotus cymatias 109 -1100 -600 433 339 403 73

Naesiotus ochsneri 1 3

Naesiotus nesioticus 9 70 23 17 7 10 5

Naesiotus reibischi 4 112 4

Naesiotus blombergi 1

Naesiotus kublerensis

Naesiotus steadmani

Guppya bauri

Habroconus? galapaganus

Retinellal chathamensis 1 1 0

contained both species, but A^. reibischi was by far the more common. This is curious
because these samples were taken from places that would seem to be source areas for
snail shells washed into Cueva de Kubler after severe rains. We believe, however, that
the snails are from the immediate catchment basin and have not been transported from
other habitats. The sample of shells from the trail to Tortuga Bay (collected from the
surface of soil deposits among boulders, just as in the surface sample from outside
Cueva de Kubler) contained TV. nesioticus, but not A^. reibischi. Of these two species,
the more common one (A^. nesioticus) in the Kubler fossil sites and in the surface site
near the trail to Tortuga Bay (downslope from Cueva de Kubler) is less common at
and near the entrance of Cueva de Kubler. The absence of A^. nesioticus from the Cueva
de Iguana sites may indicate vegetational preference, because Cueva de Iguana is about
65 m lower in elevation than Cueva de Kubler, and one of us (DWS) has observed
that the area around Cueva de Iguana lacks several species of woody plants that are
common near Cueva de Kubler.

Naesiotus kublerensis was found only in the surface samples from near the trail to
Tortuga Bay and near the entrance to Kubler, and in the top level of Kubler Excavation
IIA. It is absent from deeper levels of IIA and from other excavations in Kubler and
the Iguana sites.

Table 6. Land snails from Cueva de Kubler, Excavations IIC and HE, Santa Cruz.

Excavation IIC Excavation HE

0-6 6-12 12-18 18-24 24-30 20-30 30-40

cm cm cm cm cm cm cm

Helicina nesiotica 9 100 9 24

Tornatellides chathamensis 1

Gastrocopta duncana

Gastrocopta clausa

Succinea corbis 1 1

Naesiotus cymatias 2 9 12 6 9

Naesiotus ochsneri 1 1

Naesiotus nesioticus 3 8 4 3 6

Naesiotus reibischi 1

Naesiotus blombergi

Naesiotus kublerensis

Naesiotus steadmani

Guppya bauri

Habroconusl galapaganus

Retinellal chathamensis

500

-500

105

Twelve of the 17 shells of A^. ochsneri were found in Kubler Excavation HE. The
five additional shells were found in Excavations IIB and IIC. Strangely, this species
was absent from Excavation IIA, whose sediments represent the source area for the
sediments of Excavations IIB and IIC. This is significant because only Excavation IIA
is uncontaminated by post-European introductions. Several of these fossils consist of
only a body whorl, lacking a shell spire. This damage pattern may indicate predation
by rodents (Stokes 1917), and it is possible that these snails were carried into the cave
by introduced rodents (most likely Rattus rattus) after the extinction of native rodents
(Steadman and Ray 1982).

Deposition of land snails in fossil sites. —The snails probably entered the caves by
several means. 1) Land snails commonly retreat into moist areas, including crevices
and caves, during daily or seasonal dry periods. 2) Snails or their empty shells are
washed into the caves with sediment influx during periods of extremely high rainfall.

3) Birds, rodents, or lizards may bring snails into caves as prey items. Most fossil shells,
however, lacked damage patterns that might indicate such predation. An exception is
Naesiotus ochsneri, discussed above. Snail shells were not present in owl pellets {see
Mienis [197 1] for a report of snail shells in pellets from the owl Athene noctua in Israel).

4) Snails entering the caves may have remained there to feed upon the accumulated
bones and shells, which represent a rich source of calcium.

If some species of snails tend to feed on bones and shells more than others, then
factor 4 may at least partially explain why some species and not others were found in
cave deposits. Of the 5 1 species of land snails reported from Floreana or Santa Cruz
or both, five have been recorded in the literature as having been collected on bones
outside of cayQS— Tornatellides chathamensis, Gastrocopta clausa, Gastrocopta munita,
Succinea corbis, and Guppya baud (Dall 1896, Dall and Ochsner 1928). All but Gas-
trocopta munita are among the 16 species found as fossils in the present study. This
suggests that at least some species may have entered and/or remained in the caves
because of the accumulations of bone and shell inside. The numbers of species reported
as occurring on bones versus those that have not falls short, however, of being signif-
icantly heterogeneous (x"i = 3.6346, P = .052) between species found as fossils and all
species recorded on Floreana and Santa Cruz. We have also identified fossil fecal strands
from Cueva de Kubler that were probably left by one of the larger Naesiotus species,
indicating that some snails were alive in the cave for at least a short time. To summarize,
we believe that factors 1, 2, and 4 are important means of entry into fossil caves by
snails, with factor 2 perhaps being especially important for the various species of
Naesiotus, whose relatively sturdy shells are better able to withstand the rigors of
sediment influx.

Comparison of fossil and historic snail faunas.— EsseniiaWy all fossil records are
only subsets of the entire fauna being sampled, so it is expected that only a portion of
the known land snail species from Floreana and Santa Cruz were found in the fossil
deposits. On Santa Cruz, 1 5 species were found as fossils in or near deposits out of a
reported total of 34 species in the historic fauna for that island (Dall 1900, 1917, Dall
and Ochsner 1928, Pilsbry 1931, Odhner 1950, A. G. Smith 1966, 1972, Vagvolgyi
1977, Coppois and Glowacki 1983, this study). Of the historic fauna of 26 species on
Floreana (Dall 1896, Dall and Ochsner 1928, Pilsbry 1931, A. G. Smith 1966), only
three were found as fossils. On both islands, habitat preference probably accounts for
many of these absences, for numerous species are known only from higher elevations
than those of the fossil sites. We are not certain, however, why the Floreana fossil sites
sampled the snail fauna so much more poorly than those of Santa Cruz, although
perhaps the mode of sedimentary influx, especially the smaller sizes of the catchment
basins on Floreana, is involved.

Among the species found as fossils on Santa Cruz, nine had not been reported
from that island previous to A. G. Smith's visit in 1964. These are Helicina nesiotica,
Tornatellides chathamensis, Gastrocopta duncana, Succinea corbis, Guppya bauri,
Habroconus? galapaganus, Retinellal chathamensis, Naesiotus kublerensis, and Nae-
siotus steadmani. Except for Succinea corbis, which belongs to a taxonomically difficult

106

family, and the two Naesiotus, these are small snails that are no more than a few mm
in their greatest shell dimension. A. G. Smith (1966) added new Santa Cruz records
for all of these small species except Gastrocopta duncana and Guppya bauri. Our new
records for Gastrocopta duncana and Guppya bauri consist, respectively, of only one
and three shells.

Comparison of the fossil records of snails and vertebrates. —The distinction between
historic faunas and paleofaunas is more difficult to discern with land snails than with
vertebrates. Historic vertebrate faunas are based on specimens or field accounts taken
of living individuals, whereas the historic land snail fauna of Galapagos is based largely
on shell material, which under favorable conditions may persist intact and relatively
unchanged for many years after the death of the animal. Thus the "historic" fauna may
include species that were already extinct when first collected, and therefore we may be
underestimating the extent of extinction in land snails. Historic faunas of snails therefore
may be more representative of the natural (pre-human contact) fauna than are vertebrate
faunas. In this respect, well-known historic faunas of land snails may be more appro-
priate subjects than birds and other vertebrates for tests of equilibrium ecological
theories {see Solem [1982] for a recent study).

The fossil records of vertebrates from Floreana and Santa Cruz are more complete
samples of the local fauna than those of snails. From both islands, the fossils included
every species of terrestrial mammal or reptile, including those now extinct. The resident
land bird faunas of Floreana and Santa Cruz are quite diverse (over 20 species), but
the fossil record lacks only five species, three of which {Neocrex erythrops, Coccyzus
melacoryphus, and Dendroica petechia) probably colonized Galapagos relatively re-
cently, perhaps less than a thousand years ago (Steadman 1986). The fourth species,
Buteo galapagoensis, is a large hawk that does not live in caves and is not preyed upon
by bam owls; the absence of the fifth species, the owl Asioflammeus, can be accounted
for in the same way.

The main reason that the fossil snails represent a much less complete sample of
each island's local fauna is probably that the snails were not being concentrated in the
caves by predators. Therefore, unlike the vertebrates that were being sampled within
approximately a 1 km radius of the cave (the estimated home range of the bam owl
Tyto punctatissima), only the snails that lived in the immediate vicinity of the caves
had an opportunity to be deposited within the caves.

Vertebrate extinction in the late Holocene of Galapagos occurred mainly or entirely
in historic times, and can be related circumstantially to human-related impacts. Such
impacts, especially habitat disturbance, may have affected the present snail faunas. In
contrast to some cases of vertebrate extinction in Galapagos, direct human predation
is an unlikely factor in land snail declines. The detrimental, often catastrophic, effects
of land clearing for agriculture and of introduced mammals on land snail faunas on
Pacific islands and elsewhere, however, has been noted repeatedly (e.g., Solem 1974,
1976, Christensen and Kirch 1981a, b. Wells et al. 1983, Neck 1984). Agricultural
conversion has very likely been detrimental to Galapagos land snails on Floreana, the
island in the archipelago with the longest history (beginning early in the 1 9th century)
of human settlement (Slevin 1959). Santa Cruz was not settled until the present century,
but is now the most heavily populated and visited island, and much of the southern
part, including areas near the fossil localities, has been converted to agricultural uses
(Schofield 1973).

Introduction of exotic organisms, especially mammals, is probably the most per-
vasive human-caused threat to the native land snails in Galapagos. Feral goats {Capra
hircus), cattle (Bos taurus), donkeys {Equus asinus), pigs (Sus scrofa), dogs (Canis
familiaris), and cats (Felis catus) have lived or are living on both Floreana and Santa
Cruz; and goats, cats, and donkeys remain common today in the vicinity of the Floreana
fossil sites (Steadman 1986). Cats and dogs probably had no effect on snails, but
cattle, donkeys, pigs, and especially goats can destroy land snail habitat by removing
or altering native plant communities through persistent grazing and browsing (Weber
1971, Hamann 1975). Pigs have the additional destmctive habit of rooting through

107

litter and soil; this turning over of the substrate can kill snails directly and, more
importantly, exposes moist, subsurface refuges to desiccation. Rooting pigs may also
eat snails that they encounter.

Introduced rats (Rattus rattus) and mice {Mus musculus) are present in Galapagos.
Rodent-gnawed shells have been found on islands that have declining land snail faunas
(e.g., Stokes 1917). Although predation by introduced rodents on land snails is extremely
likely, it is possible that in some cases they gnaw already dead shells for calcium, as
they sometimes do on vertebrate bone. Interactions between rodents and living land
snails deserve intensive investigation. Indications of rodent predation on Galapagos
fossils are limited to Naesiotus ochsneh, as discussed earlier.

Although detrimental effects have yet to be reported, introduced snails have been
recorded from Galapagos (Smith 1966). Replacement of native land snails by intro-
duced snails has been noted on islands elsewhere (Solem 1974, Christensen and Kirch
1981a, b), although it is sometimes not clear if these cases involve direct competition
and replacement or simple occupation by introduced snails of human-modified habitat
that has become unsuitable for native species. The introduced predatory snails that
have proven so catastrophic to other island land snail faunas (Hadfield and Mountain
1980, Clarke et al. 1984) have not yet made an appearance in Galapagos. Introduced
ants (Lubin 1984) are also potential predators on native land snails (Solem 1976).

Although direct evidence of impacts of humans and introduced mammals is lack-
ing, except for possible rodent predation, there are a number of indications that such
influences exist. Despite the efforts of Ochsner in 1905-1906 and A. G. Smith in 1964,
Gastrocopta duncana and Guppya bauri, both reported here as fossils, were not pre-
viously reported from Santa Cruz. Naesiotus cymatias, N. ochsneri, N. blombergi, and
many of the smaller species found as fossils have been reported from historic collections
on Santa Cruz, although generally from higher elevations than the fossil sites. Naesiotus
kublerensis and Naesiotus steadmani are known only from limited shell material and
may be extinct. Naesiotus cymatias on Santa Cruz and Naesiotus galapaganus on
Floreana are rare in historic collections, but both are ubiquitous and extraordinarily
abundant as fossils.

Dall long ago warned of the vulnerability of the Galapagos land snail fauna, citing
gaps in the understanding of the Hawaiian fauna "because the sheep and goat have
preceded the investigator" (Dall 1896:29). Dall's warning was repeated by A. G. Smith
(1966). The DeRoy family, which has lived on Santa Cruz since 1958, has told DWS
(personal communication 1978, 1980) that it is much more difficult to find living
examples of most land snails today on Santa Cruz than it was only two decades ago.
Coppois and Glowacki (1983) made the general observation (supported in Coppois
[1984]) that some Santa Cruz bulimulid snails "are extinct or on their way to extinc-
tion." Extinction is difficult to prove in these land snails because living snails can be
overlooked owing to their inconspicuous color, size, and habits. Regardless, there are
clear signs of reductions in range and abundance.

Acknowledgments

Funds for field work were provided by the Smithsonian Institution's Fluid Research
Grants and Scholarly Studies Program, through the efforts of D. Challinor, S. L. Olson,
and S. D. Ripley. Museum work was funded by the National Geographic Society (Grant
2088 to DWS), Smithsonian Fellowships, and a National Science Foundation Grant
(DEB-7923840 to P. S. Martin). Field work was done with the assistance and coop-
eration of Parque Nacional Galapagos (M. Cifuentes, F. Cepeda) and Charles Darwin
Research Station (C. MacFarland, H. Hoeck, D. Duffy, F. Koster, G. Reck), as well as
numerous field companions. A. Long and R. Stuckenrath provided radiocarbon ages.
Curators and staffs of these collections allowed access to and (for CAS and MCZ) loans
of specimens (ANSP-G. M. Davis; CAS-T. M. Gosliner and B. Roth; MCZ-K. J.
Boss; National Museum of Natural History— J. Rosewater). SMC carried out most of
his contribution to this study while a Research Associate of the Department of Inver-

108

tebrate Zoology of the National Museum of Natural History, Smithsonian Institution.
He thanks the staff of the Division of Mollusks for their aid and forbearance. The
manuscript has been improved by thorough reviews and comments by B. Roth and C.
Christensen on an earlier draft. Figure 1 was drawn by E. Paige. Photographs for Figures
1-2 are by V. Krantz. This is Contribution Number 381 of the Charles Darwin Foun-
dation for Galapagos and Contribution Number 480 of the New York State Science
Service.

Literature Cited

Baker, H. B. 1941. Zonitid snails from Pacific
islands. Parts 3 and 4. Bemice P. Bishop Mu-
seum Bulletin 166:203-370.

. 1963. Type land snails in the Academy

of Natural Sciences of Philadelphia. Part II.
Land Pulmonata exclusive of North America
north of Mexico. Proceedings of the Academy
of Natural Sciences of Philadelphia 115:191-
259.

Balasz, D. 1972. Mapping oflava tunnels on Santa
Cruz Island. Noticias de Galapagos 19/20:10-
15.

Betancourt, J. L., D. J. Donahue, A. J. T. Jull, and
T. H. Zabel. 1984. Pre-Columbian age for
North American Corispermum L. (Chenopo-
diaceae) confirmed by accelerator radiocarbon
dating. Nature 21 1:653-655.

Breure, A. S. H. 1979. Systematics, phylogenyand
zoogeography of Bulimulinae (Mollusca).
Zoologische Verhandelingen (Rijksmuseum
van Natuurlijke Historic, Leiden), No. 168.

, andG. Coppois. 1978. Notes on the genus

Naesiotus Albers, 1850 (Mollusca, Gastropo-
da, Bulimulidae). Netherlands Journal of Zo-
ology 28:161-192.

Chambers, S. M. 1986. Two new bulimulid land
snails from Isla Santa Cruz, Galapagos. The
Veliger 28:287-293.

Christensen, C. C, and P. V. Kirch. 1981a. Non-
marine mollusks from archaeological sites on
Tikopia, southeastern Solomon Islands. Pacific
Science 35:75-88.

, and . 1981i». Land snails and en-
vironmental change at Barbers Point, Oahu,
Hawaii [Abstract]. Bulletin of the American
Malacological Union 1981:31.

Clarke, B., J. Murray, and M. S. Johnson. 1984.
The extinction of endemic species by a pro-
gram of biological control. Pacific Science 38:
97-104.

Cooke, C. M., Jr., and Y. Kondo. 1960. Revision
of Tomatellinidae and Achatinellidae (Gas-
tropoda, Pulmonata). Bemice P. Bishop Mu-
seum Bulletin 221.

Coppois, G. 1984. Distribution of bulimulid land
snails on the northern slope of Santa Cruz Is-
land, Galapagos. Biological Journal of the Lin-
nean Society 21:217-227.

, and C. Glowacki. 1983. Bulimulid land

snails from the Galapagos: 1 . Factor analysis
of Santa Cruz Island species. Malacologia 23:
209-219.

Dall, W. H. 1892. On some types new to the fauna
of the Galapagos Islands. The Nautilus 5:97-
99.

. iS93. Preliminary notice of new species

of land-snails from the Galapagos Islands, col-
lected by Dr. G. Baur. The Nautilus 7:52-56.

— . 1895. New species ofland-shells from the
Galapagos Islands. The Nautilus 8:126-127.

— . 1896. Insular landshell faunas, especially
as illustrated by the data obtained by Dr. G.
Baur in the Galapagos Islands. Proceedings of
the Academy of Natural Sciences of Philadel-
phia 1896:395-460.

— . 1900. Additions to the insular land-shell
faunas of the Pacific coast, especially of the
Galapagos and Cocos Islands. Proceedings of
the Academy of Natural Sciences of Philadel-
phia 1900:88-106.

— . 1917. Preliminary descriptions of new
species of Pulmonata of the Galapagos Islands.
Proceedings of the California Academy of Sci-
ences, 4th Series 2:375-382.

— . 1920. On the relations of the sectional
groups of Bulimulus of the subgenus Naesiotus
Albers. Journal of the Washington Academy
of Sciences 10:117-122.
-, and W. H. Ochsner. 1928. Landshells of

the Galapagos Islands. Proceedings of the Cal-
ifornia Academy of Sciences, 4th Series 17:
141-185.

Goodfriend, G. A., and D. G. Hood. 1983. Car-
bon isotope analysis of land snail shells: im-
plications for carbon sources and radiocarbon
dating. Radiocarbon 25:810-830.

, and J. J. Stipp. 1983. Limestone and the

problem of radiocarbon dating in land-snail
shell carbonate. Geology 1 1:575-577.

Hadfield. M. G., and B. S. Mountain. 1980. A
field study of a vanishing species, Achatinella
mustelina (Gastropoda, Pulmonata), in the
Waianae Mountains of Oahu. Pacific Science
34:345-358.

Hamann, O. 1975. Vegetational changes in the
Galapagos Islands during the period 1966-73.
Biological Conservation 7:37-59.

Hertlein, L. G. 1972. Pliocene fossils from Baltra
(South Seymour) Island, Galapagos Islands.
Proceedings of the California Academy of Sci-
ences, 4th Series 39:25-46.

Hickman, C. S., and J. H. Lipps. 1985. Geologic
youth of Galapagos Islands confirmed by ma-
rine stratigraphy and paleontology. Science 227:
1578-1580.

James, M. J. 1984. A new look at evolution in
the Galapagos: evidence from the late Ceno-
zoic marine molluscan fauna. Biological Jour-
nal of the Linnean Society 21:77-95.

Lack, D. 1 960. Preface to the Torchbook Edition
[of "Darwin's Finches"]. In Darwin's Finches.

109

1968. 204 pp. Peter Smith, Gloucester, Mas-
sachusetts. [Reprint of 1947 edition.]

LaRochelle, P. B. 1983. Shell morphological vari-
ation in Pupilla (Pulmonata: Pupillidac) [Ab-
stract]. American Malacological Bulletin 1:99.

Lubin, Y. D. 1984. Changes in the native fauna
of the Galapagos Islands following invasion by
the little red fire ant H'asmannia auropunctata.
Biological Journal of the Linnean Society 2 1 :
229-242.

Mienis, H. K. 1971. Theba pisana in pellets of an
Israelian owl. Basteria 35:1-4.

Montoriol-Pous, J., and O. Escola. 1975. Contri-
bucion al conocimiento vulcano-espeleologico
de la isla Roreana (Galapagos, Ecuador). Spe-
leon, Monografia I, V Symposium de Espeleo-
logia:57-67.

Montoriol-Pous, J., and J. de Mier. 1977. Con-
tribucion al conocimiento vulcano-espeleolo-
gico de la isla de Santa Cruz (Galapagos, Ec-
uador). Speleon 23:75-91.

Neck, R. 1984. Living terrestrial gastropods from
the Eastern Caprock Escarpment, Texas. The
Nautilus 98:68-74.

Ochsner, W. H. 1905-1906. Land shell faunas.
Unpublished transcript of Galapagos Islands
field notes deposited in the Division of Mol-
lusks Library, National Museum of Natural
History, Smithsonian Institution, Washington,
D.C.

Odhner, N. 1950. Studies on Galapagos buli-
mulids. Journal de Conchyliologie 90:253-268.

Olson, S. L., and W. B. Hilgartner. 1982. Fossil
and subfossil birds from the Bahamas. Pp. 22-
56 in S. L. Olson (ed.). Fossil Vertebrates from
the Bahamas. Smithsonian Contributions to
Paleobiology. No. 48.

, and H. F. James. 1982<2. Prodromus of

the fossil avifauna of the Hawaiian Islands.
Smithsonian Contributions to Zoology, No.
365.

, and . 1982^. Fossil birds from the

Hawaiian Islands: Evidence for wholesale ex-
tinction by man before Western contact. Sci-
ence 217:633-635.

Pfeiffer, L. 1 854. Descriptions of four new species
of Bulimus from the collection of H. Cuming,
Esq. Proceedings of the Zoological Society of
London 1854:57-58.

Pilsbry, H. A. 1897-1898. Manual of Conchol-
ogy, 2nd Series: Pulmonata. Volume 1 1 . Acad-
emy of Natural Sciences of Philadelphia.

. 1916-1918. Manual of Conchology, 2nd

Series: Pulmonata. Volume 24. Academy of
Natural Sciences of Philadelphia.
-. 1927-1935. Manual of Conchology, 2nd

Series: Pulmonata. Volume 28. Academy of
Natural Sciences of Philadelphia.

Pregill, G. K., and S. L. Olson. 1981. Zoogeog-
raphy of West Indian vertebrates in relation to
Pleistocene climatic cycles. Annual Review of
Ecology and Systematics 1981:75-98.

Quick, H. E. 1939. Some particulars of four In-
dopacific Succinea. Proceedings of the Mala-
cological Society of London 23:298-302.

. 1951. Succinea archeyi PovjeW. KQQord^

of the Auckland Institute and Museum 4:123-
126.

Reibisch, P. 1892. Die conchyliogischc Fauna der
Galapagos-Inseln. Sitzungsbcrichte und Ab-
handlungen Naturwissenschaftlichen Gesell-
schaft Isis in Dresden 1892:1-20.

Schofield, E. K. 1973. Galapagos flora: the threat
of introduced plants. Biological Conservation
5:48-51.

Slevin, J. R. 1959. The Galapagos Islands: a his-
tory of their exploration. Occasional Papers of
the California Academy of Sciences, No. XXV.

Smith, A. G. 1966. Land snails of the Galapagos.
Pp. 240-251 in R. I. Bowman (ed.). The Ga-
lapagos; Proceedings of the Symposia of the
Galapagos International Scientific Project.
University of California Press, Berkeley and
Los Angeles.

. 1971. New record for a rare Galapagos

land snail. The Nautilus 85:5-8.

. 1972. Three new land snails from Isla

Santa Cruz (Indefatigable Island), Galapagos.
Proceedings of the California Academy of Sci-
ences, 4th Series 39:7-24.

. 1974. Galapagos bulimulids: A taxonom-

ic correction. The Nautilus 88:67.

Smith, R. P., Jr. 1971. Factors governing the dis-
persal, distribution, and microevolution of land
snails of Naesiotus in the Galapagos Archipel-
ago. Unpublished B. A. Honors thesis. Harvard
University, Cambridge, Massachusetts.

Solem, A. 1959. Systematics of the land and fresh-
water Mollusca of the New Hebrides. Fieldiana
(Zoology) 43:1-238.

. 1974. The Shellmakers: Introducing Mol-

lusks. Wiley, New York.

. 1976. Endodontid land snails from Pacific

islands (Mollusca: Pulmonata: Sigmurethra).
Part I. Family Endodontidae. Field Museum
of Natural History, Chicago.

. 1982. Endodontid land snails from Pacific

islands (Mollusca: Pulmonata: Sigmurethra).
Part II. Families Punctidae and Charopidae,
Zoogeography. Field Museum of Natural His-
tory, Chicago.

Steadman, D. W. 1981. Vertebrate fossils in lava
tubes in the Galapagos Islands. Proceedings of
the 8th International Congress of Speleology 2:
549-550.

. 1982. The origin of Darwin's finches

(Fringillidae, Passeriformes). Transactions of
the San Diego Society of Natural History 19:
279-296.

. 1985. Vertebrate paleontology of the Ga-
lapagos Islands. National Geographic Re-
search Reports 20:717-724.

. 1986. Holocene vertebrate fossils from

Isla Floreana, Galapagos. Smithsonian Con-
tributions to Zoology. No. 413.

,G.K. Pregill, and S.L.Olson. 1984. Fossil

vertebrates from Antigua, Lesser Antilles: Evi-
dence for late Holocene human-caused extinc-
tions in the West Indies. Proceedings of the
National Academy of Sciences, U.S.A. 81:
4448-4451.

, and C. E. Ray. 1982. The relationships

of Megaoryzomys curioi, an extinct cricetine
rodent (Muroidea, Muridae) from the Gala-
pagos Islands, Ecuador. Smithsonian Contri-
butions to Paleobiology, No. 5 1 .

110

Stokes, J. F. G. 191 7. Notes on the Hawaiian rat.

Occasional Papers of the Bemice P. Bishop

Museum 3:1 1-21.
Stoops, G. 1967. On the presence of lava tunnels

on Isla Santa Cruz. Noticias de Galapagos 5/6:

17-18.
Vagvolgyi, J. 1 974. Nesopupa galapaganus, a new

Indo-Pacific element in the land snail fauna of

the Galapagos Islands (Pulmonata: Vertigini-

dae). The Nautilis 88:86-88.
. 1975. Body size, aerial dispersal, and or-
igin of the Pacific land snail fauna. Systematic

Zoology 24:465-488.
. 1977. Six new species and subspecies of

Naesiotus from the Galapagos Islands (Pul-

monata: Bulimulidae). Proceedings of the Bi-
ological Society of Washington 90:764-777.
1979. Systematics and evolution of Ga-

lapagos Gastrocopta [Abstract]. Bulletin of the

American Malacological Union 1979:63.
Wagner, A. 1 905-1 9 1 1 . Die Familie der Helicin-

idae. Systematisches Conchylien-Cabinet von

Martini und Chemnitz, neue Folge. Bauer and

Raspe, Niimberg.
Weber, D. 1971. Pinta, Galapagos: une ile a sau-

ver. Biological Conservation 4:8-12.
Wells, S. M., R. M. Pyle, and N. M. Collins. 1983.

The lUCN Invertebrate Red Data Book. lUCN,

Gland, Switzerland.

TRANSACTIONS
OF THE SAN DIEGO
SOCIETY OF
NATURAL HISTORY

Volume 21 Number 7 pp. 111-126 5 December 1986

Callorhinus gilmorei n. sp., (Carnivora: Otariidae) from the

San Diego Formation (Blancan) and its implications for . . iCZ

otariid phylogeny LIBRA F?y

Annalisa Berta DEC T 9

Department of Biology. San Diego State University, San Diego, CA 92182 USA ^^

Thomas A. Demere

Department of Paleontology, San Diego Natural History Museum, P.O. Box 1390,
San Diego, CA 92112 USA

Abstract. A new species of fur seal, Callorhinus gilmorei, described from the San Diego Formation
of southern California and Mexico, fills a critical stratigraphic and evolutionary gap in our knowledge
of otariids. This Late Pliocene (Late Blancan) occurrence of Callorhinus represents the earliest record
of modem otariid genera. Mandibular and dental characters distinguish Callorhinus gilmorei from the
living northern fur seal, C ursinus.

Cladistic analysis supports a sister group relationship between Callorhinus and the Hemphillian
fur seal "'Thalassoleori" macnallyae. Relationships among Arctocephalus species are unresolved. Re-
evaluation of Hydrarctos lomasiensis from the Pliocene of Peru suggests that it is the primitive sister
taxon of all modem otariids. Modem fur seals and sea lions form separate monophyletic groups.

Introduction

The poor representation and isolated occurrences of the Otariidae (fur seals and
sea lions, following the classification of Repenning and Tedford 1977) in the fossil
record inhibits our understanding of phylogenetic relationships within this group. The
earliest known otariid is Pithanotaria starri Kellogg 1925 from the Clarendonian (late
Middle and early Late Miocene; 11-12 MYA) of California. Better preserved and more
complete material of a younger otariid, Thalassoleon mexicanus Repenning and Ted-
ford, 1977 is known from the Hemphillian (late Late Miocene; 5-8 MYA) of Mexico.
A second species of Thalassoleon, T. macnallyae Repenning and Tedford 1977, from
the late Hemphillian (late Late Miocene and Early Pliocene; 5-6 MYA) of California,
is less well known. At this point the record of otariids becomes scant, and as noted by
Repenning and Tedford a major gap exists between Thalassoleon at about 5 MYA
and the more diverse otariid faunas of the Pleistocene and Recent. These authors
suggested that within this gap, which involves most of the Blancan (Pliocene; 2-5
MYA), lies the history of fur seal diversification and the origin of sea lions.

The modem fur seals include the monotypic northern fur seal, Callorhinus ursinus
(Linnaeus), and the polytypic southern fur seal, Arctocephalus (F. Cuvier), with eight
species currently recognized (Repenning et al. 1971). Until now, the earliest record of
a fur seal referred to a modem genus was based on a partial skeleton from the Pliocene
of Peru, ""Arctocephalus"' (Hydrarctos) lomasiensis de Muizon, 1978. However, we
question this generic assignment and suggest that the subgenus Hydrarctos be elevated
to generic rank to include this primitive taxon.

We provide evidence of a new fur seal from the Blancan of Califomia and Mexico
which represents the oldest known fossil otariid referable to a modem genus. This new
species is described from a partial skeleton lacking the skull, collected from the Upper

112

Table 1. Recent otariids studied. (*, skull(s) only; all others include skull(s) and skeleton(s)).

Taxa Number of specimens

Callorhinus ursinus 20

Arctocephalus australis 1

Arctocephalus forsteri 3

Arctocephalus galapagoensis 2

Arctocephalus gazella 1

Arctocephalus philippii 1

Arctocephalus pusillus 1

Arctocephalus townsendi 3

Arctocephalus tropicalis* 1

Eumetopias jubata 8

Neophoca cinerea 2

Otaria byronia 7

Phocarctos hookeri 7

Zalophus californicus 14

Pliocene San Diego Formation. In addition, a number of isolated dentaries, maxilla
and postcranial elements from the San Diego Formation are referred to this new
species. Included in this referred material is a fragmentary lower jaw, previously de-
scribed by Burleson (1948) and Repenning and Tedford (1977).

In the initial stages of this study we were primarily concerned with the identity
and relationship of this new fur seal. However, as our study progressed, we soon realized
that in order to determine systematic affinities of the fossil taxon we needed to un-
derstand the broader phylogenetic relationships among all otariids. From this we ex-
panded our study to include a cladistic analysis of all living and some fossil otariids.

Recent otariids examined in this study are listed in Table 1 . Additional osteological
data for extant and fossil otariids were obtained from the literature (de Muizon 1978,
Repenning et al. 1971, King 1960, Repenning and Tedford 1977, Scheffer 1958, Sivert-
sen 1954).

The following institutional abbreviations are used in the text. SDSNH, San Diego
Natural History Museum, San Diego, California. LACM, Natural History Museum of
Los Angeles County, Los Angeles, California. USNM, National Museum of Natural
History, Smithsonian Institution, Washington, D.C.

Systematic Paleontology

Family Otariidae Gill, 1866

Subfamily Arctocephalinae von Boetticher, 1934

Genus Callorhinus Gray, 1859

Callorhinus gilmorei, new species

Figures 1,2

Pithanotaria sp., Burleson, 1948:248.

cf. Callorhinus ursinus, Repenning and Tedford, 1977:73.

Holotype. —SDSNH 25176, partial young adult female skeleton including: left P
and P-, right upper C, I' °'^-, and P', right I,, right dentary with P2_3 and M,; left L and
P,_3; right and left innominates each lacking posterior one-third of pubis and ischium;
ribs and rib fragments; lumbar, thoracic, and caudal vertebrae and fragments; all as-
sociated and from the same individual.

Type locality. —SDSNH locality 3 1 74-D, San Diego, San Diego County, California;
San Diego Formation, lower member (of Demere 1983); collected by B. O. Riney and
R. A. Cerutti, 9 August 1982.

Known distribution. —Late Pliocene (late Blancan), of California and Mexico.

Referred material and localities. —SDSNH 26239, partial right dentary with P2_3
and Ml from La Joya, Baja CaHfomia Norte, Mexico (SDSNH locality 3125), San
Diego Formation (lower member), collected by A. B. Brockmeir; LACM 1 15253, left

113

-?«A..f<n

Figure 1. Callorhinus gilmorei, n. sp., Holotype: A-D, SDSNH 25176, (A) medial, (B) occlusal, and (C)
lateral views of right dentary with P,.,, M,, (D) lingual view of right P,. Referred material: E-H, LACM
1 15253, (E) medial, (F) occlusal, and (G) lateral views of left dentary with P3, SDSNH 25531, (H) occlusal
view of right maxilla with P'^. Scales = 1 cm.

114

Figure 2. Callorhinus gilmorei, n. sp. Holotype: A-C, SDSNH 25176 (A) anterior and (B) lateral view of
lumbar vertebra (L2), and (C) lateral view of left innominate. Scales = 1 cm.

dentary with C and P3 from Ward Road (LACM locality 4294), San Diego, San Diego
County, California, San Diego Formation (lower member), collected by A. B. Brock-
meir; LACM 4323, partial left dentary with P., P4, and Mi from Reynard Way (LACM
locality 1072), San Diego, San Diego County, California, San Diego Formation (lower
member), collected by C. W. Kennell; SDSNH 25554, edentulous right dentary, SDSNH
25535, partial left dentary with C, SDSNH 25531, partial right maxilla with P^"^ and
right jugal, and SDSNH 25616, left P^ in maxillary fragment, all from Mission Hills
Quarry (SDSNH locality 3206), San Diego, San Diego County, California, San Diego
Formation (lower member), collected by SDSNH field party.

Diagnosis.— A species of Callorhinus with a long, shallow pterygoid process on
the mandible that does not form a medial shelf; with double-rooted lower third and
fourth premolars and closely spaced upper first and second molars; small third upper
incisor with oval cross section; and dorsally directed anterior margin of the mandibular
foramen.

Etymology.— ThQ name honors the late Dr. Raymond M. Gilmore for his lasting
contributions to the field of marine mammalogy.

Description. —Except where noted, the following description refers to the holo-
type. The dentary has a gently sloping symphyseal area (Fig. 1). Two large mental
foramina are below P^ and P3, just above the midline of the ramus; smaller foramina
mark the anterior one-half of the jaw. The mandibular foramen has a dorsally directed
anterior margin (Fig. 3). The coronoid process is broad at the base but tapers to a
relatively high, narrow dorsal margin. The pterygoid process of the mandible is long
and shallow with a reduced medial surface that slopes ventromedially and is not pro-
duced into a shelf as in living Callorhinus. The articular condyle is at the same level
as the base of the ascending ramus. The cheektooth row is short relative to the distance
from P, to the ascending ramus as shown on Figure 4. The horizontal ramus is elongate

115

Table 2. Mandible and lower tooth measurements for Callorhinus gilmorei (a, alveolus only; e, estimated;
*, holotype).

USNM

SDSNH*

SDSNH

LACM

Measurement

184065

25176

26239

25554

25535

115253

4323

Depth of mandible behind M,

15.8

16.5

17.0

15.5

18.9

15.5

Length of toothrow P.-M,

40.1

—

42.5

35.6e

41. le

33.4e

Height of mandible

36.4

—

C, anteroposterior length

10.9

8.6a

—

13.5

10.8

C, transverse width

8.7

—

8.9

7.4

Pi, anteroposterior length

5.4a

5.7a

—

5.0a

—

P,, transverse width

4.3a

4.1a

—

3.0a

—

Pj, anteroposterior length

7.6a

5.5

6.1

6.5a

—

10.7a

5.3

P,, transverse width

4.8a

4.0

4.7

3.5a

—

3.0

P3, anteroposterior length

7.4a

6.5

8.3a

—

6.7

6.8a

P3, transverse width

3.8a

4.2

4.8

4.0a

—

4.7

3.4a

P4, anteroposterior length

6.7a

6.5a

7.7a

—

7.9a

5.5

Pj, tranverse width

3.4a

3.0a

3.4a

—

4.0a

3.5

M|, anteroposterior length

7.4

6.7

8.4a

—

8.2a

6.1

M,, transverse width

4.1

3.9

3.6a

—

3.9a

3.8

and slender in the type, and in SDSNH 26239, SDSNH 25554 and LACM 4323, which,
presumably represent females. The robust jaw and larger canines in SDSNH 25535
and LACM 1 1523 suggest that these specimens represent males.

Isolated lower incisors are associated with the type jaw. The top one-half of the
crown of 1 1 is worn flat. The tooth is single-cusped, triangular in cross section, and has
a strongly compressed root. L is larger, with a high medial cusp and a low basal cusp
that slopes posteromedially. The small size of the canine alveolus in the type and
SDSNH 25554 suggests that the canine was relatively small and slender in contrast to
the large, robust canine in SDSNH 25535 and LACM 1 15253. Again these differences
are attributed to sexual dimorphism.

Relative to the size of the jaw, the check teeth are proportionately small and high
crowned with prominent lingual cingula (Table 2, Fig. 1). P, has a large central cusp
preceded by a small accessory cusp. The tooth crown slopes posteriorly. P. is single-
rooted with a vertical sulcus on the labial surface of the root. There is a small anterior
accessory cusp on P.-a. The left P, is double-rooted with strongly divergent roots,
whereas the right P3 is single-rooted with a vertical sulcus on the lateral and medial
surfaces of the root. This tooth is double-rooted in LACM 4323, LACM 115253,
SDSNH 25554, SDSNH 25535 and single-rooted in SDSNH 26239. P4 is double-
rooted in all specimens except SDSNH 26239. Apart from its larger size, P4 is very
similar to P3. M, is double-rooted in all specimens except SDSNH 25535 in which the
alveolus indicates a single root. The tooth consists of a central cusp that is strongly
inclined posteriorly and followed by a small accessory cusp on the tooth heel. The
anterior accessory cusp is indistinct in the holotype but prominent in SDSNH 26239.

Isolated upper teeth were found in association with the type jaw and are presumed
to be from the same individual. A tooth broken near the base of the crown is identified
as either I' "'- based on lateral compression of the root. I^ is small and caniniform with
a strongly curved root and an oval cross section. The slender upper canine displays
less curvature than the corresponding lower tooth. The anterior premolars, P'"\ are
single-rooted and lack accessory cusps. P- differs from P' in its slightly larger size and
vertical sulcus on the lateral and medial surfaces of the root.

A right maxillary with P^"^, SDSNH 25531, and a left P^ in a maxillary fragment,
SDSNH 25616, probably from the same individual, are provisionally referred to this
species. In occlusal view, the cheek tooth row converges at P-"^ and diverges at M',
creating a sinuous toothrow (Figs. 1, 5). P-""* and M'~' are double-rooted. The teeth are
proportionally small and high crowned with strong lingual cingula. No accessory cusps
are developed. Judging from the alveoli, M' - were positioned close together. Mea-

116

Figure 3. Diagram showing shape of mandibular foramen in (A) Callorhinus ursinus and (B) Arctocephalus
townsendi. Arrow indicates slope of anterior margin of mandibular foramen.

surements are as follows: P^, anteroposterior length 5.8 mm, transverse width 4.3 mm;
P^, anteroposterior length 6.3 mm, transverse width 4.3 mm.

That the type specimen was a young adult is indicated by the only slightly worn
dentition and the lack of epiphyses on the innominates and vertebrae. Although most
of the pubis and ischium is missing, the pubis appears to be relatively broad dorso-
ventrally, characteristic of a female. This specimen has a broad, low pectineopsoal
process projecting ventrally from the ilium at the acetabulum (Fig. 2). The holotype
includes the shafts and heads of two ribs, the shafts of two ribs, the heads of three ribs,
the centra of three thoracic, two lumbar (L2 and 3?) (Fig. 2), and four caudal vertebrae.

Discussion. — Callorhinus gilmorei appears to be more primitive than the living
northern fur seal, C. ursinus on the basis of dental and mandibular characters. In C
gilmorei, P3_4 are usually double-rooted by contrast to their single-rooted condition in
C. ursinus. In addition, the pterygoid process of the mandible in C. gilmorei has a
ventromedially sloped medial surface rather than the strongly produced medial shelf
characteristic of C. ursinus. Also, in C. gilmorei M^-^ are positioned close to one another,
whereas in C. ursinus M'~^ are separated by a persistent diastema.

Repenning and Tedford (1977) commented on the similarity between Thalassoleon
macnallyae and Callorhinus and suggested that a large sample of the former species
might provide evidence for the origin of the genus Callorhinus from T. macnallyae.
As noted by Repenning and Tedford similarities between these taxa include smaller
cheekteeth, greater ornamentation of the medial lip of the ectotympanic bone, postcruci-
ate sulcus separating postcruciatus and lateral gyrus, unconvoluted and relatively nar-
row gyrus ectosylvius posterior, and posterior position of the frontal-parietal suture.
Unfortunately, neither a cranium nor endocranial cast are available for the fossil species
Callorhinus gilmorei. The following characters distinguish C gilmorei from T. mac-
nallyae: considerably smaller size, small V with oval cross section and M'~^ positioned
close together.

Our study offers additional support for a closer relationship between Callorhinus
and Thalassoleon macnallyae than between Callorhinus and Thalassoleon mexicanus,
or between Callorhinus and Arctocephalus. Thalassoleon mexicanus is more primitive
than T. macnallyae in its possession of smaller vertebral foramina, less ornamentation
of the medial edge of the ectotympanic and lack of fusion of the tibia and fibula.
Arctocephalus, together with all sea lions, is more derived than either Thalassoleon or
Callorhinus in having a mandibular foramen with a ventrally directed anterior margin.

Although relationships among Arctocephalus species are largely unresolved, and
will be discussed below, Callorhinus gilmorei can be readily distinguished from A.
townsendi, the only modem fur seal in addition to C ursinus with a known distribution
along the Pacific coast of North America. In C gilmorei the length of the cheek toothrow
relative to the distance from P, to the ascending ramus is short, rather than long as in
A. to\~ isendi (Fig. 4). Additionally, in the fossil species the pectineopsoal process on
the iliu 1 is broad and low rather than narrow and projecting as in A. townsendi. Finally,
in C gi norei the pterygoid process of the mandible is long and shallow rather than

90,

80,
70J

60_

117

Thalassoleon

* mexicanus

Hydrarctos
▲ lomasiensis

Callorhinus
o gilmorei n.

• ursinus

o
o

o«.'

sp.

Arctocephalus
V austral is
D galapagoensis
0 philippii
4 pusillus
■ townsendi

1 0

T-
30

Figure 4. Scatter plot of length of lower cheek toothrow relative to length of horizontal ramus among fur
seals.

short and deep as in A. townsendi. Earlier, Burleson (1948) noted that a mandibular
ramus (LACM 4323) from the San Diego Formation, here referred to C. gilmorei, could
be distinguished from A. townsendi in having P4 and M, on the dorsal crest of the
ramus rather than on the medial side of the crest as in /I. townsendi. Our study of other
dentaries referred to C. gilmorei confirms Burleson's observation.

Implications For Otariid Phylogeny

Traditionally, modem otariids have been grouped into two subfamilies: Otariinae
(sea lions) and Arctocephalinae (fur seals) {see Scheffer 1958). Repenning et al. (1971)
suggested that subfamilial distinction is unwarranted since they were unable to find
osteological characters that consistently separated these two groups. Repenning and
Tedford (1977) retained the "Otariinae" and "Arctocephalinae'' only as nomenclatural
conveniences and did not use them in their formal classification. Our analysis provides
support for the traditional view that fur seals and sea lions belong to different groups.
Sea lions, which include five living, monotypic genera, Zalophus, Neophoca, Phocarctos,
Otaria, and Eumetopias, are recognized by most workers as a monophyletic group.
The monophyly of fur seals, which include the living genera Arctocephalus and Cal-
lorhinus, has been questioned, most recently by Repenning and Tedford (1977) and de
Muizon (1978).

118

Figure 5. Diagram of palate showing outline of upper cheek toothrow in (A) Zalophus californicus and (B)
Arctocephalus pusillus.

Interpretations of otariid relationship are summarized in Figure 6. Both previous
studies and this one view sea hons as monophyletic. Traditionally, fur seals have been
recognized as polyphyletic, although this study distinguishes modem fur seals as mono-
phyletic. While Repenning and Tedford (1977) recognized Pithanotaria as the earliest
known otariid, they suggested that the better known, more derived fossil taxon Thal-
assoleon might be ancestral to both lineages of living fur seals and the living sea lions.
De Muizon (1978) used the distinctive morphology of the baculum to argue that
Thalassoleon and Callorhinus are more closely related and should be recognized as a
separate subfamily, the Callorhininae.

Cladistic analysis was used to evaluate relationships among all living and some
fossil otariids, using the characters discussed in the Appendix. Fossil otariids studied
include Pithanotaria starri {CXdiYQndonidir]., California), Thalassoleon mexicanus (Hemp-
hillian, Mexico), Thalassoleon macnallyae (latest Hemphillian, California [? Blancan,
Repenning, personal communication]) and ''Arctocephalus'^ (Hydrarctos) lomasiensis
(Pliocene, Peru [Montehermosan or Chapadmalalan?]). The polarity of characters was
determined by outgroup comparison using the most primitive known otarioid (includes
fur seals, sea lions, walruses and their extinct relatives), Enaliarctos mealsi Mitchell
and Tedford (1973) from the Late Oligocene/Early Miocene of California. Published
descriptions of this species (Mitchell and Tedford 1973, Barnes 1979) were supple-
mented by an evaluation of unpublished enaliarctid material housed in the Emlong
collection at the National Museum of Natural History, Smithsonian Institution, Wash-
ington, D.C. and the U.S. Geological Survey (Denver). An attempt was made to use
only material that could be definitely assigned to Enaliarctos; although those characters
that were present among all enaliarctids (including Enaliarctos and Pinnarctidion) were
noted.

In our analysis we attempted to account for variation by examining, when possible,
more than just a single specimen of a taxon (Table 1). Only those characters that
withstood careful scrutiny were used in the analysis. A total of 4 1 osteological, soft
anatomical and behavioral characters were selected. We acknowledge the fact that while
some of these characters are undoubtedly related, both functionally and phyletically
(e.g., characters 5, 6, 7 tooth and root simplification), our recognition of these as separate
characters has not biased their weighting in the analysis. We independently examined
those special cases where double-weighting of characters may have applied, and found
no difference in the branching pattern than that obtained by considering these characters
separately.

Characters were analyzed and minimum-step cladograms generated by computer
using the PHYSYS program written by J. S. Farris. Cladograms were constructed by

119

o.<-<>' ^vo^

Repenning and Tedford, 1977

"^^'' ..sO^^°

,-.<-^^ ^v^^

de Muizon, 1978

This study

Figure 6. Cladistic representation of previous and present interpretations of otariid relationships.

120

■*-»

X
u

u
u

•c

u
o

■*-•
A

IH
U

cfl

•s

C
u
o
u

JS
</i

c
o

o "

2 g?

e 8

o ^^

"2 "^
J3 c
(J «

121

the Wagner procedure (Farris 1970) and its global branch swapping option (Mickevich
1978). One Wagner and a single Pimentel tree were obtained, with the Wagner tree
being shorter. Several modifications of the computer generated trees necessitated con-
struction of a consensus cladogram based in large part on the Wagner tree (Fig. 7).
These modifications involve two characters ( 1 4, 1 5) that the computer analysis showed
to be derived for both fur seals and sea lions, prior to divergence of these two groups.
Although the analysis indicated that sea lions must have lost these characters, we feel
that it is more parsimonious to consider that they were derived only once in the modem
fur seals.

Monophyly of the Otanidae and its distinction from Enaliarctos is supported by
four shared derived characters: absence of lacrimal foramen, nasolabialis fossa, fissiped-
like dentition, and presence of large, well-developed supraorbital processes (characters
1-4). Pithanotaria starii, the most primitive otariid analyzed is distinguished from all
other otariids in lacking M- (character 8). The fossil otariid, Thalassoleon mexicanus
and all other otariids share a single derived character, a simple lateral upper incisor
(character 5). "'Arctocephalus'' (Hydrarctos) lomasiensis, fur seals and sea lions can be
distinguished from Thalassoleon mexicanus by five synapomorphies (characters 6, 7,
9, 12, 13). Our analysis oVArctocephalus"" (//.) lomasiensis suggests that it should not
be recognized as a species of Arctocephalus. This taxon is recognized here as a primitive
otariid distinct from the Arctocephalus-Callorhinus clade. Based on this we recommend
elevation of the subgenus Hydrarctos to generic status.

In this analysis advanced otariids share a single derived character— calcaneum with
well-developed secondary shelf of the sustentaculum (character 11). Although rela-
tionships among fur seals are here represented as an unresolved polychotomy, three
separate groups can be identified which share the following two derived characters:
narrow basioccipital, and I^ with oval cross section (characters 14, 15). The fossil otariid
Thalassoleon macnallyae and the northern fur seal, Callorhinus ursinus share a sister
group relationship that is supported by four shared derived characters (characters 23,
32, 33, 34). The identity of the fossil fur seal described in this paper as a species of
Callorhinus is supported by mandibular and dental characters as previously discussed.
Callorhinus gilmorei is more primitive than C. ursinus in having a long, shallow pter-
ygoid process that does not form a medial shelf, P3_4 that are usually double-rooted,
and M'"- positioned close together.

Relationships among Arctocephalus species are less well resolved, owing to a high
degree of convergence among several of the characters (e.g., characters 18, 26, both of
which appear to be independently derived among the various fur seal and sea lion
clades). In an earlier discussion of arctocephaline relationships, Repenning et al. ( 1 97 1 )
recognized A. pusillus and A. gazella as distinct from all other Arctocephalus species.
Our analysis provides further support for this interpretation. Although A. pusillus is
distinguished from all other species of the genus by three characters, two of these are
convergences (characters 18, 20) that occur in other Arctocephalus species. Arctocepha-
lus townsendi, A. australis, A. philippii, A. galapagoensis, and A. forsteri are separated
from A. gazella and A. tropicalis in having a short, deep pterygoid process on the
mandible (character 25).

Recognition of sea lions as a natural group is supported by osteological (19, 27,
28, 29), soft anatomical (31, 35, 36) and behavioral (37) characters. Eumetopias, Neo-
phoca, Phocarctos and Otaria are more derived than Zalophus in their possession of
a single derived character, apex of baculum further expanded laterally (character 30).
The southern sea lions, Otaria, Neophoca, and Phocarctos share well-developed ac-
cessory cusps on cheek teeth and a deep palate (characters 20, 39). The most derived
sea lions, Otaria and Phocarctos share two derived characters, both of which represent
convergences elsewhere on the cladogram.

A classification of modem genera in the Family Otariidae developed in this paper
is presented in Table 3. Fossil otariids, Pithanotaria starri, Thalassoleon mexicanus,
and Hydrarctos lomasiensis are recognized as primitive members of the Otariidae.
Modem fur seals and sea lions are defined here as belonging to separate monophyletic

122

Table 3. Classification of Recent Otariidae.

Order Camivora Bowdich, 1821
Family Otariidae Gill, 1866
Subfamily Arctocephalinae von Boetticher, 1934

Arctocephalus Geoffroy and Cuvier, 1826

Callorhinus Gray, 1859
Subfamily Otariinae von Boetticher, 1934

Eumetopias Gil\, 1866

Otaria Peron, 1816

Neophoca Gray , 1866

Phocarctos VtXers, 1866

Zalophus Gray, 1859

groups and designated as subfamilies. The Arctocephalinae, which includes the modem
fur seals, Arctocephalus and Callorhinus, as well as the fossil fur seal ""Thalassoleon''
macnallyae is defined by two derived characters— rectangular basioccipital, and P with
oval cross section. Although we do not recognize the Callorhininae at the subfamilial
level, our analysis does support the close relationship between Thalassoleon macnallyae
and Callorhinus originally suggested by de Muizon (1978). Pending further analysis of
the Callorhinus-Arctocephalus clade, we have chosen not to formally designate this
monophyletic group. More derived otariids, the sea lions are grouped in the Otariinae,
which includes Eumetopias, Neophoca, Phocarctos, Otaria, and Zalophus. The follow-
ing derived characters distinguish this group: M' single-rooted, cheektooth row straight,
humerus stout, pectoral crest directed toward midpoint of distal articulation, apex of
baculum broad with keels, more convoluted neopallium, sparse underfur, sucking louse
host specificity, and strongly thigmotactic behavior.

Conclusions

A new fur seal, Callorhinus gilmorei n. sp., from the Late Pliocene of California
and Mexico represents the oldest fossil otariid referable to a modem genus. As the only
nominal Blancan-aged otariid from North America, this taxon helps to fill a gap in the
fossil record of the group.

The new fur seal shares numerous dental and mandibular characters with the living
Northern fur seal Callorhinus ursinus while retaining several primitive characters such
as double-rooted cheekteeth.

Cladistic analysis utilizing 41 osteological, soft anatomical and behavioral char-
acters supports monophyly of the family Otariidae. The Late Oligocene/Early Miocene
genus Enaliarctos represents the primitive sister taxon of all otariids. The sea lions and
modem fur seals represent separate monophyletic groups. The Peruvian fossil fur seal
''Arctocephalus^' (Hydrarctos) lomasiensis is sufficiently primitive to warrant placing
it in the newly elevated genus Hydrarctos. The suggested sister group relationship
between Callorhinus ursinus and ''Thalassoleon'" macnallyae indicates the need of a
new generic concept for the latter species. This relationship also points to the antiquity
of this group of fur seals, and serves to highlight the lack of a recognized Arctocephalus
ancestor. Unfortunately, the analysis failed to resolve the confusing relationships be-
tween taxa presently grouped in the genus Arctocephalus.

Acknowledgments

We thank Lawrence G. Bames (LACM), Charles A. Repenning (U.S. Geological
Survey, Denver), James G. Mead and Clayton E. Ray (USNM) for permission to study
specimens in collections under their care. Travel funds to study collections were pro-
vided by Sigma Xi and the Smithsonian Institution. Daryl Domning, Clayton E. Ray
and Charles A. Repenning critically reviewed this manuscript. We are especially grateful
to Rep, who "sweated through innumerable earlier versions trying to make it into
something he could understand."

123

The Gersten Companies of Chula Vista, California, are acknowledged for permit-
ting and supporting the collection of fossils (including the holotype specimen) on their
property. In addition the Planning Department, City of Chula Vista, and especially
Doug Reid of that office are to be commended for realizing the significance of paleon-
tological resources within their jurisdiction.

Several of the specimens discussed in this paper were collected under National
Geographic Society Grant 2754-83 to Thomas A. Demere.

Special thanks are extended to Joseph and Joan Parker of Coronado, California,
and to the J. W. Sefton Foundation, San Diego, California, for their continued support
of fossil vertebrate studies.

Literature Cited

Barnes, L. G. 1979. Fossil enaliarctine pinnipeds
(Mammalia: Otariidae) from Pyramid Hill,
Kern County, California. Natural History Mu-
seum of Los Angeles County, Contributions in
Science 318:1-41.

Burleson, G. L. 1948. A Pliocene pinniped from
the San Diego Formation of southern Califor-
nia. University of California Publications in
Zoology 47(1 0):247-254.

Demere, T. A. 1983. The Neogene San Diego
Basin: a review of the marine Pliocene San
Diego Formation. Pp. 187-195 in D. K. Larue
and R. J. Steel (eds.). Cenozoic Marine Sedi-
mentation, Pacific Margin, U.S.A. Society of
Economic Paleontologists and Mineralogists,
Pacific Section.

Farris,J.S. 1970. Methods for computing Wagner
trees. Systematic Zoology 19:83-92.

Kellogg, R. 1925. New pinnipeds from the Mio-
cene diatomaceous earth near Lompoc, Cali-
fornia, Part IV. Pp. 71-96 in Additions to the
Tertiary History of the Pelagic Mammals of
the Pacific Coast of North America. Carnegie
Institute of Washington, Contributions in Pa-
leontology.

Kim, K. C, C. A. Repenning, and G. V. Morejohn.
1975. Specific antiquity of the sucking lice and
the evolution of otariid seals: Symposium on
the Biology of the Seals at the University of
Guelph, Guelph, Canada, 1972. Rapports et
Proces-Verbaux des Reunions, Conseil inter-
national pour 1 'exploration de la mer 1 69:544-
549.

King, J. E. 1960. Sea-lions of the genera A^6'o/7/?oca
and Phocarctos. Mammalia 24(3):445-456.

. 1983. Seals of the World. 2nd edition.

Oxford University Press, London.

Lyon, G. M. 1937. Pinnipeds and a sea otter from
the Point Mugu shell mound of California.
University of California Los Angeles Publi-
cations in Biological Sciences 1(8): 133-1 68.

Michkevich, M. F. 1978. Taxonomic congruence.
Systematic Zoology 27:143-158.

Mitchell, E. D. 1968. The Mio-Pliocene pinniped
Imagotaria. Journal of the Fisheries Research
Board of Canada 25:1843-1900.

. 1975. Parallelism and convergence in the

evolution of Otariidae and Phocidae: Sympo-
sium on the Biology of the Seals at the Uni-

versity of Guelph, Guelph, Canada, 1972.
Rapports et Proces-Verbaux des Reunions,
Conseil international pour I'exploration de la
mer 169:12-26.
— , and R. H. Tedford. 1973. The Enaliarc-

tinae. A new group of extinct aquatic Camivora
and a consideration of the origin of the Otari-
idae. Bulletin of the American Museum of Nat-
ural History 151(3):201-284.

Morejohn, G. V. 1975. A phylogeny of otariid
seals based on morphology of the baculum:
Symposium on the Biology of the Seals at the
University of Guelph, Guelph, Canada, 1972.
Rapports et Proces-Verbaux des Reunions,
Conseil international pour I'exploration de la
mer 169:49-56.

Muizon, C. de. 1978. Arctocephalus (Hydrarctos)
lomasiensis, subgen. nov. et nov. sp., un nouvel
Otariidae du Mio-Pliocene de Sacaco (Perou).
Institut Fran9ais d'Etudes Andines, Bulletin 7
3-4:168-188.

Repenning, C. A., R. S. Peterson, and C. C. Hubbs.
1971. Contributions to the systematics of the
southern fur seals, with particular reference to
the Juan Fernandez and Guadalupe species.
Pp. 1-34 in W. H. Burt (ed.). Antarctic Pin-
nipedia. Antarctic Research Series 18.

, and R. H. Tedford. 1977. Otarioid seals

of the Neogene. U.S. Geological Survey Profes-
sional Paper 992:1-93.

Robinette, H. R., and Stains. H. J. 1970. Com-
parative study of the calcanea of the Pinnipe-
dia. Journal of Mammalogy 51(3):527-541.

Scheffer, V. B. 1958. Seals, Sea Lions, and Wal-
ruses. Stanford University Press, Stanford.
California.

Sivertsen, E. 1954. A survey of the eared seals
(Family Otariidae) with remarks on the Ant-
arctic seals collected by M/K Norvegia in 1928-
1929. Det Norske Videnskaps- Akademi i Oslo.
Scientific results of the Norwegian Antarctic
Expedition 1927-1928 et seqq., instituted and
financed by Consul Lars Christensen 36:1-76.

Stirling, I., and R. M. Wameke. 1971. Implica-
tions of a comparison of the airborne vocal-
izations and some aspects of the behavior of
the two Australian fur seals, Arctocephalus spp.,
on the evolution and present taxonomy of the
genus. Australian Journal of Zoology 19:227-
241.

124

Note Added in Proof

The framework under which this research was undertaken assumed a working hypothesis of pinniped
diphyly. Repenning and Tedford's (1977) definition of the Otarioidea as including the Enaliarctidae, Otariidae,
Odobenidae, and the Desmatophocidae was followed. Recent compelling evidence (Wyss, in prep.) casts
doubt on pinniped diphyly and argues that the otarioids are not a natural group and are nested within the
Pinnipedia which includes the above mentioned families and the Phocidae.

While we support relationships among members of the Otariidae proposed herein we acknowledge the
fact that several basal characters used to separate the Otariidae from Enaliarctos are also found among other
pinnipeds.

Appendix

Definitions and evaluations of the characters used in the cladistic analysis.

1. Lacrimal foramen absent

Presence of the lacrimal foramen in enaliarctids distinguishes them from all other otarioids (Mitchell
and Tedford 1973) with the exception of some allodesmids (Repenning, personal communication).

2. Supraorbital processes large and well-developed

The presence of large supraorbital processes, especially strong in adult males, is diagnostic of the
Otariidae and distinguishes them from the Enaliarctidae (Repenning and Tedford 1977).

3. Nasolabialis fossa absent

The nasolabiahs fossa described by Mitchell and Tedford (1973:232, 234) as a triangular, shallow
fossa on the side of the snout is found in enaliarctids. The absence of this fossa is a derived condition
in otarioids.

4. Carnassials absent

The enaliarctids can be distinguished from all other otarioids in their possession of a fissiped-like
dentition in which P"* has a protocone or protocone shelf, and M, has a talonid. A homodont
dentition is derived and characteristic of later otarioids.

5. P simple

A simple lateral upper incisor characterizes most fossil and modem otariids. Pithanotaria starri
shows the primitive ursine condition, in which F displays a posterior broadening of the crown near
the base with a distinct posteromedial lingual cingulum preserved in a referred specimen (Repenning
and Tedford 1977).

6. P2, single-rooted

The development of single-rooted cheekteeth, a trend that began with Pj, is a derived condition
among otarioids, also seen in more advanced desmatophocids and odobenids (Mitchell 1975).

7. Pj_4, single- rooted

Further modification of the trend towards single-rooted cheekteeth occurs in the posterior premolars,
P3_4; a feature long recognized as diagnostic of living fur seals and sea lions (Repenning and Tedford
1977).

8. M-' absent

Since, as noted by Repenning and Tedford (1977), the absence of M^ in the holotype and only
known referred specimen oi Pithanotaria starri may be the result of individual variation, its absence
is tentatively regarded as a uniquely derived character for the monotypic genus.

9. Mandibular foramen anteroventrally directed

The anterior margin of the mandibular foramen is directed anterodorsally in Enaliarctos {this study),
Thalassoleon mexicanus and Callorhinus. In the derived condition seen in Arctocephalus and sea
lions this margin slopes anteroventrally (Fig. 3).

10. Mandibular condyle elevated high above the base of the ascending ramus

A high mandibular condyle is described and figured by Repenning, Peterson and Hubbs (1971:21;
Fig. 7) as diagnostic of Arctocephalus australis. According to de Muizon (1978, Fig. 2) the derived
condition is also seen in the fossil Hydrarctos lomasiensis and Otaria.

11. Calcaneum with well-developed secondary shelf of sustentaculum

All living otariids possess a well-developed secondary shelf of the sustentaculum (Robinette and
Stains 1 970). This shelf is lacking in Enaliarctos (this study). As reported by Repenning and Tedford
(1977), this shelf is also lacking in Thalassoleon mexicanus and only slightly developed in Hydrarctos
lomasiensis (de Muizon 1978).

12. Vertebral foramen enlarged

Thalassoleon mexicanus is diagnosed as having vertebral foramina of all vertebrae small relative
to those of living otariids (Repenning and Tedford 1977), but they are larger than in terrestrial
carnivores. The derived condition, enlarged vertebral foramen, characterizes all other living otariids.

13. Tibia and fibula fused proximally

The unfused tibia and fibula of Callorhinus noted by Lyon (1937) is tentatively interpreted as
retention of the primitive condition, seen in Enaliarctos (this study) and reported by Kellogg (1925)
for Pithanotaria. ''Thalassoleon" macnallyae, in contrast to T. mexicanus, has a fibula fused proxi-
mally to the head of the tibia (Repenning and Tedford 1977). In all other living otariids the tibia
and fibula are likewise fused at their proximal ends.

14. Basioccipital rectangular

According to Repenning and Tedford (1977) the basioccipital is trapezoidal in Thalassoleon, Neo-
phoca, and Zalophus. Our analysis indicates that Enaliarctos, Eumetopias and Otaria also share

125

the primitive condition. The shape of the basioccipital in Pithanotaria is equivocal, owing to
incompleteness of this region of the skull in published specimens. In the derived condition, observed
in all living fur seals and Phocarctos. this bone is rectangular with parallel lateral margins.

15. P oval in cross section

The size and shape of I' has been recognized as distinguishing fur seals from sea lions (Repenning
et al. 1971). A large I' with a circular cross section typifies sea lions. Fossil otarioids including
Enaliarctos. Thalassoleon and Pithanotaria share the primitive condition of an oval I' although
they generally lack the large size of this tooth.

16. Coronoid process narrow

The coronoid process is very broad and overhanging along its posterior margin in Enaliarctos (this
study) and Thalassoleon mexicanus (Repenning and Tedford, 1977). Arctocephalus has been dis-
tinguished by Repenning, Peterson, and Hubbs (1971, Fig. 7) on the shape of the coronoid process.
The presumably derived condition, a narrow process with posterior margin undercut and over-
hanging at the base is found in A. gazella, A.forsteri, A. galapagoensis, A. philippii, A. australis and
A. townsendi and Callorhinus.

17. Reduced premaxillary

The derived condition, defined as transverse width of premaxilla less than 40% of nasal length,
especially apparent in lateral view, is an uniquely derived character for Callorhinus ursinus (Re-
penning et al. 1971, this study).

18. Lower cheek toothrow short

This character is defined as the length of the cheek toothrow relative to the distance from P, to the
ascending ramus. The derived condition, a short toothrow, is here defined as a toothrow less than
75% of distance from P, to the ascending ramus (Fig. 4).

19. M', single-rooted

Among sea lions, M' is consistently single-rooted. Some variation was observed in fur seals, although
in most species this tooth is double-rooted. The most variation recognized by Repenning et al.
(197 1) was in Arctocephalus gazella, where approximately 50% of this sample exhibited the double-
rooted condition.

20. Accessory cusps on cheek teeth

The presence of prominent, anterior and posterior accessory cusps on the cheek teeth is a derived
character observed in several species of fur seal, Arctocephalus pusillus and A. australis (variable)
and sea lions Neophoca, Otaria, and Phocarctos (Repenning and Tedford 1977, this study).

2 1 . M'-^ positioned close together

Since a "persistent diastema between M'-" is diagnostic of Thalassoleon (Repenning and Tedford
1977), and was observed in Enaliarctos (Mitchell and Tedford 1973: fig. 5, Barnes 1979: fig. 20),
the lack of a diastema is recognized as the derived condition.

22. Facial angle less than 125°

The facial angle is one of two characters identified by Repenning, Peterson, and Hubbs (1971 Fig.
1 ) that consistently distinguishes Callorhinus from Arctocephalus and all other otariids. In the derived
condition, seen in Callorhinus, the facial angle is less than 125°.

23. Ectotympanic bone ornamented

In the derived state, the medial border of the ectotympanic bone is ornamented, producing a flat,
knobby bulla especially characteristic of male Callorhinus ursinus and ^"Thalassoleon'' macnallyae,
unlike that of other species oi Arctocephalus (Repenning et al. 1971, Repenning and Tedford 1977).
Among sea lions, Neophoca has an ornamented ectotympanic bone although the degree and position
of the ornamentation differs from that of C ursinus.

24. Pterygoid process of mandible with medial shelf

Projection of the pterygoid process as a prominent medial shelf is recognized here as an autapo-
morphy in Callorhinus ursinus. Zalophus shows a tendency to develop a shelf of smaller size and
different proportion.

25. Pterygoid process of mandible short and deep

The shape of the pterygoid process was used by Repenning, Peterson, and Hubbs (1971 fig. 7) to
distinguish Arctocephalus. In Thalassoleon mexicanus, the pterygoid process was described as similar
to that o{ Arctocephalus pusillus in being long and shallow (Repenning and Tedford 1977) and the
same is true for Enaliarctos (this study). The derived condition, a short, deep pterygoid process, is
observed in Otaria in addition to A. galapagoensis, A. australis. A. forsteri, A. philippii, and A.
townsendi.

26. Nasals narrow

The derived condition defined as nasal width 70% of nasal length was recognized in Arctocephalus
philippii, A. tropicalis, Zalophus, Phocarctos and Otaria (Repenning et al. 1971: fig. 7, Sivertsen
1954).

27. Cheek toothrow straight

In the primitive condition observed in fur seals, the cheek toothrow curves inward at P-' and
diverges at M' creating a sinuous toothrow. In the derived condition, diagnostic of sea lions, the
cheek toothrow is nearly straight (Fig. 5). In Otaria, Eumetopias and Phocarctos the derived state
is slightly modified and the teeth converge at M'.

28. Humerus stout, pectoral crest directed toward midpoint of distal articulation

The derived condition of a robust humerus has been recognized as distinctive of sea lions. It has
been suggested that the position of the pectoral crest resulted in a strengthening of the humerus,
possibly related to their larger body size (Repenning and Tedford 1977).

126

29. Apex ofbaculum broad with keels

The derived condition has been recognized as distinguishing sea hons from fur seals, which have a
transversely narrow apex (Morejohn 1975). Thalassoleon and Callorhinus share a unique bacular
morphology in which the bulbous ventral knob of the apex in anterior view resembles a "figure of
eight" (Repenning and Tedford 1977).

30. Apex of baculum further expanded laterally

A further modification of the derived state discussed above, in which the lateral edges of the apex
are expanded, is observed in Otaria, Neophoca, Eumetopias, and Phocarctos (see references cited
above).

31. Neopallium more convoluted

The cerebrum of sea lions is characterized by more convolutions of the neopallium than that of fur
seals (Repenning and Tedford 1977). More numerous neopallial convolutions are here interpreted
as the derived condition based on the phylogeny established for fur seals and sea lions {see text).

32. Postcruciate sulcus

The postcruciate sulcus which connects the longitudinal fissure to the lateral sulcus appears to be a
unique feature of Callorhinus. Presence of this sulcus in a juvenile endocranial cast of a skull referred
to "Thalassoleon" macnallyae is here considered a shared derived feature linking these taxa (Re-
penning and Tedford 1977).

33. Posterior ectosylvian gyrus, narrow and unconvoluted

Among fur seals, Callorhinus appears unique in having a noticeably narrow and unconvoluted
posterior ectosylvian gyrus relative to the width of the adjacent posterior supersylvian gyrus (Re-
penning and Tedford 1977). Presence of this derived feature in ''Thalassoleon" macnallyae is
considered evidence of their close relationship.

34. Frontal-Parietal suture in posterior position

A posterior position of the frontal-parietal suture relative to the distance between the front of the
braincase and the lambdoidal crest was observed in immature Callorhinus and "Thalassoleon"
macnallyae as a feature distinguishing them from Thalassoleon mexicanus and Arctocephalus (Re-
penning and Tedford 1977).

35. Underfur sparse

The sparse underfur of sea lions has long been used to distinguish them from fur seals (Scheffer
1958). The presence of abundant underfur in fur seals has been considered retention of the primitive
condition (Repenning and Tedford 1977).

36. Underfur terminates at wrist

Among fur seals, Callorhinus can be distinguished from Arctocephalus in having the fur of the
forelimb terminate in an abrupt line at the wrist, whereas in Arctocephalus, the fur extends distally
past the wrist (Repenning et al. 1971). Since the loss of abundant underfur is recognized as the
derived condition (see character 35) its more restricted occurrence in Callorhinus is judged derived.

37. Sucking louse host specificity

The restricted occurrence of a more advanced sucking louse species, Antarctophirus microchir, on
sea lions is interpreted as the derived condition. The presence of a more generalized taxon Proechi-
nophthirus as a unique parasite on Callorhinus ursinus and Arctocephalus pusillus (and presumed,
but not yet established on other species oi Arctocephalus), judged to be the primitive condition, has
been interpreted as evidence for the greater antiquity of fur seals. The fact that different species of
Proechinophthirus inhabit the two genera of fur seals indicates that they have evolved separately for
some time (Kim et al. 1975).

38. Strongly thigmotactic

The tendency for sea lions and Arctocephalus pusillus to be strongly thigmotactic (limbs of different
individuals in direct contact) while Callorhinus ursinus and other Arctocephalus species are not has
been previously noted (Stirling and Wameke 1971 and references cited therein). Thigmotactic
behavior is here interpreted as the derived condition based on the phylogeny established for fur
seals and sea lions (see text).

39. Palate deep and concave

The sea lions Otaria, Neophoca and Phocarctos share the derived condition of having deep, concave
palates (Scheffer 1958, King 1960). The palate is more highly arched in Phocarctos and Otaria than
in Neophoca. In Phocarctos, the palate is deep anteriorly like that in Otaria however it is flattened
posteriorly like that in Eumetopias and Neophoca (Mitchell 1968).

40 Tympanic bulla with elongate posterior or posteroventral projection

Phocarctos is characterized by having a "cylindrical projection of the bulla" (King 1960). As noted
by Mitchell (1968) this projection is directed far posteroventrally in Otaria (where it is subequal in
cross section) and posteriorly in Eumetopias (where it is more ovate in cross section). An elongate
posterior or posteroventral projection of the tympanic bulla represents the derived condition.

41. Cheekteeth 5/5

Reduction in number of cheekteeth from 6/5 to 5/5 is a derived feature in Eumetopias and Neophoca.
According to King (1983) the number is variable in Zalophus; Califomian animals more frequently
having 5/5, Galapagos animals 6/5, while all variations are found in the Japanese animals.

"^S y^ TRANSACTIONS

OF THE SAN DIEGO
SOCIETY OF
NATURAL HISTORY

Volume 21 Number 8 pp. 127-144 5 December 1986

Fossil Tanaidacea

Frederick R. Schram

San Diego Natural History Museum. P.O. Box 1390, San Diego. CA 92112 USA

u L. u J. /J

Jiirgen Sieg

Universitdt Osnahriick. 2848 Vechta. Federal Republic of Germany

Eric Malzahn

Aufder Heide 33, 3004 Isernhagen, Federal Republic of Germany

Abstract. All known fossil tanaidaceans have been restudied and a taxonomic revision is provided.
Some small alterations in the reconstruction of Anthracocaris scotica and Cryptocaris hootchi are made;
Ophthalmapseudes rhenanus is reassigned to the Anthracocaridomorpha; O. friedericianus and O.
acutirostris are placed in their own genus Jurapseudes. and O. giganteus (in part) is placed within its
own genus Carlclausus. all within a new superfamily Jurapseudoidea within the suborder Apseudo-
morpha; and O. giganteus (in part) is placed within another new genus, Cretitanais. within its own
superfamily within the Tanaidomorpha.

Introduction

Tanaidaceans are among the most specialized of eumalacostracans. Morphologi-
cally, ecologically, and behaviorally they have a modestly preserved, and in many
respects intellectually satisfying, fossil record. They range from the Lower Carboniferous
through the Cretaceous, and preserve a nice series from the extinct and very primitive
to the extant and highly derived. Though the record is far from complete, we now know
far more about the evolution of Tanaidacea than any other group within the brachy-
caridan types.

The oldest form known is Anthracocaris scotica (Peach) 1882, from the Lower
Carboniferous of Scotland. Generic status was recognized by Caiman (1933), and a
complete reconstruction and recognition as a tanaidacean was achieved by Schram
(1979). Cryptocaris hootchi Schram, 1974 is from the Middle Pennsylvanian of Illinois.
Ophthalmapseudes rhenanus (Malzahn) 1957, from the Permian of Germany, is the
best preserved and most completely known of the Paleozoic forms; however, until now
it was incorrectly placed among the apseudomorphs.

The status of the Mesozoic tanaidaceans has heretofore been obscured by their
mistaken placement, for the most part, all within a single genus, Ophthalmapseudes.
The Triassic of Hungary contains a non-descript chela from Hungary designated as
Ophthalmapseudes sp. by Vegh and Bachmayer. The Jurassic has much tanaid material.
Malzahn (1965) described O. friedericianus, from the Middle Jurassic of Germany;
Sachariewa-Kowatschewa and Bachmayer (1965) named O. acutirostris from the Mid-
dle Jurassic of Bulgaria; and Reiff ( 1 936) named Palaeotanais quenstedti from the Lower
Jurassic of Germany (although the types of this species are now lost). Cretaceous
tanaidaceans are limited in number. Malzahn (1979) described a diverse array of
specimens under a single species, O. giganteus, from the Lower Cretaceous of Germany.

Over the years continued collection and preparation of specimens by one of us
(EM) have resulted in much new material of various species of Ophthalmapseudes.

128

Analysis of these new specimens, combined with restudy of type material (FRS and
JS), has allowed us to recognize that the tanaidacean fossils are much more diverse
than previously suspected. This examination necessitates the complete revision of these
fossils not only at the generic level, but also extending up to the superfamilial and
subordinal levels.

The synonymies of species are presented in the annotated format of Richter (1948)
as outlined by Matthews (1973). Prefixes to numbers denote the following collections:

EM — private collection of Eric Malzahn.
EX— private collection of Dan Damrow.
GSE— Institute of Geological Sciences, Edinburgh, Scotland.
NMW — Natural History Museum, Vienna, Austria.

P— Field Museum of Natural History, Chicago, USA.
SDSNH— San Diego Society of Natural History, San Diego, USA.

Z— Niedersachsisches Landesamt fiir Bodenforschung, Hannover, Germany.

Systematic Paleontology
Infraorder: Anthracocaridomorpha Sieg, 1980

Diagnosis.— Eyes lobed. Thoracic pleurites present. Pereiopods cylindrical and
stalk-like, exopods probably present on at least anterior 3 pereiopods. Abdomen with
6 free pleomeres and telson, sixth pleomere larger than any of the first 5 pleomeres.

Remarks. —Though the above characters are very descriptive of the Paleozoic
tanaidaceans, in comparison to the living groups most of the characters could probably
be considered primitive, which might indicate that this taxon is a paraphyletic one at
best. Nonetheless, though we currently lack knowledge about possible derived features
that the Paleozoic forms might share, these characters do consistently serve to separate
the Paleozoic tanaidaceans from the Mesozoic and Cenozoic forms.

Family Anthracocarididae Schram 1979

Diagnosis.— Vropods multisegmented, uniramous. Telson either well developed
or small.

Type genus.— Anthracocaris Caiman, 1933.

Remarks.— The uropods on specimens o^ Anthracocaris scotica appear to be uni-
ramous, and except for the protopod are not preserved on Ophthalmapseudes rhenanus.
However, we must point out that on modem tanaidaceans the exopod of the uropod
is frequently greatly reduced. It is conceivable that this reduction might also be the
case in the anthracocarids, with the vestigial uropodal exopods not being preserved or
perhaps just not yet observed on the fossil material.

The recognition of the anthracocaridomorph status of Ophthalmapseudes rhenanus
and the inability to distinguish this taxon above the level of genus from Anthracocaris
places the Ophthalmapseudidae Sieg, 1980, in synonymy with Anthracocarididae
Schram, 1979.

Genus Anthracocaris C3[m2Ln, 1933
Figure 1

Diagnosis.— Kosirum small. Telson long, subrectangular, terminally lobate (spat-
ulate). Abdominal pleurites weakly developed and rounded, sixth pleomere vaulted
and suboval in cross-section.

Type species.— Palaeocaris scotica Peach, 1882.

Gender. —Yemimne.

Anthracocaris scotica (Peach), 1882

V*. 1882 Palaeocaris scotica Peach, p. 85, pi. 10, figs. 10-lOb.
1883 Palaeocaris scotica Peach. Peach, p. 515.

129

Figure 1. Reconstruction of Ant hracocaris scotica (Peach). (Modified from Schram 1979a.)

1903 Palaeocaris scotica Peach. Peach and Home, p. 846.

V. 1908 Palaeocaris scotica Peach. Peach, p. 154, pi. 8, figs. 1-5.

1911 Palaeocaris scotica Peach. Woodward, p. 363.

1933 Anthrococaris scotica (Peach). Caiman, p. 562, fig. 1.

1962a Anthracocaris scotica (Peach). Brooks, p. 239.

1962b Anthracocaris scotica (Peach). Hessler, p. R392, fig. 211, 1.

1969a Anthracocaris scotia (Peach). Schram, p. 218, table 1.

1974b Anthracocaris scotica (Peach). Schram, p. 107.

V. 1979(2 Anthracocaris scotica (Peach). Schram, p. 100, figs. 46, 47, table 18.

1979b Anthracocaris scotica (Peach). Schram, p. 164, table 1.

1980 Anthracocaris scotica (Peach). Sieg, p. 406, figs. 2.1, 4.

1981 Anthrocacaris scotica (Peach). Schram, p. 128, table 1, text-fig. 3.

1983 Anthracocaris scotica (Peach). Sieg, p. 32, fig. 2.

1984 Anthracocaris scotica (Peach). Sieg, pp. 34, 88, fig. 29.

Lectotype.—GSE 5803; River Esk, Glencartholm, Dumfriesshire; Calciferous
Sandstone Measures, Lower Carboniferous.

Diagnosis. —SincQ there is presently only one species, the diagnosis is the same as
that of the genus.

Remarks.— To correct a lapse in Schram (1979), the lectotype was designated by
Caiman ( 1 933), mistakenly termed at that time as a holotype. The reconstruction offered
here (Fig. 1 ) is slightly modified from that in Schram ( \919a) to display more accurately
the relationship of the chelipede to the carapace.

Genus Ophthalmapseudes Glaessner (in Glaessner and Malzahn 1962)

Diagnosis. —KosXruva prominent. Telson short, truncate, with a pair of large anal
flaps. Abdominal pleurites well developed, projecting ventrolaterally as plate-like pro-
cesses. Sixth pleomere incompletely vaulted, but posterolaterally flattened to form a
shelf to which uropods articulate.

Type species.— Macrura rhenana Malzahn, 1957.

Gewt^^^T —Masculine.

Ophthalmapseudes rhenanus (Malzahn), 1957
Figures 2, 3

V. 1957 Prosoponiscus problematicus Genitz. Malzahn; pi. 10, figs. 7, 8.
';.* 1957 Macrura rhenana Malzahn, p. 104; PI. 10, figs. 9-11.

130

1 mm

Figure 2. Reconstruction of Ophthalmapseudes rhenanus (Malzahn). Chelipedes in lateral view have been
drawn more ventrad than they probably were in life to reveal more clearly the mandible and labrum.

7955 Macrura rhenana Malzahn. Malzahn, p. 355.

v. 1962 Ophthalmapseudes rhenanus (Malzahn). Glaessner in Glaessner and Malzahn, p. 259; fig. 4; pi. 2,

figs. 6-13; pi. 3, figs. 1-13; pi. 4, figs. 1-22.
7965 Ophthalmapseudes rhenanus (Malzahn). Malzahn, p. 228.
7965 Ophthalmapseudes rhenanus (Malzahn). Sachariew-Kowatschewa & Bachmayer, p. 240; pi. 5, fig. 2.

7965 Ophthalmapseudes rhenanus (Malzahn). Vegh and Bachmayer, p. 241; pi. 7, figs. 2, 3.

7966 Ophthalmapseudes rhenanus (Malzahn). Forster, p. 34.

1969 Ophthalmapseudes rhenanus (Malzahn). Hessler, p. R371; fig. 188-1.

7969 Ophthalmapseudes rhenanus (Malzahn). Schram, p. 221, table 1.

7970 Ophthalmapseudes rhenanus (Malzahn). Malzahn, p. 62.
797-^ Ophthalmapseudes rhenanus (Malzahn). Schram, p. 104.
7979 Ophthalmapseudes rhenanus (Malzahn). Malzahn, p. 74.

1980 Ophthalmapseudes rhenanus (Malzahn). Sieg, p. 404, fig. 2H, fig. 4.

Lectotype.—iyvQVQ designated) ZlOa; Borehole 57, Friedrich Heinrich Mine, near
Kamp-Lintfort, Federal Republic of Germany; Zechstein 1 , Lower Permian.

Paralectotypes.—ZlOh, ZlOc in the Landesamt, Hannover.

Diagnosis. —Since there is presently only one species, the diagnosis is the same as
that of the genus.

Remarks.— A reexamination of all the original specimens, in addition to new
material which has since become available, allows a detailed reconstruction of this
species to be made for the first time (Fig. 2). We thus add to the otherwise excellent
description of Glaessner (in Glaessner and Malzahn 1962) with these additional ob-
servations.

The distal portions of the antennules and antennae are still unknown, but the
basalmost joint of the antenna is short and followed by a long joint that extends beyond

131

Figure 3. Ophthalmapseudes rhenanus (Malzahn). A) SDSNH 22255, dorsal view of anterior cephalotho-
rax, X25.8; B) SDSNH 26257, ventral view of cephalon, x26.2; C) SDSNH 26256, left lateral view of
cephalon, x39.0; D) SDSNH 26259, lateral view of thorax and abdomen, x27.3; E) SDSNH 26260, right
lateral view of anterior thorax and cephalon, x 23.7; F) SDSNH 26258, ventral view of posterior thorax and
abdomen, x24.4; G) SDSNH 26261, body terminus, x36.6. Antennule (a,), antenna (a^), anal plate (ap),
basis of pereiopods (b), carapace (c), basis of chelipede (ch), dikonophor (dk), mandible (m), mandibular
palp (mp), pleopod (pi), sixth pleomere (p^), pleomere pleura (pp), rostrum (r), third thoracomere (T,).

132

5 mm

Figure 4. Reconstruction of Cryptocaris hootchi Schram. (Modified from Schram 1974.)

the tip of the rostrum (Fig. 3B). The mandibles are massive and seem to bear a palp
near the base (Fig. 3C) that extends anteriorly to the labrum. The chelipede is
composed of a short coxa, long basis (Fig. 3E), a short ischium, short merus, and a
long carpus. The claw itself has a long and moderately deep propodus with a long finger,
and a long dactylus. The form of the first pereiopod is still uncertain. The posterior
pereiopods have short coxae and long cylindrical bases (Fig. 3D), and the carpus (at
least on the anterior limbs) is equipped with stout spine-like setae. The posterior portion
of the carapace is very much like that seen in modem forms with an opening into the
branchiostegal chamber between the carapace rim and the chelipede (Fig. 3E). Males
of this species are dikonophoric (Fig. 3F). The abdominal pleurites are well-developed
and directed ventrad to protect the rather robust protopods of the pleopods (Fig. 3E).
The small telson is terminally truncate with a pair of large anal flaps totally covering
the posterior surface (Fig. 3G). The protopods of the uropods are small and cylindrical,
and articulated with the posterolateral shelf of the sixth pleomeres. The distal rami of
the uropods are not preserved on any of the specimens at hand.

The equally developed ischium and merus on the chelipede represents a distinctly
more primitive state than that seen in living forms, where the ischium and merus are
either fused or the ischium is possibly reduced to a mere remnant (Gardiner 1975,
Lauterbach 1970). Since this feature is not preserved on any of the known specimens
of other anthracocaridomorphs, it is impossible at this time to comment on the sig-
nificance of the equal and separate ischium and merus. However, if this character is
consistent in the other Paleozoic species, it may be another diagnostic feature of the
Anthracocaridomorpha.

Ophthalmapseudes sp. (Vegh and Bachmayer, 1965)

796^^ crustacean-like form, Vegh, p. 65.

1965 Ophthalmapseudes sp., Vegh and Bachmayer, p. 241, pi. 7, figs. 4-6.

1980 Ophthalmapseudes sp., Sieg, p. 406, fig. 4.

Remarks. —ThtSQ rather nondescript portions of claw came from a borehole near
Szentgal, Hungary, and are of Rhaetic, Triassic age. They have been compared to
propodal and dactylar elements of O. rhenanus, but whether they actually are that

133

Figure 5. Cryptocahs hootchi Schram latex peel of EX 1882 showing the cephalon and anterior thorax,
X 8.7. Anterolateral comer of carapace (ale), eye lobe (el), rostrum (r), third thoracomere (T,).

species or not, or even in the genus Ophthalmapseudes, cannot definitely be determined
without actual body specimens. It seems likely this matenal may eventually be deter-
mined to be more akin to Jurapseudes {see below).

Family Cryptocarididae Sieg, 1980

Diagnosis.— XJropods biramous, rami 2-segmented and flap-like. Telson well de-
veloped.

Type genus. — Cryptocaris Schram, 1 974.

Genus Cryptocaris Schram, 1974
Figures 4, 5

Diagnosis. —KosXwivn prominent. Cephalothorax with prominent anterolateral cor-
ners, well-developed optic notch. Pereiomeres somewhat flattened, with paired longi-
tudinal ridges on either side of dorsal midline, pleura well developed and extending
laterad while each bears 3 longitudinal ridges. Abdominal pleura well developed. Telson
moderate in length and rounded.

Type species.— Cryptocaris hootchi Schram, 1974.

G^«(^^r. —Feminine.

Cryptocaris hootchi Schram, 1974

v.* 1974 Cryptocaris hootchi Schram, p. 100, figs. 4-10.
1976 Cryptocaris hootchi Schram. Schram, p. 26.
1979a Cryptocaris hootchi Schram. Schram, p. 100.
1979b Cryptocaris hootchi Schram. Schram, p. 164, table 1.

1980 Cryptocaris hootchi Schram. Sieg, p. 406, figs. 2.1, 4.

1981 Cryptocaris hootchi Schram. Schram, p. 128, table 1, text-fig. 3.

1983 Cryptocaris hootchi Schram. Sieg, p. 232, fig. 2.

1984 Cryptocaris hootchi Schram. Sieg, pp. 34, 88, fig. 29.

134

Holotype. — P32053; Peabody Coal Co. Pit 1 1, Will, Grundy, and Kankakee Coun-
ties, Illinois, USA; Francis Creek Shale, Carbondale Fm., Desmoinsian, Upper Penn-
sylvanian (Westphalian D).

Diagnosis. — Since there is presently only one species, the diagnosis is the same
as that of the genus.

Remarks.— K detailed description is to be found in Schram (1974). However,
reexamination of available material in light of more complete understanding of the
other Paleozoic tanaidaceans requires some adjustments in the diagnosis and recon-
struction (Fig. 4). The thoracic pleura are directed laterad (Fig. 5), and the anterolateral
comers of the carapace are prominent.

In regards to this latter feature there are two interpretations. One of us (JS) feels
these comers may represent a condition like that seen in many living tanaidaceans,
where the lobed eyes become fused with the antero-lateral region of the cephalothorax.
However, another of us (FRS) feels there is some evidence on the fossils that suggest
separate eye lobes (mistakenly referred to and reconstructed as stalked eyes in Schram,
1974) associated with the optic notches (Fig. 5). The issue can only be resolved with
the discovery of better preserved material of this species.

Infraorder: Apseudomorpha Sieg, 1980

Diagnosis. —Body more or less dorsoventrally flattened. Eyes primitively lobed or
fused to cephalothorax. Pereion with tendency for first pereiomere to fuse with ceph-
alothorax, males with one or two genital cones, without thoracic glands. Pleon with 5
free pleomeres and a pleotelson. Sexual dimorphism weakly developed, only affecting
antennae and chelipedes.

Superfamily Jurapseudoidea nov.

Diagnosis.— Body slightly dorsoventrally flattened. Males dikonophoric, with strong
chelipedes.

Family Jurapseudidae nov.

Diagnosis.— Since only one family is presently recognized, the diagnosis is the
same as that of the superfamily.

Type genus. —Jurapseudes gen. nov.

Genus Jurapseudes nov.

Diagnosis. — Pleon with free pleomeres short, pleurites developed as ventrolaterally
directed processes, stemites undecorated. Pleotelson long, highly vaulted, laterally de-
veloped with flange or ridge.

Type species. — Ophthalmapseudes friedericianus Malzahn, 1965.

Gender. — Masculine.

Etymology.— ¥or Jurassic, and the resemblance to living apseudomorphs.

Remarks. —The pleotelson of this genus (Fig. 6 A) greatly resembles that distinctive
pleotelson of the modem genus Discapseudes (Bacescu and Gutu 1975).

Jurapseudes friedericianus (Malzahn) 1965
Figures 6A, B, and 7

v.* 1965 Ophthalmapseudes friedericianus Malzahn; p. 223; Pis. 1-4.

7965 Ophthalmapseudes friedericianus Malzahn. Sachariewa-Kowatschewa & Bachmayer; p. 238; pi. 5, fig. 4.

1966 Ophthalmapseudes friedericianus Malzahn. Forster, p. 33.

V. 1970 Ophthalmapseudes friedericianus Malzahn. Malzahn, p. 64; pi. 1, figs. 1-7; pi. 2.

7979 Ophthalmapsuedes friedericianus Malzahn. Malzahn, p. 74.

7950 Ophthalmapseudes friedericianus Malzahn. Sieg, p. 406, fig. 4.

Holotype. —NM'W 632/1965/1; Level 13, Friedericke Mine, near Bundheim/Bad
Harzburg, Federal Republic of Germany; alpha Dogger, Lineatum Zone, Middle Ju-
rassic.

135

C
2 mm

1 mm

Figure 6. Reconstructions of fossil Apseudomorpha. A & B) Jurapseudes friedericianus (Malzahn), A)
dorsal body, B) large male chela, and two variant female chelae, C) J. acutirostris (Sachariewa-Kowatschewa
and Bachmayer), D & E) Carlclausus emersoni n. gen., n. sp., D) dorsal body without anterior part of
cephalon, E) chela with two variant daclyli opposed to the massive propodus.

136

Figure 7. Jurapseudes friedericianus (Malzahn). A) EM 1, carapace with left anterior portion broken away,
x37; B) SDSNH 26253, ventral view of abdomen, x 17.5; C) SDSNH 26254, pleotelson, x24.3. Rostrum
(r), optic notch (on), broken hyposphanium (h), places of pleopod attachment (p).

Paratypes.—l<iyV^ 632/1965/2-27, from type locality.

Additional specimens. -EM 1-8 (illustrated in Malzahn 1970) SDSNH 26251-
26254; Lower Bathonian, near Hildesheim (Malzahn 1970), Lower Saxony, Federal
Republic of Germany.

Diagnosis, —^ody small (cephalothorax ~2 mm). Rostrum broad. Cephalothorax
relatively longer than wide (length/width ratio 1:0.9). First 2 periomeres almost as long
as wide (length/width ratio 1:1.8).

Remarks. —The presence of a pleotelson (Fig. 7C) clearly separates this genus from
the Permian anthracocaridomorph Ophthalmapseudes, whereas the slightly flattened
body form, completely segmented pleon, and long pleotelson most closely ally these
Jurassic forms to the modem apseudomorphs.

Malzahn originally characterized males of the species as having one or possibly
two genital cones. However, the single specimen which seemed to suggest a monoko-
nophoric condition (Malzahn 1965, plate II, fig. 4) appears to have (Fig. 7B) a broken
hyposphanium (=midventral process of the stemite). The species thus is probably
dikonophoric.

We have also noted three distinctly different forms of claw (Fig. 6B). One obviously
belongs to a male in which the dactylus is thin and widely separated from the propodal
finger; the entire claw is larger on the whole than either of the other forms. The other
two morphs are smaller and probably belong to females; they are distinguished on the
basis of whether there is one or two teeth on the inner margin of the dactylus and on
the relative length of the dactylus. These two "female" morphs could represent variants
between copulatory and precopulatory phases.

Earlier illustrations of the carapace of this species (Malzahn 1970: table 1, fig. la)
were not particularly clear. That specimen is re-illustrated here (Fig. 7A).

Jurapseudes acutirostris (Sachariewa-Kowatschewa and Bachmayer) 1965

Figure 6C

v.* 1965 Ophthalmapseudes acutirostris, Sachariewa-Kowatschewa and Bachmayer; p. 238; pi. 5, fig. 3; pi. 4.
1966 Ophthalmapseudes acutirostris, Sachariewa-Kowatschewa and Bachmayer. Forster, p. 34.

137

1980 Ophthalmapseudes acutirostris. Sachariewa-Kowatschewa and Bachmayer. Sieg; p. 406, figs. 2.2F, G,
and 4.

//o/ory/7£'. -(by monotypy) NMW 633/1 96 5/C 10; Borehole Nikola Koslewo, depth
751.6 m, northern Bulgaria; Dogger, Middle Jurassic.

Diagnosis.— Body moderate in size (cephalothorax length ^6 mm). Rostrum nar-
row, terminally pointed. Cephalothorax relatively shorter than wide (length/width ratio
1:1.1). First 2 pereiomeres much shorter than wide (length/width ratio 1:3).

Remarks.— The diagnostic characters of the genus Jurapseudes involve the pos-
terior end of the body. However, the resemblance of 7. acutirostris to the known anterior
portions of J. friedericiamis is so close that there seems little doubt that these species
should be retained in the same genus, at least until information to the contrary becomes
available.

Forster (1966) compared a single Lower Dogger tanaidacean fossil to O.friederi-
cianus. That specimen, from borehole Reichertshausen 1 from the Brigitta Mine in
southern Germany at a depth of 1343.9 m, consists of a pereion and portions of the
anterior pleomeres.

Carlclausus gen. nov.

Diagnosis. -VXeornQves highly vaulted; with well-developed, laterally directed pleu-
ral processes; stemites with prominent, tubercular hyposphaenia. Pleotelson long, highly
vaulted, developed posterolaterally as a flange or ridge.

Type species. — Carlclausus emersoni sp. nov.

G^«<^^r. —Masculine.

Ervmc/ogT.— Named after the pioneer tanaidacean worker Carl Claus.

Carlclausus emersoni sp. nov.
Figures 6D, 8

vp.* 1979 Ophthalmapseudes giganteus (partim) Malzahn; p. 780; pi. 1, figs. 6-9; pi. 2, figs. 3-18; pi. 3.

Holotype. —NMW 1985/44/1 (Fig. 8E); Engelbostel Brickyard claypit, west of the
Flughafen Langenhagen highway in Hanover, Federal Republic of Germany; Lower
Hauterivian, high in Endemoceras amblygonium Series, Lower Cretaceous.

Paratypes. —NMW 1985/44/2-1 1, same locality as holotype.

Etymology. —Named in honor of Michael J. Emerson, whose powers of observation
and contributions to this project both scientifically as well as artistically resulted in a
far better paper than what might have been.

Diagnosis.— Since only one species is presently recognized, the diagnosis is the
same as that of the genus.

Description. —The anterior pereiomeres have rounded pleura (Fig. 8 A). The pos-
terior pereiomeres seem to be developed with pointed, laterally directed processes (Fig.
8B). The pereiomere stemites have hyposphaenia, and the males are apparently dikon-
ophoric (Fig. 8B). The 5 free pleomeres have large, laterally directed pleural processes
(Fig. 8C, D) which arise slightly anteriad of the pleopod articulations. These processes
arc posteriad as they extend laterally away from the body. The articular areas of the
pleopods are quite large, and between any one pair of them, on the midline of the
stemite, is a prominent hyposphaenium, the distal tips frequently being broken (Fig.
8D). The highly vaulted telson is wider distally than proximally because of the pos-
terolateral flange or ridge to which the uropods articulate (Fig. 8E).

Malzahn (1979: plate 3) illustrated a variety of chelae. These seem to be of two
kinds (Fig. 6E). One is a long thin form with a single small tooth near the base; the
other is a shorter, more massive form with a large tooth arising at the base. These are
opposed to a massive protopod with two teeth on the finger.

138

Figure 8. Carlclausus emersoni n. gen., n. sp. A) NMW 1985/44/2, posterior portion of carapace and two
anteriormost pereiomeres, xl8.5; B) NMW 1985/44/3, ventral view of last two pereiomers and first two
pleomeres, hyposphanum (h), dikonophore (dk), x24.3; C) NMW 1985/44/4, dorsal view of pleon, with
bases of laterally directed pleura, x 28.6; D) NMW 1985/44/5, ventral view of portion of pleon, with laterally
directed pleura, x26.6; place of pleopod attachment (p), hyposphaena (h); E) NMW 1985/44/1, holotype,
pleotelson showing diagnostic posteriorly flaring lateral ridges, x 37.5.

Remarks.— MosX of the material used in Malzahn's (1979) supplemental descrip-
tion of Ophthalmapseudes giganteus, noted by him as exceptions to the holotype of
that species, is assignable to this entirely separate genus and species, C emersoni. This
new species has only the most distant taxonomic affinities to the former. Rather,
Carclausus seems to bear some relationship to the Jurassic jurapseudids, based on the
possession of a long pleotelson with some development of lateral flanges or ridges, and
the prominent laterally directed pleural processes on the pleomeres.

139

Jurapseudoidea incerta sedis
Palaeotanais quenstedi Reiff, 1936

1885 Isopodites sp. Quenstedt, p. 423, fig. 14.

1936 Palaeotanais quenstedti Reiff, p. 86, figs. 17, 18.

7962 Palaeotanais quenstedti Reiff. Glaessner and Malzahn, p. 262.

1965 Palaeotanais quenstedti Reiff. Bachmeyer et al., p. 221.

1966 Isopodites Forster, p. 33.

1966 Palaeotanais quenstedti Reiff. Forster, p. 34.

1969 Palaeotanais quenstedti Reiff. Hessler, p. R371, fig. 188-2.

7970 Palaeotanais quenstedti Reiff. Malzahn, p. 61.

7979 Palaeotanais quenstedti Reiff. Malzahn, p. 68.

1980 Palaeotanais quenstedti Reiff. Sieg, p. 406, figs. 2.2E, 4.

Holotype. —lost; Dueraau near Boll, Federal Republic of Germany; Liassic, Lower
Jurassic; originally deposited in the collections of the Geological Institute, Tiibingen.

Remarks.— \3nXW the holotype is found and additional material is collected from
the Liassic, the affinities of this fossil must remain uncertain. Its placement here among
the apseudomorphs is a matter of interpretation from the literature. Although no
diagnostic features were preserved on the type specimen, none of the recorded infor-
mation on this species excludes it from possible apseudomorph assignment.

Superfamily Apseudoidea Leach, 1814

Diagnosis.— Body strongly flattened dorsoventrally. Eyes fused to cephalothorax.
Males monokonophoric. Uropods biramous and multisegmented.

Remarks.— \n light of our better understanding of fossil forms, some slight mod-
ification of the diagnosis of this superfamily is necessary in regards to the fused condition
of the eyes. No fossils of this superfamily are known.

Infraorder Tanaidomorpha Sieg, 1980

Diagnosis.— Body more or less cylindrical. Mandible without palp, maxillule with
only a single endite and palp, maxilla greatly reduced. First pereionite without tendency
to fuse to cephalothorax. Males mono- or dikonophoric. Pleon with tendency to fuse
segments, pleotelson small. Sexual dimorphism may be strongly developed; involving
antennae, chelipedes, mouthparts, and body shape.

Remarks.— ThQVQ are no fossils currently known that can be assigned to the
superfamilies Tanaoidea and Paratanaoidea. The single fossil tanaidomorph recognized
here possesses such an array of distinctively primitive features that it requires its own
superfamily.

Superfamily Cretitanaoidea nov.

Diagnosis.— knXtrior pereiomeres developed with small pleurites. Pleon with 5
free segments, pleotelson small.

Family Cretitanaidae nov.

Diagnosis. —SincQ only one family is presently known, the diagnosis is the same
as that of the superfamily.

Type genus. — C ret it anais gen. nov.
Genc^^r. —Masculine.

Genus Cretitanais nov.

Diagnosis.— Body large. Branchiostegal portion of carapace separated from dorsal
field of cephalothorax by longitudinal furrow. First 5 pereiomeres subequal, sixth pe-
reiomere distinctly shorter than anterior segments. Pleotelson short, apparently broadly
rounded.

Type species. —Ophthalmapseudes giganteus Malzahn, 1979.

Gender.— y\.diSC\x\\nQ.

140

5 mm

Figure 9. Reconstruction of Cretitanais giganteus (Malzahn).

Cretitanais giganteus (Malzahn) 1979
Figures 9, 10

v.* 1979 Ophthalmapseudes giganteus Malzahn, p. 67; pi. 1, figs. 1-5; pi. 2, figs. 1, 2.

1979 Apseudes giganteus Malzahn, p. 67.

1982 Apseudes giganteus (Malzahn). Malzahn and Pockrandt, p. 57.

Holotype. — NMW 1978/1997/1; Engelbostel Brickyard claypit, west of the Flugha-
fen Langenhagen highway in Hannover, Federal Republic of Germany; Lower Hau-
terivian, high in the Endemoceras amblygonium Series, Lower Cretaceous.

Diagnosis.— Since, only one species is presently recognized, the diagnosis is the
same as that of the genus.

Remarks. —Though Malzahn (1979) confused specimens of what we now recognize
as two different species, he carefully separated the diagnosis of the taxon and the
description of the holotype specimen from the "additional examples" (now assigned
to a new taxon, Carlclausus emersoni). The pertinent features of the type specimen
which allow placement of Cretitanais giganteus within the Tanaidomorpha are as
follows: 1) the posterior of the carapace (Fig. 10 A, B) is inflated and complete (not
deeply excavated as is generally the case in the neotanaidomorphs); and 2) the sixth
pereiomere (Fig. IOC, D) is much shorter than that of the fifth or anterior segments,
and bears well-developed pereiopods. The pereiopods are apparently cylindrical or
stalk-like (Fig. IOC), not fossorial or flattened. This condition of the legs is generally
considered a primitive feature and more characteristic of tanaidomorphs, while neo-
tanaidomorphs exhibit tendencies toward fossorial type legs.

Non-tanaidacean fossils
Apseudes sp. (Malzahn and Pockrandt, 1982)

Remarks. —This specimen, NMW 1979/2057, is not a tanaid, but rather a portion
of a decapod abdomen. The published figures (Malzahn and Pockrandt 1982, plate 1,
especially figs. 5, 6) have the matrix and part of the fossil whitened out, thus mistakenly
highlighting non-existent tanaidacean features.

14:

Figure 10. Cretitanais giganteus (Malzahn), holotype, NMW 1978/1997/1. A) left side of cephalon, x 9.6;
B) right side of cephalon, with chelipede, basis (b), possible ischium (?i), merus (m), carpus (c), propodus
(p), X 10.8; C) left view of posterior pereion and abdomen, pereiomeres (5, 6), pleomeres (1-5), pleotelson
(pt), a posterior pereiopod extending below b, x6.9; D) dorsal view of C, x 7.9.

Charassocarcinus mayalis (Eudes-Deslongchamps) 1878

Remarks. —This species was arbitrarily assigned by Glaessner (1969:R628) to the
tanaidaceans. The type and only known specimen has long been lost, but from ex-
amination of descriptions and illustrations of this form in comparison to known fossil
and recent tanaidaceans we feel confident in returning this problematic form— as a
nomen dubium — to the ranks of the Decapoda.

Discussion

Although the Tanaidacea are now perceived to have a remarkably good fossil
record, all things considered, our knowledge is still not comprehensive enough to be
able to present an unequivocal cladogram of relationships. Classic cladislic analysis

142

would require defining lists of symplesiomorphies and synapomorphies. Unfortunately,
our ignorance of the fine details of fossil appendage morphology, especially mouthparts,
allows us to deal only with gross changes in body plan. So while we might conceptualize
the main steps in tanaidacean evolution with the use of the fossils discussed here, we
still lack the knowledge to analyze the small phylogenetic steps, as is possible with
living forms (see e.g., Sieg 1983, 1984). These latter naturally would have been the
basis for the changes in gross body morphology.

Little more can be added to the hypothetical "urtanaidacean" recently proposed
by Sieg (1984). Corrections presented here in the reconstruction of Cryptocaris hootchi
Schram, 1974, would seem to verify that the body shape of the archaic tanaidaceans
was more or less dorsoventrally flattened. This perception agrees with current under-
standing of the morphological changes that occurred when the neotanaidomorphs and
tanaidomorphs developed (Sieg 1983, 1984). Furthermore, the ancestral tanaidacean
type fused the first 2 thoracomeres with the cephalon, transformed the second thora-
copod into a chelipede, and possessed an abdomen of 6 pleomeres and a free telson.
Equally it is noteworthy that the sixth pleomere is nearly always much longer than any
of those preceding it. We might also expect the basal tanaidacean stock to have possessed
a tailfan with broad uropodal rami, similar to that of Cryptocaris.

Indeed, with its extensive array of primitive features, Cryptocaris could be con-
sidered as the sister group to all other tanaidaceans. Unfortunately, we currently lack
any apomorphies that would unambiguously diagnose the Cryptocarididae as mono-
phyletic in relation to the Anthracocarididae. However, because Cryptocaris is younger
than the more advanced Anthracocaris, we can anticipate future fossil discoveries in
the late Paleozoic that will allow us to clarify the relationships among these archaic
forms. Presently, we would hypothesize that in the Lower Carboniferous there were
probably 2 distinct evolutionary lineages. One (represented by Cryptocaris) was basi-
cally a derivation of the ancestral stock, the other (represented by Anthracocaris and
Ophthalmapseudes) was convergent in form, if it did not directly lead, to the recent
tanaidaceans. By the beginning of the Mesozoic the fusion of the sixth pleomere and
telson occurred, since all Mesozoic and Recent forms possess a pleotelson.

Anthracocaridomorpha, as currently understood, is a paraphyletic taxon because
it can only be characterized by primitive features. However, since at this time we cannot
define adequately the monophyletic status of either of the cryptocarids or anthracocarids
we feel justified in placing these families within a single suborder.

The fossils described here suggest a solution to a minor problem related to deter-
mining the number and identity of chelipede joints. It was formerly thought that within
the apseudomorphs the ischium was totally reduced, whereas there was still a small
remnant in the neotanaidomorphs (Gardiner 1975). It was thought that tanaidomorphs
also originally possessed an ischium. Lauterbach (1970) observed a small chitinous
bracelet on Tanais cavolinii (=T. dulongii), but this structure can be interpreted as
either an ischium or as a rudiment of the dorsal portion of the merus (Sieg 1983Z)).
The well-developed ischium and merus in Ophthalmapseudes rhenanus (Fig. 2) would
seem, to at least one of us (JS), to support the idea that the apseudomorph "merus" is
in reality an ischio-merus, and that tanaidomorphs might possess only a merus. This
would perhaps serve to explain the relative size of the large aspseudomorph "merus"
in comparison to the more diminutive joint seen in the neotanaidomorph/tanaido-
morph line. However, it is unclear (FRS) whether Cretitanais giganteus may preserve
a remnant of a small ischium on what appear to be its chelipedes (Fig. 1 OB).

The radiation of the modem Tanaidacea must have taken place in the Mesozoic.
With little doubt the Jurassic Jurapseudes belongs within the apseudomorphs, and the
same conclusion can be drawn for the Cretaceous Carlclausus. On the other hand
Cretitanais would seem best placed within the tanaidomorphs. Though fossils assignable
to Recent tanaidacean families and/or superfamilies are lacking, the record implies that
the evolution of the apseudoidean and tanaidomorph families probably took place by
late Mesozoic time (Late Cretaceous). Unfortunately, as is the case among the Paleozoic
taxa, our current knowledge of the Mesozoic tanaidaceans does not allow us to char-

143

acterize unambiguously with apomorphic features the jurapseudoids and cretitanaoids.
However, we are reasonably confident that future fossil discoveries will support our
hypothesized phyletic relationships within the known fossil and Recent Tanaidacea.

Acknowledgments

We would like to extend special thanks to Michael J. Emerson who assisted in
preparing the fossils and who produced the figures, and to Marjorie Rea who typed the
text. Research was supported in part by NSF grants DEB 79-03602 and BSR 82-12335
to FRS and by grants from the Deutsche Forschungsgemeinschaft to JS.

Literature Cited

Bacescu, M., and M. Gutu. 1975. A new genus
{Discapseudes) and three new species of Ap-
seudidae from the north-eastern coast of South
America. Zoologische MededeHngen 49:95-
113.

Bachmayer, F., E. Malzahn, K. Sachariewa-Ko-
watschewa, and S. Vegh. 1965. NeueScheren-
assel-Funde aus den Dogger-Schichten von
Norddeutschland und Bulgarien sowie aus
Trias-Ablagerungen von Ungam. Annalen des
Naturhistorischen Museum in Wien 68:221-
222.

Caiman, W. T. 1933. On Anthracocaris scotica, a
fossil crustacean of the Lower Carboniferous.
Annals and Magazine of Natural History ( 1 0) 1 1 :
562-565.

Eudes-Deslongchamps, E. 1878. Le Jura Nor-
mand. Paris et Caen.

Forster, R. 1966. Ein neuer Scherenassel-fund,
Ophthalmapseudes cf friedericianus Malzahn
aus dem unteren Dogger Siiddeutschlands.
Mitteilungen der Bayerischen Staatssamm-
lungen fiir Palaontologie und historishe Geo-
logic, Miinchen 6:33-36.

Gardiner, L. F. 1975. The systematics, postmar-
supial development, and ecology of the deep-
sea family Neotanaidae. Smithsonian Contri-
butions to Zoology 170:1-265.

Glaessner, M. F. 1969. Decapoda. Pp. R399-R533
in R. C. Moore (ed.). Treatise on Invertebrate
Paleontology, Part R, Arthropoda 4, Vol. 2.
Geological Society of America and University
of Kansas Press, Lawrence.

, and E. Malzahn. 1962. Neue Crustacean

aus dem niederrheinischen Zechstein. Fort-
schritte in der Geologic von Rheinland und
Westfalen, Krefeld 6:245-264.

Hessler, R. R. 1969. Peracarida. Pp. R360-R393
in R. C. Moore (ed.). Treatise on Invertebrate
Paleontology, Part R, Arthropoda 4, Vol. 1.
Geological Society of America and University
of Kansas Press, Lawrence.

Lauterbach, K.-E. 1970. Der Cephalothorax von
Tanais cavolinii, ein Beitrag zur vergleischen-
den Anatomic und Phylogenie der Tanaidacea.
Zoologisches Jahrbuch, Abteilung Anatomic
87:94-204.

Malzahn, E. 1957. Neue Fossilfunde und verti-
kale Verbreitung der niederrheinischen Zech-
steinfauna in den Bohrungen Kemp 4 und
Friedrich Heinrich 57 bei Kamp-Lintfort.
Geologisches Jahrbuch 73:91-126.

. 1965. Fine neue fossile Scherenassel

(.Ophthalmapseudes friedericianus) aus dem
norddeutschen Dogger. Annalen des Naturhis-
torischen Museum in Wien 68:223-235.

— . 1970. Die Scherenassel Ophthalmap-
seudes friedericianus im Dogger von Hildes-
cheim. Berliner Naturhistorisches Gesellschaft
114:61-73.

— . 1979. Apseudes giganteus—d'iQ txsXQ
Scherenassel aus der Kreide. Annalen des Na-
turhistorischen Museum in Wien 82:67-81.

— , and W. Pockrandt. 1982. Fine zweite

Scherenassel aus der Unterkreide. Annalen des
Naturhistorishen Museum in Wien 89/A:57-
61.

Matthews, S. C. 1973. Notes on open nomencla-
ture and on synonymy lists. Paleontology 16:
713-719.

Peach, B. N. 1882. On some new Crustacea from
the Lower Carboniferous rocks of Eskdale and
Liddesdale. Proceedings of the Royal Society
of Edinburgh 30:73-91.

. 1883. Further researches among the Crus-
tacea and Arachnida of the Carboniferous rocks
of the Scottish border. Proceedings of the Roy-
al Society of Edinburgh 30:51 1-529.

Reiff, E. 1936. Isopoden aus dem Lias Delta
Schwabens. Palaeontologische Zeitschrift 18:
49-90.

Richter, R. 1948. Einfiihrung in der Zoologische
Nomenklatur 2nd ed. Kramer, Frankfurt.

Sachariewa-Kowatschewa. K., and F. Bachmayer.
1965. Fine neue fossile Scherenassel
(Ophthalmapseudes acutirostris) aus den Dog-
ger-Schichten von Bulgarien. Annalen des Na-
turhistorischen Museum in Wien 68:236-240.

Schram, F. R. 1969. Stratigraphic distribution of
the Paleozoic Eumalacostraca. Fieldiana: Ge-
ology 12:213-234.

. 1974. Late Paleozoic Peracarida of North

America. Fieldiana: Geology 33:95-124.

. 1976. Some notes on Pennsylvanian crus-
taceans of the Illinois basin. Fieldiana: Geology
35:21-28.

. 1979a. British Carboniferous Malacos-

traca. Fieldiana: Geology 40:1-129.

. 1979/7. The Mazon Creek biotas in the

context of a Carboniferous found continuum.
Pp. 159-190 m M. H. Nitecki (ed.). Mazon
Creek Fossils. Academic Press, New York.

. 1981. Late Paleozoic crustacean com-
munities. Journal of Paleontology 55: 1 26-1 37.

. 1982. The fossil record and evolution of

Crustacea. Pp. 93-147 in L. G. Abele(ed.). The

144

Biology of Crustacea, Vol. 1. Academic Press,
New York.

Sieg, J. 1980. Sind die Dikonophora eine poly-
phyletische Gruppe? Zoologische Anzeiger 205:
401-416.

. 1983. Evolution of Tanaidacea. Crusta-
cean Issues 1:229-256.

. 1984. Neuere Erkenntnisse zum natiir-

lichen System der Tanaidacea, eine phyloge-
netische Studie. Zoologica 136:1-132.
Vegh, S. 1964. A deli bakony raeti kepzodmen-

yeinek foeldtana. Geologica Hungarica 14:3-
53.
— , and F. Bachmeyer. 1965. Fossile Sche-

renasselreste aus triadischen Schichten von
Ungam. Annalen des Naturhistorischen Mu-
seum in Wien 68:241-242.
Woodward, H. 1911. On a large form of /l«?/zra-
palaemon from the clay-ironstone nodules of
the Middle Coal Measures, Sparth Bottoms,
Rochdale. Geological Magazine (5)8:361-366.

TRANSACTIONS
OF THE SAN DIEGO
SOCIETY OF
NATURAL HISTORY

Volume 21 Number 9 pp. 145-153 5 December 1986

Another new forest-dwelling frog (Leptodactylidae: Eleutherodactylus)
from the Cockpit Country of Jamaica

DEC

Ronald I. Crombie

Department of Vertebrate Zoology, National Museum of Natural History. Smithsonian Institution, Wash-
ington D.C. 20560 USA

Abstract. A new, diminutive species of Eleutherodactylus is described from the mesic forests of
the Cockpit Country, Trelawny Parish, west-central Jamaica. The new species is placed in the gossei
group (sensu Crombie 1977) and is distinguished from other members of this assemblage by its small
size, bright yellow belly in life, smooth dorsum, and a variety of other morphological characters. The
species is compared with similar Jamaican congeners and data are presented on its natural history,
variation, and possible relationships.

Introduction

In 1938 the late George S. Myers commented that, ". . . it would seem that one
of the chief diversions of contemporary American herpetologists is the describing of
new West Indian Eleutherodactyli! If I am not believed, I would refer my questioner
to Dr. Barbour's recent list (1935)" (Myers 1938:355). Barbour listed 60 species of
Eleutherodactylus in his 1935 West Indian checklist. Forty years later, despite the
synonymization of several of the taxa Barbour mentioned, the total had more than
doubled (Schwartz and Thomas 1975, Schwartz et al. 1978). With apologies to Dr.
Myers, I herein contribute another, albeit quite distinctive, new species from Jamaica.
I also suggest that the situation in South America, where nearly 1 00 new species have
been described since 1968 (27 in 1980 alone), would have horrified Dr. Myers even
more.

In the past twelve years of field work in the Cockpit Country of west-central
Jamaica, I have been fortunate to catch a glimpse of what much of the West Indian
wet forests must have been like before the arrival of humans. The brutal, unforgiving
terrain of the Cockpits has largely prevented the wholesale habitat destruction that has
modified the distribution and abundance of many Jamaican animals. The result is a
unique pocket of relatively undisturbed forest that supports a number of endemic taxa
and acts as a refuge for species that could not adapt to the cane fields, rolling pasture,
and patchy scrub forest that now characterize much of the island. Sadly, even the
Cockpits have recently been under considerable pressure to accommodate the bur-
geoning population of Jamaica, and modification of the forests has intensified in the
past five years.

In describing Eleutherodactylus sisyphodemus from the deep forests of the Cockpits
(Crombie 1977), I compared the new taxon with an equally small, yellow-bellied,
syntopic species that I believed was E. luteolus (Gosse). Additional field work and an
examination of Coin's (1953) material at the Carnegie Museum revealed that E. luteolus
and the yellow-bellied frog were not conspecific.

As pointed out by Schwartz and Fowler ( 1 973: 1 22-1 24), Eleutherodactylus luteolus
is a small to medium-sized species (males to 17.3 mm SVL, females to 25.8 mm SVL)
that usually lacks bright ventral or inguinal coloration, has a prominent dark facial
mask, and has distinct supra-axillary and inguinal glands; the latter character Goin

146

(1953) neglected to mention in his redescription of the species. Eleutherodactylus lu-
teolus is found in a variety of open, disturbed habitats, including pastures, roadsides
and even beaches (Goin 1953, Crombie, personal observation). Prior to 1977 I had
collected only a few E. luteolus in such habitats in Hanover Parish and, on casual
examination, considered them identical to the yellow-bellied Cockpit frog, despite the
great discrepancy in habitat. In 1978, I collected specimens of a moderate-sized, drab
frog with prominent supra-axillary and inguinal glands from road cuts, rock walls and
in gardens near the town of Quick Step on the southern edge of the Cockpits. I tentatively
regarded them as a new species since they differed so strikingly from similarly sized
Jamaican Eleutherodactylus. However, in examining Coin's material of E. luteolus at
the Carnegie Museum, I found that females were very much larger and stockier than
males and that even poorly preserved specimens had indications of glands. Reexam-
ination of my specimens from the Quick Step road revealed that they were indeed large
female E. luteolus and that the yellow-bellied species from the forest was distinct and
undescribed. References to Eleutherodactylus luteolus in my 1977 paper refer to the
new species.

Eleutherodactylus griphus, sp. nov.

Holotype. —National Museum of Natural History (USNM) 250000, a gravid female
from the vicinity of "the cave," about 7 mi (11.2 km) WNW Quick Step, Trelawny
Parish, Jamaica, ca. 250 m elevation, collected by L. Richard Franz and R. I. Crombie
on 8 April 1978.

Paratopotypes (59).— USNM 250033-48, same data as holotype; San Diego Society
of Natural History (SDSNH) 64197-99, 64201, USNM 244472-73, collected by Greg-
ory K. Pregill, R. I. Crombie and Linda K. Gordon on 1 1 June 1983; USNM 244469-
71, collected by G. K. Pregill, R. I. Crombie and L. K. Gordon on 10 June 1983;
USNM 250005-1 1, Carnegie Museum of Natural History (CM) 1 12377-78, Museum
of Comparative Zoology, Harvard University (MCZ) 107864-65, Albert Schwartz Field
Series (ASFS) V3 6 3 84-8 5, collected by R. I. Crombie, Jeremy F. Jacobs and Barbara
A. Harvey on 12 July 1975; USNM 250012-32, collected by R. I. Crombie, Frances
I. McCullough, J. F. Jacobs and Menocal Stephenson on 15 July 1977.

Additional paratypes (4).-USNM 250001-04, from 0.5-1.0 mi (0.8-1.6 km) N
of Quick Step, ca. 350 m, Trelawny Parish, Jamaica, collected by R. I. Crombie, F. I.
McCullough, J. F. Jacobs and M. Stephenson on 14 July 1977.

Referred specimens.— \5S^M 244607 (dry skeleton) collected at the type locality
by G. K. Pregill, L. K. Gordon, William B. Hilgartner and Richard Thomas, 1 6 June
1983; USNM 244627 (cleared and stained), same locality, collected by G. K. Pregill,
L. K. Gordon and R. I. Crombie on 1 1 June 1983.

Diagnosis. —A small species (males to 1 4.2, females to 1 8.4 mm SVL) distinguished
from all other Jamaican Eleutherodactylus by the following combination of characters:
prominent dark canthal bars or facial mask and dark lateral stripes extending to near
midbody, belly metallic yellow in life with no red or orange in groin or on concealed
parts of legs, throat with distinct dark spots or extensive marbling, smooth dorsal skin
with no scapular "W," no inguinal or supra-axillary glands, no tarsal fringe or calcar,
no toe webbing.

Description of holotype.— A gravid female with the following measurements (in
mm): snout vent length (SVL) 16.4; head length (HL) 6.9; head width (HW) 6.9;
tympanum diameter (TYM) 1.0; eye diameter (EYE) 2.6; naris-eye distance (NE) 1.9;
femur length (FEM) 8.5; tibia length (TIB) 8.0; foot length (FT) 8.0. Head as long as
broad; HW/SVL 42%. Snout rounded in dorsal and lateral view, canthus rostralis
rounded; loreal region obtuse; lips not flared. Nostrils lateral, much closer to tip of
snout than eye; eye diameter greater than distance from naris to eye, interorbital distance
2.2, less than eye diameter. A single indistinct tubercle on each upper eyelid. Tympanum
distinct, round, proportionally larger in males. Tongue lanceolate, slightly nicked be-
hind, free posteriorly for more than half its length. Choanae moderate-sized, elliptical;
prevomerine dentigerous processes in two long, arched series from level of outer choanal

147

border, almost meeting on palatal midline; separated by a distance of less than Haifa
choanal diameter. Fingers moderately long, unwebbed. III longest, IV, II, and I sub-
equal. Digital pads flattened, longer than wide, pointed (particularly III and IV), with
circumferential grooves. Two flattened palmar tubercles; two indistinct conical tubercles
between palmar tubercle and basal subarticular tubercle on finger IV; no ulnar or
supernumerary tubercles. Toes long, unwebbed; IV, III, II, V, I in order of decreasing
length; a pale, flattened inner metatarsal tubercle and a conical outer one; digital pads
similar to those on fingers but slightly larger and more pointed. Heels touch when
femora at right angles to body axis; TIB/SVL 49%. Vent directed posteriorly with an
indistinct dark line above it. Skin of dorsum smooth with a few low, pale tubercles on
hind limbs. Venter smooth, becoming faintly granular on thighs and near vent.

Coloration of holotype. —In life, the dark chocolate brown dorsal stripes, more
intense toward the snout where they meet, broke up at midbody and disappeared near
the inguinal area. The middorsal area was lighter wood brown with an indistinct pale
middorsal hairline beginning just above the vent and ending in the scapular area. The
light dorsolateral stripes were tan, becoming silvery on upper eyelid and continuing to
where they meet on the tip of the snout. The loreal area was medium brown with a
darker spot at the anterior comer of each eye. A black lateral line started at the eye
and continued over the tympanum to midbody, where it broke up into a series of spots,
and ended. The legs were medium brown above, the thighs faintly and irregularly
barred with darker brown. The posterior thighs were light brown with no bright colors
on concealed surfaces or in groin. There was one dark brown blotch on the dorsolateral
right forearm, two on the left, and a similar one on the anterior face of each humerus.
The entire venter was uniform pale metallic yellow with a vague dusky suffusion on
the throat. The iris was gold above and red-brown below.

Morphological variation.— Nin&tQen adult females (including the holotype) have
the following measurements (in mm) and proportions: SVL 15.5-18.4 (x = 17.0 ±
0.80), HL 6.1-7.3 (6.9 ± 0.30), HW 6.4-7.6 (7.0 ± 0.32), TYM 1.0-1.3 (1.1 ± 0.1 1),
EYE 2.1-2.8 (2.5 ± 0.16), NE 1.7-2.3 (2.0 ± 0.13), FEM 7.7-8.9 (8.3 ± 0.35), TIB
7.4-8.5 (8.1 ± 0.29), FT 7.0-8.5 (7.9 ± 0.45), HW/SVL 39-42% (41 ± 0.74), TIB/
SVL 45-51% (47 ± 1.45).

Thirty two adult males have the following measurements and proportions: SVL
9.4-14.2 (12.5 ± 2.48), HL 3.9-6.0 (5.4 ± 0.42), HW 3.6-5.9 (5.3 ± 0.45), TYM 0.8-
1.3 (1.1 ± 0.25), EYE 1.6-2.2 (2.0 ± 0.14), NE 1.0-1.8 (1.5 ± 0.18), FEM 4.6-7.7
(6.2 ± 1.25), TIB 4.7-7.0 (6.3 ± 0.41), FT 4.0-6.6 (5.8 ± 1.16), HW/SVL 38-44%
(40 ± 7.4), TIB/SVL 44-53% (49 ± 1.89).

Morphological variation in the sample is comparatively slight, with a few excep-
tions. Eyelid tubercles may be almost indistinguishable (as in the holotype) or prominent
(USNM 250043). Digital discs may be distinctly pointed or rounded, and the heels
may barely meet or may overlap considerably (see TIB/SVL ratios above). The head
varies from slightly longer than broad to broader than long in both sexes.

In contrast, both dorsal and ventral patterns are extremely variable. The dark spots
on the forelimbs, body, and above the anus, and the hindlimb barring may be distinct,
absent, or any condition in between. In the tricolor morph (see below), the dark dorsal
stripes may be present only in the postocular area, extend to the inguinal area (Fig.
2A), or break up near midbody as in the holotype. The middorsal hairline, when present,
is usually confined to the posterior body but it can (rarely) extend onto the posterior
thighs; one individual (USNM 250039) even had hairlines on the posterior tarsi. The
pale spots and/or tubercles on the hindlimbs (see Fig. 1) are not visible in life but
appear after preservation in some individuals.

The ventral color is invariably yellow, often almost metallic. The dark pigmentation
on the throat is quite variable, and may consist of obscure marbling or stippling, discrete
dark blotches restricted to the edges of the mandible, or a general gray suffusion ex-
tending to the pectoral area. Some individuals have distinct gray spots on the throat,
similar to the characteristic pattern of E. grabhami. The extreme condition is found
in the single juvenile (USNM 250007) in which the entire belly is marbled with gray.

148

Figure 1. Dorsal view of the holotype of Eleutherodactylus griphus (USNM 250000). SVL 16.4 mm.

Pattern polymorphism. —Pattern variation in frogs of the genus Eleutherodactylus
can be extreme and this has led to considerable taxonomic confusion (Lynch 1966).
Jamaican frogs of the gossei group may have as many as 9 morphs in a single species
(Goin 1954:193, fig. 2 and data presented below). Goin (1950, 1954) attempted to
quantify this variation and standardize terminology for the various morphs. I previously
discussed polymorphism in some members of the groups and suggested some changes
in Goin's arrangement and terminology (Crombie 1977:198-199).

Compared to other members of the gossei group, polymorphism in E. griphus is
conservative {see Fig. 2), but some individuals may have a combination of two or three
pattern elements regarded as distinct morphs by Goin {see below).

The holotype and 14 other specimens of Eleutherodactylus griphus have light
dorsolateral stripes (Figs. 1 , 2A) that start on the tip of the snout, continue across the
eyelids and onto the lateral body, becoming much wider posteriorly {see coloration of
the holotype for more complete description of this morph). This is not the dorsolateral
stripe morph of Goin (1950, 1954), which consists of stripes that are more dorsal than
lateral and approximately the same width anteriorly and posteriorly {see Lynn 1 940,
PI. VI, fig. 1 Ic). Although Goin (1954) did not recognize these differently striped frogs
as a distinct morph, Lynn (1940) illustrated a similar pattern for both E. gossei, which
he incorrectly called luteolus (PI. IV, fig. 7d), and E. orcutti (PI. XII, fig. 23b). This is
one of the most distinctive, albeit uncommon morphs in the gossei group and, for
convenience, I propose to call it the "tricolor" morph, in allusion to the pale dorsolateral
stripes, the dark outlining, and the less intensely dark middorsal area.

The second morph o^ Eleutherodactylus griphus apparently does not occur in other
members of the gossei group and I have called it "plain" (Fig. 2B). It consists of a
basically unicolor dorsum, with or without a dark interocular bar. Roughly 50% of the
present sample is this morph.

The third morph was termed "purple" by Goin (1954:191) and was illustrated by
Lynn (1940, PI. IV, fig. 7f). A few specimens of £". griphus compare well with the

149

Figure 2. Dorsal and ventral view of the three commonest morphs of Eleutherodactylus griphus: A) tricolor,
USNM 244471; B) plain, USNM 250041; C) purple, USNM 250038.

description of this morph (Fig. 2C), previously found only in E. gossei (Goin 1 954: 191),
but my collections document its presence in E. pentasyringos also (USNM 250949 and
250971).

Five (mottled, broad dorsolateral stripe, broad middorsal stripe, interocular bar,
picket) of the seven other morphs in the gossei group are unknown in E. griphus.
Although a dark interocular bar is common in the plain morph and may be faintly
indicated in some tricolor frogs, it is different from Coin's interocular bar morph, which
consists of a light bar, outlined with black. Pelvic spots, which I prefer to call lumbar
spots (Crombie 1977:199), occasionally occur in the plain morph off", griphus. The
middorsal stripe (=middorsal hairline) may also be indistinctly visible in both tricolor
and plain morphs but it is restricted to the posterior body, never extending to the snout
and rarely onto the thighs as it does in other members of the gossei group.

Comparisons. —Eleutherodactylus griphus is only slightly larger than the smallest
known Jamaican frog, E. sisyphodemus (males to 13.8, females to 17.9 mm SVL), with
which it is syntopic in the Cockpit forests. However, as with many members of the
genus, absolute morphological differences between E. griphus and sympatric congeners
may not exist. Accurate identification may often depend on coloration in life, adver-
tisement call, distribution, habitat, and other non-morphological characters that are
difficult or impossible to assess in older museum specimens. Perhaps the best example
in Jamaica is E. junori, a small (19-27 mm SVL) species with a distinctive, loud,
rachet-like call, but otherwise indistinguishable from the slightly larger E. gossei. In
the following discussion I have attempted to use distinguishing characters that do not
depend on familiarity with the species in life whenever possible, but in some cases size
and/or distribution must be used.

I have previously (Crombie 1977:200) discussed the species groups of Jamaican
Eleutherodactylus. Although there are conflicting data on this arrangement {see Rela-

150

tionships), it remains a convenient tool for making pertinent comparisons. Since E.
griphus is clearly a member of the gossei group as previously defined (Crombie 1977),
distinguishing it from the members of the very different auriculatus, jamaicensis or
ricordii groups, with the exception of E. grabhami {see below) is unnecessary.

The eastern endemics of the gossei group from the granitic Blue Mountains (£".
alticola, E. andrewsi, E. nubicola, E. orcutti, and E. pentasyringos) are distributionally
far removed from the range of -£". griphus. Most are much larger frogs that occur above
2500 feet (810 m) in the mountains. The smallest of them, E. andrewsi (18-23 mm
SVL), usually has a pale dorsum with distinct dark inguinal spots, a venter heavily
pigmented with dark spots or a reticulum, and red flash colors in the inguinal areas
and concealed thighs. Eleutherodactylus orcutti is a stream- or seep-inhabiting species
with conspicuous basal toe webbing and a tuberculate dorsum; E. nubicola has poorly
developed digital discs and a uniform gray belly, even in preservative; E. alticola is
restricted to the highest peaks of the Blue Mountains, has very short vomerine series
and red groin patches. I regard E. pentasyringos as a distinct species rather than a
subspecies of £". pantoni. Schwartz and Fowler (1973: 1 18) suggested that the two might
not be conspecific and my unpublished data confirm the morphological and acoustic
differences between the two taxa. Although E. pentasyringos occurs in the lowlands
north of the Blue Mountains and often has a pale yellow belly like E. griphus, it is a
larger, more robust species with a loud six-note call.

The most pertinent comparisons are with the six species of the gossei group with
which E. griphus is actually or potentially sympatric and E. grabhami, a small sympatric
member of the ricordii group. I previously (Crombie 1977:200) compared E. sisypho-
demus with E. griphus (which I then called luteolus), concluding that the calcar, tarsal
fringe, ulnar stripe, and black ventral coloration oi E. sisyphodemus distinguished even
recently hatched specimens.

Eleutherodactylus luteolus is generally found in more open areas then E. griphus
but the two may be syntopic at the forest edge. Males are similarly sized but E. griphus
is slightly smaller, with dark throat markings, and a bright yellow belly in life. All the
E. luteolus I have collected have been singularly drab frogs, and I have not seen the reddish
dorsal markings or pale yellow bellies mentioned by Schwartz and Fowler (1973:123-
124). However, the prominent supra-axillary and inguinal glands of £". luteolus are
visible even in preserved material and serve to distinguish it from all similar species.

As previously mentioned, the throat markings of E. griphus may resemble those
of E. grabhami, but the similarities end there. Eleutherodactylus grabhami is a pale,
mottled frog (occasionally with broad dorsolateral light stripes) with fragile dorsal skin,
a white belly, and pinkish hindlimbs and brachia. Although E. grabhami has been
found less than a meter from individuals of £". griphus in the Cockpit forest, E. grabhami
are usually up on limestone rocks as opposed to concealed in the leaf litter. Eleutherodac-
tylus grabhami has also been found in terrestrial bromeliads and on low shrubs (Schwartz
and Fowler 1973:8 1; Crombie, personal observation), indicating that it is more arboreal
than E. griphus.

The remaining four species, E. fuscus, E. gossei, E. junori, and E. pantoni, are very
similar and often difficult to distinguish in the field, although their advertisement calls
are very different. Perhaps the most distinctive is E. fuscus, which often has a bright
yellow venter, orange or reddish in the groin and on the concealed legs, a continuous
dark supra- and post-tympanic crescent, and a tubercular scapular "W." My obser-
vations on the coloration of this species agree with those of Schwartz and Fowler (1973:
119-120) rather than the original description, in which Lynn and Dent (1942:236)
described the venter in life as "immaculate white." In ventral color, E. fuscus and E.
griphus are similar, but E. griphus is a much smaller species {fuscus males 25-35,
females 31-37 mm SVL), with distinct dark throat markings, canthal stripes and/or a
facial mask, no bright colors in the groin or on concealed limbs, and smooth dorsal
skin. Although many E. griphus may have both supra- and post-tympanic dark spots,
they do not form a continuous crescent as in E. fuscus. Reportedly, one of the paratypes

151

ofE. fuscus (USNM 11 5978) was collected at Quick Step (Lynn and Dent 1942:235).
However, I have never heard the distinctive call of this species in the southern Cockpits,
so sympatry with E. griphus remains to be demonstrated.

Like E. fuscus and E. griphus, E. pantoni has bright ventral coloration, ranging
from yellow to burnt orange. Schwartz and Fowler (1973) recognized three subspecies
of this widespread and variable frog, one of which (pentasyringos) I regard as a distinct
species {see above). The southern Cockpit Country populations are intergradient be-
tween E. p. pantoni and E. p. amiantus. Adults (to 40 mm +) have a prominent raised
scapular "W" and cannot be confused with E. griphus; even juvenile E. pantoni lack
dark canthal and lateral body stripes.

As noted above, E. gossei and E. junori are virtually indistinguishable without
information on the call so they will be considered together here. Eleutherodactylus
junori is the smaller species (19-27 mm SVL vs. 28-34 mm in gossei), but both have
prominent orange or pink patches in the groin and a raised (often outlined in brown)
scapular "W," lacking in E. griphus. Some individuals of E. gossei may have a pale
yellow belly (Schwartz and Fowler 1973:92; Crombie, personal observation) but it is
usually dull white or ivory. Cockpit Country E. gossei also lack the dark canthal stripe
or facial mask of £". griphus but this pattern may be present in E. gossei from localities
to the east.

Relationships. —Since studies on the relationships of Jamaican Eleutherodactylus
based on osteology (Glenn Flores) and electrophoresis (Blair Hedges) are in progress,
my speculative comments on the relationships of E. griphus will be brief.

Although the preliminary osteological and electrophoretic data are not in agreement
on the species groups of Jamaican Eleutherodactylus as I defined them (Crombie 1977),
E. griphus is clearly more closely related to the members of the gossei group than to
any other West Indian Eleutherodactylus. Pending the outcome of other studies, I
continue to recognize the gossei group as a natural assemblage.

There are two main centers of inter- and intra-specific diversity in the group, both
associated with extremely mesic areas that were probably isolated during the drier
periods of the Pleistocene (Pregill and Olson 1981). The higher elevations of the eastern
Blue Mountains and their windward slopes harbour six endemic taxa of the gossei
group and the western limestone region contains five, including E. griphus. It seems
likely that E. griphus evolved from the widespread, ecologically versatile gossei-pantoni
stock in the mesic enclave of the Cockpits.

Natural history.— Eleutherodactylus griphus is the commonest leaf litter frog in
the Cockpit forest and it has been collected on each of my visits to the area, as compared
to E. sisyphodemus which was found on only two of five occasions. Both species are
completely terrestrial and nocturnal but individuals can often be found by day, par-
ticularly following afternoon rains. Eleutherodactylus griphus appears tolerant of drier
conditions and, unlike E. sisyphodemus, it has been found in open areas (around tree
falls) within the forest and on occasions when the leaf litter was less than saturated.

Although E. griphus is largely confined to pockets of leaf litter in undisturbed
forest, I collected a small series (USNM 250001-04) at the forest edge along the road
north of Quick Step in 1977. They were found after dark in leaf litter along rock walls
and cliffs, associated with E. cundalli, E. gossei, E. grabhami, E. luteolus and E.
pantoni. Although I suspect that E. griphus is a Cockpit endemic, this apparent tolerance
of disturbed areas may indicate a wider distribution.

Although nests were not found in the field, 13 (42%) of the female paratypes were
gravid and six others had distended, convoluted oviducts, suggesting recent reproduc-
tive activity. The smallest of these adult females were 15.5 (convoluted oviducts, small
ova) to 15.7 (gravid) mm SVL. Four of the 12 immature females were larger (15.6-
16. 1 mm SVL) than the smallest adult female. Immature individuals were characterized
by thin, straight oviducts and flattened, translucent ovaries with barely recognizable
follicles.

The one juvenile (USNM 250007, 6.5 mm SVL) appeared to be a recent hatchling

152

but a 9.4 mm individual (USNM 250034) had moderately enlarged, rounded, granular
testes and was regarded as an adult. All the other males (11.0-14.2 mm SVL) had
moderately to greatly enlarged testes and appeared to be reproductively active.

The "soft call of £". luteolus'" {=griphus) I mentioned in my 1977 paper is actually
that of £". sisyphodemus (Crombie MS). Despite considerable attention given to tracking
calls in the leaf litter under favorable conditions on the 1983 trip, no call was heard
that was attributable to E. griphus.

Gut contents, examined superficially in skeletonized, cleared and stained, and
selected preserved specimens, consisted primarily of ants, spiders, and small cock-
roaches. However, two greatly distended individuals (USNM 250001, 14.2 mm SVL,
and USNM 250042, 13.6 mm; both immature females) each contained a lepidopteran
larva longer than their own body (18 and 15 mm, respectively). USNM 250001 also
contained a few ants and cockroach legs.

The type locality was discussed in some detail previously (Crombie 1977), but the
area has changed somewhat since my first visit in 1971. In my 1977 paper I placed
"the cave" at about 4 mi (6.4 km) WNW of Quick Step. This was based on a road
distance of 2 miles (3.2 km) north of the village of Quick Step, then an estimated two
mile overland walk roughly WNW of the road to the cave. Since that time the Quick
Step road, formerly a treacherous mud and rock track that was impassible in wet
weather, has been altered and improved. It is now paved as far as Quick Step and the
unpaved stretch north to the cave trail is considerably smoother and less steep. In
1983, the odometer reading from Quick Step P.O. to the beginning of the cave trail
was 4.9 miles (7.8 km), resulting in the type locality (ca. 7 mi WNW Quick Step) as
stated in the above description. Despite the slight mileage differences in my previous
paper and this, the type localities off", griphus and E. sisyphodemus are the same cave.
Recent work in the area by cavers has resulted in an excellent map of the cave (called
Marta Tick Cave) and a general discussion of the area (Baker et al. 1986).

A botanical survey of the Cockpits by Frank W. Davis (U.C. Santa Barbara)
provides an expanded vegetational profile of the type locality. The cave is located on
a 20-35° scree slope that is covered with slightly disturbed wet limestone forest (Asprey
and Robbins 1953). The forest canopy is at 8-10 m but it is broken by emergents with
heights to 33 m. Common tree species include Nectandra antillana, N. patens, Guarea
schwartzii, Ficus sp., Calophyllum calaba, and Trichilia moschata. The fairly open
shrub layer includes saplings of overstory species as well as Eugenia sp., Psychotria
sp., Calyptwnomum occidentalis, and Quiina jamaicensis. A sparse herb layer is dom-
inated by the trailing liana Syngonium auritum; other common lianas include Vitis
tilliifolia and Cissus sycioides. Tillandsia antillana is a common large epiphyte.

Etymology.— A noun in apposition, taken from the Greek "griphos," used idio-
matically to refer to anything chaotic, confusing, or inexplicable. Given the 400 +
species in the genus Eleutherodactylus and the bewildering variation and pattern poly-
morphism exhibited by many species, I feel the combination is singularly appropriate.
Although this species is not particularly variable compared to other Jamaican Eleu-
therodactylus, the name also commemorates my initial confusion in mistaking E.
griphus for E. luteolus, a thoroughly different species.

Acknowledgments

Since the discovery of Eleutherodactylus griphus is but one segment of a project
begun in 1 970, 1 naturally owe a debt of gratitude to a great many people and institutions.
I will try to thank these friends and colleagues adequately in future synthetic works but
for now I mention only those who actively assisted in the Cockpit work.

During the 1983 trip I benefitted greatly from the expertise and companionship
of Frank W. Davis, Linda Gordon, Bill Hilgartner, Dyer Moore, Greg Pregill, Dave
Steadman, and Richard Thomas. Frank Davis kindly provided the botanical profile of
the type locality. In previous years Dick Franz, Barbara A. Harvey, Frances J. Irish
(McCuUough), Jeremy F. Jacobs, and Fred G. Thompson all braved the rigors of the
Cockpits with me.

153

As always, I am continually grateful to Menocal Stephenson of Quick Step, who
has unselfishly shared his incomparable knowledge of the Cockpits and his home with
me during my field work. His sons Jeffrey, Collin, John, and Win were of immeasureable
help on our forays through the bush while Mrs. Stephenson and her daughters spared
no effort to make us welcome and comfortable on our return to Quick Step. Another
resident of Quick Step, particularly knowledgeable about the bush and inexplicably but
affectionately known only as "Ratty," contributed much to the success of the 1983 trip
and patiently tolerated many of our idiosyncracies.

Over the years it has been a pleasure to work with Patrick Fairbaim of the De-
partment of Natural Resources in Kingston, who efficiently processed our often eccentric
permit requests and provided pleasant interludes on our visits to the big city.

Funding for early exploratory work in the Cockpits was provided by a grant from
the Penrose Fund of the American Philosophical Society (to RIC); the 1983 trip was
supported by a National Geographic Society grant (#2482-82) to G. K. Pregill. Ad-
ditional funds were received from the U.S. Fish & Wildlife Service through the late
Howard W. Campbell, and the Alexander Wetmore Fund of the National Museum of
Natural History. Thanks are due Bea Wetmore and Storrs L. Olson for facilitating the
latter.

Clarification of the status of £". griphus and E. luteolus would not have been possible
without access to the Coleman J. Goin collections in the Carnegie Museum of Natural
History; Ellen J. Censky and C. J. McCoy provided working space and innumerable
courtesies during my visits to Pittsburgh.

Molly Dwyer Griffin accurately and artistically rendered the drawings of the ho-
lotype. Vic Krantz photographed the specimens, and Addison Wynn prepared Fig. 2.

W. Ronald Heyer, Roy W. McDiarmid, Gregory K. Pregill, Robert P. Reynolds,
David W. Steadman, and George R. Zug read and commented on the manuscript. Any
unwarranted literary license occurs despite their protests and is my own responsibility.
I have enjoyed discussions on Eleuthewdactylus with and have freely parasitized ideas
from Glenn Flores, S. Blair Hedges, Ron Heyer, John D. Lynch, Roy McDiarmid, and
Albert Schwartz.

Literature Cited

Asprey, G. F., and R. G. Robbins. 1953. The
vegetation of Jamaica. Ecological Monographs
23(4):359-412.

Baker, Linda L., Edward A. Devine, and Michael
A. Di Tonto. 1986. Jamaica. The 1985 ex-
pedition of the NSS Jamaica Cockpits Project.
National Speleological Society News 44(1):4-
15.

Barbour, Thomas. 1935. A second list of Antil-
lean reptiles and amphibians. Zoologica 19(3):
77-141.

Crombie, Ronald I. 1977. A new species of the
genus Eleuthewdactylus (Amphibia: Lepto-
dactylidae) from the Cockpit Country of Ja-
maica. Proceedings of the Biological Society of
Washington 90(2): 194-204.

Goin, Coleman J. 1950. Color pattern inheritance
in some frogs of the genus Eleuthewdactylus.
Bulletin of the Chicago Academy of Sciences
9(1):1-15.

. 1953. Rediscovery of the frog Lz/or/a /m-

teola Gosse in Jamaica. Occasional Papers of
the Museum of the Institute of Jamaica No. 7.
1954. Remarks on the evolution of color

pattern in the gossei group of the frog genus
Eleuthewdactylus. Annals of the Carnegie Mu-
seum 33(10):185-195.
Lynch, John D. 1966. Multiple morphotypy and

parallel polymorphism in some neotropical
frogs. Systematic Zoology 15(1): 18-23.

Lynn, W. Gardner. 1940. L Amphibians. Pp. 1-
60 in W. G. Lynn and C. Grant. The Herpe-
tology of Jamaica. Bulletin of the Institute of
Jamaica, Science Series No. 1.

, and James N. Dent. 1942. Notes on Ja-
maican amphibians. Copeia (4):234-242.

Myers, George S. 1938. Fresh-water fishes and
West Indian zoogeography. Annual Report of
the Smithsonian Institution for 1937, pp. 339-
364.

Pregill, Gregory K., and Storrs L. Olson. 1981.
Zoogeography of West Indian vertebrates in
relation to Pleistocene climatic cycles. Annual
Review of Ecology and Systematics 12:75-98.

Schwartz, Albert, and D. C. Fowler. 1973. The
anura of Jamaica: a progress report. Studies on
the Fauna of Curacao and other Caribbean Is-
lands 43(142):50-142.

, and Richard Thomas. 1975. A check-list

of West Indian amphibians and reptiles. Car-
negie Museum of Natural History Special Pub-
lication No. 1.

, , and Lewis D. Ober. 1978. First

supplement to a check-list of West Indian am-
phibians and reptiles. Carnegie Museum of
Natural History Special Publication No. 5.

"^ >^ TRANSACTIONS

OF THE SAN DIEGO
SOCIETY OF
NATURAL HISTORY

Volume 21 Number 10 pp. 155-165 5 December 1986

A new night lizard {Xantusia hensham) from a sandstone
habitat in San Diego County, California

L. Lee Grismer

Department of Biology, San Diego State University, San Diego, CA 92182 USA

DEC i;::

Mark A. Galvan

The Micromanipulator Microscope Company, 1461 N. Elm Street,
Escondido, CA 92026 USA

Abstract. A new subspecies of night lizard, Xantusia henshawi, is described and differentiated
from X. h. henshawi and X. h. bolsonae based on the presence of an enlarged temporal scale, absence
of enlarged auriculars, a narrower head and body, significantly fewer scales around the upper portions
of the hindlimbs, no black peppering on the ventral surfaces of the limbs, a reduced dorsal pattern
consisting of small round spots, no marked light and dark diel color phase, weakly defined vertebral
furrow, and less scansorial habits.

Introduction

The geographical distribution of the Night Lizard genus Xantusia is notable for
its numerous isolated populations (Webb 1965, 1970, Smith and Brodie 1982). Col-
lectively, these populations comprise three species (Bezy 1972) ranging from northern
Mexico and southwestern United States to the Channel Islands of California. In spite
of this fragmented distribution, many populations are morphologically quite uniform
within a species, yet the distinctiveness between others has promoted the recognition
of several subspecies (Savage 1952, Webb 1965, 1970, Bezy 1967<3, b). We report here
on another isolated population, one confined to a sandstone habitat in San Diego
County, California, and sufficiently distinct morphologically, biochemically, behav-
iorally, and in color pattern to warrent subspecific recognition within X. henshawi.
Scale terminology follows Savage (1963) except where noted. All measurements and
counts are taken from preserved specimens.

Xantusia henshawi gracilis new subspecies
Figure la

Suggested common «am^.— Sandstone night lizard.

Holotype.—SU^^H 64830, adult male collected by L. L. Grismer and M. A.
Galvan on 17 February 1985 from the Truckhaven Rocks in the Anza-Borrego Desert
State Park, located 24.5 km east and 6.3 km north of Borrego Springs, San Diego
County, California.

Paratypes.—Co\\QC\.Qd by authors at same locale as holotype. LACM 132488, 4
April 1978; SDSNH 64824, 31 December 1979; SDSNH 64814-23, 1 December 1984;
SDSNH 64804-1 1, 8 December 1984; SDSNH 64812-13, 9 December 1984; SDSNH
64825-29, 17 February 1985.

Diagnosis.— Xantusia henshawi gracilis differs from X. h. henshawi and X. h.
bolsonae by having a greatly enlarged temporal scale equal to nearly one-half the size
of the postparietal; absence of enlarged auriculars; absence of a vertebral furrow (in

156

-» -1 in

rt:'— f v-v>''vni7t<ti-^y- vr.^:«-,' A

"^^^t^

'ti

Figure 1 . a) Holotype of Xantusia henshawi gracilis, b) Left row X. h. gracilis, middle row X. h. henshawi,
right row X. h. bolsonae.

life); significantly different morphometric ratios concerning head depth/head width and
interforelimb distance (Table 1 ); the lack of marked light and dark diel color phases;
the almost complete absence of black peppering on all ventral surfaces; a reduced dorsal
body pattern consisting primarily of small uniform round spots; and at least four fixed
allelic differences out of 22 presumptive gene loci (Bezy and Sites 1986). Xantusia h.
gracilis is significantly differentiated further from X. h. henshawi by having fewer scales
around the upper arm and leg, higher number of supralabials, fewer longitudinal rows
of dorsal scales, and a smaller interhindlimb distance/SVL (Table 1). Xantusia h. gracilis
is significantly differentiated further from X. h. bolsonae by having a higher number
of gular scales, fewer enlarged scales on pregular fold, a higher number of temporal
scales, dorsal scales, and femoral pores (Table 1).

Description of holotype.— Adult male SVL 59.6 mm; see Table 2 for other mea-
surements; head triangular, slightly wider than neck; nostrils visible in dorsal view; eye
large, closer to nostril than ear opening; ear opening elliptical, twice as high as wide,
long axis directed anteroventrally; anterior pregular fold ventral to ear opening indicated
by transverse row of reduced scales medially; posterior pregular fold six scale rows
anterior to gular fold; gular fold indicated by large rectangular scales on edge, increasing
in size medially and abruptly differentiated from scales on fold posteriorly; digits of
pes and manus overlapping when limbs adpressed.

Rostral slightly broader than high, with pointed dorsoposterior margin, followed
in order by two nasals, a hexagonal frontoparietal, two prefrontals, a median, two
frontals, a hexagonal interparietal separating two parietals, and two large postparietals;
interparietal with conspicuous eye spot in posterior one-third; postparietals separated
posteriorly by two small triangular interpostparietals that touch nuchals; nasals, pre-

157

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158

Table 2. Selected measurements (mm) of holotype SDSNH 64830.

Tail length 82.2

Head length (tip of snout to anterior of ear opening) 12.7

Maximal head width anterior to ear opening 9.5

Maximal head depth anterior to ear opening 5.7

Tip of snout to posterior margin of postparietal 13.3

Diameter of eye 3.0

Anterior of eye to tip of snout 5.4

Tip of snout to gular fold 19.6

Length of right leg (insertion to tip of 4th toe) 27. 1

Length of 4th toe 7.0

Length of right arm (insertion to tip of 4th finger) 19.7

Length of 4th finger 4.8

Axilla-groin length 27.9

Interforelimb distance 8.0

Interhindlimb distance 6.4

frontals, frontals, and postparietals in contact at midline; enlarged scales of head pitted
throughout; nostril elliptical, bordering rostral, first supralabial, nasal, and postnasal,
followed in order by postnasal, anterior loreal, loreal, and two loreolabials (dorsal
loreolabial smaller), and small preocular scales of ocular ring; scales of ocular ring small,
two postoculars largest; uppermost postocular touching fifth supraocular; five supra-
oculars, third and fourth on left side with slightly damaged lateral margins; temporals
nine (R) nine (L) (Fig. 4). Supralabials seven (R) eight (L); infralabials six (R) six (L);
pretympanic scales decreasing in size ventrally; auricular scales slightly enlarged dor-
sally; mental longer than broad; three large pairs of postmentals, first pair contacting
medially; anteriormost four rows of gular scales largest; 43 transverse rows of gular
scales (includes all scale rows between gular fold and first pair of postmentals), 20 rows
between anterior postmental and anterior pregular fold, 1 7 rows between anterior and
posterior pregular folds, and 6 rows between gular fold and posterior pregular fold,
curving to the anteromedially; 10 enlarged rectangular scales on gular fold, increasing
in size medially; five rows of small scales in gular fold, anterior row smallest.

Back, sides, and limbs covered with granular scales; some brachials and femorals
slightly enlarged; 19 (R) 22 (L) scales around upper arm and 27 (R) 27 (L) scales around
upper leg; 14 longitudinal rows of rectangular ventrals at midbody, two bordering
midline slightly narrower, lateralmost with curved lateral margins and slightly narrower
adjacent ventrals; 30 transverse rows of ventral scales; one pair of enlarged preanal
scales bordered posteriorly by six small precloacal scales, laterally by two larger scales,
and anteriorly by three larger scales; 54 longitudinal rows of dorsal scales at midbody;
130 transverse rows of middorsal scales from postparietals to posterior margin of
hindlimb insertion; vertebral furrow of dorsum slightly evident in sacral region; 25 (R)
24 (L) lamellae on fourth toe; nine femoral pores on each hindlimb; caudal scales
rectangular roughly twice as wide ventrally as dorsally.

Coloration of holotype in life. —Dorsal ground color of head, body, hindlimbs, and
distal portion of forelimbs yellow to white; interorbital region bluish; ground color of
all dorsal surfaces much more extensive than dorsal markings; proximal region of
forelimbs white to pinkish; sides of body white; all ventral surfaces white with minute
amounts of black peppering present only on lateral gular and ventral scales, pes, manus,
and forelimbs; dorsal body pattern consisting of dark brown, small round spots; head
plates anterior to parietals covered moderately with black peppering producing poorly
defined blotches, largest posteriorly; small dark brown markings on dorsal surfaces of
limbs present except on proximal portion of forelimbs; dark markings on side of head,
neck, and body paler, and smaller than those dorsally; labial scales moderately punctate
with black peppering; dark brown markings on tail confined to groups of scales, pro-
ducing squarish markings; some scales of tail with black peppering, others immaculate.

159

Variation. —The paratypes approximate the holotype in general morphology. Most
variation occurs in the presence of intercalary scales between some of the large dorsal
head plates and, in some cases, their fusion to the anterior supraocular scales. In SDSNH
64804 the frontoparietal is divided. In SDSNH 6481 1 the left parietal is divided into
two larger lateral scales and one smaller medial scale, and the right parietal is incom-
pletely divided. The right parietal is also completely divided in SDSNH 64822 In
SDSNH 64808-09, 64815, 64818-20, 64822, 64826, and 64829 the temporals bor-
dering the lateral margin of the postparietal are two to three times larger than those of
other specimens. SDSNH 64816 has one interpost parietal. In SDSNH 64810 there is
one slightly enlarged auricular dorsally and two in SDSNH 6481 1. In SDSNH 64808
the third postmental on the left side reaches the lip and separates the third and fourth
infralabials. The single pair of enlarged preanal scales in SDSNH 64809 is bordered
anteriorly by three smaller scales. SDSNH 64807, 6481 1, 64817, 64819, and 64827-
28 have two pairs of enlarged preanal scales and, with the exception of SDSNH 64807,
have a small intercalary scale at their center, contacting all of them. In SDSNH 64808
and 64820 there are three pairs of enlarged preanal scales.

Generally, the paratypes approximate the holotype in basic features of coloration
and pattern. The major difference is in LACM 132488, which almost entirely lacks
dorsal spots and has a uniform tan-white ground color overlaid with a yellow reticulum
(in life). IN SDSNH 64829 the dorsal spots are reduced and intermediate between
LACM 132488 and the remaining paratypes. The dorsal body markings of SDSNH
64804, 64815, 64818, 64821, 64827-28 are more irregular and slightly larger. There
appears to be a slight ontogenetic change in dorsal body blotching, with markings
becoming more rounded and better defined in larger specimens (Fig. lb). The ventral
peppering of most paratypes is slightly less concentrated than that of the holtoype,
manifesting itself in SDSNH 64813, 64827, 64829, and LACM 132488 which have
almost a complete absence of black peppering on the ventral surfaces.

The smallest two individuals are SDSNH 64806 and 64814 at 30.5 mm SVL and
30.7 mm SVL, respectively, and the largest two individuals are SDSNH 64804 and
64812 at 70.5 mm SVL and 70.8 mm SVL, respectively. Adult males have larger,
better developed femoral pores than females and show a slight swelling posterior to
the vent.

Etymology. —The adjectival name gracilis, meaning slender, comes from the Latin
root gracil, and pertains to this population's slender habitus.

Comparisons with other subspecies.— A total of 139 specimens of Xantusia hen-
shawi henshawi from the eastern most portion of its range in Riverside, San Diego,
and Imperial Counties was examined. These specimens showed major geographic vari-
ation in numbers of femoral pores and temporal scales. Specimens from Riverside
County had an average of 23.8 (18-30) femoral pores (count includes both legs) and
an average temporal scale count of 7.9 (7-1 1). Those of San Diego and Imperial Counties
had combined averages of 17.4 (12-22) femoral pores and 8.4 (6-1 1) temporals. Webb
(1970) also noted a similar cline in these counts for X. h. henshawi. A total of 19 X.
h. bolsonae was examined and showed no noteworthy intrapopulational variation.

Xantusia henshawi gracilis is more terrestrial and less scansorial than other sub-
species of X henshawi {see below) being less of an obligate exfoliation-dwelling lizard.
Presumably, this is reflected in its narrower head (greater head depth/head width ratio
[Table 1]), body (smaller interlimb distances [Fig. 2a] and significantly fewer dorsal
scales at midbody [Table 1 ]), and thinner limbs (significantly fewer rows of scales around
their proximal portions [Table 1]) (Fig. 3). The interlimb distances and average limb
growth rates seem to be reliable diagnostic characters for X. h. gracilis, although de-
termining the point of limb insertion on the body is somewhat arbitrary, which is
probably reflected in the wide range of measurements (Table I).

Neonate, juvenile, and subadult Xantusia henshawi gracilis have longer limbs than
comparably-sized X. h. henshawi. The limbs of X. h. henshawi. however, grow signif-
icantly faster, so that at snout-vent lengths of 60 mm to 70 mm their limb length/SVL

160

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161

Figure 3. Top. Adult Xantusia henshawi henshawi from Ranchita, San Diego County, California. Bottom.
Adult X. h. gracilis from Truckhaven Rocks, San Diego County, California.

ratios approach those of X. h. gracilis (Fig. 2b). The hindlimbs of X. h. bolsonae are
relatively shorter than the hindlimbs of X. h. gracilis and X. h. henshawi, whereas their
forelimbs are longer.

Xantusia henshawi gracilis has a greatly enlarged temporal scale that is nearly one-
half the size of the postparietal. That of X h. henshawi is also enlarged, but equals less
than one-quarter the size of the postparietal (Fig. 4). The temporal scale in X. h. bolsonae
is much smaller and only slightly enlarged in some specimens. This is a particularly
useful character for diagnosing X. h. gracilis because it does not vary, whereas other
head scales do so considerably {see variation of paratypes for X. h. gracilis).

Field and laboratory observations indicate that Xantusia henshawi gracilis does
not exhibit marked light and dark diel color phases that are common in X. h. henshawi
(Atsatt 1939). Compared with X. h. henshawi, they appear to remain in the light phase,
which is further accentuated by the reduction of dark dorsal markings to small, round
spots, rather than large, irregular blotches (Fig. 1). In one specimen (LACM 132488),
the dorsal markings are almost absent. Some X. h. henshawi from Imperial County
approach the color pattern of X. h. gracilis when in their light phase, but differ in
having much larger dorsal markings (see top two specimens of middle row in Fig. 1 b).
The ventral coloring of X. h. gracilis is for the most part immaculate, there being only
a slight amount of black peppering on the limb and lateral gular surfaces in some
specimens. Xantusia h. henshawi, on the other hand has extensive peppering on the
ventral surface of the head, body, limbs, and tail. The ventral markings of X h. bolsonae
are less extensive than those of X. h. henshawi on the head and body but nearly equal
on the limbs and tail.

Biochemical comparisons.— A preliminary allozyme analysis suggests that Xan-
tusia henshawi henshawi and X. h. gracilis are sister taxa, based on the presence of
three unique alleles; two of these are unique among xantusiids and one is unique among
Xantusia (Bezy and Sites 1986). The data also demonstrate that X. h. gracilis and X.
h. henshawi are separated by a genetic distance of 0. 1 88 with four fixed allelic differences
out of 22 presumptive gene loci. The level of allozyme divergence is comparable to

162

PARIETAL

TEMPORAL

POSTPARIETAL

Figure 4. Heads of Xantusia henshawi henshawi and X. h. gracilis demonstrating difference in size of
temporal scale, a) Xantusia h. henshawi SDSNH 57395, SVL = 65.7 mm. b) Holotype of X. h. gracilis
SDSNH 64830, SVL = 59.6 mm. Scale equals 5 mm.

that between several subspecies of X. vigilis. Xantusia h. bolsonae appears to be most
closely related to the sympatric X. v. extorris (Webb 1965) and should probably be
considered as a separate species (Bezy and Sites 1986). Xantusia h. gracilis also appears
to differ from X. h. henshawi in the expression of certain lactate dehydrogenase enzymes
(Sites etal. 1986).

Traditionally, the rank of subspecies has accounted for geographic variation ob-
served in peripherially located, interbreeding parapatric populations. Where allopatry
is the case, such as in Xantusia henshawi henshawi and X. h. gracilis, intergradation
is not possible and other criteria must be employed. Since the morphological and
biochemical data suggest that these two populations are sister groups, and their level
of divergence is similar to that between several subspecies of X vigilis (Savage 1952,
Webb 1965, Bezy 1967a, b, Bezy and Sites 1986, Sites et al. 1986), we elect to place
gracilis in X. henshawi.

Behavioral observations. —Four specimens of Xantusia henshawi gracilis (SDSNH
64823, 64826-28) were maintained alive for a period of two weeks at room temperature
in a 9.7 liter glass terrarium. Pieces of sandstone were placed in the terrarium to provide
retreats. Five specimens of Xantusia h. henshawi were maintained under identical
conditions in a separate terrarium, except they were provided with granitic flakes. Both
terraria were kept side by side and observed at least once a night for a minimum of
thirty minutes between 18:00 and 23:00 hours. A 25 watt red light bulb was suspended
approximately one meter above the terraria to provide illumination for observation.

All specimens of Xantusia henshawi gracilis were always abroad at night during
the observation periods, and on several occasions were observed digging at the bases
of the rocks placed on the substrate. Subsequently, they would place their head into
the hole, withdraw it, and repeat the process at a different spot beside the same or
different rock.

The Xantusia henshawi henshawi spent most of their time concealed (only two
specimens observed on four of 14 observation periods) and, when abroad, remained
on the granite flakes. Conversely, X. h. gracilis spent roughly as much time on the
substrate moving about the enclosure as on the sandstone.

In another 9.7 liter glass terrarium three Xantusia henshawi gracilis, four X. h.
henshawi, and four Phyllodactylus xanti were kept together. On 13 May 1986, two

163

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■J*>-:.

■>|P'-'

»4

Figure 5. a) Southern view of Truckhaven Rocks, San Diego County, California, b) Slabs of exfoliating
sandstone, c) Rodent burrows in sandstone.

164

clutches of two eggs each of P. xanti were observed on a horizontal piece of sandstone.
One of the X. h. gracilis approached an egg, grasped the end of it in its mouth, and
began pulling on it while trying to walk backwards. Consequently, the end of the egg
broke off and the lizard ate the part of the shell that remained in its mouth. It then
placed its head inside the egg and began lapping up the yolk. When the two other X.
h. gracilis approached the eggs they were chased away by the lizard that was eating.
One of these other lizards then went to an undisturbed egg and repeated the process
of breaking it open as described above. Combat between all three X. h. gracilis followed
with various individuals having dominance over the others until eventually the yolk
of all four eggs had been devoured. Following this, they all shared equally in eating the
remaining empty shell cases. Interestingly, none of the X. h. henshawi showed any
interest in the eggs even though they had equal access to them.

The fact that all three Xantusia henshawi gracilis were eating and fighting over the
eggs, and that they all broke and devoured the eggs in the same manner, suggests that
this behavior is not a chance event induced by captivity, but a part of their behavioral
repertoire. Conceivably, this was why we were unable to find but one Phyllodactylns
xanti in the Truckhaven Rocks although in the peripheral regions where X. henshawi
is presumably absent, P. xanti seemed to be in unusual abundance {see below).

Habitat and distribution. —Xantusia henshawi gracilis is found within the bound-
aries of the Anza-Borrego Desert State Park in a small circumscribed region known as
the Truckhaven Rocks, approximately 240 m to 305 m elevation. This area is part of
the southeastern flank of the Santa Rosa Mountains in northeast San Diego County.
It is roughly 3 km long east to west and 1.3 km wide north to south. The Truckhaven
Rocks have a complex and as yet unresolved geomorphological history. The region is
composed of sandstone and siltstone sediments (Hoover 1965) of unknown age, and
it is not certain if its emergence was concomitant with the uplift of the Santa Rosa
Mountains (Threet 1974), or the result of an eastward strike-slip displacement along
the San Jacinto fault (Sharp 1972). In either case, the sandstone has subsequently
undergone tremendous erosion (Fig. 5a) resulting in several arroyos 30 m to 60 m deep,
running northwest to southeast.

Xantusia henshawi gracilis is the only known xantusiid from a sandstone habitat.
Compared to other Xantusia henshawi, its relatively slender physique presumably
allows it to exploit the wide range of microhabitats produced by the eroding substrate,
as opposed to being restricted to exfoliating microhabitats even though these are also
present (Fig. 5b). Some specimens were unearthed in what appeared to be rodent
burrows atop piles of hardened siltstone (Fig. 5c). Also, the reduced dorsal markings
and lightened color pattern appears more cryptic on the tan-colored sandstone.

Specimens were collected at both the western and eastern extremes of the habitat,
but within this region Xantusia henshawi gracilis seems to be more abundant in lo-
calized areas and not evenly distributed.

The nearest reported locality for X. h. henshawi is approximately 38 km to the
southwest from Oak Grove (Lee 1976, Julian Lee, personal communication 1985). We
report two additional specimens from Borrego-Palm Canyon (SDSNH 39426 and 4 1 090),
reducing this distance to 32 km. According to Lee (1976), X. h. henshawi is found on
both the coastal and desert slopes of the Santa Rosa Mountains. The Santa Rosa
Mountains, however, run northwest to southeast and have no coastal slope; his locality
data show specimens to be present in only the extreme northwest portion. We searched
all arroyos on the south facing side of the Santa Rosa Mountains between the Truck-
haven Rocks and the nearest reported X. h. henshawi locality, as well as those accessible
arroyos on the northeastern side. Although the habitat appeared suitable in some places
for X. h. henshawi, none was found. There did, however, seem to be an unusual
abundance of Phyllodactylus xanti.

Material examined.— Xantusia henshawi bolsonae LACM 5595-64, 72324-25,
76156-59, 106803-06, 116260-61. Xantusia henshawi gracilis SDSNH 64804-30,
LACM 132488. Xantusia henshawi henshawi Riverside County: SDSNH 10872-76,
23364, 23367, 31517-18, 31571-614, 34740-61, 38042, 62304. San Diego County:

165

SDSNH 13368-70, 18484, 18505-06, 18653, 18639, 19039, 26891, 35495, 36347
39371-73, 39421-26, 3991 1-12, 40206, 41002-03, 41090. Imperial County: SDSNH
20021, 23695, 26826-27, 49882, 57398-401, 57404, 57685-97, 57690-97 58392-
94, 59266-68, 59432, 60128-34.

Acknowledgments

Many friends and colleagues helped in various phases of this study. For field
assistance we wish to thank Jim and Barry Sherman, Larry Grismer, Frankie Grismer,
Don Barrios, and Edith Wise. Richard E. Etheridge, Richard Estes, Robert L. Bezy]
John R. Ottley, Hobart M. Smith, Douglas D. Edwards, and Julian C. Lee provided
helpful comments on various drafts of the manuscript. We wish to thank Fred Jee for
help in finding pertainent geological literature. For the loan of specimens we wish to
thank Robert L. Bezy of the Los Angeles County Museum of Natural History (LACM)
and Gregory K. Pregill of the San Diego Natural History Museum (SDSNH). We wish
to express special thanks to our good friend Mark Jorgenson of the Anza-Borrego Desert
State Park who personally facilitated the speedy procurement of the necessary permits
required to collect within the park boundaries. To him we owe many favors.

Literature Cited

Atsatt, S. R. 1939. Color changes as controlled
by temperature and light in the lizards of the
desert regions of southern California. Univer-
sity of California (Los Angeles) Publications in
Biological Sciences 1:237-276.

Bezy, R. L. 1967(3. A new night lizard (A'amjis/a
vigilis sierrae) from the southwestern Sierra
California. Journal of Arizona Academy of Sci-
ences 4:163-167.

. 1967^. Variation, distribution, and taxo-

nomic status of the Arizona night lizard {Xan-
tusia arizonae). Copeia 1967:653-661.

. 1972. Karyotypic variation and evolution

of the lizards in the family Xantusiidae. Los
Angeles County Natural History Museum
Contributions in Science 227:1-27.
-, and J. W. Sites, Jr. 1986. A preliminary

analysis of allozyme evolution in the lizard
family Xantusiidae. Herpetologica, in press.

Hoover, R. A. 1965. Areal geology and physical
stratigraphy of a portion of the southern Santa
Rosa Mountains, San Diego County, Califor-
nia. Unpublished Masters Thesis, University
of California, Riverside. Pp. 1-81.

Lee, J. C. 1976. Xantusia henshawi.CaiaXogueoi
American Amphibians and Reptiles. P. 189.

Savage, J. M. 1952. Studies on the lizard family
Xantusiidae. I. The systematic status of the
Baja California night lizards allied to Xantusia
vigilis, with the description of a new subspecies.
American Midland Naturalist 48:467-497.

. 1963. Studies on the lizard family Xan-
tusiidae. IV. The genera. Los Angeles County
Natural History Museum Contributions in Sci-
ence 71:1-38.

Sharp, R. V. 1972. Tectonic setting of the Salton
trough. Pp. 3-1 3 m R. v. Sharp (ed.). The Bor-
rego Mountain Earthquake of April 9, 1968.
United States Geological Survey Professional
Paper 787.

Sites, Jr., J. W., R. L. Bezy, and P. Thompson.
1986. Nonrandom expression of lactate de-
hydrogenase isozymes in the lizard family
Xantusiidae (Reptilia, Sauna). Biochemical
Systematics and Ecology, in press.

Smith, H.M., and E.D.Brodie, Jr. 1982. A Guide
to Field Identification. Reptiles of North
America. Golden Press, New York, New York.

Threet, R. L. 1974. Alternative interpretations for
the southern portion of the San Jacinto fault
zone. Pp. 25-38 in M. W. Hart and R. J. Dow-
len (eds.). Recent Geologic and Hydrologic
Studies, Eastern San Diego County and Ad-
jacent Areas. San Diego Association of Geol-
ogists, San Diego, California.

Webb, R. G. 1965. A new night lizard (genus
Xantusia) from Durango, Mexico. American
Museum Novitates 2231:1-16.

. 1970. Another new night lizard (Xantu-
sia) from Durango, Mexico. Los Angeles County
Natural History Museum Contributions in Sci-
ence 194:1-10.

TRANSACTIONS
OF THE SAN DIEGO
SOCIETY OF
NATURAL HISTORY

Volume 21 Number 11 pp. 167-202 5 December 1986

The evolution of helodermatid squamates, with description of a
new taxon and an overview of Varanoidea

Gregory K. Pregill

San Diego Natural History Museum, P.O. Box 1390, San Diego, California 92112 USA

Jacques A. Gauthier ")FC i'

Museum of Zoology. University of Michigan, Ann Arbor, Michigan 48109 USA

Harry W. Greene

Museum of Vertebrate Zoology and Department of Zoology, University of California, Berkeley, California
94720 USA

Abstract. New fossils of helodermatid squamates from the early Miocene of Nebraska prompted
us to examine all known material actually or potentially referrable to Helodermatidae. Although rep-
resented today only by two species ranging from southwestern United States south to Guatemala, the
fossil record of Helodermatidae encompasses the Late Eocene of France, and the latest Paleocene to
Recent of North America. If Paraderma bogerti Estes is a helodermatid, as we contend, Helodermatidae
extends to the late Cretaceous in North America. Extinct lanthanotines and varanines from the late
Cretaceous of Mongolia, together forming the sister taxon (Varanidae) of Helodermatidae, confirm the
antiquity of these groups.

From early in their history the principal morphological specialization of helodermatids has been
their powerful, stoutly constructed jaws capable of crushing large prey; living Heloderma may consume
proportionally larger prey than any other squamate aside from certain snakes. Teeth grooved for venom
delivery appear in all Cenozoic helodermatids, but that attribute is fully elaborated only in the two
extant species, Heloderma horridum and H. suspectum.

Within Helodermatidae, Eurheloderma gallicum Hoffstetter is distinguished by a markedly con-
stricted parietal, an attribute that may be ancestral for Varanoidea. A similarly constricted helodermatid
parietal is herein reported from the latest Paleocene of Wyoming. Because of the diagnostic triangular
frontal bones, we reassign the late Oligocene-early Miocene species Heloderma mattheni Gilmore to
a new taxon, Lowesaurus. We reexamine its contemporary, Heloderma texanum Stevens, from the
early Miocene of Texas, and infer its relationship with living Heloderma according to osteoderm
morphology and a wide basal opening of the venom groove.

By necessity, our evaluation of helodermatid phylogeny requires a review of character states found
in their sister taxon, Varanidae (Lanthanotinae + Varaninae). We clarify a number of morphological
features such as the structure of the intramandibular joint and retraction of the bony nares. Monophyly
of the group Helodermatidae + Varanidae is easily documented, and we restrict the name Varanoidea
to that taxon. However, the phylogeny of a more encompassing taxon, Platynota, is ambiguous and
we recommend that designation only as a term of convenience, to include varanoids and those other
taxa with which they have been traditionally associated ("Necrosauridae," Mosasauridae, Aigialo-
sauridae, and Dolichosauridae).

Our interpretations of helodermatid phylogeny are consistent with morphological evidence, and
with behavioral and ecological aspects of their feeding biology.

Introduction

Prior to Gilmore's (1928) review of the fossil lizards of North America, nearly all
lizard remains with hexagonal cephalic osteoderms had been assigned to Helodermat-
idae. Gilmore (1928) restricted the taxon to the two living species, Heloderma suspec-
tum Cope (Gila monster) and H. horridum Wiegmann (Beaded lizard), and a new
species, H. matthewi Gilmore, based on a partial maxilla from the Middle Oligocene

168

(Orellan) of Colorado that exhibited the group's unique dentition: grooved teeth used
for venom delivery. Fossils previously assigned to helodermatids (e.g., by Nopsca 1908)
were referred to Anguidae (viz., Glyptosaurinae; see Sullivan 1979). After Gilmore's
(1928) revision, no additional fossils of helodermatids were described until 1957 when
Eurheloderma gallicum Hoffstetter was reported from the late Eocene/early Oligocene
Phosphorites du Quercy of France (Hoffstetter 1957). Subsequently, more material of
E. gallicum was reported from the phosporite locality at Escamps (DeBonis et al. 1 973).
Currently, the species is represented by maxillae, a dentary, pterygoids, parietals and
vertebrae.

In the last decade, additional fossils of North American helodermatids were found
in deposits of the White River Formation of Colorado (late Oligocene-Whitneyan).
This material consists of dentaries, maxillae, frontals, parietals and other cranial frag-
ments, all of which Yatkola (1976) referred to Heloderma matthewi. In his discussion
of the helodermatid fossil record, Yatkola concluded that all lizards possessing teeth
grooved for venom conduction were sufficiently similar to be included in a single genus,
Heloderma. He thus relegated Eurheloderma Hoffstetter to synonymy.

Shortly after Yatkola's (1976) paper was published, Larry Martin (University of
Kansas) provided us with a frontal bone and two vertebrae collected from early Miocene
deposits of Nebraska. These fossils are helodermatid, as described below, and are
comparable to other middle Tertiary specimens that have been assigned to Heloderma
matthewi, but we believe that they comprise a taxon diagnoseable from Heloderma
proper. In the early Miocene, Heloderma was represented by H. texanum Stevens, a
species described from a remarkably complete skull found in the Castolon Local Fauna
of Big Bend, Texas (Stevens 1977); however, its relationship with other helodermatids
was not considered at the time of its description (Stevens 1977).

Finally, Bartels (1983) has described a varanoid parietal collected from the latest
Paleocene of the Bighorn Basin, Wyoming. That fossil, too, is from a helodermatid, as
discussed below.

McDowell and Bogert (1954) were the first to place helodermatids in a systematic
framework that combined them with Varanus and Lanthanotus as a group distinct
from other extant anguimorph squamates. McDowell and Bogert ( 1954) altered Romer's
(1956) classification by removing Lanthanotus from Helodermatidae and placing it
closer to Varanidae. They assigned Helodermatidae to Varanoidea instead of Anguioi-
dea (Diploglossa), and recommended the designation "Varanoidea" over "Platynota."
Hence, Varanoidea included Varanidae, Lanthanotidae, Helodermatidae, and the ex-
tinct families Dolichosauridae, "Aigialosauridae" and Mosasauridae. With some mod-
ifications, Rieppel (1 980a) corroborated their conclusions, but used the name Platynota
for this taxon. In that paper and in a companion study on the postcranial osteology of
Lanthanotus (Rieppel 1980Z?), he regarded the three extant families as a monophyletic
assemblage within the more inclusive Platynota. Elsewhere, Gauthier (1982) discussed
Varanoidea with reference to the articulation between the dentary and post-dentary
bones, a character complex providing insight into anguimorph phylogeny.

The evolutionary history becomes cluttered, however, in consideration of several
fossils from the late Cretaceous of North America and Asia, and the Paleogene of
Europe that can be interpreted as at or near the base of helodermatid and varanoid
phylogeny. For example, Estes (1964) proposed Parasaniwidae to accommodate two
taxa from the late Cretaceous Lance Formation of Wyoming: Parasaniwa wyomingensis
Gilmore and Paraderma bogerti Estes. More recently Estes (1983a) synonymized Par-
asaniwidae with the more inclusive designation Necrosauridae Hoffstetter, a family
constituted by Estes to include Necrosaurus, Parasaniwa, Eosaniwa, Provaranasaurus,
and Colpodontosaurus.

Paraderma bogerti is in ways similar to necrosaurids but remains even more
problematical, primarily because it is so poorly represented by fossils. We regard it as
the earliest known member of Helodermatidae.

Borsuk-Bialynicka (1984) described several new anguimorphs collected from Up-
per Cretaceous deposits of Mongolia. Two of these, Proplatynotia longirostrata and

169

Gobidenna pulchrum, she referred to as "necrosaurian grade lizards," primitive platy-
notans whose relationships among anguimorphs remain problematic. Furthermore,
Gobidenna possesses a few features described as Hcloderma-\ike. Besides these taxa,
Borsuk-Bialynicka (1984) reported the first known remains of a fossil lanthanotine,
Cherminotus longifrons, a new varanine, Saniwides mongoliensis, as well as additional
material of the enigmatic varanid Tel masaurus granger! Gilmore. These new varanoids,
though difficult to place unambiguously, do suggest that the lineages represented by
Heloderma, Lanthanotus and Varanus are of considerable antiquity. The incomplete
nature of the Cretaceous fossils makes their early history difficult to resolve.

The discovery of these new helodermatid and varanid fossils, and our interpretation
of novel characters, inspired this review of helodermatid phylogeny. The paper is
organized into three parts. Part I reviews the diagnosis of Varanoidea in an attempt to
clarify those characters that have been troublesome and ambiguous. We then (Part II)
describe the new helodermatid fossils from the early Miocene of Nebraska, and discuss
another from the latest Paleocene of Wyoming. In light of these we reinterpret Helo-
derma texanum and those fossils previously assigned to H. matthewi in a discussion
of the diagnostic features of Helodermatidae. A phylogeny based on this evidence is
presented. Having this background, together with information from Part III on their
natural history, we propose that the principal specialization of helodermatid squamates
is a distinctive feeding mode. This is readily observed in the stout jaws and sturdily
constructed skull architecture designed for crushing large prey. Venom delivery occurs
in the more derived species as a superimposed specialization. For these reasons we will
argue for the inclusion of Paraderma bogerti in Helodermatidae. We conclude our
presentation of helodermatid phylogeny based on morphology by demonstrating (Part
III) some concomitant associations with the natural history, behavior, and feeding
biology of captive and wild animals.

Materials and Methods
Museum abbreviations of catalogued specimens:

AMNH American Museum of Natural History, New York

BHB Bayard H. Brattstrom, California State University, Fullerton
KU University of Kansas Museum of Natural History, Lawrence
KUVP University of Kansas, Vertebrate Paleontology, Lawrence
MVZ Museum of Vertebrate Zoology, University of California, Berkeley

PU Princeton University
REE Richard Etheridge, San Diego State University
SDSNH San Diego Natural History Museum

TM Texas Memorial Museum, University of Texas, Austin
UCMP University of California Museum of Paleontology, Berkeley
UMMZ Museum of Zoology, University of Michigan, Ann Arbor
UMMP Museum of Paleontology, University of Michigan, Ann Arbor
UNSM University of Nebraska State Museum, Lincoln

WP William Presch, California State University, Fullerton

Specimens Examined.

Skeletons of Recent Heloderma. -H. horridum AMNH 7216, 56439, 57768,
57863, 64128; MVZ 79417; SDSNH 8906, 55596, 59469; REE 802; UCMP 1 17512,
1 18927, 1 18928, 123071, 131263, 131264, 131265; UMMZ 149609, 181151, 181637;
WP 648.

H. suspectum AMNH 56432, 66998, 71082, 71864, 72646, 72748, 72908, 72999,
73771 74777, 74778, 109521; BHB 802, 3158; KU 129, 1 173, 13998, 23002-23010,
78906- MVZ 6313, 29398, 64208, 95990, 128983; SDSNH 55287, 57084, 62991;
REE 1030, 1026, 1029; UCMP 117511, 131261, 131262; UMMZ 128115, 130160,
149610, 149611, 173549, 173550, 178528, 178529, 180467, 181130, 181638, 181640,
181641; WP 120, 235, 649, 650, 651, 652, 687 (skull only).

170

Two frozen specimens of H. suspectum were available for dissection (SDSNH

uncat.)-

Skeletons of Recent varanids. — Lanthanotus borneensis REE 1445. Varanus ben-
galensis SDSNH 57081, 60436, 60437; UMMZ 128572, 130172. V. exanthematicus
REE 1987; UMMZ 151113. V. komodoensis UMMZ 149612. V. nebulosus SDSNH
26058. V. niloticus SDSNH 55279, 63815; UMMZ 149613. V. prasinus SDSNH
57082, 59468, 60438, 60441. V. sahator SDSNH 57080; UMMZ 128112, 128113,
130167, 149614, 149615, 168411, 173096. V. var/w5 AMNH 28698.

Fossils. -Paraderma bogerti UCMP 49939, 49895, 49940, 54199, 54213, 54261
(holotype); Heloderma matthewi AMNH 990A (holotype), KUVP 7652, 4965 1, 49652,
UNSM 5001 1; H. texanum TM 40635-1 19, -123 (holotype), 40635-137, -138, -140;
Eurheloderma gallicum PU 12280; helodermatid parietal UMMP 74619.

Osteological terminology follows Estes (1983a), McDowell and Bogert (1954) and
Meszoely (1970).

Our method of assessing character polarity follows the recommendations of Mad-
dison et al. (1984). Monophyletic taxa successively removed from Helodermatidae
were consulted as the need arose. Although not formally considered in this analysis,
the Mongolian Cretaceous varanoids described by Borsuk-Bialynick (1984) also were
evaluated to help resolve cases of character ambiguity. In several instances, so noted,
multi-state characters were recoded in order to achieve consistency in coding all char-
acters in standard binary fashion (0 = ancestral; 1 = derived; 9 = missing data). A
character matrix was compiled and subjected to computer analysis using Swofford's
(1984) PAUP program installed at the University of Michigan, and PHYSYS available
through the California State University system (CSU CYBER). The results of these
procedures were used mainly as a check of our own analyses.

I. Varanoidea

Because our polarity assessment of helodermatid characters relies on their distri-
bution first among Varaninae and Lanthanotinae and second among other anguimorphs,
it is necessary to review the attributes of Varanoidea that others have considered
diagnostic. This review collates a scattered literature on the subject, but essentially the
purpose is for assessing relationships within helodermatids in the context of character
distribution within their sister taxa.

The following characters (and character complexes) have been considered diag-
nostic for Varanoidea, several of which require comment. Parenthetical numbers denote
the corresponding character(s) in Tables 2 and 3.

McDowell and Bogert (1954) (also Romer 1956):

A. Loss of caudal autotomy (52).

B. More deeply cleft fore-tongue (notched not less than 20% of length) (71).

C. Intramandibular kinesis (37-45).— The progressive development of intraman-
dibular kinesis figured prominently in McDowell and Bogert's characterization of Va-
ranoidea, and also has been discussed by Rieppel (1980a) and Gauthier (1982). In these
and other studies several characters affecting mandibular kinesis have been identified:
a truncated margin of the posterolateral edge of the dentary; surangular foreshortened
anteriorly; splenial reduced anteriorly and posteriorly; anterior extension of the lateral
and medial arms of the coronoid present, but not broadly overlapping the dentary; a
tiny, free posteroventral process on the intramandibular septum (IMS); and a fibrous
connection between the dentary and postdentary bones. These modifications appear to
form a developmentally and functionally related complex of characters that distinguish
the mandible of varanoids from all other anguimorph squamates. That is, there is at
least some mobihty of the dentary with respect to the post-dentary bones.

McDowell and Bogert (1954:108) believed that the principal modification in the
evolution of intramandibular kinesis was the formation of a vertically truncated pos-
terior margin of the dentary, such that the dentary overlaps little or not at all with the

171

post-dentary bones. In helodermatids, they thought (incorrectly) that the intramandib-
ular hinge was absent (//. suspectum) or rudimentary (//. horridum) because the pos-
terolateral edge of the dentary is not truncated in these species, the structure being
more like the primitive anguimorph condition in having an obvious surangular notch
at the posterolateral edge (Gauthier 1982). However, manipulation of freshly excised
mandibles of both species of Heloderma demonstrated to us that the dentary can move
freely through an arc of approximately 1 0° with respect to the post-dentary bones;
similarly, the dentary of Varanus prasinus can be moved through an arc of approxi-
mately 17°. The splenial passes posterior to this joint in Heloderma. However, the
splenial is quite thin and it simply bends during kinesis. By contrast, in varanines, and
presumably lanthanotines, the splenial moves as a unit with the dentary. A vertically
truncated posterolateral margin of the dentary (and splenial) is, therefore, not required
for kinesis, although it apparently enhances mobility.

Our dissections indicate that the internal structure of the mandible at the coronoid
juncture probably plays the most important role in facilitating movement in the lower
jaw. In anguids and xenosaurids the surangular is long, tapers anteriorly and terminates
inside the dentary well forward of the last tooth, as in most squamates (Gauthier 1982).
The surangular bone is recessed laterally to receive a prominent overlapping portion
of the dentary. Thus, a broad mutual overlap between the dentary and postdentary
bones prevents flexure at the coronoid juncture. In varanoids, however, the surangular
is not tapered, and the anterior end is truncated so that it barely reaches the posterior
end of the tooth row. Accordingly, overlap between the dentary and surangular is
restricted; the bones are secured to one another by a thick band of connective tissue
rather than by the firm osseous connection seen generally in anguids, xenosaurids, and
other squamates (Gauthier 1982).

Another feature of the mandible of some varanoids is the presence of a small notch
in the posteroventral margin of the intramandibular septum (IMS). The anteroventral
end of the surangular fits into this notch, thus restricting torque about the intraman-
dibular joint. In Varanidae and some Heloderma suspectum this character has reversed,
the notch being absent.

Preliminary developmental studies suggest that there are few neomorphic structures
in the mandible of varanoids that promote kinesis; rather the action is accomplished
by an apparently paedomorphic reduction in the extent of contact among the bones
comprising the dentary/post-dentary articulation, as well as an incorporation of fibrous
connective tissue into this joint.

D. Maxillary tooth row not extending posteriorly below orbit {11); ectopterygoid
elongate and contacting palatine to exclude maxilla from suborbital fenestra (36).

E. Bases of teeth expanded and infolded (plicidentine) (24); teeth sharply pointed,
trenchant, recurved and widely-spaced (25); teeth without replacement pits, i.e., teeth
develop outside tooth bases (26) {see also Rieppel 1978).

F. Partial retraction of nares, i.e., nasals barely or not at all in contact with pre-
frontals (2,3,4). -McDowell and Bogert (1954) characterized helodermatids and all
other platynotans as having retracted nares. That is, the external nares are elongated
posteriorly such that they separate the nasal from the prefrontal and maxilla. Appar-
ently, they based their conclusion regarding Heloderma on a specimen of H. horridum
(AMNH 57863) that was also illustrated in their monograph (p. 36). This same illus-
tration and the character itself was used later by Bogert and Martin del Campo (1956:
1 8). Rieppel ( 1 980<3) also included this feature as a character of Varanoidea. On AMNH
57863 the osteoderms had been removed from the left side of the skull to reveal a
narrow slit in the posterodorsal end of the bony nares between the nasal, maxilla,
prefrontal and part of the frontal, giving the appearance of "retracted" nares. However,
in Heloderma extensive connective tissue occurs in the nasal-maxilla-prefrontal region
that usually shrinks when the skull is prepared as a dry specimen. Depending on the
degree of desiccation, the nasal bone can show varying degrees of separation from the
maxilla and prefrontal. This appears to be the case with AMNH 57863. These bones
have smooth narial margins in varanids and form true retracted nares: there is no

172

contact between the nasal and maxilla, and very little {Lanthanotus) or none (all other
varanids) between the nasal and prefrontal. Anguids and xenosaurids exhibit broad
contact of the nasal with the maxilla, but very little occurs in Heloderma. Heloderma
does possess a broad nasal-prefrontal contact, as seen generally in squamates. Thus,
moderately retracted nares occur in Heloderma by an anterior narrowing of the nasals,
although the bones are not as reduced in length as they appear in Lanthanotus and
Varanus.

Miller (1966):

G. Cochlear duct robust and broad, limbus elongate and heavily constructed (75).

Lecuru (1968a, b):

H. Mesosternum absent (60).

I. Anterior process of interclavicle reduced or absent (59).— An anterior process of
the interclavicle is absent in some species of Varanus (e.g., V. niloticus) but a short
process is present in others (e.g., V. griseus; also Saniwa— personal observation). Lecuru
(l96Sa) and Rieppel (1980Z?) present conflicting evidence for Lanthanotus. Lecuru
( 1 968a: fig. 1 5) illustrated the interclavicle having a pair of horn-like anterior processes,
whereas Rieppel (1980b: 103) figured the structure without any sort of anterior process,
the crossbar or lateral processes being a rectangular plate at the anterior end of the
bone. In this respect, our specimen of Lanthantus (REE 1445) agrees with that figured
by Lecuru.

J. Clavicles gracile (58).

K. Ulnar nerve passes deep in forearm ("varanid condition") (76) {see Renous-
Lecuru 1973).

Hoffstetter and Gasc (1969):

L. Vertebrae with precondylar constriction (not listed).— Precondylar constriction
of the trunk vertebrae is marked in Varanus, and hardly noticeable in Heloderma. In
fact, McDowell and Bogert (1954) claimed that in Heloderma the vertebrae were not
constricted anterior to the condyles. Rieppel ( 1 980Z)) reported that Lanthanotus exhibits
a condition very similar to that of Heloderma, wherein the precondylar constriction is
present, but faint. Actually, this character can only be evaluated subjectively and we
prefer not to consider it diagnostic of Varanoidea; undoubtedly it is a synapomorphy
of Varanus.

M. Peduncles on cervical and caudal vertebrae supporting hypapophyses and chev-
rons, respectively (53, 54). — In following Hoffstetter and Gasc (1969) and his own
observations, Rieppel (1980Z)) recorded the presence of cervical and caudal peduncles
as a synapomorphy of Varanus and Lanthanotus. On the other hand, McDowell and
Bogert (1954:124) stated that "Even the most primitive platynotan [Heloderma] has
distinct pedicles for the caudal chevrons, as far as known, all platynotans have the
chevrons freely articulated to the caudal centra." We concur with McDowell and Bogert.
Whereas caudal peduncles are certainly most prominent on Varanus, they are not
unique. They are present, albeit feebly, on our comparative skeletons of Heloderma,
and in fact can be observed in other anguimorphs, such as Xenosaurus. The hyper-
developed cervical and caudal peduncles of varanids, and the fact that neither the
chevrons nor the cervical intercentra contact the centrum condyle, will distinguish this
taxon, but the presence of caudal peduncles themselves will not diagnose Varanoidea.

Saint Girons (1976):

N. Large, anatomically differentiated sero- mucous gland on lower jaw [Gland of
Gabe (Kochva 1974)] (73).

O. Calyciform duodenal cells of muco- serous rather than mucous type (74).

173

Gabe and Saint Girons (1976):
P. Double lacrimal canal (80).

Rieppel (1980a. b):

Q. Epicoracoid does not contact the suprascapula and mesoscapula to enclose a
scapular fenestra (55) (also Camp 1923).

R. Narrow-based bodenaponeurosis attached to caudomesial edge of coronoid pro-
cess (except LanthanotuSy) (69).

S. Insertion of M. episterno-cleido-mastoideus reaches supratemporal process of
parietal (62).

T. M. adductor mandibulae externus profundus (3b-layer) originates from supra-
temporal only (64).

U. Origin ofM. geniomyoideus is deep to M. genioglossus medialis (65). — In Lan-
thanotus the origin of the M. geniomyoideus is superficial relative to the M. genioglossus
medialus, as in all xenosaurids and anguids; therefore the condition appears ancestral.
In Varanus, however, the muscle has shifted its origin and is entirely deep to the M.
genioglossus medialis. In Heloderma the origin is transitional in that some fibers still
retain an attachment with the symphyseal tip of the dentary, whereas others are deep
to the M. genioglossus medialis (Rieppel 1980a). We consider the condition in Lan-
thanotus secondary in this regard.

V. Insertion ofM. levator pterygoidii does not extend posteriorly beyond columellar
fossa of pterygoid (67).— Also in Heloderma suspectum, but not H. horridum; alter-
natively, H. suspectum and Varanidae may have acquired this condition separately.

W. Vomers with distinct palatal shelves (32).— The vomers are narrow, elongate
structures only in Heloderma and Varanus, i.e., distinct palatal shelves are absent.
Ancestrally, the vomers are broad as in Lanthanotus borneensis. However, in this species
attainment of broad palatal shelves is probably a character reversal, judging from the
narrow and elongate vomers exhibited by the late Cretaceous lanthanotine, Cherminotus
longifrons {see Borsuk-Bialynicka 1984).

X. Odontoid sutured and not fused to axis (not listed, see Y).

Y. Second intercentrum sutured and not fused to axis (not listed).— The unfused
odontoid and second intercentrum are size and age related characters (Gauthier 1982).
These structures fuse to the axis in large, older individuals (e.g., Varanus salvator
SDSNH 57080), as they do in all lepidosaurs.

This Paper:

Z. Vomers more than twice as long as palatines (3 1 ); palatines approximately as
wide as /o«^ (3 3).— Although the form of the snout differs among these taxa, the vomers
of helodermatids, and varanids are elongate, being nearly twice the length of the pal-
atines. This condition is diagnostic of varanoids among anguimorphs, and among
squamates generally. Elongate vomers may be associated with the transverse ptery-
gopalatine suture, which has been interpreted as a functional response to over retraction
of the hypokinetic axis (Borsuk-Bialynicka 1984). Concomitantly, the palatines and
anterior ends of the pterygoids are shortened with respect to the vomers. In Recent
Heloderma we note that the vomerine process of the palatine is further reduced such
that it does not extend anteriorly beyond the level of the last maxillary tooth.

Elongate vomers also are characteristic of certain late Cretaceous anguimorphs
from Mongolia shown in the plates and figures in Borsuk-Bialynicka (1984: figs. 2, 8,
1 1; plates 1, 5). They occur in Gobiderma pulchrum, perhaps Paravaranus angusitfrons,
and Proplatynotia longirostrata. Thus, the character may be applicable at a taxonomic
level more inclusive than Varanoidea, as constituted here.

AA. Premaxillary teeth abruptly smaller than maxillary teeth (23).

BB. Supratemporal bone reaches level of parietal notch (apex of angle formed by

174

Figure 1 . Lateral view of left maxilla of Heloderma (top) and Varnaus showing the derived, posterior
position of the nasal process in the latter.

supratemporal processes) (19).— In varanoids the supratemporal is longer than in other
Anguimorpha; it reaches anteriorly level with the apex of the parietal notch. This
character may be associated with the 3b-layer of the MAME profundus (T, above),
which takes its origin soley from this bone in varanoids, whereas in other anguimorphs
it invades the descensus parietalis to varying degrees. Rieppel (1980a) considered that
the varanoid condition of the muscle is primitive with respect to other squamates,
although he used it as a diagnostic feature. Hence, a long supratemporal might also
represent an ancestral condition. Our inspection of other anguimorphs brought mixed
results; most have a short supratemporal relative to its distance from the parietal notch.
Thus, the origin of the MAME profundus and the length of the supratemporal may be
a synapomorphy of varanoids, and we believe that the consequent restriction of the
MAME profunds to the supratemporal might therefore be a redundant character.

Synapomorphies of Varanidae (Varaninae + Lanthanotinae)

ThCi are a number of characters within Varanoidea that designate varanines and
lanthanoti is as monophyletic and the sister group of helodermatids. Many of these

175

were first noted by McDowell and Bogert (1954). Rieppel (1980a, b) has reviewed the
literature on alternative interpretations, favoring those with a phylogenetic emphasis.
Based on head musculature (Rieppel 1980a) and the postcranial skeleton (Rieppel
\9S0b), he concluded, as have others before him, that Lanthanotus is phylogenetically
closer to Varanus than it is to Heloderma

The following is a compilation of characters shared between Lanthanotus and
Varanus that have been considered derived; they are not found in Heloderma, or in
squamates generally. The number in parentheses refers to the corresponding character(s)
in Tables 2 and 3.

McDowell and Bogert (1954):

A. Nasals fused (1). — Borsuk-Bialynicka (1984) stated that the nasals might be
paired in the early lanthanotine Cherminotus; however, photographs of the holotype
(the best preserved specimen) reveal that the condition of the nasals cannot be deter-
mined with certainty.

B. Fully retracted nares (2, 4, and see F above).

C. Nasal process of maxilla rises from a posterior position on that bone (5). In
helodermatids the nasal process of the maxilla is located in the middle of the maxilla
(Fig. 1), the ancestral condition in anguimorphs. In Varanus and Lanthanotus the nasal
process is positioned posteriorly as a result of elongation of the premaxillary process
and reduction of the orbital process of the maxilla. This feature probably occurs in
conjunction with fully retracted nares.

D. Well-developed subolfactory processes directed posteromedially that closely ap-
proach one another, or contact midventrally (9) (Fig. 2).

E. Supraoccipital makes broad contact with /7ar/>/a/ (1 5). — Rieppel ( 1 980(3) further
emphasized this synapomorphy. By contrast, Borsuk-Bialynicka (1984) regarded broad
parietal contact as convergent, a response to reduced metakinesis in skulls of different
proportions. Although possibly unrelated, we add (1 8) that the supratemporal processes
of the parietal are very compressed mesolaterally in Varanus and Lanthanotus, and
not so in other anguimorphs.

F. Hypoglossal foramen enlarged, confluent with vagal foramen (16).

G. Double posterior lacrimal foramen (22).— Two lacrimal ducts are present in
Heloderma, Lanthanotus, and Varanus (P, above), whereas the duct is single in all
other lepidosaurs (Gabe and Saint Girons 1976). There is, however, only a single
posterior and anterior lacrimal foramen in Heloderma, but there are two posterior
foramina in varanids. The anterior foramen is single in Saniwa and Lanthanotus
(personal observation), and double in Varanus.

H. Increased intramandibular kinesis (37-45, and see C above).
I. Osteoderms, when present, reduced, not fused to skull. (48).
J. Reduction of the outer conch of the quadrate (20).

Hoffstetter and Gasc (1969):

K. Nine cervical vertebrae (49); well-developed cervical and caudal peduncles (53);
caudal chevrons do not contact centra condyles (54).— Table 1 provides additional
meristic data on the varanoid axial skeleton.

Lecuru (1968); Rieppel (1980Z?):

L. Posterior coracoid emargination present (57).— The presence of a posterior cor-
acoid emargination is variable in Lanthanotus; see the conflicting descriptions of Lecuru
(emargination absent) and Rieppel (present, but small). Our specimen of Lanthanotus
is like Lecuru's in that no posterior coracoid emargination is present. It is also absent
in Saniwa {personal observation).

M. Fewer than four phalanges on pedal digit V (not listed). — Rieppel (1980/))
considered the loss of a phalanx in pedal digit V an apomorphic condition shared by

176

Figure 2. Frontal bones of Heloderma (top), Lanthanotus (middle), and Varanus (bottom). Ventral view
(right) shows orientation of the subolfactory processes (anterior in Heloderma).

177
Table 1. Meristic characters of the varanoid axial skeleton.

Heloderma

Lanthanotus

Varanus

No. cervical vert.

1st cervical rib

V5-7

No. presac. vert.

32-36

No. lumbar ribs

3-4

No. true lumbar vert.

No. caudal vert.

25-40

63-69

60-110

1 St caudal chevron

V2(3)

Heloderma and Lanthanotus. We confirm that only three phalanges are present in
Lanthanotus, but all H. suspectum and at least some H. horridum at our disposal have
the ancestral condition of four phalanges on the fifth pedal digit. Of seven H. horridum
from the same brood bom in the Detroit Zoo, four of these had four phalanges on the
fifth pedal digit and three had three. We consider the variable number diagnostic of
H. horridum among Heloderma.

Rieppel (1980a):

N. Articular socket present on dorsal surface of cephalic condyle of quadrate to
receive squamosal peg (not listed).— We note the presence of this socket in large indi-
viduals of Heloderma and its absence in small Varanus. It may, therefore, be a size
related character; more important, the peg and socket articulation appears to be a basic
squamate character, as described by Robinson (1967).

O. M. constrictor colli extends anteriorly covering first ceratobranchials (63).

P. M. genioglossus lateralis subdivided into separate bundles (66).

Q. Anterior head of M. pseudotemporalis profundus enlarged (68).

Branch (1982):

R. Hemipeneal morphology, viz., paired horns develop as extensions of the main
retractor muscle (70). — In a recent examination of cloacal and hemipenial musculature
of lizards, Arnold (1984), not citing Branch (1982), described a combination of derived
characteristics for Varaninae. He (Arnold 1984:75) concluded, "but, as these are not
shared with the other two surviving platynotan families, which approach the generalized
lizard condition, they provide no evidence of relationships among these groups." Ar-
nold's assessment may not be in contradiction of Branch (1982), who apparently was
referring to cartilage-like conical horns penetrating the hemipenal lumen in Lanthanotus
and Varanus. We retain this character as a synapomorphy of Varanidae.

Gauthier(1982):

S. Surangular does not extend anteriorly far beyond coronoid eminence (40).
T. Coronoid and surangular processes on posterolateral margin ofdentary reduced
(38).

U. Intramandibular septum without posteroventral notch (41).
V. Splenial moves with dentary (44).

Schwenk (MS):

W. Foretongue notched for at least 40% of length (72).

Estes, de Queiroz, and Gauthier (MS):

X. Second epibranchial absent {11).

Y, Three or fewer pairs of sternal rib attachments (61).

178

Convergent Characters within Varanoidea

Monophyly of Varanoidea, composed of Helodermatidae, Lanthanotinae and Var-
aninae, is supported by 37 synapomorphies (Tables 2 and 3); 26 others unite Lanthano-
tinae and Varaninae as Varanidae, the sister group of Helodermatidae (Fig. 3). Hel-
odermatidae is diagnosed by 23 characters {see Part II). Several derived characters,
therefore, must be regarded as convergent acquisitions between Lanthanotus and Helo-
derma.

Heloderma and Lanthanotus are convergent in the following nine derived char-
acters: frontals trapezoidal (6); prefrontal and postfrontal contact above the orbit (10);
parietal foramen absent (1 1); absence of upper temporal bar (12 and 1 3); rounded snout
(21); and more than 30 presacral vertebrae (51). Estes et al. (MS) also note that Lan-
thanotus and Heloderma have acquired independently the absence of an ossified pal-
pebral (78), and a reduced number of scleral ossicles (79).

Convergence in the skull characters is revealed by the early lanthanotine Cher-
minotus longifrons Borsuk-Bialynicka, which retains the ancestral conditions of some
of these characters (e.g., characters 6, 10, 11, 12, and 21) by comparison to Lanthanotus
and Heloderma. Moreover, unlike Lanthanotus, in Cherminotus the parietals are not
elongate nor are the frontals foreshortened; the splenial is not as short posteriorly; and
the vomers are narrow. However, it can be identified as a lanthanotine by details of
skull morphology, in addition to those characters above that Lanthanotus shares (con-
vergently) with Heloderma. Cherminotus also shares apomorphies with varanines, such
as external nares that are nearly completely retracted, broad contact of the supraoccipital
with the parietal, and the absence of fused cephalic osteoderms.

Discussion of Varanoidea

Operationally, Varanoidea needs to be placed in a framework with necrosaurids
and other extinct "platynotans." Unfortunately, the state of preservation of most nec-
rosaurian taxa is insufficient for more than a provisional diagnosis of the group. More-
over, necrosaurids are characterized primarily by ancestral features. Although they
display some unusual combinations of ancestral anguimorph and varanoid characters,
only the condition of fused frontal bones in some adult necrosaurids could be considered
diagnostic. The shape of the parietal, maxilla and teeth, as well as features of the
mandible indicating limited kinesis, suggest that these early and generalized angui-
morphs are related to varanoids. However, necrosaurids lack well-developed subol-
factory processes below the frontals, at least in the better preserved specimens. Likewise,
the external nares are only weakly retracted, and in some there is only incipient infolding
of the tooth bases (Borsuk-Bialynicka 1984, Estes 1983<2). Osteoscutes may be rhom-
boid, polygonal or oval, fused to the skull roof or free (Estes 1983). At this time,
necrosaurids, as Estes (1983) hypothesized, are probably best understood as being a
collection of fairly generalized platynotans.

Borsuk-Bialynicka (1984) has evaluated Platynota in the context of a polyphyletic
origin from various members of a "necrosaurian stock." She recognized a polyphyletic
grade "modem Platynota" that consists of Varanidae, Lanthanotidae, Helodermatidae
and Mosasuridae. This group is identified by those classical characters used by previous
workers: 1) a high degree of intramandibular kinesis (less so in Helodermatidae); 2)
strong development of the subolfactory processes (not in Mosasauridae); 3) teeth with
prominent basal infolding (less so in Helodermatidae); 4) a transverse pterygopalatine
suture; 5) retracted external nares (only incipient in Helodermatidae); 6) size increase;
7) fragmentation of cephalic osteoderms (unknown in mosasaurs).

Borsuk-Bialynicka (1984) argued from functional considerations of the skull, es-
pecially with regard to gradual improvement of predatory adaptations (such as mod-
ifications of the palatal elements). In her scheme, helodermatids were independently
deriv(?d, and even lanthanotines and varanines were regarded as clades that originated
separately from "necrosaurs." The host of derived osteological features shared by

179

Heloderma

-6

-8

-10

-11

-12

-13

-14C-3

-21

-29

-30

-47

-50

-51

-56

-78

-79

Lanthanotus

—

-6

—

-10

—

-11

—

-12

—

-13

—

-21

—

-32C-]

—

-51

—

-69C-]

—

-78

—

-79

Varanus

--34
--35
--57

Varanidae
1,2,4,5,9,15,16,17

1 8,20,22,38,40.4 1C-3

44,48,49,53,54,61

63,66,68.70,72,77

Varanoidea

3,7,14,19,23,24,25,26

27,28.31.32,33,36,37

39,41,42,43,45,46,52

55,58,59.60,62,64,65

67,69,71,73.74,75,76,80

Figure 3. The relationships of Varanoidea as determined from character states in Tables 2 and 3. [PAUP:
93 steps, C.I. = 0.86]

varanines and lanthanotines (^^^^ above) are believed by Borsuk-Bialynicka to be parallel
achievements, a conclusion with which we strongly disagree. For example, she believed
that the broad contact of the supraoccipital with the parietal was a convergent means
of restricting metakinetic movement, which itself was a response to overall proportions
of the brain case and snout, these supposedly being different in the two taxa.

We conclude that monophyly of Recent varanoids and varanids are highly cor-
roborated hypotheses. A phylogeny envisioning a polyphyletic origin implies only that
considerable work remains to be done in character analysis of "Necrosauridae." Dol-
ichosauridae, "Aigialosauridae" and Mosasauridae. It is safe to say that by the late
Cretaceous Helodermatidae was represented by Paraderma, Lanthanotinae by Cher-
minotus, and Varaninae by Saniwides and Telmasaurus (Estes 1983a, Borsuk-Bialyn-
icka 1984). For now, we are inclined towards a conservative interpretation, as suggested
by Rieppel (1980a, b), that would recognize the monophyly of Varanoidea as a group
restricted to Helodermatidae, Lanthanotinae and Varaninae. The name "Platynota"
may be retained for convenience as it was applied by McDowell and Bogert, and by

180

Table 2. Character summary of Varanoidea, arranged in anatomical sequence, and scored as ancestral (0)
or derived (1). Those preceded by "v" are diagnostic of Varanoidea. See Table 3 for character state
distribution.

Skull characters

1. Nasal bones paired (0), or fused (1).

2. Nasal and prefrontal bones in broad contact (0), or with little or no contact (1).
3.V Nasal and maxillary bones in broad contact (0), or with little or no contact (1).

4. Nasals and maxillary bones in narrow contact (0), or not in contact (1).

5. Nasal process of maxilla rises from the middle (0), or posterior (1) aspect of maxillary.

6. Frontal more or less parallel-sided (0), or trapezoidal (1).

7.V Subolfactory processes of frontals short, not in contact ventromedially (0), or well-developed and
closely opposed or contacting ventromedially (1).

8. Subolfactory processes of frontals do not descend to contact each other anteromedially (0), or do

so(l).

9. Subolfactory processes of frontal do not descend to approach or contact each other posteromedially

(0), or do so (1).

10. Prefrontal does not (0), or does closely approach or contact postfrontal above orbit (1).

1 1. Parietal foramen present (0), or absent (1).

12. Postorbital present (0), or absent (1).

13. Squamosal large, extending to postorbital (0), or small and reduced (1).
14.V Temporal musculature inserts ventrally (0), or dorsally (1) on parietal table.

15. Supraoccipital not in broad contact with parietal (0), or with broad contact (1).

16. Hypoglossal foramen not enlarged (0), or enlarged (confluent with vagal foramen) (1).

17. Carotid duct present (0), or absent (1).

18. Supratemporal process of parietal broad in dorsal aspect (0), or narrow (1).

19.V Supratemporal bone does not reach level of apex of parietal notch (0), or does (1).

20. Quadrate with large outer conch (0), or conch reduced ( 1 ).

21. Muzzle tapered, narrowing anteriorly (0), or blunt and rounded (1).

22. Posterior lacrimal foramen single (0), or double (1).

23. V Premaxillary teeth large (0), or abruptly smaller than maxillary teeth (1).

24. V Plicidentine teeth absent (0), or present (1).

25. V Teeth bluntly pointed (0), or sharply pointed, trenchent, recurved, and widely-spaced (1).

26. V Successional replacement teeth in resorption pits (0), or replacement teeth develop posteriorly, no

resorption pits present (1).

27. V Maxillary tooth row extends posteriad of orbit (0), or is entirely antorbital (1).

28. V Maxillary teeth number 13 or more (0), or less than 13 (1).

29. Maxillary teeth greater than 9 (0), or less than/equal 9(1).

30. Venom groove absent (0), or present (1).

31.V Vomer short (0), or nearly twice the length of palatine (1).

32. V Palatal shelves of vomer wide (0), or narrow (1).

33. V Palatine longer than wide (0), or equally wide as long (1).

34. Palatine teeth present (0), or absent (1).

35. Pterygoid teeth present (0), or absent (1).

36. V Ectopterygoid does not contact palatine anteriorly (0), or does to exclude maxilla from suborbital

fenestra (1).

37. V Dentary and surangular overlap considerably (0), or very little (1).

38. Coronoid and surangular proceses of dentary well-developed (0), or processes reduced (1).

39. V Surangular tapered anteriorly (0), or blunt and expanded anterodorsally (1).

40. Surangular extends well beyond coronoid eminence (0), or does not (1).

41.V Intramandibular septum (IMS) without posteroventral notch (0), or notched (1).

42. V Splenial extends posterior of coronoid eminence (0), or does not (1).

43. V Splenial-dentary suture firm (0), or loose, with much connective tissue between the two bones (1).

44. Splenial does not move with dentary (0), or does (1)

45. V Coronoid without long anterolateral and anteromedial proceses (0), or processes present (1).

46. V Head scales large and plate-like (0), or partly or completely fragmented (1).

47. Osteoderms thin, plate-like (0), or rounded and thick (1)

48. Osteoderms fused to skull (0), or not (1).

Axial characters

49. Number of cervical vertebrae eight (0), or nine (1).

50. Vertebral centra long and neural spines broad (0), or centra short and neural spines narrow and

tall (1).

51. Number of presacral vertebrae fewer than 30 (0), or more (1).
52. V Caudal vertebrae autotomic (0), or not (1).

53. Peduncles on cervical and caudal vertebrae short (0), or long (1).

54. Caudal chevrons and cervical hypapophyses (=intercenta) contact centrum condyle (0), or on

centrum only (1).

181

Table 2. Continued.

Appendicular characters

55.V Epicoracoid contacts suprascapula and mesoscapula (0), or not (1).

56. Anterior coracoid emargination present (0), or absent (1).

57. Posterior coracoid emargination absent (0), or present (1).

58. V Clavicle loop-shaped medially (0), or gracile and not expanded (1).

59. V Interclavicle with long anterior process (0), or process short or absent (1).

60. V Mesostemum present (0), or absent (1).

61. Rib attachments on sternum more than three pairs (0), or three or fewer pairs (1).

Myological characters
62. V M. epistemo-cleido-mastoideus does not reach parietal (0), or has extensive insertion on parietal

(1).
63. M. constrictor colli does not cover 1st ceratobranchials (0), or does (1).
64. V Origin of MAME profundus from supratemporal and parietal (0), or supratemporal only (1) [may

be redundant with 19, see text].
65. V Insertion of M. geniomyoideus is completely superficial to M. genioglossus medialis (0), or insertion

is at least partly deep to M. genioglossus medialis (1).
66. M. genioglossus lateralis single (0), or subdivided into separate bundles (1).
67. V? Insertion of M. levator pterygoidii extends posteriorly beyond columellar fossa of pterygoid (0), or

does not (1).
68. Anterior head of M. pseudotemporalis profundus not enlarged (0), or enlarged (1).
69. V? Bodenaponeurosis with broad base (0), or narrow base attached only to caudomesial edge of coronoid

(1).
Other characters

70. Hemipenis without paired horns as extensions of main retractor muscles (0), or with them (1).

71.V Foretongue not deeply cleft (0), or deeply cleft (not less than 20% of length) (1).

72. Foretongue cleft for 20% of length or less (0), or not less than 40% of length (1).

73. V Gland of Gabe absent (0), or present (1).

74. V Calyciform duodenal cells simple (0), or sero-mucous type (1).

75. V Cochlear duct not robust (0), or robust and broad, limbus elongate and heavy (1).

76. V Ulnar nerve superficial (0), or deep (1) in forearm.

77. Second epibranchial present (0), or absent.

78. Ossified palpebrals present (0), or absent (1).

79. Scleral ossicles 14 (0), or fewer (1).
80. V Lacrimal duct single (0), or double (1).

Rieppel, but with the understanding that the monophyly of that group has not yet been
established.

II. Systematic Account of Helodermatidae

In this section we describe new fossils of helodermatids, and provide a systematic
review of the taxa assigned. Our decisions on character state polarity are based on the
foregoing assessment of varanoid characters and relationships.

Amniota

Squamata

Autarchoglossa

Anguimorpha

Varanoidea

Helodermatidae

Lowesaunis, new taxon

Figures 4-6

Type species.— Heloderma matthewi GWvaovQ, 1928.

Diagnosis.— A taxon distinct from other Helodermatidae in possessing triangular
frontal bones, as opposed to trapezoidal.

Etymology.— The name honors Charles H. Lowe, Professor of Biological Sciences
at the University of Arizona, in recognition of his extensive contributions to the ecology
of western North America.

182

Table 3. Distribution of varanoid character states from Table 2 (1 = derived, 0 = ancestral, 9 = missing
data); a phylogeny is shown as Fig. 3.

"Necrosauridae"

Heloderma Lanthanotus Varanus

Character:

0 1

1 1

0 1

0/1

0 1

10.

11.

12.

9/0

13.

9/0

14.

0 1

15.

0 1

16.

0 1

17.

0 1

18.

0 1

19.

1 1

20.

0 1

21.

1 1

22.

0 1

23.

1 1

24.

1/0

1 1

25.

1 1

26.

0/1

1 1

27.

1/0

1 1

28.

1 1

29.

1 0

30.

1 0

31.

1 1

32.

1/9 0

33.

1 1

34.

0 0

35.

0 0

36.

0/1

1 1

37.

1 1

38.

0 1

39.

1 1

40.

0 1

41.

1/0 0

42.

1 1

43.

1 1

44.

0 1

45.

1 1

46.

1 1

47.

1 0

48.

0/1

0 1

49.

0 1

50.

1 0

51.

1 1

52.

1 1

53.

0 1

54.

0 1

55.

1 1

56.

1 0

57.

0 0

58.

1 1

59.

9 1?

60.

1 1

61.

0 1

183

Table 3. Continued.

"Necrosauridac"

Heloderma

Lanthanolus

Varanus

62.

63.

64.

65.

66.

67.

1/0

68.

69.

70.

71.

72.

73.

74.

75.

76.

77.

78.

79.

80.

Lowesaurus matthewi (Gilmore)

Synonym.— Heloderma matthewi Gilmore.

Holotype.—AMNYl 990A, posterior part of left maxilla with three teeth.

Type locality. —Lev/is Creek, Logan County, Colorado.

Previously referred specimens.— KUVP 7652, maxilla, Middle Oligocene, White
River Formation, Logan Co., Colorado; UNSM 50011, partial skull represented by
right maxilla, frontal, partial parietal, partial right jugal, right postfrontal, partial right
pterygoid, partial right prefrontal, partial basisphenoid, supraoccipital, partial quadrate,
isolated osteoscutes and a partial right dentary; Late Oligocene (Whitneyan), Brule
Member, White River Formation, Morrill Co., Nebraska (Gilmore 1928, Yatkola 1976).

New material (this paper). — KUVP 49651, a nearly complete right frontal bone;
KUVP 49652, two trunk vertebrae.

Locality and horizon (new material). — Redington Gap SW'/2, SE'A, Sec. 14, T. 19n.,
R.52W., 3V2 miles south and 9'/2 miles west of Bridgeport, Morrill County, Nebraska.
Mitchell Pass Member, Gering Formation, Arikaree group (early Miocene; approxi-
mately 25-27 mybp).

Description of new material.— The frontal bone (KUVP 49651) tapers anteriorly
giving it a distinctive triangular outline (Fig. 4). It measures 16.6 mm and 7.8 mm
along the medial and parietal borders, respectively. Articular surfaces for the pre- and
postfrontal bones are clearly visible on the lateral margin, where they approach but
not quite meet each other above the orbital rim. A scar marking the nasal overlap
extends posterolaterally to the prefrontal suture. Dorsally, the bone is covered with
polygonal osteoderms that presumably would have conformed to the shape of the
epidermal scales. The osteoderms are irregular; they are shaped like flattened domes
separated from one another by moderately deep grooves. Most have a granular texture,
although the larger ones display tubercles and pits.

On the ventral surface, the robust subolfactory process is broken distally, and we
cannot determine with certainty that it would have sutured midventrally with its coun-
terpart from the left frontal, as happens in Heloderma (Fig. 2). The basal portion of
the subolfactory process is concave and penetrated by two foramina at the center of
the concavity.

Of the two referred vertebrae (KUVP 49652), one is missing the distal extent of
each zygapophysis (Fig. 5). All that remains of the other is the centrum. The more

184

Figure 4. Lowesaurus matthewi (gen. nov.) right frontal (KUVP 4965 1) drawn in dorsal (left) and ventral
(right) views. Approx. x 7.

complete specimen has a low, square profile not unlike characteristic trunk vertebrae
of Heloderma. It is 5.8 mm from the inferior margin of the cotyla back to the tip of
the condyle, and 7.8 mm across the tips of the prezygapophyses. The bone is 5.4 mm
high measured from the posteroventral edge of the condyle to the top of the neural
arch; the tip of the neural spine is missing. The lateral borders of the centrum are
parallel, and the condyle is large, elliptical and preceded by a faint constriction. The
neural arch is low and slopes gently posterodorsally.

Remarks.— Y3X\.o\?i (1976:6) illustrated a complete frontal bone articulating with
a partial parietal (UNSM 5001 1), as part of the material that he referred to H. matthewi.
Reexamination of this fossil (Fig. 6) and comparison with KUVP 4965 1 in hand shows
them to be similar in overall shape, position of the articular facets, and robustness of
the subolfactory processes. KUVP 49651 differs in having slightly larger, higher and
more tuberculate osteoderms separated by deeper grooves. Certainly the most com-
pelling feature in common is their triangular shape.

Ancestrally, the frontal bones of anguimorphs are parallel-sided above the orbits
and laterally expanded at the anterior and especially posterior ends; the frontal partic-
ipates broadly in the orbital rim (Gauthier 1982). In helodermatids ancestrally, the
frontals are trapezoidal, broad above the orbits, and with very little {Lowesaurus) or
no {Heloderma) participation in the orbital rim owing to the contact of the pre- and
postfrontal bones. Also important is that the descending subolfactory processes suture
anteromedially. The triangular frontals of Lowesaurus are thus unusual among angui-
morphs, the shape being repeated elsewhere only in certain glyptosaurine anguids, for

185

Figure 5. Lowesaurus matthewi (gen. nov.) vertebra (KUVP 49652) drawn in A) anterior, B) posterior, C)
dorsal, and D) ventral views. Approx. x 7.

example Paraglyptosaurus princeps (Sullivan 1979). In helodermatids, the direction of
change in shape probably coincides with that seen within glyptosaurines, that is, from
parallel-sided to trapezoidal to triangular. The frontals of Paraderma bogerti and Eur-
heloderma gallicum must be found in order to verify this hypothesis.

A New Helodermatid (Indet. Taxon) from the Latest Paleocene,
Bighorn Basin, Wyoming

cf. Eurheloderma

Bartels (1983) recently described an isolated parietal (UMMP 74619) from the
latest Paleocene of Wyoming (fig. 5; p. 367). He referred to this specimen as a varanoid
of "indeterminate family, genus and species" (p. 367). Our examination of the speci-
men confirms that it is varanoid in that the supratemporal scar anteriorly extends to
the level of the posterior end of the parietal table. Moreover, the absence of a parietal
foramen and the insertion of the temporal musculature ventrally on the parietal table
are derived characters diagnostic of Helodermatidae. The parietal table displays dermal
rugosities, but the overlying osteoderms did not adhere (indicating a subadult individ-
ual) and were not preserved with the specimen. The parietal is constricted in the manner
o^ Eurheloderma {see below), but assignment to that taxon would be premature in view
of our uncertainty regarding the level at which this attribute appeared in helodermatid
phylogeny. We list it conferee Eurheloderma merely to indicate the similarity. Beyond
those diagnostic of Helodermatidae, the fossil reveals no other apomorphies, and we
leave the taxon unnamed pending the discovery of additional material.

186

Figure 6. Lowesaurus matthewi (gen. nov). Dorsal (left) and ventral view (right) of frontal and partial
parietal (UNSM 5001 1). Approx. x3.

Morphology of Helodermatidae

Our generic reassignment of the fossils previously referred to Heloderma matthewi
implies that two lineages of helodermatid varanoids existed during the middle Tertiary
of North America: Lowesaurus and Heloderma (represented by H. texanum, Fig. 7).
Only the latter has persisted to the present. We also believe that Paraderma bogerti is
an early helodermatid, which would thus extend the temporal range of the group back
to the late Cretaceous in North America. Derived features discussed below are shared
by all these taxa, at least where known.

Teeth and venom delivery.— Tht most unusual feature of helodermatids is their
dentition. The anterior margin of each tooth is inflected medially to form a groove for
the conduction of venom. The two living species Heloderma suspectum and H. hor-
ridum possess deeply infolded, well-developed venom grooves on the anteromedial
margins of all maxillary and dentary teeth (Fig. 8), and frequently there are shallow
grooves on the more lateral teeth of the premaxilla. The groove is best expressed on
the largest teeth, those nearest the middle of the tooth row. In Eurheloderma gallicum
and Lowesaurus matthewi the groove is not as pronounced as it is in the two Recent
forms, but it does extend to the distal end of the tooth. The venom groove in H.
texanum is similar to that in E. gallicum and L. matthewi except for having a wider
basal opening as in the Recent species.

There are few teeth well preserved on the jaw elements referred to Paraderma
bogerti. On the holotype (UCMP 5426 1 ; Fig. 9) the most complete tooth is near the
middle of the dental row and bears an incipient groove on the anteromedial margin
near the base. We can only speculate, however, that the groove is a venom-conducting
precursor. The well-preserved premaxillary teeth of this lizard show no grooves, but
weakly grooved premaxillary teeth occur only in living helodermatid species.

In fossils of the early varanoids Palaeosaniwa canadensis, Parasaniwa wyomingen-
sis, Provaranosaurus acutus, and Necrosaurus cayluxi the trenchant margins of the teeth
are distinctly delimited from the main shaft of the tooth, leaving what could also be
interpreted as a precursor of a venom conducting groove. Here it is of interest that

187

Figure 7. Stereopairs of Heloderma texanum Stevens (holotype UT 40635-123); skull in dorsal (top) and
ventral views (bottom). Approx. x 2.

Saint Girons (1977) and Kochva (1974) noted the presence of a large sero-mucous
gland on the lower jaw of all varanoids, the Gland of Gabe, which is the venom
producing organ in Heloderma. Thus, it is not unlikely that the potential for venom
delivery was present early in the history of varanoid lizards. The desert monitor of
Pakistan, Varanus griseus, may itself produce toxic secretions according to Gorelov
(1970), although Kochva (1978) has noted contradictory evidence. In any case, the

188

Figure 8. Right dentary of Paraderma bogerti (top, UCMP 49939; x 2), and Heloderma honidum (bottom,
SDSNH 59469; x4.5).

capability for venom injection was elaborated only within the more derived Helo-
dermatidae, and as discussed in Part III, probably plays an important role in feeding.
Characteristic of varanoids, Helodermatidae have a reduced tooth count by com-
parison with other Anguimorpha. The number of teeth has decreased within helo-
dermatid phylogeny as well. Eurheloderma gallicum has 11-12 maxillary teeth, and
12-13 dentary teeth. Lowesaurus matthewi has 1 1 teeth on the maxilla and Heloderma
texanum has 9 (not 6 as reported by Stevens 1977). The dentary of H. texanum is
unknown, and only a partial right dentary has been described for Lowesaurus (Yatkola
1977). Of the two Recent species, H. horridum is thought to possess the fewest number
of maxillary teeth: 6-7 as opposed to 8-9 in H. suspectum (McDowell and Bogert 1954,
Bogert and Martin del Campo 1956, Yatkola 1976). Our sample {n = 80) of skeletons
confirms this only incidentally; the overlap in tooth count is in fact considerable. The
maxillary tooth count of//, horridum varies from 6-9 with a mean and mode of 7. In
H. suspectum the range is 7-9 with a mean and mode of 8. In both species, approxi-
mately one-third of our sample included individuals with a one-tooth count difference
between left and right jaws.

189

Figure 9. Paraderma bogerti. Maxilla (hololype UCMP 54261) in lateral (top) and medial (middle) views;
premaxilla (bottom, UCMP 54199). Approx. x3.

The mean and mode of dentary teeth for both species samples is 9. Helodenna
horridum varies from 8-10, and all individuals of//, suspectum examined had 9 dentary
teeth except for one, which had 10 teeth on one jaw and 1 1 on the other.

Maxillary arch.— The maxillary arch of helodermatids is similar to both Lan-

190

thanotus and Varanus in that the tooth row is entirely antorbital, a feature emphasized
by McDowell and Bogert (1954) to distinguish Varanoidea from other Anguimorpha
{see above). A consequence of the antorbital tooth row in varanoids is that the palatine
and ectopterygoid contact one another distally to exclude the supradental shelf from
participating in the suborbital fenestra. This condition is evident in H. texanum and
appears also to be the case in Eurheloderma and Lowesaurus, to judge from the palatine
and ectopterygoid articular surfaces on the fossil maxillae. It was probably also the case
for Paraderma bogerti, but more difficult to discern on this fossil.

Within Helodermatidae differences exist in the morphology of the maxilla. In the
early forms Paraderma, Eurheloderma, and Lowesaurus, the dental shelf, indeed the
entire maxilla, is deeply curved medially. The shelf is essentially straight in Varanus
and Lanthanotus. In Heloderma texanum the shelf is rather narrow and straight (Fig.
7), whereas in the two Recent species the shelf is also strongly curved. In these two,
the anterior end of the shelf widens to form a cup-like depression that isolates the first
3 or 4 teeth. This depression is scarcely evident in H. texanum, and not at all in
Eurheloderma or Paraderma.

Palate. —Teeth are present primitively on the palatal bones (vomer, palatine, pter-
ygoid) of diapsid amniotes. In general, lepidosaurs have retained palatal dentition
throughout their evolution, but reduction and loss have occurred independently several
times, particularly within squamates. Consequently, the absence of palatal teeth is a
character often difficult to resolve phylogenetically. Within squamates, the loss of palatal
teeth proceeds from the vomer to the palatine to the pterygoid (Camp 1923, Estes et
al. MS). Neither modem species of Heloderma retains teeth on the vomer, but in
contrast to previous reports, teeth may be present or absent on one or both of the
pterygoids and palatines. On the holotype of//, texanum, a few small teeth are present
on the palatine, but not on the pterygoid as reported by Stevens (1977). This condition
is aberrant and may be peculiar to that specimen, or an artifact of preparation or
fossilization.

A primitive feature of the palatine of H. texanum is that the vomerine process
extends anteriorly beyond the level of the penultimate tooth of the maxilla, where it
articulates with the vomer. This condition also occurs in Varanidea. The derived
palato vomer articulation is posterior to the level of the last maxillary tooth, as in living
Heloderma.

Jugal.— The angle formed by the dorsal and anterior processes of the jugal is less
acute in Heloderma texanum than it is in //. suspectum and //. horridum. The deflection
is like that of other anguimorphs, such that the orbits are more oval than round and
contribute to a lower profile of the skull. The low skull profile of//, texanum could be
the result of allometry, i.e., the holotype specimen being a subadult {see below). A
partial right jugal is known for Lowesaurus (UNSM 5001 1), but it is too incomplete
to reconstruct accurately the shape of the orbit.

Parietal— In helodermatids the parietal is flat and the adductors take their origin
from the ventral surface, a derived condition among Varanoidea. The parietal of Low-
esaurus and Heloderma is broad and trapezoidal, a shape common to all anguimorphs.
The parietal of Paraderma bogerti is unknown. That of Eurheloderma gallicum is
markedly constricted just anterior to the diverging supratemporal processes, as in
UMMP 74619 described above. Yatkola (1976) considered this to be a derived con-
dition, which may be correct, but the parietal of Paraderma must be found to verify
the polarity.

Cephalic osteoderma. — A.\xX2LVc\\og\ossdins primitively have large, plate-like dorsal
scales that grade into smaller scales anteriorly and laterally. Varanoids are distinguished
from other anguimorphs by the fragmentation of the large scales and osteoderms on
the frontal and parietal, except for those of Parasaniwa wyomingensis and Palaeosaniwa
canadensis, which are like those of anguimorphs ancestrally (Estes 1964, 1983iz).

As characters, osteoderm size and surface texture are difficult to interpret and
score. Descriptions are likely to be subjective, and the structures themselves probably

191

vary individually, with position on the skull, and ontogenetically. The dilemma is that
there are precious few other features with which to evaluate many of the fossil taxa.

In helodermatids the parietal osteoderms are largest in Eurheloderma gallicum,
smaller in Lowesaurus matthewi, smaller still in Heloderma texanum, and smallest in
H. suspectum and H. horridum. The maxillary osteoderms are larger than those on the
frontal in E. gallicum, L. matthewi and H. texanum, but approximately equal in size
in H. suspectum and H. horridum.

Within helodermatids, the grooves between adjacent osteoderms deepen with frag-
mentation and thickening of the osteoderms themselves. They are shallow in P. bogerti,
E. gallicum, and L. matthewi, deep in H. texanum, and deeper yet in H. suspectum
and H. horridum. Finally, the surface of the osteoderms is simply vermiculate in P.
bogerti and E. gallicum, whereas in L. matthewi the surface is mostly vermiculate but
with tubercles on the largest osteoderms. The osteoderms of H. texanum are mostly
tuberculate, and pitted and tuberculate in H. suspectum and H. horridum.

Vertebrae.— The. vertebrae of Paraderma bogerti are unknown, and, except for a
more constricted vertebral canal, there is little to distinguish those of Lowesaurus
matthewi from the vertebrae of Eurheloderma gallicum figured by Hoffstetter (1957:
784). Estes (1963) illustrated a vertebrae from the early Miocene Thomas Farm locality
of Florida and described it as Heloderma-like, although he referred it to Anguidae;
subsequently it was placed provisionally with helodermatids (Estes 1983a). By com-
parison to the Florida specimen, the KUVP vertebra of L. matthewi is half as large,
and the centrum is not compressed laterally. The vertebra of L. matthewi is larger than
that of H. texanum, which also has a laterally compressed centrum.

In Heloderma the trunk vertebrae are short relative to those of Lanthanotus and
Varanus, and the neural spines are narrower and more acute. There is a modest increase
in the centrum length of posterior vertebrae of Heloderma, Lanthanotus, and squamates
generally. Yet, in Varanus the vertebral centra tend to increase in length towards the
anterior trunk region.

Body 5zz^.— The modem species of Heloderma are larger than their Tertiary rel-
atives, assuming that the fossils represent adults of near average maximum size. How-
ever, for most of the fossil material none of the reliable signs of adulthood and maximum
size, such as fusion of the epiphyses, basicranial elements, and girdles, are known.

Stevens (1977) suggested that the relative degree of fusion of osteoderms to the
skull of//, texanum indicated that the holotype represents an adult. More important to
us are the unfused sutures on the basicranium and low skull profile, both characteristic
of a subadult individual. In //. suspectum and //. horridum the head tends to become
broader in proportion to its length during growth, especially in males (Bogert and Martin
del Campo 1956). That being the case, allometry may explain the wide angle of the
jugal and comparatively elongate skull of the H. texanum holotype. We would estimate
the snout-vent length of that individual at approximately 180 mm, and that of the
other fossil helodermatids at no more than 250 mm, except one specimen (UCMP
49939) that may represent P. bogerti, which was at least 800 mm by extrapolation from
the mandible of Recent Heloderma.

Bogert and Martin del Campo (1956) listed the average maximum snout-vent
lengths of H. suspectum and H. horridum at 325 mm and 350 mm, respectively.
However, two UMMZ specimens of //. horridum are considerably larger (<3 382 mm
SVL, 2 421 mm SVL), and neither specimen displays all the developmental charac-
teristics marking cessation of growth. Our sample of skeletons indicates that the dis-
parity in size between the smaller //. suspectum and the larger //. horridum is consid-
erably greater than Bogert and Martin del Campo (1956) thought.

Other characters.— ThQ two living species of Heloderma differ from one another
in several ways {see part III). The most obvious of these is the proportionately longer
tail of H. horridum. Bogert and Martin del Campo (1956) noted this difference and
isolated several characters of this condition: in H. horridum the tail comprises at least
65 per cent of the snout-vent length; there are 40 instead of 25 to 28 caudal vertebrae;

192

and at least 75 rows of subcaudal scales instead of no more than 62. A relatively long
tail is ancestral among Anguimorpha (see Part III).

The general color pattern of H. horridum is a mottled dark dorsum and banded
tail; perhaps cryptic under some circumstances, this pattern is widespread among an-
guimorph lizards (e.g., Anguidae such as Gerrhonotus, the xenosaurs, and varanids
such as V. tristis). The more brightly marked, pink and black pattern of H. suspectum
is derived, perhaps serving biological roles of camouflage, aposematism, or both (Bogert
and Martin del Campo 1956; see also part III).

Finally, Heloderma suspectum retains the ancestral state of enlarged preanal scales,
and four phalanges in pedal digit V.

Diagnosis of Helodermatidae

In a strict sense, a diagnosis is a list of a taxon's derived character states (autap-
omorphies). For Helodermatidae these are given below, and will distinguish this taxon
from other varanoid lizards; additional descriptive, ancestral features are listed in the
preceding accounts on varanoid characteristics.

Our diagnosis also is intended to serve as a means of hypothesizing intrafamilial
relationships (Fig. 10). Obviously, we must make assumptions about the inclusion of
referred fossil taxa in the absence of complete knowledge of their anatomy. None of
these assumptions, however, is inviolate from the standpoint of available evidence.
Helodermatidae is a taxon of varanoid Anguimorpha with the following attributes:

1 . Osteoderms thick, hexagonal and covering the entire head and body as a "coat
of mail."

2. Skull of robust construction having a steep nasal process of the maxilla, which
contributes to a rounded muzzle and short face.

3. Parietal foramen absent.

4. Gland of Gabe elaborated as a venom producing organ, concomitant with
grooved teeth on the maxilla and dentary; grooved teeth for venom delivery are best
developed in the two living species.

5. Upper temporal arch lost through reduction of the squamosal and loss of
postorbital (convergent in Lanthanotus).

6. Participation of frontal in orbit restricted, owing to approach (but not contact)
of pre- and postfrontals along orbital margin,

7. Subolfactory processes of the frontal descending anteromedially, joining ven-
trally in a midline suture.

8. Maxillary dental shelf curved medially.

9. Palatines lacking deep choanal grooves (convergent in Varanus).

10. Palpebral ossification absent (convergent in Lanthanotus).

1 1 . Pterygoid lappet of quadrate present.

12. Posterior opening of vidian canal at basisphenoid-prootic suture.

13. Splenial not extending anteriorly beyond tooth row midpoint.

14. Scleral ossicles fewer than 14.

1 5. Innervation of dorsal leg muscles by interosseous nerve [characters 10-15 from
Estes et al. MS].

16. Vertebral neural spines narrow and tall, rising at an acute angle.

17. Hypapophyses on posterior cervicals reduced (Hoffstetter and Gasc 1969).

18. Body long (32-36 presacral vertebrae— Table 1).

19. Tail short (25-40 caudal vertebrae— Table 1).

20. Interclavicle simple, rod-shaped.

2 1 . Anterior coracoid emargination absent.

22. Adductor musculature inserting on the ventral surface of the parietal table.

23. Diet includes unusually large prey items {see Part III).

Discussion of Helodermatidae

The phylogeny of Helodermatidae is depicted in Figure 1 0 (Table 4); it is nearly
free of homoplasy (convergence and reversals) and describes a fairly unambiguous

D
<

o
2

es
u

T3
U

a
.B

c
o

194

Table 4. Character summary of Helodermatidae, scored as ancestral (0), or derived (1). Distribution of
character states is presented in Table 5.

1. Venom groove absent (0), or present and continuous along tooth margin (1).

2. Base of venom groove narrow (0), or wider than groove itself (1).

3. Maxillary dental shelf straight (0), or curved medially (1).

4. Maxillary dental shelf without anterior depression (0), or expanded and depression present (1).

5. Maxillary teeth greater than nine (0), or equal/less than nine (1).

6. Maxillary teeth more than seven (0), or seven (1).

7. Frontal trapezoidal (not triangular) (0), or triangular (1).

8. Parietal is not strongly constricted medially (0), or is (1).

9. Vomerine process of palatine extends anteriad of last maxillary tooth (0), or not (1).

10. Osteoderms on skull roof wide, separated by shallow grooves (0), or narrow and smaller, separated by
deep grooves (1).

1 1 . Osteoderms on maxilla larger than those on frontal (0), or equal to them ( 1 ).

12. Cephalic osteoderms mostly flat, vermiculate (0), or domed and tuberculate (1).

13. Caudal vertebrae 40 or more (0), or less than 40 (1).

14. Enlarged preanal scales present (0), or absent (1).

15. Color pattern mottled dark, tail banded (0), or pattern bright pink and black, disrupted (1).

16. Four phalanges on pedal digit V (0), or three or four phalanges (1).

17. Body size large, at least 350 mm SVL (0), or small; less than 330 mm SVL (1).

18. Toes long (0), or short (1).

19. Habitat preference mesic or semimesic (0), or xeric (1).

20. Insertion of M. levator pterygoidii extends posterior to columellar fossa (0), or not (1).

hypothesis of phylogenetic relationships. But it also reflects the paucity of fossil material
and, hence, our assumptions about the origin of certain characters. For example, without
knowledge of the frontal bone of Eurheloderma we cannot resolve the position of that
taxon relative to Lowesaurus and Heloderma. Equally, we have assumed that certain
features of the frontal that specify Helodermatidae do in fact apply to Paraderma,
where again that structure is unknown. Naturally, the problem of character origin is
most acute with features of soft anatomy.

Yatkola (1976:3) stated that "the overall morphologic similarities between E.
gallicum, H. matthewi, H. suspectum and H. horridum are more impressive than their
differences. Therefore, I have included all four taxa within the genus Heloderma.^'
However, we prefer names that indicate monophyly rather than overall similarity. We
also wish to avoid redundant names, viz., if all taxa are referred to Heloderma then
there is no need to recognize another name, Helodermatidae, that specifies the same
taxon. We stated above our reasons for recognition of Lowesaurus, namely the triangular
frontals (character 7). We also retain Eurheloderma Hoffstetter for the early Cenozoic
species of France because of the distinctively constricted parietal (character 8). Helo-
derma is diagnosed by the wide basal opening of the venom groove (character 2) and
morphologically more robust osteoderms (characters 10, 12). Heloderma texanum is
primitive with respect to H. horridum and H. suspectum in its absence of: the anterior
depression of the maxillary shelf (character 4), the foreshortened vomerine process of
the palatine (character 9), and frontal and maxillary osteoderms of equal size (character
1 1). Heloderma texanum is derived compared to other helodermatids in possessing a
straight maxillary dental shelf (reversal, character 3).

Derived characters of Heloderma suspectum are its bright coloration (character
1 5), smaller size (character 1 7), short, non-prehensile tail (character 1 3), shorter toes
(character 1 8), and occupation of xeric habitats (character 1 9).

Derived characters of Heloderma horridum are its fewer number of maxillary teeth
(character 6), insertion of the M. levator pterygoidii not extending posterior of the
columellar fossa (reversal, character 20), loss of enlarged preanal scales (character 14),
variable number of phalanges (three or four) in pedal digit V (character 16).

Although lacking a continuous venom groove (character 1) the late Cretaceous
Paraderma bogerti is included within Helodermatidae because the jaws are suggestive
of a varanoid having a stoutly constructed skull and rounded snout, and it has a dental

195

Table 5. Character distribution within Helodermatidae and outgroups, from Table 4(1= derived, 0 =
ancestral, 9 = missing data); a phylogeny is shown as Fig. 10.

Character

Varanidae

0/1

Necrosauridae

0/1

Paraderma

Eurheloderma

Lowesaurus

H. texanum

H. suspectum

H. horridum

morphology that can be interpreted as "early helodermatid." This implies that helo-
dermatids diverged rather early from their varanoid ancestry in a split that primarily
favored different predatory modes. In varanines and lanthanotines the skull is consid-
erably narrower than its length, whereas that of helodermatids is nearly as wide as long.
McDowell and Bogert (1954) considered the skull of Heloderma to be an early stage
in a progressive modification of the "platynotan type." As viewed by us, it appears
that the morphology of the helodermatid skull probably evolved in response to these
squamates using massive, powerful jaws to kill and partially process large, defenseless
prey. Varanids on the other hand differentiated as active, searching predators on rel-
atively smaller prey. In this respect, Paraderma bogerti appears to be derived in the
direction of helodermatids.

By contrast, we can remove Gobiderma pulchrum from consideration as a helo-
dermatid. This fossil was described by Borsuk-Bialynicka (1984) from a nearly complete
skull and mandible (holotype ZPAL MgR-III/64) and two other partial skulls that were
taken from ?middle Campanian Red beds of Khermeen Tsav, Mongolia. Gobiderma
was featured as a "" Heloderma-\ike lizard" although its precise relationship was left
unresolved, being designated as a medium-sized "platynotan" of about 5 cm skull
length. It differs critically from "necrosaurids" and other varanoids in possessing a flat
parietal, one in which the adductors attach to the ventral surface; in this respect it is
like Heloderma. The osteoderms are small, plate-like and have a pitted surface, but
they are fused only to the posterior aspect of the skull. In several other features, however,
Gobiderma is generalized compared to Heloderma: the maxillary segment is tapered,
there is no approach or contact of the pre- and postfrontals above the orbit, and it
retains the upper temporal arch. Actually, the overall appearance of the skull recalls
that of Xenosaurus. In appreciating the peculiarities of this taxon, Borsuk-Bialynicka
(1984) offered that it might have been "an Asiatic substitute of the American group
[rather] than a group ancestral to the Helodermatidae." The external nares are not at
all retracted in the manner of varanoids, nor do the subolfactory processes of the frontal
exhibit the characteristic downgrowth and ventromedial contact. The tooth row is nearly
entirely antorbital, although the maxilla appears to participate in the suborbital fenestra,
to judge from her figures, plates and descriptions (Borsuk-Bialynicka 1984). We also
leave this taxon unassigned pending further study of "Platynota" and Necrosauridae.

III. An Evolutionary Scenario for Helodermatidae

The goal of this section is to offer a natural history perspective of helodermatids
that is consistent with their fossil history, phylogeny, ecology, and behavior. We make
no attempt to invoke a particular process (e.g., natural selection) for the origin of
adaptive patterns {cf. Greene 1 986). Our remarks are based on the phylogenetic analysis
presented above, information in the literature, examination of stomach contents, casual
observations on captive individuals, and unpublished observations provided by others.
We are interested in identifying concordant changes in natural history and morphology
through evolutionary time. Therefore, the discussion proceeds from higher taxa to the

196

species of helodermatids themselves. Because the relationships of varanoids to other
anguimorphs are controversial, we rely on general attributes of anguids and xenosaurids
to postulate the polarities of ecological and behavioral characteristics.

Natural History of Anguids and Xenosaurids

Relative to other living squamates (Pough 1980), anguids range in size from rather
small (e.g., SVL of 55-70 mm in Elgariaparva Knight and Scudday 1 985) to moderately
large (more than 500 mm total length in Ophisaurus apodus and some Diploglossus).
A few species are fossorial (e.g., Anniella), but most are terrestrial {E. coeruled) or
arboreal (Abronia). A semiprehensile tail is probably primitive for anguids (Greene
1986). Most anguids are probably insectivorous, but some are known occasionally to
eat vertebrates, for example E. multicarinata (Cunningham 1956). The anguid tongue
is modified for chemoreception (Schwenk 1984) and likely plays a prominent role in
finding and/or recognizing food. Greene (in Burghardt 1978) demonstrated innate
chemically mediated recognition of prey by naive Gerrhonotus liocephalus. For reviews
of lizard feeding biology see Greene (1982), Pough (1973), Regal (1978), and Stamps
(1977).

The New World xenosaurids inhabit crevices in rocks and trees (Alvarez del Toro
1982, King and Thompson 1968). In captivity they are secretive and active noctumally
{personal observation). Presch (1981) reported an iguanid lizard (Sceloporus) in the
stomach of a Xenosaurus grandis from Mexico, although several dozen other stomachs
of this species from the same locality yielded only a variety of insects (Greene and
McDiarmid, unpubl. data). The only Old World xenosaurid, Shinisaurus crocodilurus,
lives along streams where it feeds on tadpoles, fish and aquatic invertebrates. It bites
powerfully if restrained (J. B. Murphy, personal communication).

A number of antipredator responses are so widespread among anguids and xeno-
saurids (as well as varanoids; see below) that they are surely ancestral for Anguimorpha.
These squamates characteristically are cryptic, being of drab dorsal color that is marked
by some type of disruptive pattern (e.g., cross bars). When threatened they attempt to
flee towards the nearest retreat; if seized, they struggle violently, defecate copiously,
hiss, gape and bite fiercely. The tail is autotomic in anguids (aside from Ophisaurus
apodus) and Shinisaurus, but not in Xenosaurus {see Greene, MSa, for a review of
defense behavior in lizards).

Natural History of Varanus and Lanthanotus

Varanids are small to very large lizards ( Varanus brevicauda, total length 24 cm
vs. V. komodoensis, total length 3 m). The extinct Megalania prisca from the Quaternary
of Australia is thought to have achieved a total length of 6 m (Hecht 1975). Judging
from stomach contents of living species, an ancestral varanid was moderately large,
terrestrial or semiarboreal, and fed on a variety of small invertebrates and vertebrates.
Gigantism and consumption of relatively large vertebrates (mammals in the case of
varanids) are probably derived attributes within Varanidae, as is extremely small size
(Losos and Greene MS). Varanids have tongues that are highly modified for chemo-
reception (Schwenk 1984) and apparently are used to locate hidden prey during their
wide search activities (Auflenberg 1981, Pianka 1982, Losos and Greene MS). Varanids
are cryptic, wary, and fast moving lizards that exhibit stereotyped threat postures when
cornered. If approached or handled they lash with the tail, gape, hiss, struggle, defecate,
and bite (Greene MSa).

Almost nothing is known about the natural history of Lanthanotus borneensis.
Apparently it is a specialized burrower, but swims well and has a partially prehensile
tail (Proud 1978, Sprackland 1972). A specimen in the Museum of Comparative Zo-
ology had earthworm setae in its gut (Greene, unpublished data). Captives flatten their
body when threatened, and when handled struggle, defecate, hiss, and sometimes bite
(Greene MS<2).

197

Natural History of Living Helodermatids

Behaviorally and morphologically helodermatids are in some respects generalized
varanoids. Like other anguimorphs and unlike varanids, the two living helodermatids
prefer relatively cool temperatures (John-Alder et al. 1983). They arc not as agile as
varanids, yet not so clumsy as often portrayed. The popular vision of a rotund, sluggish
beast stems from the appearance of captive specimens (usually Helodenna suspect urn)
that have been housed in small cages and fed a diet of infertile chicken eggs. It is true
that Gila monsters (//. suspectum), being shorter and stouter, resemble this portrait
more so than do Beaded lizards (//. horhdum). Our observations on both species are
consistent with those of John-Alder et al. (1983), that these animals cannot capture an
adult, uninjured rodent except in a very confined space. Nevertheless, helodermatids
typically take a broader range of prey than is implied by the usual captive diet. Freshly
collected individuals, especially H. horhdum, are rarely, if ever, obese.

Bogert and Martin del Campo (1956) summarized records for natural prey of
Helodenna horhdum, based on stomach and/or intestinal contents of 20 animals. These
consisted of five mammals, including a rabbit (Sylvilagus sp.) and a cotton rat {Sig-
modon sp.) found in one stomach; two birds including a nestling squirrel cuckoo {Piaya
cayana); ten sets of bird eggs, numbering up to 13 per stomach and possibly including
those of unidentified doves and Douglas quail (Lophortyx douglasi); two sets of reptile
eggs, numbering up to 35 per stomach, including those of an unidentified lizard and
of a turtle (Kinosternon); and six sets of insect parts that the authors discounted as
likely to have been ingested accidentally. Bogert and Martin del Campo (1956) also
noted that some H. horridum they examined were juveniles, suggesting, perhaps, that
there are no major ontogenetic changes in diet. In the KU and Los Angeles County
Museum collections we examined the stomachs of five beaded lizards that contained
prey, the food items consisting of two sets of reptile eggs, a set of bird eggs, and two
sets of large coleopteran larvae (includes items mentioned by McDiarmid 1963).

Bogert and Martin del Campo (1956) also summarized published observations on
the natural prey of 1 1 Heloderma suspectum. They found 14 mammals (ground squirrels
and rabbits) in nine animals, reptile eggs in four, bird eggs in one, and a lizard in one.
Using radiotelemetry, Jones (1983) studied the foraging biology of nine H. suspectum
in Arizona. The individuals he followed hunted over wide areas, and consumed 24 sets
of quail eggs, two sets of dove eggs, and three mammals, or groups of mammals.

The climbing habits of helodermatids have been known for some time (Bogert and
Martin del Campo 1956), but only recently has there been substantial evidence to
document this activity. Cross and Rand (1979) observed two Heloderma suspectum
for more than 1 5 hours, and witnessed each animal ascend and descend the rough bark
of a desert willow; in one case the tail was used in locomotion. Alvarez del Toro ( 1 982)
described climbing behavior and semiprehensile use of the tail by captive H. horridum
collected from Chiapas, Mexico. J. W. Hardy {personal communication) found adult
H. horridum raiding the nests of Beechey's jay {Cissilopha beecheyi), high in trees in
Nayarit, Mexico.

Greene raised a juvenile Heloderma horridum (initial weight ca. 55 grams) from
Colima, and observed frequent arboreal activity. The lizard was kept in a 20 gal
aquarium containing a hollow limb that extended from one bottom corner diagonally
up to the opposite comer. The beaded lizard spent most of its time concealed in a
cavity at the upper extent of the limb, emerging only to feed and drink. It climbed
without difficulty, and curled its tail about branches when descending. Ambulatory
juvenile mice were chased and subdued without obvious difficulty, albeit somewhat
clumsily.

Helodermatids spend large amounts of time in underground burrows (Bogert and
Martin del Campo 1956, Cross and Rand 1979, Jones 1983); they are potentially more
vulnerable to predators when hunting. If threatened, individuals of both species
usually flee towards shelter in a bush or burrow. An adult Heloderma horridum in
Oaxaca, Mexico, rapidly ascended a pine tree when it was approached (V. Fitch, personal

198

cummunication). If a helodermatid is aggravated or handled, it hisses, gapes, struggles,
and bites (Bogert and Martin del Campo 1956).

Adaptive Trends among Varanoidea

Anguimorphs probably began as terrestrial and semiarboreal squamates in tropical
or subtropical mid-latitudes of Laurasia during the late Mesozoic {see above and Estes
1983Z)). They fed predominantly on insects that were encountered by searching actively,
using both visual and chemical cues. Larger species preyed on large insects and the
occasional small vertebrate. Primitively, varanoids were larger than other anguimorphs,
and more widely foraging. Likely, they relied more on chemoreception for locating prey
and took vertebrates more often, but these were probably small relative to their body
size. The defensive behavior of helodermatids and Lanthanotus is similar to that of
anguids and xenosaurids, and except for venom use in helodermatids, is likely to
represent an ancestral anguimorph response.

The adaptive zone of monitor lizards ( Varanus) is specialized beyond the primitive
varanoid condition. Physiologically these animals are capable of unusual locomotor
stamina (Bennett (1978), they prefer high temperatures, and travel extensively while
hunting (Auffenberg 1981, Losos and Greene MS, Pianka 1982). Predation on large
mammalian prey (e.g., by Varanus komodoensis, Auffenberg 1981) is a derived con-
dition within Varanidae, and involves ingestion of pieces rather than large, intact items.
The living members of the subfamily exhibit considerable ecological diversity (Auf-
fenberg 1981, Greene 1986) although most species are reasonably similar in their feeding
biology (Losos and Greene MS).

What little is known about Lanthanotus borneensis suggests that this bizarre crea-
ture is a burrower. For instance certain cranial features shared with other anguimorphs
are associated with fossoriality (Borsuk-Bialynicka 1984, Gauthier 1982, Rieppel 1983).
If some or all of the synapomorphies of Lanthanotinae are functionally related to
fossoriality, they represent an adaptive shift that is unique in the evolution of varanoids.

Available information shows that living helodermatids take a potential range of
prey types, from vertebrate eggs to large insect larvae, and that mammals are of major
importance. Although complete comparative data are lacking, it appears that both
species may take relatively larger, intact prey than any other living squamate aside
from some snakes (Stahnke 1952, Greene 1982, 1983). Hunting is characterized by
wide searches and investigating specific sites in terrestrial and arboreal microhabitats
{see above and Bogert and Martin del Campo 1956, Jones 1983).

There is evidence that tissue-destructive venoms of viperid snakes facilitate diges-
tion of large, bulky prey, especially under conditions like mild temperature where such
items might putrify prior to digestion by intestinal secretions (Greene 1983, MSb,
Pough and Groves 1983, Thomas and Pough 1979). Venom injection is a derived
characteristic of Helodermatidae, developed most fully in Heloderma, and we suggest
that it is an adaptation for preying on large, bulky vertebrates under temperature regimes
that are periodically cool. Information on the venom of helodermatids is incomplete,
sometimes contradictory (Russell and Bogert 1981), and controlled studies using natural
prey would be of great interest.

Evolutionary trends in diet parallel morphologies of the tongue and throat region
of Varanoidea (McDowell 1972, Schwenk 1984). Anguimorphas primitively have a
tongue that is functionally and structurally divided, such that the hind-tongue functions
in food transport and the foretongue serves as a chemoreceptor (via taste buds, Schwenk
1984) and a vehicle for carrying odor molecules to the vomeronasal organ. McDowell
(1972) noted that helodermatids show features plausibly related to increased gape (e.g.,
reduction of the posterior limbs of the tongue), and suggested that the tongue of Lan-
thanotus is used to swallow "less bulky food" than that of helodermatids. The tongue
of Varanus is highly derived and protrusible; it serves a chemoreceptive role and no
longer functions in frictional food transport. Swallowing in monitors results entirely

199

from throat compression, lateral movements of the neck, and esophageal peristalsis
(Smith 1986).

Bogert and Martin del Campo (1956) commented that in helodermatids venom
was certainly not necessary to immobilize prey and, because it is clearly associated
with the bite, they hypothesized that venom and teeth are primarily a means for
thwarting predation. That explanation is consistent with other research demonstrating
that wide foraging habits and preoccupied feeding techniques (e.g., digging for prey)
often correspond with increased risk of predation (Huey and Pianka 1981, Vitt 1983),
and the evolution of defensive specializations (Greene MSa). We favor the hypothesis
that venom delivery in helodermatids evolved in a feeding context and was later co-
opted for defense under some circumstances {see below). However, a decisive choice
between these alternatives is as yet not possible.

The two living species of Heloderma differ mainly in three characteristics. Helo-
derma horridum has a higher mean number of subdigital scales and a longer tail. An
increased number of subdigital lamellae is associated with arboreality in certain other
lizards {Anolis, Collette 1961; Aristelliger, Hecht 1952). However, high lamellar counts
and arboreality are also correlated with increased body size in those taxa and in H.
horridum, thus obscuring functional interpretations and character state polarities. To
judge from other anguimorphs, including varanids (Mertens 1942, Greene 1986), the
high subdigital scale counts and the comparatively long, semiprehensile tail of H.
horridum are primitive for varanids, and probably anguimorphs. They need not be
explained as specializations arising in Heloderma. The short tail and toes of H. sus-
pectum are derived attributes, perhaps associated with fat storage and digging for prey,
respectively.

Heloderma horridum is a predominantly black animal with irregular yellow mark-
ings on the body and yellow rings on the tail [adult H. h. alvarezi are entirely black,
whereas juveniles are patterned like adults of other subspecies (Alvarez del Toro 1 982)];
H. suspectum is a black and pink animal, the latter color often predominating. A
mottled, cryptic dorsal pattern and a ringed tail, as in H. horridum, are probably
ancestral for anguimorphs (Gauthier 1 982, Greene 1 986). The more brightly contrasting
pattern of H. suspectum is clearly derived; it is probably both cryptic and aposematic
(Bogert and Martin del Campo 1956), and functionally coupled with the venomous
bite.

The moderate diversity and fairly widespread occurence of helodermatids in North
America and Europe during the late Cretaceous and early and middle Tertiary suggest
that they inhabited a once broader spectrum of environments than would be inferred
from their present distribution. Our analysis indicates that primitively these venomous
varanoids inhabited non-desert environments, and that among the two living species
the habits and habitat of Heloderma horridum are more representative of an ancestral
helodermatid. The few derived attributes of//, suspectum are associated with the xeric,
open conditions characteristic of the latest Cenozoic in southwestern North America.

Although they resemble ancestral varanoids in several respects, helodermatids
exhibit morphological and natural history traits that are derived and unique among all
other living squamates. Our appraisal of their known history and biology suggests that
the extant species are appropriately regarded as living fossils.

Acknowledgments

Throughout the protracted development of this study we have approached innu-
merable colleagues for loans of specimens, access to their notes and ideas, and comments
on the manuscript. Each responded generously and it is our regrettable oversight if we
fail to mention some of them by name.

For loaning fossil material we are grateful to D. Baird, H. Hutchinson, G. Gaffney,
P. Gingerich, W. Langston, L. D. Martin, and M. Voorhies, and for comparative

200

skeletons B. Brattstrom, R. Drewes, W. E. Duellman, R. Etheridge, M. Greenwald, R.
Heyer, A. Kluge, A. Leviton, C. Myers, W. Presch, G. Zug and R. Zweifel.

Opportunities to study live anguids, helodermatids, xenosaurids, a Lanthanotus,
and varanines were provided by J. A. Campbell, K. Klemmer, R. W. McDiarmid, J.
B. Murphy, W. E. Rainey, L. J. Vitt, and T. B. Johnson and C. Schwalbe of the Non-
game Branch of the Arizona Game and Fish Department.

For providing access to computer facilities and consultation we thank A. Kluge
and W. Presch.

We especially appreciate the kindness of Richard Estes for his ideas, discussion,
and comments on the manuscript, various drafts of which were also read by D. R.
Frost, K. de Queiroz, D. Good, M. Lang, J. B. Losos, W. Presch, and R. W. McDiarmid.

Figures 3 and 10 were drawn by Lynn A. Barretti.

Greene's studies were supported by the National Science Foundation (BNS 76-
19903, BSR 83-00346) and the Museum of Vertebrate Zoology (Annie M. Alexander
Fund). Gauthier received support from the Theodore Roosevelt Memorial Fund
(AMNH), the California Academy of Sciences, and NSF grant BSR-8304581. Pregill's
work was aided in part by the Smithsonian Institution during a Postdoctoral Fellowship
at the United States National Museum, and from NSF grant DEB-8207347.

Literature Cited

Alvrez del Toro, W. 1 982. Los Reptiles de Chia-
pas, 3rd Edition. Publicationes Instituto His-
toria Natural, Tuxtla Gutierrez, Mexico.

Arnold, E. N. 1984. Variation in the cloacal and
hemipenial muscles of lizards and its bearing
on their relationships. Pp. 47-85 in M. W. J.
Ferguson (ed.). The Structure, Development
and Evolution of Reptiles. Symposium of the
Zoological Society of London No. 52. Academ-
ic Press, New York.

Auffenberg, W. 1981. Behavioral Ecology of the
Komodo Dragon. University of Florida Press,
Gainesville.

Bartels, W. S. 1983. A transitional Paleocene-
Eocene reptile fauna from the Bighorn Basin,
Wyoming. Herpetologica 39:359-374.

Bennett, A. F. 1978. Activity metabolism of the
lower vertebrates. Annual Review of Physiol-
ogy 40:444-469.

Bogert, C. M., and R. Martin del Campo. 1956.
The Giia Monster and its allies. The relation-
ships, habits, and behavior of the lizards of the
family Helodermatidae. Bulletin American
Museum of Natural History 109:1-238.

Borsuk-Bialynicka, M. 1984. Anguimorphs and
related lizards from the Late Cretaceous of the
Gobi Desert, Mongolia. Results of the Polish-
Mongolian Paleontological Expeditions Part 10.
Paleontologica Polonica 46-1984:5-105.

Branch, W. R. 1982. Hemipeneal morphology of
platynotan lizards. Journal of Herpetology 16:
16-38.

Burghardt, G. M. 1978. Behavioral ontogeny in
reptiles: whence, whither, and why? Pp. 149-
174 in G. M. Burghardt and M. Bekoff (eds.).
The Development of Behavior. Garland STPM
Press, New York.

Camp, C. L. 1923. Classification of the lizards.
Bulletin American Museum Natural History
48:289-481.

Collette, B. B. 1961. Correlations between ecology

and morphology in anoline lizards from Ha-
vana, Cuba and southern Florida. Bulletin Mu-
seum Comparative Zoology 125:137-162.

Cross, J. K., and M. S. Rand. 1979. Climbing
activity in wild-ranging Gila monsters, Helo-
derma suspectum (Helodermatidae). South-
western Naturalist 24:703-705.

Cunningham, J. D. 1956. Food habits of the San
Diego alligator lizard. Herpetologica 12:225-
230.

DeBonis, L., Crochet, J.-Y., and J.-C. Rage. 1 973.
Nouvelles faunes de Vertebres oligocenes des
phosphorites du Quercy. Bulletin Museum Na-
tional Du Histoire Naturelle, Paris 28:105-1 13.

Estes, R. 1963. Early Miocene salamanders and
lizards from Florida. Quarterly Journal Florida
Academy 26:234-256.

. 1964. Fossil vertebrates from the late Cre-
taceous Lance Formation, eastern Wyoming.
University California Publications in Geolog-
ical Sciences 49:1-186.

. 1983a. Sauria terrestria, Amphisbaenia.

Handbuch der Palaoherpetologie, Part lOA.
Gustav Fischer Verlag, Stuttgart.

. 19836. The fossil record and early dis-
tribution of lizards. Pp. 365-398 in A. G.
Rhodin and K. Miyata (eds.). Advances in Her-
petology and Evolutionary Biology: Essays in
Honor of Ernest E. Williams. Museum of Com-
parative Zoology, Harvard University, Cam-
bridge.
-, K. de Queiroz, and J. Gauthier. Phyloge-

netic relationships within squamate reptiles.
Manuscript.

Gabe, M., and H. Saint Girons. 1976. Contri-
bution a la morphologic comparee des fosses
nasales et de leurs annexes chez les lepidosau-
riens. Memoires Museum National du Histoire
Naturelle, Paris A98: 1-106.

Gauthier, J. A. 1982. Fossil xenosaurid and an-
guid lizards from the early Eocene Wasatch

201

Formation, southeast Wyoming, and a revi-
sion of the Anguioidea. Contributions to Ge-
ology, University of Wyoming 21:7-54.

Gilmore, C. W. 1928. The fossil lizards of North
America. Memoirs National Academy of Sci-
ences 22:1-201.

Greene, H. W. 1982. Dietary and phenotypic di-
versity in lizards: why are some organisms spe-
cialized? Pp. 107-128 in D. Mossakowski and
G. Roth (eds.). Environmental Adaptation and
Evolution: A Theoretical and Empirical Ap-
proach. Gustav Fischer Verlag, Stuttgart.

. 1983. Dietary correlates of the origin and

radiation of snakes. American Zoologist 23:
431-441.

. 1 986. Diet and arboreality in the emerald

monitor, Varanus prasinus, with comments on
the study of adaptation. Fieldiana, Zoology,
New Series (31): 1-1 2.

. MSa. Antipredator mechanisms. In C.

Gans and R. B. Huey (eds.). Biology of the
Reptilia. John Wiley & Sons, New York. In
press.

. MS/). A diet-based model of snake evo-

281-286 in L. Arvy (ed.). Rechcrches Biolo-
giques Contaemporaincs. Ouvragc dcdiee a la
Memoire du Dr. Manfred Gabe. Vagncr.

1978. Oral glands of the Reptilia. Pp. 43-

lution, [manuscript].

Gorelov, Yu. K. 1973. Izuchenie pitaniya serogo
varana beskrovnym sposobom [A study of the
feeding of Varnus griseus by a bloodless meth-
od]. In I. S. Darevsky (ed.). Voprosy herpe-
tologii. Nauka, Leningrad (in Russian).

Hecht, M. K. 1952. Naural selection in the lizard
genus Aristelliger. Evolution 6:1 12-124.

. 1975. The morphology and relationships

of the largest known terrestrial lizard, Mega-
lania prisca Owen from the Pleistocene of Aus-
tralia. Proceedings Royal Society of Victoria
87:239-250.

Huey, R. B., and E. R. Pianka. 1981. Ecological
consequences of foraging mode. Ecology 62:
991-999.

Hoffstetter, R. 1957. Un saurien helodermatide
(Eurheloderma gallicum nov. gen. et sp.) dans
la faune fossile des Phosphorites du Quercy.
Bulletin Geological Society France 7:775-786.

, and J. P. Gasc. 1969. Vertebrae and ribs

of modem reptiles. Pp. 201-310 in C. Gans
(ed.). Biology of the Reptilia 1 : (Morphology
A), Academic Press, New York.

John-Alder, H., C. H. Lowe, and A. F. Bennett.
1983. Thermal dependence of locomotor en-
ergetics and aerobic capacity of the Gila mon-
ster {Heloderma suspectum). Journal Compar-
ative Physiology 1 5 1 : 1 1 9-1 26.

Jones, K. B. 1983. Movement patterns and for-
aging ecology of Gila monsters (Helodenna
suspectum Cope) in northwestern Arizona.
Herpetologica 39:247-253.

King, F. W., and F. G.Thompson. 1968. A review
of the American lizards of the genus Xenosau-
rus Peters. Bulletin Florida State Museum 2:
93-103.

Knight, R. A., and J. F. Scudday. 1985. A new
Gerrhonotus (Lacertilia: Anguidea) from the
Sierra Madre Oriental, Nuevo Leon, Mexico.
Southwestern Naturalist 30:89-94.

Kochva, E. 1974. Glandes specialisees de la ma-
choire inferieure chez les Anguimorphcs. Pp.

161 in C. Gans and K. A. Gans (eds.). Biology
of the Reptilia, Vol. 8, Physiology B. Academic
Press, New York.

Lecuru, S. 1968a. Etude des variations morpho-
logiques du sternum, des clavicules et de I'in-
terclavicule des lacertiliens. Annales des Sci-
ences Naturelles, Zoologic. Paris 10:51 1-544.

. 1968/). Remarqucs sur le scapulo-cora-

coide des lacertiliens. Annales des Sciences Na-
turelles, Zoologie, Paris 10:475-510.

Losos, J. B., and H. W. Greene. MS. The feeding
biology of varanid lizards, [manuscript]

Maddison, W. P., M. J. Donoghue, and D. R. Mad-
dison. 1984. Outgroup analysis and parsi-
mony. Systematic Zoology 33:83-103.

McDiarmid, R. W. 1963. A collection of reptiles
and amphibians from the highland faunal as-
semblage of western Mexico. Los Angeles
County Museum Contribution Science (68): 1-
15.

McDowell, S. B. 1972. The evolution of the tongue
of snakes, and its bearing on snake origins. Pp.
191-272 inT. Dobzhansky, M. Hechi, and W.
Steere (eds.). Evolutionary Biology, Vol. 6. Ap-
pleton-Century-Crofts, New York.

, and C. M. Bogert. 1954. The systematic

position of Lanthanotus and the affinities of
anguinomorphan lizards. Bulletin American
Museum Natural History 105:1-141.

Mertens, R. 1942. Die Familie der Warane (Va-
ranidae). Dritter Teil: Taxonomie. Abhand-
lungen der Senckenbergischen Naturforschen-
den Gesellschaft 466:235-391.

Meszoely, C. 1970. North American fossil anguid
lizards. Bulletin Museum Comparative Zool-
ogy, Harvard 139:87-149.

Miller, M. R. 1966. The cochlear ducts of Lan-
thanotus and Anelytropsis with remarks on the
familial relationship between Anelytropsis and
Dibamus. Occasional Papers California Acad-
emy of Sciences 60:1-15'.

Nopsca, F. 1908. Zur Kenntniss der fossilen Ei-
dechsen. Beitrage zur Paleontologic und Geo-
logic Osterreich-Ungams und des Orientcs 2 1 :
33-62.

Pianka, E. R. 1982. Observations on the ecology
of Varanus in the Great Victoria Desert. West-
em Australian Naturalist 15:1-8.

Rough, F. H. 1973. Lizard energetics and diet.
Ecology 54:837-844.

. 1980. The advantages of ectothermy for

tetrapods. American Naturalist 1 15:95-1 12.
-, and J. D. Groves. 1983. Specialization of

the body form and food habits of snakes.

American Zoologist 23:443-454.
Presch, W. 1981. Life history notes: Xenosaurus

grandis, food. Herpetological Review 12:81.
Proud, K. R. S. 1978. Some notes on a captive

earless monitor lizard, Lanthanotus horneen-

sis. Sarawak Museum Journal Id.li-lAl.
Regal, P. J. 1978. Behavioral differences between

reptiles and mammals: an analysis of activity

and mental capabilities. Pp. 183-202 //; N.

202

Greenberg and P. D. MacLean (eds.)- Behavior
and Neurobiology of Lizards. Department
Health, Education and Welfare, Washington,
DC.

Renous-Lecuru, S. 1973. Morphologic comparee
du carpe chez les Lepidosaurians actuels
(Rhynchocephales, Lacertiliens, Amphisbeni-
ens). Gegenbaurs Morphologie Jahrbuch 1 19:
727-766.

Rieppel, O. 1978. Tooth replacement in angui-
morph lizards. Zoomorphologie 91:77-90.

. 1980a. The Phylogeny of Anguinomorph

Lizards. Birkhauser Verlag, Basel.

. 19806. The postcranial skeleton of La«-

thanotus borneensis (Reptilia, Lacertilia). Am-
phibia-Reptilia 1:95-112.
-. 1983. A comparison of the skull of Lan-

the lepidosaur tongue. Ph.D. Dissertation,
University of California, Berkeley.
-. A phylogenetic analysis of the lepidosaur

thanotus borneensis (Reptilia: Varanoidea) with
the skull of primitive snakes. Zeitschrift fur
Zoologische Systematik und Evolustionsfor-
schung 21:142-153.

Robinson, P. L. 1967. The evolution of the Lac-
ertilia. Colloques Intemationaux du Centre
National de la Recherche Scientifique 104:243-
279.

Romer, A. S. 1956. Osteology of the Reptiles.
University Chicago Press, Chicago.

Russell, F. E., and C. M. Bogert. 1981. Gila mon-
ster: its biology, venom and bite— a review.
Toxicon 19(3):341-359.

Saint Girons, H. 1976. Comparative histology of
the endocrine glands, nasal cavities and diges-
tive tract in anguinomorph lizards. Pp. 205-
216 in A. d'A. Bellairs and C. B. Cox (eds.).
Morphology and Biology of Reptiles. Linnean
Society Symposium Ser. 3.

Schwenk, K. 1984. Evolutionary morphology of

tongue. Manuscript.

Sprackland, G. B. 1972. A summary of obser-
vations of the earless monitor, Lanthanotus
borneensis. Sarawak Museum Journal 20:323-
327.

Stahnke, H. L. 1952. A note of the food of the
Gila monster, Heloderma suspectum Cope.
Herpetologica 8:64-65.

Stamps, J. A. 1977. Social behavior and spacing
patterns in lizards. Pp. 265-334 in G. Gans
and D. W. Tinkle (eds.). Biology of the Rep-
tilia, Vol. 7 Ecology and Behavior A. Academic
Press, New York.

Stevens, M. 1977. Further study of Castolon local
fauna (Early Miocene), Big Bend National Park,
Texas. Pearce-Sellards Series. Texas Memorial
Museum 28:1-69.

Sullivan, R. M. 1979. Revision of the Paleogene
genus Glyptosaurus (Reptilia, Anguidae). Bul-
letin American Museum Natural History 163:
1-72.

Swofford, J. 1984. PAUP. Phylogenetic Analysis
Using Parsimony. A computer program man-
ual. Illinois Natural History Survey.

Thomas, R., and F. H. Rough. 1979. The effect
of rattlesnake venom on digestion of prey. Tox-
icon 17:221-228.

Vitt, L. J. 1983. Tail loss in lizards: the signifi-
cance of foraging and predator escape modes.
Herpetologica 39:151-162.

Yatkola, D. A. 1976. Fossil Heloderma (Reptilia,
Helodermatidae). Occasional Papers Museum
Natural History University Kansas 51:1-14.

p.yiQ7 TRANSACTIONS

LIPRARY OF THE SAN DIEGO

SOCIETY OF
MAR 0 71388 NATURAL HISTORY

HARVARD
UNIVERSITY

Volume 21 Number 12 pp. 203-220 24 February 1988

Camaenid land snails (Gastropoda: Pulmonata) from the Eocene
of southern California and their bearing on the history
of the American Camaenidae

Barry Roth

Museum of Paleontology, University of California, Berkeley, California 94720 USA

Abstract. Zachrysia fraterna. new species, is described from the upper middle Eocene Friars
Formation. San Diego County, California. All other records of Zachrysia are from Cuba, as Quaternary
fossils or living. The presence of Z. fraterna implies forested land and a tropical climate with ample
summer rainfall. Two Eocene species, described as Helminthoglypta obtusa from the Tejon Formation
and HP. stocki from the Sespe Formation, are not Helminthoglyptidae but Camaenidae. Discoveries
of extant Neotropical camaenid genera as Paleogene fossils in North America establish a middle Eocene
minimum age for these genera and constrain hypotheses about the sources and timing of origin of the
Caribbean biota. Recent and fossil distributions form a north-south generalized track from North
America to the Caribbean region. As a family the Camaenidae show the "interrupted Tethyan" type
of distribution. Links between the American and Australasian groups of Camaenidae are more likely
to be found in Europe and western Asia than in the Pacific realm.

Introduction

The Camaenidae are a large family of pulmonate land snails with a discontinuous
distribution. One branch of the family inhabits the West Indies, Central America as
far north as Costa Rica, and Andean South America as far south as Peru. The other
branch extends from eastern India and southern China through the Solomon Islands,
south into the northern three-quarters of Australia, with a few taxa extending as far
north as southern Japan (Solem 1979). Several recent studies have documented the
presence of camaenid land snails in lower Tertiary strata of western and mid-continent
North America (Solem 1978, 1979; Bishop 1979; Roth 1984).

In 1985 members of the Department of Paleontology of the San Diego Natural
History Museum collected fossil invertebrates from a marine stringer in the predom-
inantly nonmarine Friars Formation, of Eocene age, in southwestern San Diego County,
California. Three taxa of nonmarine gastropods were present, including a well-preserved
specimen that is conchologically indistinguishable from the modern camaenid genus
Zachrysia Pilsbry, 1 894. Zachrysia is otherwise known only from Cuba, as living species
or Quarternary fossils. In addition, the type material of two southern Californian Eocene
species originally assigned to Helminthoglypta Ancey, 1887, has been reviewed. With
different degrees of certainty, those species are also assignable to Camaenidae.

The sources of the fossils discussed in this paper are shown in Figure 1 . Figure 2
presents the correlation of rock units yielding camaenid fossils in western North Amer-
ica; age and geologic setting are discussed further below.

There is now enough material available to show that as early as middle to late
Eocene time the American Camaenidae were differentiated into several genera of mod-
ern aspect and arrayed across at least the southern part of North America, perhaps
roughly paralleling the remnants of the Tethyan seaway. The biogeographic history of
the group since that time has consisted largely of a southward, and to some extent east-
west, restriction to the present Caribbean region along with the development of a
distinctive pattern of insular allopatry.

204

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X ^^Kern County • '-^

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Figure 1. Map of southern California showing location of sources of material discussed herein. 1, Type
Tejon Formation, Live Oak Creek; 2, Sespe Formation, Tapo Canyon; 3, Mission Valley and Friars for-
mations, San Diego area.

Fortunately for paleontologists, the shells of American Camaenidae are usually
diagnostic at the generic, and sometimes the subgeneric, level. The definitive anatomical
work on the group (Wurtz 1955) did little to alter the earlier concepts of genera founded
on conchological characters. With a few modifications after Solem (1966), Wurtz's
anatomical study formed the basis for the phylogenetic analysis proposed by Bishop
(1979) and accepted here without changes.

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N. Amer. Land
Mammal 'Age'

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Radioisotopic
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Western

San Diego

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San Emigdio
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Kern County

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Sheridan
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Figure 2. Correlation of Eocene and Oligocene formations in California, Texas, and Nebraska that have
yielded camaenid land snails. Solid triangles indicate approximate stratigraphic positions of camaenid fossils.

205

The following abbreviations are used: CAS, Department of Geology, California
Academy of Sciences; CIT, California Institute of Technology (collections now at
Natural History Museum of Los Angeles County); LACMIP, Section of Invertebrate
Paleontology, Natural History Museum of Los Angeles County; SDSNH, Department
of Paleontology, San Diego Natural History Museum; UCMP, Museum of Paleontol-
ogy, University of California, Berkeley.

Systematic Paleontology

Class Gastropoda Cuvier, 1797

Subclass Pulmonata Cuvier, 1817

Order Sigmurethra Pilsbry, 1900

Superfamily Camaenacea Pilsbry, 1895

Family Camaenidae Pilsbry, 1895

Zachrysia Pilsbry, 1894

Zachrysia Pilsbry 1894:97. Pilsbry 1929:581-606. Wurtz 1955:135-137. Zilch 1960:598.

Tvpe species. —Helix auricoma Ferussac, 1 82 1 , by subsequent designation (Pilsbry
1929:586). Recent, Cuba.

Generic diagnosis. —S\\q\\ white with brownish-yellow periostracum, depressed glo-
bose, with small spire and few, rapidly expanding whorls; the first 1.5 embryonic,
polished, the first half whorl with extremely fine microscopic spiral lines, the next with
fine axial riblets, the rest with oblique growth striae and extremely fine, dense granules,
mostly arranged in irregular spiral lines. Last whorl rounded, somewhat flattened below,
not umbilicate. Aperture very oblique, without teeth; peristome expanded; basal margin
elongated, turned up and appressed (Zilch 1960, translation).

In some species all embryonic sculpture may be nearly obsolete (Pilsbry 1929).
The genital system includes distinctive characters which are of course inaccessible on
fossil specimens.

The several subgenera of Zachrysia are founded on characteristics of the genital
system (Pilsbry 1929, Bonilla 1936, Wurtz 1955). Minutely decussate shell sculpture
occurs only in the subgenus Megachrysia Pilsbry, 1929, but otherwise there are no
conchological characters that discriminate the subgenera. The following fossil species
is therefore assignable to the genus in the broad sense only.

The modem range of Zachrysia is limited to Cuba, with several human introduc-
tions elsewhere in the Caribbean region. The only other fossil record is "along the shore
east of Punta San Juan de los Perros," Cuba (Pilsbry 1929:603), where specimens of
Z. auricoma occur in a presumably Pleistocene or Holocene deposit.

Zachrysia fraterna, new species
Figures 3, 4

Holotype. -SDSNH 28388.

Tvpe locality. —SDSNH Loc. 3278, San Diego County, California. Construction
site at' 4760 Murphy Canyon Road, San Diego (39°49'26"N; 1 17°07'05"W), exposing
1 5 m of Friars Formation and at least 8 m of overlying Stadium Conglomerate, elevation
71 m; collected by B. O. Riney, 23 February 1985. Friars Formation, upper middle
Eocene. From blue-gray conglomeratic sandstones at the base of a 50-70 cm-thick
graded bed, approximately 12 m below the Friars Formation-Stadium Conglomerate
contact. A retaining wall now covers the collecting site.

Diagnosis.— A small, depressed-helicoid Zachrysia with 4.8 whorls, attenuated
base, smooth, sinuous radial riblets, and reflected but not greatly thickened lip.

Etymology.— The species is named for the Friars Formation {fraterna, L., broth-
erly).

Description.— SheW small for the genus, thin, inflated, depressed-helicoid, imper-
forate, broadest above middle of body whorl; base attenuated. Spire low, weakly convex
in profile; suture moderately impressed. Embryonic whorls 1 .4, smooth. Early teleo-

206

Figures 3-12. 3, 4, Zachrysia fratema, n. sp., holotype, SDSNH 28388, top and apertural views; major
diameter 23.5 mm. 5, 6, Zachrysia auricoma havanensis (Pilsbry), Holocene, Havana, Cuba, top and apertural
views; major diameter 25.7 mm (author's collection). 7-10, Lahyrinthus obtusus (Anderson and Hanna),
holotype, CAS Geology Type Collection 1016, top, apertural, lateral, and basal views; diameter 16.0 mm;
arrowhead points to basal constriction. 1 1, Labyhnthusp.) sp., SDSNH 32044, top view; diameter 12.6 mm.
12, Labyrinthus manueli Higgins, Holocene, Mera, Ecuador, lateral view; diameter 21.7 mm (CAS).

conch whorls irregularly corrugated by low growth rugae which grade, from about
beginning of fourth whorl on, into acute, raised, more or less regularly spaced, sinuous
radial riblets. Riblets convex in direction of growth on shoulder of whorl, retractive at
periphery, shallowly concave below periphery, and almost straight where they cross
the base; riblets on body whorl subequal in strength and spacing, triangular in cross-
section, smooth, or obscurely beaded by faint wrinkling below suture. Periphery of
penultimate whorl rounded-subangular, grading to broadly rounded on body whorl.
Last Vs whorl descending steeply to aperture, apico-basally compressed, constricted
behind lip. Aperture broadly ovate, markedly oblique, at angle of 60° to vertical; lip
expanded and strongly reflected, curving backward over pre-apertural constriction.
Parietal wall calloused, striate, reflecting underlying riblets. Basal lip rather wide, com-
pressed upward, thickened, columellar portion (all preserved) with a shallow sulcus
running outward from umbilical region. Major diameter (incomplete) 23.5 mm, minor
diameter 19.3 mm, height 16.9 mm; whorls 4.8.

Discussion.— Zachrysia fratema differs from all other species of the genus in having
4.8 whorls. As described by Pilsbry (1929), modem Cuban species have from 4 to 4.5

207

whorls. However, the low-helicoid shape, rapidly expanding whorls, and attenuated
base rapidly sloping from the periphery to the columellar area leave no doubt that this
is a species of Zac/irysia. The sinuous radial sculpture is also typical of the genus. The
lower edge of the aperture of the holotype is broken, but the remaining columellar
portion shows that the basal lip was thickened and compressed upward as in modern
species and may have had a shallow sulcus running along its length. There is no
indication whether or not denticles were developed on the basal lip.

The holotype has been slightly compressed in a direction normal to the plane of
the aperture, accentuating the difference between major and minor diameters.

The shell structure consists of (1) an outer, radial crossed-lamellar layer with first-
order lamellae parallel to the direction of growth; (2) a middle, concentric crossed-
lamellar layer with first-order lamellae at right angles to the first; and (3) an inner,
concentric crossed-lamellar layer (terminology after MacClintock 1967). The contact
between the outer and middle layers is gradational, with the first-order lamellae
undergoing a 90° rotation in the plane of the shell surface. The contact between the
middle and inner layers is sharp and unconformable, with a tendency for the two layers
to separate at the site of a break. The outer layer makes up about 20% of the total
thickness of the shell. The middle and inner layers each make up about 40%, but the
thickness of the inner layer is variable. Thickening around the peristome results mainly
from augmentation by the inner layer. Modern Zachrysia auricoma shows the same
sequence and relative thickness of shell layers, supporting the generic assignment.

No single modern taxon stands out as conchologically most similar to Z. fraterna,
but Zachrysia auricoma, particularly the small-shelled subspecies Z. a. havanensis
(Pilsbry, 1894), is generally similar in size and outline (Figures 5, 6). The periphery of
the penultimate whorl of Z. fraterna is less broadly rounded and is almost angulate
where the last whorl begins its descent to the aperture. The angulation is not as acute
as in Zachrysia torrei (Henderson, 1916) (Pilsbry 1929:pl. 29, figs. 8, 10).

Based on the scanty data of this one Eocene specimen and the twenty or so extant
species, one can infer that the trend of shell evolution in Zachrysia has been toward
(1) larger overall size, (2) reduced number of whorls, and (3) more rapidly expanding
whorls, producing a larger shell at a given whorl number. At the same time, the overall
shape has held remarkably constant.

Associated fauna. —The holotype (and only specimen) was found in a marine sand-
stone stringer in the mainly nonmarine Friars Formation, associated with a moderately
diverse nearshore molluscan assemblage dominated by Pachydesma sp.. cf. P. kellogg-
ensis (Clark and Woodford, 1927), Tellina soledadensis Hanna, 1927, and Turritella
uvasana Conrad, 1855, sensu lato. Rare estuarine molluscan taxa, including Loxotrema
turritum Gabb, 1868, and Merita triangulata Gabb, 1869, were also present (T. A.
Demere, personal communication 1986). Two other taxa of nonmarine mollusks were
present: (1) an almost planispiral gastropod 6.3 mm in diameter and 2.3 mm high,
consisting of 3.4 whorls, somewhat suggesting the ammonitellid genus Megomphix
Baker, 1930, but not further identifiable because the surface sculpture is not preserved;
and (2) two partial spires of lenticular pulmonate land snails, 12.9 and 13.6 mm in
maximum preserved diameter, of 4.7 and 4.2 whorls respectively, with ver\' oblique
growth striae and subangular periphery. These are discussed under LabyrinthusO species,
below.

Labyrinthus Beck, 1837

Labvrinthus Beck 1837:33. Wurtz 1955: 114-11 7 (in part). Zilch 1960:602-603 (in part). Solem

' 1966:37^4.
Ambages Gndt 1912:21-23. Wurlz 1955:114.

Type species. — Helix labyrinthus "Chemnitz" Deshayes, 1838 {=Helix otis Light-
foot, 1786), by subsequent designation (Herrmannsen 1846:569). Recent, Costa Rica
to Colombia.

208

Generic diagnosis. — Shell small to large; depressed globose to planulate; surface
sculpture of growth wrinkles or granulations, but never ribbed; spire nearly flat to
moderately elevated; periphery rarely rounded, usually acutely angulated or protrud-
ingly keeled; umbilicus partly (rarely completely) closed by extension of basal and
parietal lips; aperture strongly deflected near end of body whorl, partially obstructed
in adult by gross expansion of lips and development of various denticles and lamellae;
parietal lip raised and with reflected edge, basal and palatal lips thickened and strongly
reflected; parietal wall with single short to long, curved to sinuated lamella that stops
short of or merges with the elevated parietal lip; basal lip straight to sinuated, normally
with one lamellar knob marking its outer boundary, occasionally with a second inner
knob; lower palatal lip with single crescentic lamella, hooked lamellar tooth, large
transverse lamellar plate or y-shaped bifid tooth with deep indentation behind lip;
upper palatal lip with weak lamella or triangular knob in a few species (Solem 1966).

Solem's (1966) monograph gave generic rank to Isomeria Albers, 1850, which both
Wurtz (1955) and Zilch (1960) had treated as a subgenus of Labyrinthus. While noting
that anatomical evidence did not support separation of Labyrinthus and Isomeria,
Solem gave them coordinate rank because of shell characters and altitude ranges.

Although it is not stated explicitly. Bishop's (1979) figures 20-21 show that he
used "'Labyrinthus'' in the inclusive sense of Wurtz (1955) and Zilch (1960).

In spite of these differing opinions as to taxonomic rank, all authors agree that
Labyrinthus plus Isomeria form a monophyletic group distinct from the rest of the
American Camaenidae. It is to be expected that fossil species may be found that cannot
be assigned to one or the other but only to a Labyrinthus-Isomeria lineage. Note that
two Holocene species, Isomeria minuta Solem, 1966, and /. inexpectata Solem, 1966,
are regarded as intermediate in shell characters (Solem 1966:127-128).

The modern range of Labyrinthus extends from northern Costa Rica south to
Madre de Dios, Peru, east to Caracas, Venezuela, and Para, Brazil (Solem 1966). No
other fossil occurrences are known, although "Camaenid, genus and species indet." of
Roth (1984:210-21 1, figs. 29-31) shows some similarity to Labyrinthus and Isomeria.

Labyrinthus obtusus (Anderson and Hanna, 1925)

Figures 7-10

Helfninthoglvpta obtusa AndQvsomindY\a.nndi 1925: 142-143, pi. 3, figs. 12, 13. Henderson 1935:
141. Piisbry 1939:66.

Holotype.— CAS Geology Type Collection 1016.

Type locality. —Kern County, California. Live Oak Creek. Collected by M. A.
Hanna, 1922. Tejon Formation, Eocene.

Description.— The holotype is an internal mold with original shell material ad-
hering; the shape is roughly lenticular, flatter above and more deeply convex below the
periphery. The external surface appears to be well preserved. The protoconch and spire
are smooth and unsculptured. The body whorl is sculptured with traces of oblique
growth striae. There are 4.75 whorls preserved, but there were probably about five
originally. The whorls are closely coiled, not rapidly expanding; the slight elliptical
eccentricity visible in top view is probably the result of post-mortem compression. The
whorl cross-section is lunate; the parietal wall is missing. The base is narrowly um-
bilicate, the umbilical region filled with matrix that shows the impression of an ex-
panded, reflected columellar lip (now missing) that must have covered or nearly covered
the umbilicus. The suture is well marked and there is no trace of reabsorption of internal
whorl partitions; i.e., L. obtusus is a pulmonate, not a prosobranch. Only the basal part
of the peristome is preserved but that is thickened and reflected. Just in back of the
peristome the base of the body whorl is strongly constricted upward.

Diameter of holotype (incomplete) 16.0 mm, height 9.6 mm.

Discussion.— The distinct upward constriction of the base of the body whorl im-
mediately behind the aperture, the thickened and reflected peristome, and the lenticular
profile, more deeply convex below the angulate periphery, all indicate assignment to

209

Labyrinthus. A specimen of Lahyrinlhus manueli Higgins, 1872, is illuslraled for com-
parison (Figure 12); the similarities are most apparent in lateral view.

Anderson and Hanna (1925) construed Helminthoglypta rather broadly and in-
cluded species that would now be allocated to Monadenia Pilsbry, 1890. The shells of
most Monadenia species are pustulose or finely spirally striate; they have distinctive
protoconch sculpture of granules or clothlike texturing (Roth 1981). None has a basal
constriction behind the aperture.

Helminthoglypta includes species with shells of moderate to large size, helicoid or
depressed, with conic or low spire, open or covered umbilicus, and periphery rounded
to angular in the subadult (Pilsbry 1939). A wide range of shell forms is found, from
globose-conic and higher than broad to nearly planispiral. In all, however, the peristome
is reflected simply, without being preceded by a basal constriction.

Several Holocene species of Labyrinthus become adult in the 15-20 mm diameter
size range, although most are larger (to 60 mm). In all modern species the basal con-
striction is pronounced and the aperture furnished with various denticles and lamellae.
Because the aperture of the holotype of L. obtusus is incomplete and the parietal wall
is missing, no more detailed comparison with the modern species groups of Labyrinthus
is possible.

Labyrinthus{7) species
Figure 1 1

Referred material and locality.— T-wo specimens, SDSNH 32044; from SDSNH
Loc. 3278, San Diego County, California. Construction site at 4760 Murphy Canyon
Road, San Diego (39°49'26"N; 1 17°07'05"W), exposing 15 m of Friars Formation and
at least 8 m of overlying Stadium Conglomerate; elevation 7 1 m; collected by B. O.
Riney, 23 February 1985. Friars Formation, upper middle Eocene. From blue-gray
conglomeratic sandstones at the base of a 50-70 cm-thick graded bed, approximately
12 m below the Friars Formation-Stadium Conglomerate contact.

Description. —The material consists of two partial spires (with some internal whorls
present) of lenticular land snails, 12.9 and 13.6 mm in maximum preserved diameter,
consisting of 4.7 and 4.2 whorls respectively. The specimens are immature, without
thickened lip, constricted body whorl, or other characters of terminal growth. The shell
is more deeply convex below the subangular periphery. The whorls are closely coiled,
not rapidly expanding; the whorl cross-section was apparently lunate. The base and
umbilical region are not preserved. The suture is well marked and there is no indication
of reabsorption of internal whorl partitions; i.e., they are pulmonates, not prosobranchs.
The protoconch apparently consists of 1.5-1.7 whorls but is not well diflerentiated
from the neanic whorls. The only sculpture consists of low, oblique growth rugae. Both
specimens are slightly elliptical in top view, probably due to post-mortem distortion.

Z)/5a/55/OA7.— Without specimens showing the thickened and reflected lip of ma-
turity, it is not possible to allocate this material more securely. However, the characters
preserved— tight coiling, the general absence of sculpture other than growth rugae, the
low spire, and greater convexity below the subangular periphery— are consistent with
Labyrinthus and similar to L. obtusus from Kern County. The two specimens are smaller
at a given whorl than the holotype of L. obtusus; the protoconchs are slightly smaller,
and the growth rugae stronger.

Genus uncertain

[Camaenidae] 5rc»cA:/ (Hanna 1934)

Figures 13-17

Helminthoglypta'? stocki Hanna 1934:539, texi-figs. l-3a. Pilsbry 1939:66.

Type material and locality. — Hololypc: LACMIP 4261 (formerly CIT 3244). from
CIT vertebrate paleontology locality 180, Ventura County, California. Tapo Canyon,
north of Simi Valley. Sespe Formation, lower upper Eocene. Two paratypes, LACMIP

210

Figures 13-17. [Camaenidae] stocki (Hanna). 13-15, holotype, LACMIP 4261, top, basal, and apertural
views; diameter 38.0 mm. 16, 17, paratype, LACMIP 4262, detail of sculpture on body whorl and basal
view; diameter 44.0 mm.

4262 and 4263 (formerly CIT 3246 and 3245, respectively), from same locality as
holotype.

Referred material and locality.— UCMF loc. D-781 1, San Diego County, Califor-
nia. At intersection of Lake Murray Blvd. and Dallas Street behind the Jack-in-the-
Box drive-in (WV2 SE'/i sec. 7, T. 16 S, R. 1 W, San Bernardino Base and Meridian);
elev. 190 m [625 ft]. Mission Valley Formation, upper middle Eocene. This is the same
as UCMP vertebrate locality V-6893, the Jack-in-the-Box locality of Golz and Lille-
graven (1977) and other vertebrate workers.

Description. —The holotype and two paratypes are internal molds with thin partial
crusts of recrystallized shell material, and a matrix of reddish and greenish lithic wacke.
Patches of external sculpture are preserved on the last whorl of the holotype and paratype
LACMIP 4262; they consist of fine, raised, axial riblets oblique to the direction of
spiral growth, apparently parallel to lines of growth (Figure 1 6). The riblets do not
anastomose, and each evidently retains its distinctness across the whorl. The apices of
the shells are not well preserved. Hanna (1934) estimated about 6.5-7 whorls, but I
judge only about five to be present. The whorls are closely coiled and do not expand
rapidly. The whorl cross-section was apparently higher than broad, and ovate to sub-

211

Table 1 . Measurements of type specimens of [Camaenidae] stocki (Hanna

1934).

Holotype LACMIP

4261

Paratype LACMIP

4262

Paratvpe LACMIP
4263

Diameter: 38.0 mm
Height: 36.2

44.0 mm
29.9 (skewed)

36.7 mm
26.0

lunate. The base is umbilicate, best shown by paratype LACMIP 4262 (Figure 17).
There is no obvious change in direction of growth of the last whorl, so it is uncertain
whether or not these are mature shells. No obvious apertural modifications are present,
although in paratype LACMIP 4262 the umbilicus appears to grade into a transverse
basal groove like that characteristic of many New World Camaenidae (Solem 1978).

The suture is well marked, and below the suture the whorls show a narrow, steplike
shoulder with a rounded outer edge. The shoulder is particularly evident on the internal
molds, reflecting a general thickening of the shell toward the suture, but it is not solely
an internal feature, also being present where shell material and external sculpture are
preserved. Shell dimensions are summarized in Table 1 .

The two referred specimens are internal molds with impressions of external sculp-
ture in a matrix of light grayish tan lithic wacke. Their maximum diameter, with some
deformation, is 30-35 mm. One has slightly more than five whorls; the other lacks the
upper spire and the whorls cannot be counted. The better-preserved specimen shows
clearly the sculpture of radial riblets, the narrowly shouldered whorls, and the umbilicate
base of [C] stocki. The body whorl is weakly dilated just behind the aperture and the
peristome appears to have been moderately turned outward.

Discussion.— Tho. evidence for taxonomic assignment of [Camaenidae] stocki is
less satisfactory than that in the preceding cases. Finding of adult specimens with more
shell material and the adult aperture preserved would greatly improve matters.

Hanna (1934) originally assigned the species to Helminthoglypta with doubt, al-
though remarking that the essential characters of that genus were apparent. The only
living species compared was the large form described about the same time as Hel-
minthoglypta tudiculata rex Church and Smith, 1938. In 1933, Hanna had been one
of the collectors of the type lot of that Holocene subspecies. Now known as H. allyniana
rex, it has a much more depressed shell, with whorls expanding more rapidly, and the
malleated sculpture typical of the H. tudiculata group of taxa. The umbilicus is narrow
and almost covered by the expanded inner lip. The suture is moderately impressed;
there is no trace of the narrow shoulder evident in [C] stocki.

As noted above, Helminthoglypta includes a wide range of shell shapes. In no
species, however, is there a narrow, steplike shouldering of the whorl below the suture.

The sculpture in Helminthoglypta consists of simple growth lines, malleation,
papillae, or close, regular axial ribbing that is broken into granules by oblique, diverging
grooves. Often more than one of these types of sculpture are present on the same shell.
Raised axial riblets like those of [C] stocki are not known in Helminthoglypta.

No other extant genera of Helminthoglyptidae match any better. Among large,
globose or trochoid forms, Humboldtiana Ihering, 1892, has rapidly expanding whorls
sculptured with coarse, granulose wrinkles. Lysinoe Adams and Adams, 1855, has
sculpture of fine, discrete papillae on an otherwise smooth shell, or a malleated surface;
its whorls are unshouldered and expand at a greater rate. Monadenia includes smooth
shells and ones with strong, persistent papillation. The larger species of Leptarionta
Fischer and Crosse, 1870, have a glossy or silky surface with growth lines scarcely
evident in relief Polymita Beck, 1837, likewise consists of smooth-shelled species.

The only modern genus of Helminthoglyptidae that shows comparable sculpture
in some species is Hemitrochus Swainson, 1 840, of southern Florida and the Antilles.
Species of Hemitrochus have medium-sized to small, compact shells, often with a
narrow, obliquely entering umbilicus. The shell of [C] stocki is much larger than any
of these, and the umbilicus seems to have been broadly open.

212

The American camaenid genus Polydontes Montfort, 1810, and the Australian
camaenid genera Xanthomelon Martens in Albers, 1860, Thersites Pfeiffer, 1856, and
Hadra Albers, 1860, include species that combine in one way or another the features
of globose shell, slowly expanding whorls, narrow, steplike shoulder with emphasized
suture, and fine but prominent radial ribbing. Although differing in its shagreened
microsculpture and the absence of an umbilicus, the Neotropical camaenid Polydontes
(Liiquillia) luquillensis (Shuttleworth, 1854) is suggestively similar. For the present,
however, [C] stocki is assigned to family only, not to any specific genus. [Those who
insist on a generic epithet are, of course, perfectly free to cite this taxon as PolydontesC?)
stocki. I may be wrong in trying to bend nomenclatural practice in this way to express
shades of uncertainty. Note that if the taxon had not already been formally named, we
could simply cite it as "Camaenid, genus and species indet." The binomial system
forces us to combine the two essentially distinct activities of identification and clas-
sification. '"Helminthoglypta" stocki (with quotes) is an unsatisfactory form of citation
because the species is not helminthoglyptid. And the old expedient of naming a new
genus is not justified by the information available from the specimens.]

Age and Correlation

There are no radiometric dates associated with late Eocene terrestrial faunas in
southern California. Age assignments of the formations that yielded the camaenid land
snails discussed here are based on stratigraphic relationships to marine beds and faunal
correlations with fossil mammals from the western interior (Figure 2).

Correlations of the Ventura and San Diego County Eocene formations are based
on Golz and Lillegraven (1977), Lillegraven (1979), Givens and Kennedy (1979) and
information supplied by T. A. Demere {personal communication 1986). Fossil mam-
mals in the Tapo Canyon Local Fauna indicate correlation with the Myton Member
("Uinta C" level) of the Uinta Formation of northeastern Utah and with the "Tejon"
molluscan stage of the Pacific Coast marine megafossil chronology. The vertebrate
fauna of the Mission Valley Formation is probably correlative with assemblages from
the type section of the Tepee Trail (=Wagon Bed) Formation in Fremont County,
Wyoming, the "Uinta B" level of the Uinta Formation, and the "Tejon" Stage. Most
vertebrate remains from the Friars Formation have been found high in the formation
and have been correlated with the "Uinta B" level and the "Transition" molluscan
stage.

Fossil marine mollusks found in association with Zachrysia fraterna at SDSNH
loc. 3278 include Ficopsis remondii crescentensis Weaver and Palmer, 1922, Molo-
pophorus antiquatus (Gabb, 1864), Neverita globosa Gabb, 1869, Eocernina hannibali
(Dickerson, 1914), ""Spisula"'' bisculpturata Anderson and Hanna, 1925, and Tellina
soledadensis. These taxa have stratigraphic ranges that typically overlap only within
the "Transition" molluscan stage (Givens and Kennedy 1979), indicating that the type
locality of Z. fraterna is of middle Eocene age (Lutetian; approximately 45-46 Ma
before present). Flynn (1986) has recently shown that reversed magnetism in the main
body of the Friars Formation represents magnetic polarity Chron C20R (approximately
46-48 Ma before present).

The age of the type locality of Labyrinthus obtusus is less certain. The Tejon
Formation consists of marine sediments deposited during a major eastward transgres-
sion during the early, middle, and possibly late Eocene, followed by a westward regres-
sion in the late Eocene (Nilsen and Link 1 975). The holotype was said to be "embedded
in the typical hard Type Tejon sandstone with marine forms" in the canyon of Live
Oak Creek (Anderson and Hanna 1925) but the exact part of the section where it was
found is not known. Marks (1943) assigned the entire section of the Tejon Formation
exposed in Live Oak Canyon to the Liveoak Shale Member, which has yielded Ulatisian
and Narizian (middle to upper Eocene) foraminifers (Nilsen and Link 1975). A more
recent interpretation of the stratigraphy (Nilsen and Link 1975: fig. 6) indicates that
the subjacent Uvas Conglomerate Member (containing "Transition" Stage megafossils)

213

and the superjacent Metralla Sandstone Member (containing "Tejon" Stage megafossils)
may be present in Live Oak Canyon as well. In light of its nearshorc deposition and
abundant megafossils, the Uvas Conglomerate Member may be the most likely source
of the holotype of L. obtusus (L. R. Saul, personal communication 1987).

Paleoecology and Paleoclimate

The average rate of evolutionary change expressed in the shell morphology of land
mollusks is slow. Many modern genera appear first in upper Cretaceous or Paleogene
strata with species that are virtually indistinguishable from their living congeners. If
morphologic change is accepted as a fair sample of total evolutionary change, then land
snail fossils can be viewed with confidence as indicators of ancient environments (Roth
1984).

The present-day climates of Kern, Ventura, and San Diego counties, California,
are temperate, equable, and summer-dry. At Bakersfield, 50 km north of the type locality
of Labyrinth us obtusus, the mean annual temperature is 18.4°C and there is a 20.4°C
annual range of temperature; mean annual precipitation is 16.2 cm, less than 2.0 cm
falling between May and October (Elford 1970). At San Diego the mean annual tem-
perature is 17.3°C and the mean annual range is 9.3°C; mean annual precipitation is
26.4 cm, less than 2.4 cm falling between May and October. At Ventura, the mean
annual range of temperature is only a few degrees greater; annual precipitation is 36.1
cm, 1.6 cm falling between May and October.

In the middle to late Eocene a system of coastal lowlands connected these areas
and may have communicated with the western interior as well (Lillegraven 1979: fig.
2b). The San Joaquin Basin was flooded by a major marine transgression, the Transverse
Ranges did not yet exist as an east-west feature, and the Peninsular Ranges had yet
to migrate some 365 km northwest along the west side of the San Andreas fault system
(Link et al. 1979, Lillegraven 1979, Nilsen and McKee 1979). The land mollusks
indicate that the entire region from present-day Kern to San Diego counties was within
a single zone of seasonally dry tropical forest.

Frakes and Kemp's (1972) reconstruction of Eocene global weather patterns (40-
48 Ma before present) indicates that the southern margin of North America, bordering
the Caribbean limb of the Tethyan seaway, had a monsoonal climate. The west coast
of North America had a wet climate and warm marine temperatures. The area was
free from the upwelling that modulates summer temperatures along the west coast
today (Scotese and Summerhayes 1986).

Eocene strata in the San Diego area represent a complex of depositional environ-
ments including coastal plain, lagoonal, fan-delta, and paralic facies, near the mouth
of a major river system (Kennedy and Moore 1971, Howell 1975, Link et al. 1979).
Marine and nonmarine conditions alternated; a coastline was never far away.

The La Jolla and Poway Groups (which include the Friars and Mission Valley
Formations) rest unconformably on Cretaceous and older rocks that are weathered to
a lateritic paleosol. This paleosol probably developed in a humid, tropical climate with
over 130 cm annual precipitation, an average annual temperature around 20-25°C,
and lush rainforest vegetation (Peterson et al. 1975). (These authors refer to it as a
"pre-Eocene" paleosol, but it could equally well be just slightly older than the overlying
sediments and as young, in part, as middle Eocene.) Both the Friars and Mission Valley
Formations, however, contain calcareous layers interpreted as caliche deposits. These
would most likely have formed under semi-arid conditions with annual precipitation
under 65 cm and seasonally distributed (Peterson et al. 1975, Peterson and Abbott
1979). Caliches are more common in the Mission Valley Formation than in the Friars
Formation (Lillegraven 1 979). Apparently middle to late Eocene was a time of transition
locally from abundant rainfall (as in the modern equatorial belt of lateritic soils) to
diminished rainfall and seasonal drought. Under the latter conditions the vegetation
probably resembled modern steppe or savanna, with drought-resistant trees and shrubs.

Clast-composition of the Ballena Gravels to the east, deposits of the Eocene rivers

214

that drained into the San Diego delta (Steer and Abbott 1984), suggests infrequent
high-energy transport. This is interpreted as the result of major, seasonal flash floods
in response to tropical storms dropping great amounts of rain on the mountains to the
east (Lillegraven 1979, Steer and Abbott 1984). For much of the year, however, the
rivers probably experienced only minor flow.

Today the native range of Zachrysia is limited to Cuba. Snails of this genus are
inhabitants of humid and generally rocky forest, where they are found on rocks and
cliffs, tree trunks, or on the ground (Pilsbry 1929). In typical humid weather they are
often active by day, crawling on the ground, climbing trees to a height of 2-3 m, or
wandering over rocks and cliffs. In dry periods they temporarily estivate. Pilsbry's
(1929) observation that, with the exception of Z. auricoma, Zachrysia do not survive
for long when confined in a dry box suggests that they have limited ability to resist
desiccation.

Zachrysia pwvisoria (Pfeiffer, 1858) and Z. auricoma have been introduced into
Florida (Pilsbry 1939, Dundee 1974); Z. provisoria, at least, has become established
in Dade, Monroe, and Broward counties (J. E. Deisler, personal communication 1986).
Zachrysia provisoria is established as an introduction in the Bahamas (Clench 1952,
Deisler and Abbott 1984), and Z. auricoma havanensis in Puerto Rico (van der Schalie
1948). Wurtz (1955) mentioned that the genus had been introduced to the Canal Zone,
without giving further particulars. The success of these introductions indicates that the
restriction o^ Zachrysia to Cuba is not merely due to the absence of suitable conditions
elsewhere.

The modern range o{ Zachrysia is consistent with (1) tropical climate, equable and
frost-free but with some winter cooling (Seifriz 1943); (2) precipitation between 80 and
200 cm annually, ample in summer but with a pronounced winter dry season (Seifriz
1943, Portig 1976); and (3) forested land, but not necessarily rainforest. The greatest
diversity of species is recorded in mountainous regions, which are also the wettest areas.
It is not clear from published collection records whether this is mainly sympatric or
allopatric diversity. The observations of Pilsbry (1929) and van der Schalie (1948)
indicate that at least Z. auricoma may tolerate open, drier conditions fairly well.

At present Labyrinthus has an extensive range from Costa Rica to Peru and the
Amazon basin of Brazil. Perhaps a third of the species have altitude ranges of more
than 900 m (Solem 1966). This broad distribution and the scarcity of ecological in-
formation limit the usefulness of the genus for paleoclimatic interpretation. Material
collected by Solem (1966) in Panama was taken in "reasonably heavy forest." Baker
(1926) found Venezuelan species in dense forest under logs and debris or in humus
near rocky ledges. The geographic range of Labyrinthus is broad enough to take in
many tropical forest types; at least some of the regions experience a winter dry season.

The fragile shells of Zachrysia, Labryinthus{l), and the unidentified planispiral
species from the Friars Formation probably underwent only minimal transport before
being deposited in a protected, shallow marine setting. They may have been living in
a humid forest fringing a coastal lagoon. It is less likely that they were caught up in
flash flooding and transported from the interior. Heavily vegetated coastal belts per-
sisted into the later Eocene (Lillegraven 1979). In these belts the effects of seasonal
drought may have been minimized, permitting a diverse land snail fauna to thrive.

The laterally intertonguing and partly subjacent Scripps Formation, representing
submarine canyon fill or inner fan deposits (Link et al. 1979), has yielded the proso-
branch land snail ''Helicina'' dallasi (Hanna, 1926), likewise indicative of tropical
conditions (Roth and Pearce, in press).

The Sespe Formation of Ventura County is of fluvial origin and thought to have
been deposited for the most part near sea level (Lillegraven 1979). Paleoclimatic studies
are lacking, although time-equivalent marine faunas in the area indicate tropical to
subtropical marine conditions. If better material of [Camaenidae] stocki confirms its
similarity to Polydontes luquillensis, then paleoclimatic inferences could be based on
the study by Heatwole and Heatwole (1978) of P. luquillensis in Puerto Rico.

The general climatic inferences drawn from Labyrinthus above would also apply

215
Zachrysia Polydontes Pleurodonte

Caracolus

Labyrinthus-
Isomeria

Figure 18. Phylogenetic hypothesis (cladogram) for the genera of American Camaenidae, after Bishop
(1979), q.v. for pattern of apomorphies.

to the Kern County setting of L. obtusus. The holotype of L. obtusus was found with
a marine invertebrate fauna containing species of Ficus, Latirus, Niso, and Pteria —
genera that today are either exclusively or predominantly tropical in distribution.

History of the American Camaenidae

The origin of the Caribbean terrestrial biota has been the subject of considerable
debate in recent years (Hedges 1983). The principal dichotomy has been between the
view, on the one hand, that the major events of colonization and radiation occurred
in post-Oligocene time, predominantly involved over-water dispersal, and can be vi-
sualized on an essentially modern map of the distribution of land masses (e.g., Pregill
1981), and, on the other hand, the view that these events took place in the late Mesozoic
and early Tertiary, predominantly involved vicariance, and require a consideration of
the distribution of land masses prior to the middle of the Cenozoic Era (e.g., Rosen
1976, MacFadden 1980). Recent studies of phylogenetically well-understood groups
contain elements of both sides (MacFadden 1981, Cadle 1985).

Unlike the marine realm, with its spectacular if not always unequivocal fossil
record, paleontologic evidence pertaining to the terrestrial debate is extremely sparse.
Pregill (1981) was able to summarize only about ten instances of vertebrate fossils
thought to bear on the question (although it is hard to see how some of the Cretaceous
or Eocene occurrences he cites enable him to reach the conclusion that the groups in
question arrived in the Antilles no earlier than the medial Tertiary). Land snails may
prove to have the best fossil record of any terrestrial group.

A Mesozoic or early Tertiary occurrence of a taxon outside its modern Caribbean
range disproves a Caribbean origin for that taxon in the later Tertiary. It provides a
minimum age for the taxon and its sister-group, and likewise for any cladogenetic
events lower down on the phylogenetic tree of its major group. The fossil occurrence
of a taxon in North America does not mean that the same taxon was not also simul-
taneously present in the Caribbean region. For a tropical (i.e., thermally limited) taxon,
the northern occurrence merely delineates the minimum northward extent of its range
at the time. The contemporaneous southern, or cquatorward, edge of the range may
not be discoverable; the terrestrial fossil record in the Neolropics is not particularly
promising in this regard. My working assumption in such cases is that the range extended
as far toward the equator as the availability of land would permit.

Bishop (1979) produced a phylogenetic hypothesis for the American Camaenidae
(Figure 18) based on the anatomical studies of Wurtz (1955) and summarized the fossil
occurrences of American camaenids known to him, including a new species of Caracolus
Montfort, 1810, from the Oligocene While River Group of Nebraska. The fossil evi-
dence at that time suggested that Caracolus was differentiated in North America by
the Oligocene at the latest; Pleurodonte Fischer von Waldheim, 1807 (in the broad

216

sense, including Pleurodontites Pilsbry, 1939), was differentiated in Florida by the early
Miocene (the age of the Tampa Limestone); and "differentiation of Polydontes and
Zachrysia [could] best be understood in terms of modem geography and must post-
date the period of dynamic geologic change" (Bishop 1979:282).

Solem (1978) stated that the presence of advanced features of apertural barriers,
lip sinuation, and body whorl deflection in the Cretaceous and early Tertiary fossils
Kanabohelix Pilsbry, 1927, and Hodopoeus Pilsbry and Cockerell, 1945, indicated that
the initial radiation of the Camaenidae was completed by the end of the Mesozoic. He
noted the resemblance to Isomeria o{ Hodopoeus crassus Pilsbry and Cockerell, 1945,
and H. hesperarche (Cockerell, 1914), from unknown lower Tertiary localities in the
American Southwest, but refrained from considering them congeneric because of their
chronologic and geographic separation. With the recognition herein of Labyrinthus in
the middle Eocene of California, such conservatism may no longer be necessary.

Roth (1984) recognized three camaenid genera and subgenera in the upper Eocene
to lower Oligocene of Trans-Pecos Texas. Pleurodonte (Pleurodonte) and P. {Dentellaria)
Schumacher, 1817, were sympatric in the Porvenir local fauna (late Eocene) of the
Vieja Group. Their divergence and the subsequent dispersal that brought about their
sympatry had already occurred by about 38 Ma before present. An indeterminate
camaenid that is probably a member of the Labyrinthus-Isomeria lineage was present
in the Whistler Squat local fauna in the same region of Texas approximately 10 Ma
earlier.

The presence of Zachrysia fraterna in the late middle Eocene sets a minimum age
for the differentiation of Zachrysia. It further sets a minimum age for the dichotomies
farther down the cladogram: the divergence of the common ancestor of Polydontes and
Zachrysia from Pleurodonte, and, still earlier, the divergences of the Isomeria- Laby-
rinthus and Caracolus lineages from the rest of the American Camaenidae. All of the
earliest appearances of these genera are in North America.

Figure 1 9 shows the fossil occurrences of these camaenid genera relative to their
modern distribution, plotted on the geography of middle Eocene time (48 Ma) (Sykes
et al. 1982). The fossil and modern occurrences are connected by dotted lines— "tracks"
in the parlance of vicariance biogeography (see Rosen 1 976:432-433 for an explanation
of method). In every case the tracks connect lower Tertiary localities in North America
with Holocene ranges in the Caribbean region.

Except for Miocene Pleurodonte (Pleurodonte) in the Grenadines (Jung 1971) and
Pliocene or younger P. (Dentellaria) in Jamaica (Bishop 1979), there is very little
evidence for the timing of events at the southern ends of these tracks. Geological
reconstructions of the Neotropics have paid little attention to the time when various
Caribbean lands might have emerged above sea level (Hedges 1983). There is slightly
better— although still indirect— control on the timing of extinctions in the north. Many
lines of evidence show that the tropical biota was progressively restricted southward
as the planetary temperature gradient steepened through the Tertiary (Savin 1977,
Wolfe 1978). Miocene and later land mollusk faunas of western North America were
dominantly composed of genera still extant in the region (Roth 1986).

Even though broadly drawn, these tracks are probably conservative estimates of
the total ranges of their taxa. They may have overlapped much more extensively; that
is, there may well have been much more sympatry between different camaenid genera.
Sympatry of taxa now widely separated has been found repeatedly in Tertiary land
mollusk faunas of western North America (Roth 1984, 1986). Through the Tertiary,
the faunal elements came to inhabit different geographic areas. How much of this change
represents sorting out along environmental gradients and how much represents his-
torical accident is not clear. What determined, for instance, that Zachrysia should end
up restricted to Cuba and P. (Dentellaria) to Jamaica? The allopatry on the Greater
Antilles is all the more puzzling in light of the unusually high sympatric diversity shown
by the land snail faunas of Jamaica and Hispaniola (Solem 1984).

The fossil evidence now available supports the model of a variety of camaenid
genera, well differentiated by the middle Eocene, arrayed across the southern part of

217

Figure 19. "Track record" of the American Camaenidae, plotted on map of land-mass distribution for the
middle Eocene (48 Ma before present) (after Sykes et al. 1982). Dotted lines connect early to middle Tertiary
occurrences of Camaenid genera with their Holocene ranges. Ca, Caracolus; De, Pleurodonte (Dentellaria);
La, Lahyrinthus; PI, Pleurodonte {Pleurodonte): Za, Zachrysia.

North America, roughly parallel to the western limb of the Tethyan seaway. Through
the Cenozoic, the northern, antitropical, margins of their ranges retreated southward;
by the Holocene, if not earlier, they had become largely allopatric.

According to the phylogenetic hypothesis, Zachrysia is one of the most highly
derived genera of the American Camaenidae; it is also the westernmost. The vicariant
event that separated Zachrysia from Polydontes may have been related to the late
Cretaceous or early Tertiary onset of arc volcanism in the American Southwest, east
of the middle Eocene range o{ Zachrysia (Dickinson 1979: fig. 8; Minckley et al. 1986).
The phylogenetic hypothesis and the known range of Zachrysia lead to the prediction
that Eocene species assignable to Polydontes will be found in the southwestern United
States or northern Mexico, east of the volcanic arc.

Zachrysia's position as a highly derived "end member" also suggests that any
ancestral connection with the Australasian branch of the Camaenidae would have been
eastward, along lands bordering the Telhyan seaway, rather than across the Pacific.
Through the Eocene and the relevant parts of preceding geologic time, the Indopacific
Ocean was much wider than today, spanning at least 210° at the equator, while only a
narrow Atlantic Ocean separated America and Eurasia. The southern coasts of both
continents lay in a warm and wet, monsoonal climatic belt (Frakes and Kemp 1972).
The Australian Camaenidae are advanced relative to the southeast Asian members of

218

the family; their ancestors entered Australia only after collision of the Australian and
southeast Asian plates in the Miocene (Solem 1984). Many instances of biotic groups
with this "interrupted Tethyan" type of distribution are known (Croizat 1964). If the
American and Australasian camaenid groups are regarded as the two ends of this
distribution, the prediction follows that fossil forms connecting the American with the
Australasian Camaenidae will be found in Europe or western Asia.

Before anyone embarks on an all-out search, however, it would be well to re-
examine the proposition that the American Camaenidae and the Australasian Ca-
maenidae compose one monophyletic group and are not simply united by symplesio-
morphies.

Acknowledgments

I am grateful to T. A. Demere, San Diego Natural History Museum, for bringing
the fossil land mollusks from the Friars Formation to my attention and supplying
needed information on their geologic setting. D. R. Lindberg helped with the inter-
pretation of shell structure. R. L. Squires advised on Eocene biostratigraphy. E. C.
Wilson loaned the type specimens of//.? stocki. J. E. Deisler contributed information
on the status of introduced Zachrysia in Florida and the Bahamas. Photographs were
taken in the University of California Museum of Paleontology and the Department of
Invertebrate Zoology, California Academy of Sciences; the help of Jeanne M. Lynch
is gratefully acknowledged. I also appreciate the comments of reviewers, named and
anonymous, including L. R. Saul, G. L. Kennedy, and A. Solem.

Literature Cited

Anderson, F. M., and G. D. Hanna. 1925. Fauna
and stratigraphic relations of the Tejon Eocene
at the type locality in Kern County, California.
California Academy of Sciences Occasional
Paper 11:1-249.

Baker, H. B. 1926. The Mollusca collected by the
University of Michigan-Williamson expedi-
tion to Venezuela. Part IV. Occasional Papers
of the University of Michigan Museum of Zo-
ology 167:1-49.

Beck, H. 1837-1838. Index molluscorum prae-
sentis aevi musei principis augustissimi Chris-
tiani Frederici. Copenhagen.

Bishop, M. J. 1979. A new species of Caraco/w5
(Pulmonata: Camaenidae) from the Oligocene
of Nebraska and the biotic history of the Amer-
ican camaenid land snails. Zoological Journal
of the Linnean Society 67:269-284.

Bonilla, A. M. 1936. Estudio comparativo de
Zachrysia trinitaria y Z. scabwsa. Memorias
de la Sociedad Cubana de Historia Natural 10:
33-38.

Cadle, J. E. 1985. The neotropical colubrid snake
fauna (Serpentes: Colubridae): lineage com-
ponents and biogeography. Systematic Zoolo-
gy 34:1-20.

Clench, W.J. 1952. Land and freshwater mollusks
of Eleuthera Island, Bahamas Islands. Revista
de la Sociedad Malacologica "Carlos de la
Torre" 8:97-119.

Croizat, L. 1 964. Space, time, form: the biological
synthesis. Published by author, Caracas.

Deisler, J. E., and R. T. Abbott. 1984. Range
extensions of some introduced land mollusks
in the Bahama Islands, with first reports for
four species. The Nautilus 98:12-17.

Dickinson, W. R. 1979. Cenozoic plate tectonic

setting of the Cordilleran region in the United
States. Pp. 1-13 in J. M. Armentrout, M. R.
Cole, and H. TerBest, Jr. (eds.). Cenozoic Pa-
leogeography of the Western United States. Pa-
cific Coast Paleogeography Symposium 3. Pa-
cific Section, Society of Economic
Paleontologists and Mineralogists.

Dundee, D. S. 1974. Catalog of introduced mol-
luscs of eastern North America. Sterkiana 55:
1-37.

Elford, C. R. 1970. Climate of California. Cli-
matography of the United States, no. 60-4. U.S.
Dept. Commerce.

Flynn, J. J. 1986. Correlation and geochronology
of middle Eocene strata from the western United
States. Palaeogeography, Palaeoclimatology,
Palaeoecology 55:335-406.

Frakes, L. A., and E. M. Kemp. 1972. Influence
of continental positions on early Tertiary cli-
mate. Nature 240:97-100.

Givens, C. R., and M. P. Kennedy. 1979. Eocene
molluscan stages and their correlation, San
Diego Area, California. Pp. 8 1-95 in P. L. Ab-
bott (ed.). Eocene Depositicnal Systems, San
Diego, California. Pacific Section, Society of
Economic Paleontologists and Mineralogists.

Golz, D. J., and J. A. Lillegraven. 1977. Summary
of known occurrences of terrestrial vertebrates
from Eocene strata of southern California.
University of Wyoming Contributions to Ge-
ology 15:43-65.

Gude, G. K. 1912. Characters of two undescribed
land snails from the Republic of Colombia and
a new genus of helicoids. Proceedings of the
Malacological Society of London 10:21-23.

Hanna, G. D. 1934. Land shells from the upper
Eocene Sespe deposits, California. Journal of

219

the Washington Academy of Sciences 24:539-
541.

Heatwole, H., and A. Heatwole. 1978. Ecology of
the Puerto Rican camaenid tree snails. Mala-
cologia 17:241-315.

Hedges, S. B. 1983. Caribbean biogeography: im-
plications of recent plate tectonic studies. Sys-
tematic Zoology 31:51 8-522.

Henderson. J. 1935. Fossil non-marine Mollusca
of North America. Geological Society of Amer-
ica Special Paper 3:i-vii, 1-313.

Herrmannsen. A. N. 1846. Indicis generum ma-
lacozoorum primordia. T. Fischer, Cassell.

Howell, D. G. 1975. Middle Eocene paleogeog-
raphy of southern California. Pp. 272-293 //;
D. R. Weaver, G. Hornaday, and A. Tipton
(eds.). Future Energy Horizons of the Pacific
Coast; Paleogene Symposium and Technical
Papers. Pacific Sections, American Association
of Petroleum Geologists, Society of Economic
Paleontologists and Mineralogists, Society of
Economic Geologists.

Jung, P. 1971. Fossil mollusks from Carriacou,
West Indies. Bulletins of American Paleontol-
ogy 61:147-262.

Kennedy, M. P., and G. W. Moore. 1971. Strati-
graphic relations of upper Cretaceous and
Eocene formations, San Diego coastal area,
California. American Association of Petrole-
um Geologists Bulletin 55:709-722.

Lillegraven, J. A. 1979. A biogeographical prob-
lem involving comparisons of later Eocene ter-
restrial vertebrate faunas of western North
America. Pp. 333-347 in J. Gray and A. J.
Boucot (eds.). Historical Biogeography, Plate
Tectonics, and the Changing Environment. Or-
egon State University Press, Corvallis, Oregon.

Link, M. H., G. L. Peterson, and P. L. Abbott.
1979. Eocene depositional systems, San Di-
ego, California. Pp. 1-7 in P. L. Abbott (ed.).
Eocene Depositional Systems, San Diego, Cal-
ifornia. Pacific Section, Society of Economic
Paleontologists and Mineralogists.

MacClintock, C. 1967. Shell structure of patelloid
and bellerophontid gastropods (Mollusca).
Peabody Museum of Natural History Bulletin
22:1-142.

MacFadden, B. 1980. Rafting mammals or drift-
ing islands?: biogeography of the Greater An-
tillean insectivores Nesophontes and Solen-
odon. Journal of Biogeography 7:1 1-22.

MacFadden, B. 1981. Comments on PregilFs ap-
praisal of historical biogeography of Caribbean
vertebrates: vicariance, dispersal, or both? Sys-
tematic Zoology 30:370-372.

Marks, J. G. 1943. Type locality of the Tejon
Formation. California Division of Mines and
Geology Bulletin 1 18:534-538.

Minckley, W. L., D. A. Hendrickson, and C. E.
Bond. 1986. Geography of western North
American freshwater fishes: description and re-
lationships to intracontinental tectonism. Pp.
519-613 m C. H. Hocutt and E. O. Wiley (eds.).
Zoogeography of North American Freshwater
Fishes. John Wiley and Sons, New York.

Nilsen,T.H., and M. H. Link. 1975. Stratigraphy,
sedimentology and offset along the San An-
dreas Fault of Eocene to lower Miocene strata

of the northern Santa Lucia Range and the San
Emigdio Mountains, Coast Ranges, central
California. Pp. 367-400 //; D. R. Weaver, G.
Hornaday, and A. Tipton (eds.). Future Energy
Horizons of the Pacific Coast; Paleogene Sym-
posium and Technical Papers. Pacific Sections,
American Association of Petroleum Geolo-
gists, Society of Economic Paleontologists and
Mineralogists, Society of Economic Geologists.

Nilsen, T. H.,andE. H. McKee. 1979. Paleogene
paleogeography of the western United States.
Pp. 257-276 ini. M. Armentrout, M. R. Cole,
and H. TerBest, Jr. (eds.). Ccnozoic Paleo-
geography of the Western United States. Pacific
Coast Paleogeography Symposium 3. Pacific
Section, Society of Economic Paleontologists
and Mineralogists.

Peterson, G. L., and P. L. Abbott. 1979. Mid-
Eocene climatic change, southwestern Califor-
nia and northwestern Baja California. Palaeo-
geography, Palaeoclimatology, Palaeoecology
26:73-87.

Peterson, G. L., S. E. Pierce, and P. L. Abbott. 1975.
Paleogene paleosols and paleoclimates, south-
western California. Pp. 401-408 in D. R.
Weaver, G. Hornaday, and A. Tipton (eds.).
Future Energy Horizons of the Pacific Coast;
Paleogene Symposium and Technical Papers.
Pacific Sections, American Association of Pe-
troleum Geologists, Society of Economic Pa-
leontologists and Mineralogists, Society of
Economic Geologists.

Pilsbry, H. A. 1893-1895. Guide to the study of
helices (Helicidae, Vol. 7). Manual of Con-
chology (ser. 2) 9:1-48, pis. 1-14 [1893]; 49-
160, pis. 15-40 [1894]; 161-336, i-xlvii, pis.
41-71, frontis. [1895].

Pilsbry, H. A. 1 929. Studies on West Indian mol-
lusks: the genus Zachrysia. Proceedings of the
Academy of Natural Sciences of Philadelphia
80:581-606.

Pilsbry, H. A. 1939. Land Mollusca of North
America (north of Mexico). Academy of Nat-
ural Sciences of Philadelphia Monograph 3,
l(l):i-xvii, 1-573, i-ix.

Portig, W. H. 1976. The climate of Central Amer-
ica. Pp. 405-478 in W. Schwerdtfeger (ed.).
Climates of Central and South America. World
Survey of Climatology, vol. 12. Elsevier, Am-
sterdam.

Pregill, G. K. 1981. An appraisal of the vicariance
hypothesis of Caribbean biogeography and its
application to West Indian terrestrial verte-
brates. Systematic Zoology 30:147-155.

Rosen, D. E. 1976. A vicariance model of Carib-
bean biogeography. Systematic Zoology 24:
431^64.

Roth, B. 1981. Distribution, reproductive anat-
omy, and variation of Monadcnia troglodytes
Hanna and Smith (Gastropoda: Pulmonata)
with the proposal of a new subgenus. Proceed-
ings of the California Academy of Sciences 42:
379-407.

Roth, B. 1984. Lv5z>70^ (Gastropoda: Pulmonata)
and other land snails from Eocene-Oligocene
of Trans-Pecos Texas, and their paleoclimatic
significance. The Veliger 27:200-218.

Roth, B. 1986. Land mollusks (Gastropoda: Pul-

220

monata) from early Tertiary Bozeman Group,
Montana. Proceedings of the California Acad-
emy of Sciences 44:237-267.

Roth, B., and T. A. Pearce. In press. '"Micrarion-
ta'^ dallasi M. A. Hanna, a helicinid (proso-
branch), not a helminthoglyptid (pulmonate),
land snail: paleoclimatic implications. South-
western Naturalist.

Savin, S. M. 1977. The history of the earth's sur-
face temperature during the past 100 million
years. Annual Review of Earth and Planetary
Sciences 5:319-355.

Scotese, C. R., and C. P. Summerhayes. 1986.
Computer model of paleoclimate predicts
coastal upwelling in the Mesozoic and Ceno-
zoic. Geobyte 1:28-42, 94.

Seifriz, W. 1943. The plant life of Cuba. Ecolog-
ical Monographs 13:375-426.

Solem, A. 1966. The Neotropical land snail gen-
era Labyrinthus and Isomeria (Pulmonata, Ca-
maenidae). Fieldiana Zoology 50:1-226.

Solem, A. 1978. Cretaceous and early Tertiary
camaenid land snails from western North
America (Mollusca: Pulmonata). Journal of
Paleontology 52:581-589.

Solem, A. 1979. Biogeographic significance of land
snails. Paleozoic to Recent. Pp. 277-287 in J.
Gray and A. J. Boucot (eds.). Historical Bio-
geography, Plate Tectonics, and the Changing
Environment. Oregon State University Press,
Corvallis, Oregon.

Solem, A. 1984. A world model of land snail di-
versity and abundance. Pp. 6-22 in A. Solem
and A. C. van Bruggen (eds.). World-wide
Snails: Biogeographical Studies on Non-ma-
rine Mollusca. E. J. Brill/Backhuys, Leiden.

Steer, B. L., and P. L. Abbott. 1984. Paleohy-
drology of the Eocene Ballena Gravels, San
Diego County, California. Sedimentary Geol-
ogy 38:181-216.

Sykes, L. R., W. R. McCann, and A. L. Kafka.
1982. Motion of Caribbean plate during last
7 million years and implications for earlier Ce-
nozoic movements. Journal of Geophysical
Research 87:10 656-10 676.

van der Schalie, H. 1948. The land and fresh-
water mollusks of Puerto Rico. University of
Michigan Museum of Zoology Miscellaneous
Publication 70:1-134.

Wolfe, J. A. 1978. A paleobotanical interpretation
of Tertiary climates in the Northern Hemi-
sphere. American Scientist 66:694-703.

Wurtz, C. B. 1955. The American Camaenidae
(Mollusca: Pulmonata). Proceedings of the
Academy of Natural Sciences of Philadelphia
107:99-143.

Zilch, A. 1959-1960. Gastropoda, Teil 2, Euthy-
neura. Handbuch der Palaozoologie 6(2): 1^00
[1959]; 401-834 [I960].

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U r ' • Vblume 21 Number 1 3 pp. 221-225 24 February 1 988

Pseudotealliocaris palincsari n. sp., a pygocephalomorph
from the Pocono Formation, Mississippian of Pennsylvania

Frederick R. Schram

Department of Paleontology'. San Diego Natural History Museum,
P.O. Box 1390. San Diego. California 92112 USA

Abstract. Pseudotealliocaris palincsari n. sp., a pygocephalomorph eumalacostracan, is described
from the Mississippian Pocono Formation of Pennsylvania. This represents an increase in the geographic
range for the genus. Comparisons are made of the new species to two other recognized species of the
genus Pseudotealliocaris, P. caudafimbriata and P. etheridgei.

Introduction

The Pygocephalomorpha are among the most common of eumalacostracan crus-
taceans preserved in the nearshore and brackish water communities of the Late Paleo-
zoic (Schram 1981). Among these, the genus Pseudotealliocaris Brooks 1962 seems to
be one of the more important. It forms an important component of the Visean nearshore
marine community of the British Isles (Schram 1979, 1981), and is one of the more
commonly encountered crustaceans in the Upper Carboniferous deposits of Nova
Scotia (Copeland 1957).

The material described here comes from a bore hole drilled by the Pennsylvania
Department of Natural Resources. This Pseudotealliocaris is the only fossil material
found in the core sections referred to me for study. This report represents an extension
of the geographic range of the genus Pseudotealliocaris into the United States.

Systematic Paleontology

Order Pygocephalomorpha Beurlen, 1930

Family Pygocephalidae Brooks, 1962

Pseudotealliocaris Brooks, 1962

Type species.— Pseudotealliocaris caudafimbriata (Copeland) 1957.

Diagnosis.— CdiVdip^iCQ as wide as long, antero-lateral spines large and prominent,
mid-dorsal keel or ridge present, lateral carinae or ridges two in number. Telson with
prominent mid-dorsal ridge, with lateral sculpting of the margin to accommodate the
large lobate caudal furcae.

Remarks.— The least reliable of the above characters is that which refers to the
length and width of the carapace. This ratio, of course, is subject to the vagaries of
preservation and compression. However, all previous authors who have dealt with the
genus mention this feature. To be able to assess this feature in the way most authors
have done requires that the branchiostegal areas of the carapace be spread laterally in
a manner quite atypical of what its position must have been in life.

Pygocephalomorpha is treated here as an order, as suggested by the cladistic anal-
yses of Schram (1984, 1986). The exact relation of the pygocephalomorphs to the other
"mysidacean" orders is still the subject of some speculaton.

222

Figure 1. Pseudotealliocahs palincsari, n. sp. (A) SDSNH 26262, holotype, x5.3. B, C. SDSNH 26271a,
paratype, (B) cephalothorax, x 10.8, (C) antennules (a,), antennae (a.), scaphocerite (sc), antennule pendun-
cular segments (1-3), base of rostrum (r), anterolateral spine of carapace (als) x27.0. (D) SDSNH 26272a,
paratype, tailfan, sixth pleomere (P6), uropodal protopod (pr), uropodal exopod (ex), uropodal endopod (en),
telson (t), primary furca (f,), secondary furca (fj), terminal spine (s), x 19.0.

Pseudotealliocaris palincsari, new species
Figures 1, 2

//o/o?y;7^.- SDSNH 26262 (Figure lA).

Additional material. -SDSNH 26261, 26263-26272.

Locality. —Bore hole number 6, Pennsylvania Department of Natural Resources;

223

Figure 2. Pseudotealliocaris palincsari reconstruction. Scale represents 5 mm.

depth 607-613 ft.; 41°12'57"N, 78°55'16"W, PA miles northwest of Aliens Mills, War-
saw Township, Jefferson Co., Pennsylvania.

Stratum.— Lower Pocono Formation, Kinderhookian, Mississippian.

Diagnosis. —Cuticle smooth. Carapace with weakly-developed cervical grooves and
mid-dorsal ridge, inferior lateral ridges located close to lateral margins, lateral margins
not serrate. Rostrum of moderate size and slightly falciform, base delineated by grooves.
Telson with terminal spine.

Etyinolog)'. —Named in honor of my former professor. Dr. Edward Palincsar,
Loyola University of Chicago.

Description.— The cuticle is smooth, without any pits or papillae. The carapace
(Figure IB) is marked with a weakly developed mid-dorsal ridge. The lateral ridges are
robust, though the inferior lateral ridges are located close to the lateral margins. The
posterior and lateral margins of the carapace are marked by furrows, and the posterior
margin is markedly concave. The cervical grooves of the carapace are weakly developed,
and lie less than Va the total carapace length from the anterior margin. The rostrum is
short (less than V^ the length of the carapace), somewhat falciform, with its base de-
marcated by grooves (Figure IC).

The antennules have a well-developed peduncle of three segments (Figure IC).

224

Table 1 . Structural differences noted between the three recognized species of Pseudotealliocaris.

caudafimbriata

etheridgei

palincsari

Cuticle

pitted

smooth

Lateral margins

serrate

non-serrate

Cervical groove

■« 'A from anterior

'/4 from anterior

-« 'A from anterior

Rostrum/carapace length

0.34

0.32

0.18

Rostrum base

grooved

no grooves

grooved

Abdominal tergites

median ridge

strong lateral ridges

median ridge

Telson terminus

lobed

spined

Diaeresis

circular

sigmoid

Uropodal rami reinforcing ridges

prominent

weak

prominent on
endopod only

The antennae have broad setose scaphocerites (Figure IC), and the flagella are long
and quite robust. The stalked compound eyes are spherical and only moderate in size
(SDSNH 26267a).

The females bear oostegites (SDSNH 26265a, 26270a).

The abdominal tergites are without decoration except for a faint mid-dorsal ridge.
The pleura are rounded anteriorly and pointed posteriorly, and are somewhat demar-
cated from the tergites proper by a very faint groove.

The telson has a prominent mid-dorsal ridge, and bears deep lateral indentations
that extend close to the base of the telson and that accommodate the furcae. The telson
distally bears a ridged spine. The anterior furcae are large, elongate lobes with very
long setae (Figure 1 D). There is a much smaller secondary set of furcae (SDSNH 26272a,
Figure ID) located distally on the telson. The uropodal protopods are marked by a
comma-like ridge on the dorsal surface. The uropodal rami are setose: the exopod has
a reinforced lateral margin, a faint median ridge, and a sigmoid diaeresis; the endopod
bears a well-developed median ridge.

A reconstruction of P. palincsari is offered in Figure 2.

Discussion

Three species are now recognized within the genus Pseudotealliocaris. In addition
to P. palincsari, there is also P. caudafimbriata (Copeland) 1957, from the Canso Group,
Namurian, Upper Carboniferous, of Nova Scotia; and P. etheridgei (Peach) 1882 of
the Tournesian and Visean, Lower Carboniferous, of Scotland and northern England
(see also Peach 1908). These latter two species o^ Pseudotealliocaris are characterized
by thin, poorly sclerotized cuticles, which generally are preserved rather poorly. The
exceptional preservation noted for P. palincsari is due to pyrite replacement.

The morphological differences among the three recognized species are outlined in
Table 1 . In regard to the location of the cervical grooves, the grooving around the
rostrum base, median ridge on the abdominal tergites, and the character of the uro-
pod rami, P. palincsari resembles P. caudafimbriata. Only the probably primitive feature
of a non-serrate lateral margin on the carapace is shared between P. etheridgei and P.
palincsari. In addition, P. palincsari is uniquely characterized by the retention of several
primitive features such as a smooth and unpitted carapace, unpitted abdominal tergites,
and short rostrum. P. palincsari is apparently specialized in regards to the weak de-
velopment of the cervical grooves and the styliform terminus of the telson.

Acknowledgments

This material was collected by and offered to me for study by Dr. A. D. Glover,
Head Coal Geologist, Pennsylvania Department of Natural Resources; and was orig-
inally brought to my attention by Dr. W. D. I. Rolfe, Hunterian Museum Glasgow
while a visiting researcher at the Field Museum of Natural History in Chicago. Research
was supported in part by NSF grant BSR 82-12335. The reconstruction was drawn by
Michael J. Emerson.

225

Literature Cited

Brooks, H. K. 1962. The Paleozoic Eumalacos-
traca of North America. Bulletins of American
Paleontology 44:163-338.

Copeland, M. J. 1957. The arthropod fauna of the
Upper Carboniferous rocks of the Maritime
Provinces. Geological Survey of Canada Mem-
oirs 286:1-110.

Peach, B. N. 1 882. On a new Crustacean from the
Lower Carboniferous rocks of Eskdale and Lid-
desdale. Proceedings of the Royal Society of
Edinburgh 30:73-91.

Peach, B. N. 1908. A monograph on the higher
Crustacea of the Carboniferous rocks of Scot-

land. Memoirs of the Geological Survey of Great
Britain, Palaeontology 1908: 1-82.

Schram, P. R. 1979. British Carboniferous Mala-
costraca. Fieldiana: Geology 40:1-129.

Schram, F. R. 1981. Late Paleozoic crustacean
communities. Journal of Paleontology 55:126-
137.

Schram, F. R. 1984. Relationships within eu-
malacostracan Crustacea. Transactions of the
San Diego Society of Natural History 20:301-
312.

Schram, F. R. 1986. Crustacea. Oxford Univer-
sity Press, New York, pp. 1-606.

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Volume 21 Number 14 pp. 227-244 24 February 1988

A new species of hagfish, genus Eptatretus (Cyclostomata, Myxinidae),
from the Pacific Ocean near Valparaiso, Chile, with new data on
E. bischojfii and E. polytrema

Robert L. Wisner and Charmion B. McMillan

Marine Biology Research Division, A-002, Scripps Institution of Oceanography,
La Jo/la, California 92093

Abstract. — A new species of hagfish of the genus Eptatretus, E. nanii, is described from the Pacific
Ocean near Valparaiso, Chile, and a key to the eastern South Pacific species is given. New data are
presented for E. polytrema and E. bischoffii. A neotype is designated for E. polytrema. The extensive
use of the name polytrema for polybranchiate mixinids from the Chilean area is clarified.

The efferent duct of the posteriormost left gill pouch is separate from that of the pharyngocutaneous
duct in 100% of £■. bischoffii, in 61% of £■. nanii, and in 9% of £■. polytrema, but almost never in other
known species of Eptatretus.

Resumen. — Se describe una nuevo especie de babosa de mar del genero Eptatretus, E. nanii,
obtenida en el Oceano Pacifico cerca de Valparaiso, Chile, y se incluye una clave de identificacion de
las especies del Pacifico sureste. Se presentan nuevos datos sobre las especies E. polytrema y E. bischoffii.
Se designa un neotipo para E. polytrema. Se aclara el uso del nombre polytrema para mixinidos
polibranquios del area chilena. El ducto eferente del saco de la ultima branquia izquierda posterior esta
separado del bolsillo del ducto faringocutaneo en 100%, 61% y 9% de los individuos de las especies E.
bischoffii, E. nanii y E. polytrema, respectivamente, caracteristica muy raramente encontrada en las
otras especies de Eptatretus.

Introduction

Hagfishes are primitive eel-like agnathous vertebrates that are cartilaginous, en-
tirely marine, and bottom dwelling. They lack jaws, have three paired sets of sensory
barbels around the mouth and feed on invertebrates and dead or moribund fishes. Two
sets of keratinous teeth (cusps), one on each side of the mouth, are attached to dental
plates, which in turn attach to the anterior end of the dental muscle, a sub-cylindrical
complex of muscles and cartilages (the club-shaped muscle, lingual muscle, or great
muscle mass, of authors) which laterally evert and retract the two sets, providing a
biting-cutting mechanism for feeding. Hagfishes are essentially blind, with rudimentary,
light sensitive eyes embedded in the flesh of the head and covered with integument
usually less pigmented than the surrounding tissue especially in the genus Eptatretus,
but not in the genus Myxine. Internal gill pouches are supplied with water entering the
nasopharyngeal aperture above the mouth and by a velum in the pharynx which acts
as a pump. Discharge (posteriorly) is via one or more pairs of adjacent openings to the
exterior (branchial apertures) and the pharyngocutaneous duct, an enlarged opening
confluent with or contiguous to the last (or only) aperture on the left side. There is a
row of internal, mucus-secreting (slime) glands and associated external pores, usually
one per body segment, on each side. Habitat is usually soft mud at depths of 10 to
2000 m. In colder waters some species live in shallow depths (5 m) and among rocks.

Six genera of myxinoids, totalling about 37 species (about 15 in the genus Epta-
tretus), are currently recognized but the alpha taxonomy is uncertain due to a paucity
of collections and lack of published data. In addition, three new species o^ Eptatretus
and one oi Myxine are being described (Wisner and McMillan, in prep.).

228

This study of Eptatretus from the Pacific Ocean near Valparaiso, Chile, is one of
a series resulting from specimens and data largely accumulated under the direction of
the late Carl L. Hubbs. Herein we describe a new species, E. nanii, and present new
data on E. polytrema (Girard 1854) and E. bischoffii (Schneider 1880). As the putative
type specimen of £". polytrema (USNM 78530) differs from Girard's description, and
cannot in fact be the holotype, we designate a neotype (SI084-243) for E. polytrema
in order to stabilize that name. Also, we clarify the use of the species name polytrema.
Confusion has arisen because most polybranchiate hagfishes collected near Valparaiso
have been placed in synonymy with Bdellostoma polytrema Girard (1854:199; 1855:
252-253, pi. 3, figs. l-5b). We also make a nomenclatural correction of the gender
ending of the species name Eptatretus laurahubbsae McMillan and Wisner 1984 in
accordance with Article 31 a ii of the International Code of Zoological Nomenclature.

Abbreviations. —FCD: external opening of the pharyngocutaneous duct; ordinarily
confluent with the posteriormost left gill aperture, and much larger than all other
apertures.

GA: gill (branchial) aperture; external opening of the efferent duct leading from a
gill pouch.

GP: gill pouch; rounded, serially arranged structures along and posterior to the
dental muscle.

DM: dental muscle; the firm, elongate, cylindrical complex of muscles and cartilages
that moves the dental plates and sets of cusps during feeding. Posterior portions of
DM are shown in Figure 3 lying between the rows of gill pouches.

VA: ventral aorta; the portion between the heart (ventricle) and where it branches
to each side of DM.

ABA: afferent branchial artery; one of the small blood vessels that lead to each gill
pouch from VA or its branches.

Methods and Materials

Methods of measuring and counting are essentially those reported by McMillan
and Wisner (1984) with the following modification: In the present study we use only
the midline incision (of the two incisions for cusp study discussed previously) which
is faster and does much less damage to the specimen. There is almost no bilateral
variation in counts, thus any confusion caused by the "reverse image" would be in-
significant. It is essential to continue the midline incision posteriorly to slightly past
the branchial openings in order to make an accurate count of the gill pouches and
observe their relationship to the dental muscle and ventral aorta.

Due to variability in confluence in external discharge of the efferent duct of the
last gill pouch, left side, and the opening of the pharyngocutaneous duct, we have given
only the count for gill pouches (Table 1). Thus for E. polytrema the total of exterior
openings (left side) would range from 1 3 to 15, but the range 1 3-14 in Table 1 represents
the actual number of gill pouches.

Features used in counts and measures are shown in Figure 1 and abbreviations
are identified in Figures 2 and 3.

As stated by McMillan and Wisner (1984:251, 255), the external opening of PCD
ordinarily is confluent with that of the posteriormost left GA and the number of internal
GP usually is the same as that of the GA with only slight variation. Normally, PCD
is included in the count of the left GA. However, in our material, there is considerable
variation in the relationships of the last GA and PCD. In all 35 specimens of £". bischoffii
examined by us the two are separate. Often the last GA is a narrow slit very closely
adjacent to PCD, but it retains its own efferent duct to the exterior from the last GP.
In E. polytrema, seven of 18 specimens (39%) have the efferent ducts of the last GP
and the PCD confluent, and in E. nanii, 20 of 22 specimens (91%) those of the last
GP and PCD are confluent.

Such variation presents problems in counting the GA. The PCD of E. bischoffii

229

Table 1 . Number of gill pouches, prcbranchial, branchial, trunk, tail, and total slime pores for three species
of hagfishes (genus Eptatretus) from the Pacific Ocean near Valparaiso, Chile. Counts for E. polytrema
and E. nanii include those for left and right sides; counts for E. bischoffii represent the left side only.
(Values for type specimens are indicated by an asterisk.)

Gill pouches

E. polytrema
E. nanii
E. bischoffii

12
35*

24*

36
47
70

13.67
\1.1A
10.10

0.47
0.44
0.30

Prebranchial slime

pores

11 12

E. polytrema
E. nanii
E. bischoffii

10*

1
18*

14*

2 1
8 16

32
42
35

1.11

9.33

12.09

0.86
0.89
0.96

Branchial slime pores

11 12

E. polytrema
E. nanii
E. bischoffii

1 7
8* 30*

23*
3

34
41

12.82

11.88

9.06

0.62
0.50
0.41

Trunk slime pores

43 44

E. polytrema
E. nanii
E. bischoffii

5
5

10*
5
3

7
7
5

10
5

2 2
7 6*
6 9

1
3

1
2

34
46
31

41.03

Aim

41J7

0.15
0.20
0.16

Cloacal slime pores

E. polytrema
E. nanii
E. bischoffii

5
28*
14

26*
14*
16

34
42
33

3.94
3.33
3.58

0.48
0.47
0.65

Caudal slime pores

12 13

E. polytrema
E. nanii
E. bischoffii

2
2

4
6
9

11*

25
15

12*
8*

2 1

34
42
34

10.41

9.88

10.15

0.11
0.85
0.97

Total tail pores

16 17

-Y

E. polytrema
E. nanii
E. bischoffii

1
5

19
9

14*
15*
18

10*
1*
3

3 1

34
42
33

14.35
13.19
13.88

1.03
0.85
0.84

Total sli

ime pores

77 78

81 82 83 n

E. polytrema
E. nanii
E. bischoffii

2
1

4*
2

10
5
1

4*
10
■5

2 4
5 1
8 5

2*
3

3
3

1 41

1 32

75.58
76.71
77.84

2.04
2.44
2.06

does not represent a GA and normally would not be counted. But, in E. nanii the last
GA is seldom separate from the PCD (two of 22 specimens), and for practical purposes
the PCD may be included in the count of GA. The high incidence of non-confluence

230

Figure 1 . Outline of a hagfish {Eptatretus) showing regions and features used in measuring and counting:
A-H, total length (TL); A-B, prebranchial length; B-C, branchial length, including gill apertures (GA); D,
external opening of pharyngocutaneous duct (PCD); E, ventral finfold; C-F, trunk length; F, origin of cloaca;
G, caudal finfold. The linear series of dots represents the prebranchial, trunk, and cloacal-caudal (tail) slime
pores.

Figure 2. Branchial area (E. bischoffii), showing features discussed in text: A, pharynx; B, afferent duct and
gill pouches (GP); C, afferent branchial artery (ABA); D, left branch of ventral aorta; E, efferent duct from
last gill pouch; F, ventral aorta (VA), very short in E. bischoffii; G, duct leading from pharynx to external
opening (PCD); H, ventricle (V). Dental muscle (DM) not shown.

231

Figure 3. Branchial areas, showing arrangements of DM, VA, and GP in: A, E. polytrema; B, E. nanii;
C, E. bischoffii (DM often overlies VA). DM is the cylindrical mass lying between the rows of gill pouches.

(61%) in E. polytrema means that counts will often be inaccurate. An accurate count
requires dissection and examination of the efferent ducts on the left side.

Head grooves.— Ayers and Worthington (1907:331, figs. 5-10) referred to lines in
the skin of the head near the eyespots of Bdellostoma Dombeyi {^Eptatretus stoutii
(Lockington 1878)] as lateral line canals. McMillan and Wisner (1984:255) used the
term sensory canals in reference to these lines. In a study we had overlooked, Bullock
et al. ( 1 982) found no electroreceptive capacity in E. stoutii. Fernholm (1985) examined
the lateral line systems of cyclostomes by transmission electron microscopy and found
that there are no canals in E. stoutii or E. burgeri and that the lines are non-innervated
grooves containing no neuromasts; he referred to the lines as lateral line grooves. We
accept this evidence as lack of sensory capacity and adopt the term "head grooves" in
lieu of sensory canals.

Head grooves of the three species treated here are very similar in size, number,
and arrangement to those shown by McMillan and Wisner (1984, fig. 4) and by Ayers
and Worthington (1907, figs. 5-6) for other species of Eptatretus. In no species did a
groove extend across the dorsal midline.

Collection data and disposition of specimens examined in this study are listed in
the treatment of each species. Institutions which have furnished study material, or in
which type specimens have been deposited, are: Scripps Institution of Oceanography,
La Jolla, California (SIO); California Academy of Sciences, San Francisco, California
(CAS); Natural History Museum, Los Angeles County, Los Angeles, California (LACM);
National Museum of Natural History, Washington, D.C. (USNM); Museo Nacional
de Historia Natural, Santiago, Chile (MNHNC); Zoological Institute, Academy of
Sciences, Leningrad, USSR (ZIL); Gulf Coast Research Laboratory, Ocean Springs,
Mississippi (GCRL).

232

Discussion of synonymies.— TYvq problem of including PCD in the count for GA
affects the construction of meaningful synonymies for E. polytrema and E. nanii. Only
two authors who may have had these species (Dean 1903, Buzeta 1964) included
remarks on color, and only seven gave counts of 14 gill apertures. The color notes
almost certainly pertain to E. polytrema. No author stated that the PCD was included
in the count for GA.

An accurate synonymy may be available only for E. bischoffii, based on stated
counts of 10 GA. Other authors apparently followed Regan (1912) who gave 10 GA
for Heptatretus decatrema, and used the name decatrema under various genera. Un-
fortunately, Regan (1912) gave no counts of GA, or indication of having counted them.
We must assume that these authors merely followed prior references. Thus, the citations
are not includable in an accurate synonymy.

Since none of the 47 individuals of £". nanii examined have 14 GA, all references
stating 14 GA are placed in the synonymy of £". polytrema. We find no statements of
numbers of GA other than 14. Only one questionable reference (Perez Canto 1912)
may pertain to E. nanii (13 GA).

Of a total of 8 1 citations listed here dealing with polybranchiate myxinids from
the coast of Chile, only 22 (32%) included information on counts of GA or color notes,
and can be placed in the synonymies of E. bischoffii or E. polytrema. The remaining
59 citations are listed separately under the heading of "Unassignable Records."

Key to Species of Eptatretus of the Eastern South Pacific Ocean

la. Gill apertures seven. Two (rarely three) fused cusps on anterior, and three on

posterior multicusps. Total slime pores 97-105

E. laurahubbsae McMillan and Wisner 1 984

lb. Gill apertures 9-15. Always three fused cusps on anterior and posterior mul-
ticusps. Total slime pores 68-86 2

2a. Prebranchial and tail lengths each greater than branchial length. Posteriormost
gill aperture (left side) separate from, but closely adjacent to, pharyngocuta-
neous duct. Gill apertures 10 (9-11). Ventral finfold absent or scarcely de-
veloped E. bischoffii (Schneider 1 880)

2b. Prebranchial and tail lengths each less than branchial length. Posteriormost
gill aperture (left side) widely separate from pharyngocutaneous duct. Ventral
finfold absent to well developed. Gill apertures 12-15 3

3a. Color variably piebald over a dark background. Prebranchial slime pores 7-
8 (6-9). Gill apertures 14(13-15). Ventral finfold varying from absent to well
developed E. polytrema (Girard 1 854)

3b. Color black or dark purplish-brown, not piebald. Prebranchial slime pores 9-
10 (8-12). Gill apertures 13 (12-14). Ventral finfold absent or vestigial ....
E. nanii, new species

Although the characters, singly or in combination, of the three species discussed
below {E. laurahubbsae will not be further discussed), are adequately expressed in the
key to species, there is slight to considerable overlap in most counts and body pro-
portions. There is, however, no overlap in numbers of gill pouches between E. bischoffii
and the other two species (Table 1 ), and all three show no overlap in numbers of gill
pouches in positions relative to DM and VA (Table 3, Area III).

The three species of the polytrema complex maybe distinguished by meristic char-
acters. There are significant {P > .001) differences in numbers of gill pouches, slime
pores, and teeth (Tables 1 and 2). The ranges of gill pouches for E. polytrema and E.
nanii (12-14) do not overlap with that of £". bischoffii and the means for E. polytrema
and E. nanii (13.67 and 12.74 respectively) differ. Similarly, E. bischoffii can be dis-
tinguished from the other two species on the basis of mean numbers of prebranchial
and branchial slime pores and anterior unicusps. Eptatretus nanii and E. polytrema
differ in mean numbers of prebranchial slime pores, anterior unicusps and total cusps.

The greatest differences in body proportions lie in E. bischoffii having the pre-

233

Table 2. Number of unicusps in the anterior and posterior sets of cusps, and of total cusps, of three species
of hagfishes (genus Epiairciiis) from the Pacific Ocean near Valparaiso, Chile. (Values for type specimens
are indicated by an asterisk.)

Anterior unicusps

E. polytrema
E. nanii
E. b i sell off li

29*

1
53

3
14

26*

35
44
66

9.00

10.70

8.94

0.41
0.62
0.49

Posterior unicusps

E. polyirema
E. nanii
E. bischoffii

2*
3
11

29*
23*
45

4
17
10

36
44
66

9.00
9.36
8.98

0.53
0.64
0.56

Total cusps

50 51 52

E. polytrema
E. nanii
E. bischoffii

10
17

1
2

1 1

1 6 5*

1 1 1

18
22
33

47.94
52.00
47.88

1.22
1.60
1.53

branchial and tail lengths each greater than the branchial length. The reverse occurs in
E. nanii and E. polytrema. All other proportions of the three species are very similar.
Body color is useful in separating the three species: E. polytrema is notably piebald
(Figure 4); E. nanii is uniformly black or very dark-purplish brown; E. bischoffii is dark
with randomly scattered minute pale spots and areas, primarily in the anterior ventral
region.

Figure 4. Contrast in piebald color patterns in E. polyirema. The two specimens were taken together
(SI072-148).

234

Table 3. Number of GP (both sides included) in positions relative to DM and VA in Eptatretus polytrema,
E. nanii, and E. bischoffii. AREA I— anterior to tip of DM; AREA II — between tip of DM and branching
of VA; AREA III — VA posterior to branching. Boundaries of AREAS I, II, III are indicated in Figure 3.

5 6

AREA I

E. polytrema

1 7

7.96

1.23

E. nanii

17 15

5.39

0.68

E. bischoffii

3 5
AREA II

7.82

1.82

E. polytrema

7 1

3.08

1.34

E. nanii

1.33

0.62

E. bischoffii

4 3
AREA III

2.20

1.76

E. polytrema

2.52

0.83

E. nanii

4 16

6.47

0.93

E. bischoffii

0.00

Systematics

Eptatretus nanii, new species

Homea polytrema. Perez Canto 1912:1230, 1238 (anguilla negra; Bahia de Arauco, coast of
Anconcagua [E. nanii presumed].

Holotype.—Sl065-675, female, 609 mm TL, taken about 33.4 km seaward of
Valparaiso, Chile, in a commercial shrimp trawl at 274 m, 22-23 December 1965.

Pamtypes.—Sl065-675, female and three males, 510-593 mm TL, taken with the
holotype; SI08 1-104, mature female, 664 mm TL, taken at 350 m (no other data);
SI084-244, male, 541 mm TL, taken near Valparaiso, Chile, between 100 and 250 m
(no other data); SIO85-60, female, 561 mm TL, taken at 33°09'S, 7r51'W, in a 72 ft
shrimp trawl between 170 and 180 m, 1 August 1966; CAS 5612, two females, 486
and 590 mm TL, taken at 33°22'S, 7r52'W, in a 72 ft shrimp trawl between 260 and
270 m, 1 August 1966; LACM 43776-1, two, 570-640 mm TL, taken at 33°09'S,
7r51'W, in a 72 ft shrimp trawl between 170 and 180 m, 1 August 1966; USNM
272583, 6 specimens, 450-610 mm TL, taken at 33°09'S, 7r21'W, in a 72 ft shrimp
trawl between 170 and 180 m, 1 August 1966; GCRL 12464, mature female, 619 mm
TL, found in a fish-meal plant, San Antonio, Valparaiso Bay, Chile, 21 March 1974;
MNHNC (S) P. 6378, male, 6 14 mm TL, taken at 35°26.5'S, 73°01 'W, in a 72 ft shrimp
trawl between 290 and 450 m, August 1966; MNHNC (S) P. 6381, male, 570 mm TL,
taken at 28°03'S, 7ri5'W, at 505 m, 16 January 1981; MNHNC (S) P. 6382, mature
female, 600 mm TL, taken at 36°07.3'S, 73°05'W, in a shrimp trawl at 301 m, 20 April
1983.

Distribution.— Al\ specimens were taken between Valparaiso, Chile, south to
36°26.5'S, 73°05'W, at depths ranging between 100 and 470 m. E. nanii was taken
once with E. polytrema at 33°22'S, 7r52'W, in a 72 ft shrimp trawl between 260 and
270 m.

Diagnosis.— External apertures 13, 13 (13-14); gill pouches 13, 13 (12-13). Body
robust, deepest at about midlength. Branchial length greater than either the prebranchial
or tail lengths. Three fused cusps (multicusps) on both the anterior and posterior sets
of cusps. Color black or very dark purplish-brown with no indication of pale markings.
Ventral finfold variably absent to vestigial. Head grooves present near eyespots. Efferent
duct of last GP, left side, confluent with that of PCD in 91% of specimens (20 of 22).

Etymology.— Wq are pleased to dedicate this species to Professor Alberto Nani
Caputo, formerly of the Department of Oceanography, University of Chile, Vifia Del
Mar, for his early work on the Myxinidae of Chile, for his considerable aid to us via
correspondence with Carl L. Hubbs, and for providing specimens.

235

Table 4. Averages and ranges (in thousandths of total length) of selected body proportions for three species
of hagfishes (genus Eptatretus) from the Pacific Ocean near Valparaiso, Chile. *Finfold measureable on
only 7 of E. polytrema and 6 of E. nanii.

n. size ranges (mm)

19 (289^60)

E. polytrema

Mean av. (range)

22 (446-664)

E. nanii

Mean av. (range)

34 (210-680)

E. bischoffii

Mean av. (range)

Preocular length

Prebranchial length

Branchial length

Trunk length

Tail length

Tail depth

Body depth excluding finfold

Body depth including finfold

Body depth at cloaca

Length of dental muscle

55 (44-67)
155 (139-169)
182 (168-201)
499 (478-530)
152(127-179)
71 (57-86)
89 (68-109)
90(68-109)*
62 (49-80)
262 (228-305)

51 (40-61)
144(128-156)
192 (175-220)
504 (475-529)
162(152-173)
79 (62-92)
84 (73-99)
89 (73-102)*
60 (42-76)
222 (202-260)

58 (40-66)
202(176-224)
135 (114-161)
499 (450-542)
168(140-218)
71 (56-83)
89 (71-112)
90(76-112)
67 (56-87)
294(251-357)

Description.— Counts (Tables 1-3) and morphometries (Table 4) are given and
compared with similar counts for E. polytrema and E. bischoffii. Body robust, deepest
at about PCD, increasingly laterally compressed toward tail; greatest width about 70%
of greatest depth. Ventral finfold absent or vestigial, usually present only as a thin, pale
line originating at about anterior 40% of TL and ending at cloaca. In a few specimens
the finfold is about 1 mm high. Tail spatulate, its ventral outline nearly straight, its
depth 1.3 (1.0 to 1.6) times body depth at cloaca, its length about 16% (15-17%) of
TL, and slanting downward from cloaca. A thin finfold present around tip of tail, ending
dorsally about over cloaca. A narrow, pale margin present on caudal finfold of many
specimens; it is absent on the holotype.

Head at eyespots slightly deeper than wide, narrowing slightly to the rostrum.
Nasopharyngeal aperture broad, about half the width of head at eyespots. Face sloping
at about a 45° angle. Eyespots large but margins vaguely defined, minimally contrasted
with background. First two pairs of barbels about equal in length, each about 70% of
length of third pair.

Color very dark brown, almost purplish-black in some specimens; others are a
lighter brown, but apparently this is an artifact of preservation as data sheets prepared
in 1971 state "black" for all specimens. No pale spots or areas (piebald condition)
evident. Gill apertures with pale narrow margins; most slime pores appear whitish at
centers. Distal half of all barbels whitish.

Head grooves behind eyespots in all specimens in good condition. They also occur
before eyespots on most specimens, but often only on one side. The grooves are difficult
to see, particularly before eyespots, even on only moderately wrinkled specimens.
Arrangement and number of grooves similar to that of £". polytrema and E. bischoffii.
From 1 to 5 grooves occur before eyespots and 1 to 7 behind. Most of those before
eyespots lie along the longitudinal axis; those behind are primarily vertical.

Length of DM 22% (20-26%) of TL. DM width 16% (13-22%) of its length, its
depth 57% (45-64%) of its width. VA long, 38% (31-50%) of length of DM, branching
near tip of DM. An average of 6.4 (4-9) GP lies between ventricle and branching of
VA, 1 (0-3) lies between branching and DM, and 5.5 (4-7) lie anterior to tip of DM
(Fig. 3B).

£■^^5. —Large eggs are present in six females. Total length (TL), numbers of eggs
and dimensions of the largest egg are given; SI067-675, 593 mm TL, 33, 27.0 by 6.5
mm; SIO81-104, 664 mm TL, 23, 16.0 by 3.5 mm; SIO85-60, 561 mm TL, 38, 16.5
by 5.0 mm; GCRL 12464, 629 mm TL (number of eggs not recorded), 24.0 by 5.8
mm; LACM 43776-1, 582 mm TL, 22, 21.5 by 5.5 mm; USNM 272583, 612 mm TL,
31, 17.5 by 3.8 mm. Polar caps are well developed but there is no evidence of anchor
filaments (hooks) at capsule ends of any egg, as shown by Dean (1899:234, figs. 9-18,
pi. 1 5) and Jensen ( 1 966:90). [This latter reference was incorrectly cited as A. Jespersen,

236

1975, by McMillan and Wisner, 1984. Jespersen's study dealt only with spermiogene-
sis.] An unidentified nematode, about 20 mm long, was coiled among the eggs in a 664
mm female.

Food items. —A female, 585 mm TL (SIO85-60), had ingested a juvenile macrourid
195 mm long. About 35 mm of the long, slender tail protruded from the cloaca. The
head is missing but the body is relatively intact with minimal damage from digestive
action. There are no bones in the gut that can be related to the head of a macrourid
fish; perhaps some predator had bitten off the head and did not ingest the body. It is
of interest that the fish had been ingested tail first. The only other food item present
was the posterior portion of a small, shrimp-like crustacean lying anterior to the mac-
rourid.

Eptatretus bischoffii (Schneider 1880)

Bdellostoma polytrema not of Girard. Putnam 1874:160 (10 gills, each side; description; eggs;
suggests that Girard ( 1 854, 1855) included some mucus pores in his count of 14 gill openings).

Bdellostoma bischoffii Schneider 1880:1 15-1 16 (original description; 10 gill openings, each side;
no locality); Plate 1896:16-21, figs. 1-4 (detailed description of eggs presumed to be of this
species; Talcahuano Bay on mud bottom in 8 fathoms; Coquimbo south to Tierra del Fuego.

Heptatretus decatrema. Regan 1912:535 (original description; 1 0 gill openings; Chile; i^^e/Zosromfl
polytrema (non Girard), Putnam).

Eptatretus dombeyi (Shaw). Fowler 1940:743, fig. 1:744 (in part; fig. 1, drawing by Richard of
example from Napon Bay, Valparaiso, Chile, January 28, 1839; 10 gill openings shown).

Polistotrema polytrema not of Girard. deBuen 1961:105-110 (10(14?) openings; figure from
Girard 1855; reference to original account and number of gill openings questioned; reddish-
brown when fresh, dark-leaden in formalin; extensive synonymy; vernaculars; Valparaiso,
Chile).

Bdellostoma decatrema. Adam and Strahan 1963; 6(10 pairs of gills; length to 480 mm; Chile);
Rauther 1924:685 {=B. bischoffii?; 10 gill openings, each side; coast of Chile).

Polistotrema decatrema. Buzeta 1964:49-58, fig. 1, pi. 1 (in part; material with 9-1 1 gill openings
only; characters; compared to P. polytrema, with 13 to 14 gill openings; Coquimbo to Puerto
Montt, Chile).

Validity of name.— We use the name bischoffii, applied by Schneider (1880:1 15-
116) to a hagfish with 10 gill openings, presumably from off Southern Chile, despite
the fact that the name has been used only twice before (Plate 1896:16-21) Rauther
(1924:685). To our knowledge, this is the only hagfish having 10 gill openings. Ap-
parently the name was overlooked by Regan (1912:535) when he described Heptatretus
decatrema new species, characterized in part as having 10 gill openings. Subsequent
authors have applied a variety of names to this species. Inasmuch as the literature on
this species is limited, stability is hardly threatened by replacing the specific name
decatrema by its senior synonym bischoffii.

Material examined. -S1065-669, female, 276 mm TL, taken at 32°51'S, 72°08'W,
in a 5 ft Agassiz beam trawl at 30 m, 19 December 1965; SI065-673, two females,
212 and 31 1 mm TL, taken in Valparaiso Harbor, Chile, in a trap at 30 m, 23-24
December 1965; SI065-676, female, 244 mm TL, taken in Valparaiso Harbor, Chile,
in a trap at 30 m, 24 December 1965; SI065-678, two females, 313 and 346 mm TL,
taken at La Ventana, 30 miles North of Valparaiso, Chile, in a tidepool at 10 m, by
fish poison, 28 December 1965; SI072-148, five females, 215-580 mm TL, taken in
Bahia Inglesa, Chile, 27°07'S, 70°55'W, in a trap at 20m, 9-10 April 1972; SI072-149,
five males, 385-466 mm TL, and five females, 372-590 mm TL, taken in Bahia Inglesa,
Chile, 27°07'S, 70°55'W, in a trap at 8 m, 9-10 April 1972; SIO72-150, male, 482 mm
TL, taken in Bahia Inglesa, Chile, 27°07'S, 70°55'W, in a trap at 12 m, 9-10 April
1972. SI077-94, female, 331 mm TL, taken near Valparaiso, Chile, at 50 m (no other
data); SI08 1-101, juvenile, 1 13 mm TL, taken at 10 m in a tidepool near Montemar
Laboratory, Univ. Chile, Vifia del Mar (no other data); SI08 1-102, female, 485 mm
TL, taken at 6 m, near Montemar Laboratory, Univ. Chile, Vifia del Mar (no other
data); SI085-12, 9 specimens, 418-605 mm TL, taken in Bahia Concepcion, Isla
Quiriquiiia, Chile, at 10 m in a net over rocky, algae covered bottom, 5-10 April 1972;

237

ZIL 3 14-960, male, 500 mm TL, taken from a dry dock at Talcahuano, Chile. Provided
by A. P. Andriashev, Zool. Inst., Acad. Sci. U.S.S.R.; PM-4 1 3 (Univ. Austral de Chile),
juvenile, 320 mm TL, taken at Manquillahue, near Valdivia, Chile, 14 June 1976 (no
other data); PM-30 (Univ. Austral de Chile), two juveniles, 2 1 0 and 280 mm TL, taken
at Mehuin, near Valdivia, Chile, 6 July 1961 (no other data); PM-61 (Univ. Austral
de Chile), male, 680 mm TL, taken at Mehuin, near Valdivia, Chile, 3 December 1961
(no other data); USNM 75380, 440 mm TL, sex unknown, taken near Valparaiso,
Chile, U.S. Naval Expedition (no other data).

Distribution.— Pacific Coast of Chile between about 27°S and 42°S (Caldera to
Puerto Montt). Plate (1896) stated, "Coquimbo southward to Tierra del Fuego."

Z)/'^^/705/.9. — External gill apertures and gill pouches 10(11). Last gill aperture, left
side, closely adjacent to, but separate from, pharyngocutaneous duct. Prebranchial and
tail lengths each greater than branchial length. Body robust throughout. Ventral finfold
absent or very weakly developed. Color purplish-black, with pale areas and spots,
principally at mouth and on ventral surface anterior to gill apertures. Spots sparsely
scattered over body.

Description. —Counls (Tables 1-3) and measurements (Table 4) are provided and
compared with similar data for E. polytrema and E. nanii.

Body robust throughout; greatest width 67% (52-82%) of greatest depth, increas-
ingly laterally compressed toward tail. Prebranchial and tail lengths each greater than
branchial length. Depth at cloaca 71% (61-128%) of greatest body depth. Tail slender,
spatulate, the ventral outline nearly straight, slanting slightly downward from cloaca,
its length about 17% (14-22%) of TL, its depth 42% (35-52%) of its length. Ventral
finfold usually absent but a very low one occasionally present. Caudal finfold moderately
thickened throughout, ending dorsally over cloaca.

Head at eyespots slightly deeper than wide. Nasopharyngeal aperture about one-
third to one-fourth of width of head at eyespots. Eyespots small but prominent, the
margins sharply defined. Face sloping at a very slight angle from rostrum. First two
pairs of barbels about equal in length, the first 97% (66-131%) of length of second pair
and 76% (48-100%) of the third, the second 77% (55-100%) of the third.

Color a very dark brown to purplish-black with randomly scattered small pale
spots extending to about cloaca; none were observed in the tail area. The spots are
concentrated in the branchial area and are particularly prominent near the mouth.
Distal portions of barbels with pale tips. GA and slime pores without pale margins.

Head grooves present near eyespots with a greater number before than behind in
contrast to the arrangements in E. polytrema and E. nanii. The number of grooves in
each series is variable, ranging between one and four.

All GA are very small, much smaller than in E. polytrema and E. nanii. In all our
material, the efferent duct of the last GP, left side, is not confluent with that of PCD
but lies closely adjacent; the GA is an elongate slit lying very close to PCD and may
easily be overlooked.

DM long, robust, 29% (25-36%) of TL, its width 13% (10-19%) of its length, its
depth 71% (46-80%) of its width. VA very short, 9% (8-1 1%) of length of DM, branching
only slightly anterior to the ventricle. No ABA lead to GP from VA (Fig. 3C). From
0 to 4 GP may lie between VA and DM, the remainder lying anterior to tip of DM,
the latter often overlying VA (Fig. 3C). This arrangement is very similar to that of E.
cirrhatus (McMillan and Wisner, 1984, fig. 3).

Eggs.—OfXhc females examined, only three have well developed eggs. One, 590
mm TL (SI072-149), has 40 eggs ranging between 20 mm by 5.8 mm and 23 mm by
6.5 mm. Another, 480 mm TL (SI072-148), has 12 eggs between 23 by 6.8 mm and
25 by 7.7 mm. A third, 485 mm TL (SIO81-102), has 10 eggs between 15 by 4.7 mm
and 17.5 by 5.3 mm. It is not known if the two bearing few developed eggs contain
the original number, but there is no indication of damage that could have caused loss
of eggs. All three ovaries contain many tiny, round eggs, plus a few in early stages of
elongation, about 3 by 0.8 mm. No eggs have protruding anchor filaments, although
polar caps are well developed on many.

238

Eptatretus polytrema (Girard 1854)

Bdellostoma polytrema Girard 1854:199 (original description; 15 gill openings; Valparaiso Bay,
Chile), 1855:252-253, pi. 23, fig. 1, 1855b:48-49 (relation to Gastrobranche dombeyi of
Lacepede); description; 1 4 gill openings and gills; color not preserved in specimen described);
Giinther 1870:512 {Gastrobranche dombeyi of Lacepede doubtfully synonymized; Girard's
count of 14 gill openings doubted, may have included mucus pores; coast of Chile); Schneider
1880:115-116 (note on status; no locality given; 1 4 gill openings; description, after Gunther);
Porter 1903:193, 233 (14 gill openings, each side); Quijada 1913:128 (14 gill openings, each
side; coast of Chile); Rauther 1924:685 (14 gill openings, each side; coast of Chile); Adam
and Strahan 1 963:5 ( 1 4 pairs of gills, variation unknown; average length 450 mm, maximum
570 mm; Chile).

Homea polytrema. Dean 1903:295-298, fig. 3 (in part; figure of a piebald specimen showing 14
gill openings; Valparaiso, Chile).

Heptatretus polytrema. Regan 1912:534-535 (14 gill openings; Valparaiso, Chile).

Polistotrema polytrema. Fowler 1951:267 (14 gill openings; Chile); Buzeta 1964:49, 51 (13 to 14
gill openings; color slate gray with white spots over body, bordering on dappled aspect;
Valparaiso to Talcahuano, Chile).

Eptatretus polytrema. Johansen and Strahan 1963:352-353 (14 pairs of gills).

Neotype.—SIOM-IA?,, female, 431 mm, TL; taken off Valparaiso, Chile, at 350
m; no other data; received as a gift from Dr. Alberto Nani, University of Chile, Viiia
del Mar, November 1970.

Additional material examined.— S1065-613, male, 429 mm TL, and female, 397
mm TL, taken in Valparaiso Harbor, Chile, in a trap on bottom at 30 m, 23-24
December 1965; SI072-148, two females, 371-440 mm TL, taken in Bahia Inglesa,
27°07'S, 70°55'W, in a trap on bottom at 20 m, 9-10 April 1972; SI08 1-103, female,
460 mm TL, taken off Valparaiso, Chile (no other data); USNM 272582, two females,
400-430 mm TL, taken at 33°32'S, 7r52'W, in a 72 ft shrimp trawl between 260 and
270 m, 1 August 1966; CAS 56511, three females, 385-447 mm TL, one male, 420
mm TL, taken at 33°22'S, 71°53'W, in a 72 ft shrimp trawl between 240 and 260 m,
1 August 1966; LACM 43775-1, female, 410 mm TL, taken at 33°27'S, 77°52'W, in a
72 ft shrimp trawl between 175 and 180 m, 1 August 1966; MNHNC (S) P. 6379,
male, 395 mm TL, taken at 29°37.5'S, 71°21'W, in a 72 ft shrimp trawl at 1 10 m, 14
August 1966; MNHNC (S) P. 6380, male, 440 mm TL, taken in area of Talcahuano-
Concepcion, Chile, in a shrimp trawl (depth not recorded), 8 August 1972.

Distribution.— Bahia Inglesa to Concepcion Chile. All specimens examined were
taken between 10 and 350 m. On two occasions, E. polytrema was taken with E.
bischoffii in Valparaiso Harbor in traps at 30 m and once in Bahia Inglesa (27°07'S,
70°55'W) in a trap at 20 m. Also, it was taken once with E. nanii at 33°22'S, 7r52'W
in a 72 ft shrimp trawl between 260 and 270 m.

Diagnosis. — External gill apertures 14-14; gill pouches 13-14. The neotype has 12
gill apertures on the left side (excluding the PCD), 13 on the right, and 13-13 gill
pouches. Branchial length greater than prebranchial or tail lengths. Three fused cusps
(multicusps) on both the anterior and posterior sets of cusps. Body moderately slender.
Color piebald, with pale areas varying in size and numbers, randomly scattered over
a dark background (Fig. 4). Ventral finfold varies between absent to well developed.
Head grooves present near eyespots. Efferent duct of last GP, left side, confluent with
that of PCD in 39% of specimens (7 of 18). VA short, 14% (3-23%) of length of DM.

Description.— Counis (Tables 1-3) and morphometries (Table 4) are given and
compared with similar data for E. nanii and E. bischoffii. Body moderately slender,
increasingly laterally compressed toward tail, deepest at about midlength; greatest body
width about 70% of greatest depth; depth at cloaca 70% of greatest body depth. Ventral
finfold variably developed, ranging from absent to prominent; it is absent in the neotype.
Of the 19 specimens, 12 (385-470 mm TL) have no or only vestigial ventral finfolds;
two (390-420 mm TL) have slight but distinct ones, and three (289-440 mm TL) have
well developed ones. Apparently size is not a factor in development of ventral finfolds.
Tail spatulate, its ventral outline nearly straight, slanting moderately downward from

239

cloaca; its length 15% (13-18%) of TL, its depth 44% (43-45%) of its length. Caudal
finfold moderately thin, extending a short distance out from musculature. Ventrally it
is thick with no extension of tissue, but expands around tip of tail and continues dorsally
to about over cloaca, becoming thicker anteriorly. Color highly variable, with few to
many pale blotches against a dark background. Extreme variation in the piebald con-
dition is shown in Figure 4; the two specimens were taken together (SI072-148).

Head at eyespots about as deep as wide, narrowing to rostrum. Nasopharyngeal
aperture small, its width one-fourth of head width at eyespots. Face sloping 1 5 to 30
degrees from the horizontal. First two pairs of barbels nearly equal in length, the first
pair often slightly shorter, each about two-thirds the length of third pair. All barbels
white-tipped on distal third to half. Eyespots prominent, the margins well defined.

Head grooves present on all specimens in good condition, usually behind the
eyespots on each side of dorsal midline. About one-fourth, including the neotype, also
have grooves before the eyespots arranged longitudinally. There are one to six grooves
behind, and one to four before, the eyespots.

Length of DM 26% (23-30%) of TL. DM width 13% (11-16%) of its length, its
depth 65% (49-74%) of its width. VA short, 14% (3-23%) of length of DM. An average
of 2.25 (1-4) GP lie between ventricle and branching of VA, 2.28 (0-6) lie between
branching and DM, and 8 (5-10) GP lie anterior to tip of DM (Fig. 3A). In general,
the branchial slime pores lie below the level of, and about midway between, the
adjacent GA.

Eggs.— A female, 422 MM TL (SI065-676), has 40 well developed eggs, all 17 to
19 mm in length and about 7 mm in diameter. Of the 19 specimens, 13 are mature
females with developing eggs; one immature (289 mm TL) has eggs in the round
undeveloped stage. Two specimens (CAS 56511) have large eggs; a 447 mm TL female
has 32, the largest 16 mm by 4.5 mm; one well developed egg measures 8 mm by 2.5
mm. A 385 mm TL female has 24 well developed eggs, the largest 27.5 by 7 mm, the
smallest 23 by 6.5 mm. A 431 mm TL female has 40 eggs, about 17 by 6 mm. A series
of developing eggs is present in three females and range in size from 0.5 to 6.0 mm;
most are nearly round (1.0 to 1.5 mm in diameter).

Discussion o/"Eptatretus polytrema.— Girard (1854:199, and 1855:252-253, pi. 3,
figs. l-5b) based Bdellostoma polytrema on a specimen described as having "Fourteen
respiratory apertures and gills on either side." He further stated "Color not preserved
in the specimen described." and, "in a precarious state of keeping."

On February 25, 1975, at the U.S. National Museum, the late Carl L. Hubbs
examined a specimen (USNM 78530), about 440 mm TL, labeled as type oi Bdellostoma
polytrema (by J. O. Snyder), taken near Valparaiso, Chile, by the U.S. Naval Astro-
nomical Expedition. Hubbs' notes state, "It is in bad shape, but body is largely intact.
Most of the skin has sloughed off. Gill pouches still discernible, 10 left and 1 1 right,
with the last one on the right less than half the bulk of others [the specimen had not
been opened prior to Hubbs' examination]. The skin was dark, but probably not black,
and nowhere is there a trace of light areas. The main blood vessel [ventral aorta]
branches opposite the anteriormost [sic; obvious misstatement for posterior] gill pouch-
es of each side. Only 3 gill pouches, each side, lie behind [posterior to] the end of the
huge tongue muscle. Slime pore counting seems to be impossible."

However, Girard's original (1854) description, although brief, unequivocally stat-
ed, "14 respiratory apertures and gills on either side," and this is reiterated in his
subsequent (Girard 1855) account and figure of what must be the same specimen. The
question then arises, how did a specimen with 10 gill openings come to be labeled as
the type? We have asked G. David Johnson (USNM) to examine the putative holotype
for us. He reports that Hubbs' description of it is accurate; i.e., there are 10 gill openings.
However, there is a label in the bottle that reads, "Valparaiso, United States Exploring
Expedition." This is the Wilkes Expedition of 1838-42, and Girard's specimen was
collected during the U.S. Naval Astronomical Expedition to Chile of 1849-52. We can
only speculate, but it seems possible that Girard's specimen, which he stated was in
poor condition, was discarded or lost and that subsequently another specimen from
Valparaiso was mistakenly regarded as the holotype of B. polytrema and so labeled.

240

We follow Girard in using the name polytrema for a species of Eptatretus with 1 4
gill apertures. No specimen conforming to Girard's description and bearing appropriate
data is in either the National Museum of Natural History or the Academy of Natural
Sciences of Philadelphia, and therefore, the holotype of Bdellostoma polytrema Girard
must be presumed lost.

In order to stabilize usage of the name we have above selected a specimen (SI084-
243) as neotype. For full data see Material Examined.

Unassignable Records

Early in an attempt to revise the Myxinidae, the late Carl L. Hubbs constructed a
lengthy synonymy of what was then thought to be Eptatretus polytrema (Girard 1854).
Hubbs was aided in the compilation of citations in the Spanish language by Gumersindo
Revuelta A., then a student of Alberto Nani C. at the University of Chile, Viiia del
Mar. We have determined that a majority of the citations pertain to no recognizeable
species in that neither counts, useful proportions, nor color notes were provided. As
the three species discussed here are sympatric throughout much of their ranges, such
references are not useful in distinguishing between them. Thus, we have extracted those
citations that definitely pertain to E. bischoffii and E. polytrema, by reason of data
provided by authors. Unfortunately, we are unable to assign any definite references to
E. nanii.

We list below those references that provide no clue as to species but have been
placed in the synonymy of E. polytrema by various authors.

Gastrobranche Dombey Lacepede 1798:41 4-4 1 5 (original description, based on a dried
skin brought to Paris by a traveler, Dombey; apparently a myxinid but genus and
species indeterminate; nomen dubium), 1799:990-992, pi. 23, fig. 1 (German
language version of original description; nomen dubium) [The dried skin is not
now in the collection of the Paris Museum, personal communication, M. L. Bauch-
ot.]

Gastrobranchus Dombeyi. Shaw 1804:267-268 (after Lacepede); Fleming 1822:375
{Gastrobranchus Dombay of Lacepede is probably of the genus Homea); Girard
1855a:251 (relation to Bdellostoma polytrema).

Bdellostoma Dombeyi. Miiller 1834:80 (based on Gastrobranche Dombeyi Lac; no gill
openings stated; doubtful whether a Bdellostoma or Myxine)\ Schneider 1880:1 15
(notes on status); Jordan and Gilbert 1883:57 (in part; attributed to Miiller; range
to southward); Gastrobranche Dombev Lac, Miiller 1834, and B. polytrema Girard
synonymized); Diicker 1924:507-514, 524-526, pi. 27, figs. 16, 18, pi. 28, figs.
19-25 (eye structure in detail; Coquimbo, Chile); Holmberg 1970:519-520, 536-
537 (eye degenerate; after Diicker 1924).

Bdellostoma polytrema. Philippi 1857:266 (cited); Lockington 1878:793 (B. stoutii
compared; Chile); Gunther 1880:25 (cited), 82 (hsted); Jordan and Gilbert 1883:
6 (cited); Reed 1897(2:671 (catalogue; coast of Chile, Valparaiso), 1897Z):22 (cat-
alog); Delfin 1 899: 1 78 (listed), 1 900a: 1 86 (listed; Talcahuano to Valparaiso, Chile),
1 900^7:422 (voraciousness; fishes more or less consumed from within); Porter 1 900;
Gill 1901:737 (£■. Dombeii of Cloquet [1819] a composite description drawn from
two authors and representing two species); Reed 1901:23 (listed); Wolnitzky 1901:
56 ("black congrio"; coast fishery, Anconcagua [possibly an Ophidiid]); Quijada
1912:109 (Coquimbo and Valparaiso, Chile); Lahille 1915:370 (cited); Rauther
1924:685 (brief description); Ohver Schneider 1936:99 (cited); Guerrero 1939:
10-11 (cited; PI. 1); Tortonese 1942:228 (cited); Henckel 1944:69 (description of
eyes); Lama 1944; Lindberg and Legeza 1959:22, and 1967:19 (reference; not in
Japan).

Hetpatretus dombeyi. Jordan and Gilbert 1 883:867 (identity of Polistotrema stouti with
H. dombeyi doubtful; Chile).

Polistotrema dombey (or dombeyi). Jordan and Evermann 1896:6 (brief description);
Porter 1909:52, 53 (synonymies), 1910:73, 74 (listed; synonymies); Lahille 1915:

241

350, 370 (listed); Oliver Schneider 1943^:76 (habits; distribution), 1943/?:6, 49
(listed); Holmberg 1970:519-520, 536-537 (compared in eye structure with Mva7>2<?
glutinosa on basis of Diicker 1924).

Homea polytrema. Garman 1899:344 (compared with MvJC/>2^c/>c//ro/?5); Delfin 1902^2:
186 (listed), 1 902/7:2 1 9 (voraciousness); 1 903: 1 82 (cited; reference to 1 902/)); Dean
1904:20 (synonymy; characters; coast of Chile); Albert 1914:82, 85, 89, 91, 93
(listed); OUver Schneider 1936:99 (cited); Henriquez 1957:1 (cited).

Polistostrema polytrema. Fowler 1908:461 (listed); 1941:3 (listed, synonymies); Mann
1954:18 (key), 84, 90 (cited), 91, 92 (brief description); Yaiiez 1955:41 (cited), 42
(fig. 4); deBuen 1957:266 (listed), 1959:35 (listed); Pequefio 1968:6 (listed); Ba-
hamonde and Pequefio 1975:5 (listed); Pequeno and Lopez 1979 (not seen).

Polistotrema decatrema. Fowler 1941:4 (listed, synonymies).

Dodecatrema polytrema. Fowler 1947:1 1 or more gill openings on each side of body;
3 (Type Bdellostoma polytrema Girard; Polistotrema synonymous with Homea;
synonymies).

Homea decatrema. Fowler 1951:267 (gill openings 6 [error?, possibly Eptatretus laura-
hubbsaesee key]); Mann 1954:18 (key); deBuen 1957:266 (Hsted).

Bdellostoma (Polistotrema) decatrema. Tortonese 1951:86 (San Vincente, Chile [Val-
paraiso Harbor]).

Eptatretus polytrema. Femholm 1975:203 {Bdellostoma bischoffli Schntid&v synonym:
anchor filaments on egg widespread); Femholm and Holmberg 1975:253, 255-
256 (reference to Diicker 1924, on eyes, as Bdellostoma dombey).

Phylogenetic Relationships

It is not now feasible to attempt construction of a meaningful phylogeny for species
(about 1 5) o{ Eptatretus. A fossil record is non-existent for the group, body proportions,
with few exceptions, are quite similar, and color is highly variable, often within species.
As discussed already, the number of gill openings (apertures) and associated internal
gill pouches offer the only readily available means of grouping the species o^ Eptatretus.
Based on these gill characters, three species groups can be recognized: one having 5 or
6 GA; a second having 7 GA only; and a third having 8 to 1 5 GA. Whether or not
this grouping has any phylogenetic significance is a question for future investigations.

Acknowledgements

We are most grateful to the late Dr. Carl L. Hubbs for initiating a review of the
Myxinidae of the world. Without his early efforts to accumulate a large amount of
material and data, we would never have accomplished this study. Also, we are deeply
grateful to, and sincerely thank the following Chilean scientists for invaluable aid: Dr.
Alberto Nani Caputo and his student Gumersindo Revuelta Alfaro, formerly of Uni-
versity of Chile, Viiia del Mar, gave particular aid in providing specimens, literature
citations, and information on distribution. Dr. German Pequeiio, University of Chile,
Valdivia, and Dr. Roberto Melendez, National Museum of Natural History, Santiago,
kindly provided specimens. G. David Johnson, Associate Curator of Fishes, National
Museum of Natural History, kindly provided data on specimens taken by the AL-
BATROSS off Southern Chile and examined the putative type of B. polytrema.

In particular, we thank Leslie W. Knapp (R/V ANTON BRUUN, Cruise 18,
Richard S. Lee, Ronald McConnaughey, and Charles F. Phleger (Expedition South
Tow, R/V THOMAS WASHINGTON) for their efforts in collecting specimens. Richard
H. Rosenblatt critically read the manuscript and offered valuable suggestions. Maria
Vernet kindly provided the Spanish language version of the Abstract.

Two biological oceanographic expeditions provided a major share of the study
material: Cruises 1 2 and 1 8a by R/V ANTON BRUUN, Southeastern Pacific Biological
Oceanographic Program, sponsored primarily by the National Science Foundation, and

242

Expedition South Tow (Legs 3 and 4) by the Scripps Institution of Oceanography,
sponsored in part by the National Science Foundation and Office of Naval Research.
We are indebted to these sponsoring agencies for financial support, and to the many
persons aboard the vessels for their time and eifort toward the collection of specimens.

Literature Cited

Adam, H., and R. Strahan. 1963. Notes on the
habitat, aquarium maintenance, and experi-
mental use of hagfishes. Pp. 1-8 in A. Brodal
and R. Fange (eds.). The Biology of Myxine.
Universitetsforlaget, Oslo.

Albert, F. 1914. El problema pesquero en Chile.
Boletin Bosques, Pesca i caza 2:69-104.

Ayers, H., and J. Worthington. 1907. The skin-
end organs of the trigeminal and lateralis nerves
of Bdellostoma doinbeyi. American Journal of
Anatomy 7:327-336.

Bahamonde, N., and G. Pequeno. 1975. Pesces
en Chile. Lista sistematica. Publicaciones Oca-
sional Museo Nacional Historia Natural San-
tiago, Chile 21:3-20.

Bullock, T. H., R. G. Northcutt, and D. A. Bodznick.
1982. Evolution of electroreception. Trends in
Neuroscience 5:50.

Buzeta, R. 1964. El genero Polistotrema (Cyclo-
stomata, Myxinidae) en Chile. Boletin de la
Sociedad de Biologia de Concepcion, Chile 39:
49-58.

Cloquet, H. 1819. Dictionnaire des Sciences Na-
turelles, Paris 15:134-136.

Dean, B. 1899. On\\\eemhryo\ogyoi Bdellostoma
stouti. A general account of myxinoid devel-
opment from the egg and segmentation to
hatching. Reproduced from the Festschrift zum
siebenzigsten Geburtstag von Carl Von Kupp-
fer. Verlag von G. Fischer, Jena:22 1-276.

Dean, B. 1903. Albinism, partial albinism and
polychromism in hagfishes. American Natu-
ralist 37:295-298.

Dean, B. 1904. Notes on Japanese myxinoids. A
new genus, Paramyxine, and a new species,
Homea okinoseana. Reference also to their eggs.
Journal College Science Imperial University
Tokyo, Japan 19:1-23.

deBuen, F. 1957. Preliminary list of Chilean fishes
and their vernacular names. Proceedings Eighth
Pacific Science Congress 3:166-279.

deBuen, F. 1959. Lampreas, tiburones, rayas y
pescas in la Estacion de Biologia Marina de
Montemar, Chile (Primera Contribucion). Re-
vista Biologia Marina 9:3-200.

deBuen, F. 1961. Las lampreas (Marsipobranchii
o Ciclostomi) en aguas de Chile. Investiga-
ciones Zoologicas Chilenas 7:101-124.

Delfin, F. T. 1899. Lista metodica de los pesces
de la Bahia de Concepcion i sus alrededores.
Revista Chilena Historia Natural 3:176-178.

Delfin, F. T. 1900(3. Catalogo de los pesces de
Chile. Revista Chilena Historia Natural 4: 1 85-
186.

Delfin, F. T. 1 900b. Voracidad de la Bdellostoma
Polytrema de Girard. Actes de la Societe Scien-
tifique de Chile 10:419-434.

Delfin, F. T. 1902(3. Concordancia de nombres
vulgares i cientificos de los pesces de Chile.

Revista Chilena Historia Natural 6:7 1-76 (Not
seen).

Delfin, F. T. 1 902^. Voracidad de la Homea poly-
trema {Bdellostoma polytrema) Girard. Revis-
ta Chilena Historia Natural 6:218-226.

Delfin, F. T. 1 903. Los congrios de Chile. Revista
Chilena Historia Natural 7:154-192.

Diicker, M. 1924. Uber die Augen der Zyklo-
stomen. Jenaische Zeitschrift fiir Naturwissen-
schaften 60:471-530.

Fernholm, Bo. 1975. Ovulation and eggs of the
hagfish Eptatretus burgeri. Acta Zoologica
(Stockholm) 56:199-204.

Fernholm, Bo. 1985. The lateral line system of
cyclostomes. Pp. 113-128 in R. E. Foreman,
A. Gorbman, J. M. Dodd and R. Olsson (eds.).
Evolutionary Biology of Primitive Fishes. Ple-
num Press, New York, London. NATO ASI
Series, Series A: Life Sciences.

Fernholm, Bo, and K. Holmberg. 1975. The eye
in three genera of hagfish {Eptatretus, Para-
myxine. and Myxine)— a case of degenerative
evolution. Vision Research 15:253-259.

Fleming, J. 1822. The philosophy of Zoology; or
a general view of the structure, functions, and
classification of animals. Vol. 2:305-397.
Edinburgh.

Fowler, H. W. 1908. Notes on lancelets and lam-
preys. Proceedings, Philadelphia Academy of
Natural Sciences 59 (for 1907):46 1-466.

Fowler, H. W. 1940. The fishes of the Wilkes
Expedition, 1838-1842. Proceedings Ameri-
can Philosophical Society:733-800.

Fowler, H. W. 1941. (and 1945 reissue, including
years 1941-1943). Fishes of Chile. Systematic
Catalog. Revista Chilena Historia Natural: 1-
171.

Fowler, H. W. 1947. New taxonomic names of
fish-like vertebrates. Notulae Naturae 187:1-
16.

Fowler, H. W. 1951. Analysis of the fishes of Chile.
Revista Chilena Historia Natural 51-53:263-
326.

Garman, S. 1899. The fishes. Reports on an ex-
ploration of the west coasts of Mexico, Central
and South America, and off the Galapagos Is-
lands, in charge of Alexander Agassiz, by the
U.S. Fish Commission Steamer "Albatross,"
during 1891, Lieut. Commander Z. L. Tanner,
Commanding. Memoirs, Museum Compara-
tive Zoology, Harvard College 24:1-431.

Gill, T. H. 1901. The proper names of Bdello-
stoma or Heptatrema. Proceedings, U.S. Na-
tional Museum 23 No. 1234:735-738.

Girard, C. 1854. Abstract of a report to Lieut. Jas.
M. Gillis, U.S.N, upon the fishes collected dur-
ing the U.S.N. Astronomical Expedition to
Chile. Proceedings, Philadelphia Academy
Natural Sciences 7:197-199.

243

Girard, C. 1855. Fishes. Pp. 230-253, pi. 33, fig.
1 /// Lieut. J. M. Gilliss, Superintendent. The
U.S. Naval Astronomical E.xpedition to the
Southern Hemisphere during the years 1849-
'50-'5 1-52, Vol. 2. 33rd Congress, 1 st Session,
Executive Document No. 121:299 pp, 1855b:
48-49 (reprint). Contributions to the fauna of
Chile.

Guerrero, M. E. 1939. Estudios anatomicos in el
Bdellostoma polytrcma Girard (Anguila ba-
bosa, murena o morena). Mem. para optar al
titulo de Pro. de sciencas, biologicas y quimi-
cas. Faculty Filosofia e Educacion, Universi-
dad de Chile (not seen).

Gunther, A. 1870. Catalogue of the Physostomi,
containing the families Gymnotidae, Sym-
branchidae, Muraenidae, Pegasidae, and of the
Lophobranchii, Plectognathi, Dipnoi, Ganoi-
dei, Chondropterygii, Cyclostomata, Lepto-
cardii, in the British Museum. Catalogue of the
fishes in the British Museum, London 1-549.

Gunther, A. 1 880. Report on the shore fishes pro-
cured during the voyages of H. M.S. Challenger
in the years 1873-1876. Report of the Scientific
Results of voyage of H. M.S. Challenger during
years 1873-1876. Zoology 1:1-82.

Henckel, C. 1944. Algunas observaciones acerca
del organo de la vision en ciclostomos chilenos.
Boletin Sociedad Biologias de Concepcion,
Chile 19:69-74.

Henriquez, R. 1957. Estudio macroscopio en es-
pecial microscopico de la zona hipotalmica en
Homea politrema. Raja flavirostris y Sebas-
todes oculatiis. Memorias Instituto Pedagogico
Universidad de Chile (not seen).

Holmberg, K. 1 970. The hagfish retina; fine struc-
ture in retinal cells in Myxine glutlnosa. L.,
with special reference to receptor and epithelial
cells. Zeitschrift fiir Zellforschung und Mi-
kropische Anatomic 111:519-538.

Jensen, D. 1 966. The hagfish. Scientific American
214(2):82-90.

Jespersen, A. 1975. Fine structure of spermiogen-
esis in eastern Pacific species of hagfish
(Myxinidae). Acta Zoologica (Stockholm) 56:
189-198.

Johansen, K., and R. Strahan. 1963. The respi-
ratory system of Myxine glutinosa. Pp. 352-
371 in A. Brodal and R. Fange (eds.). The Bi-
ology of Afyjc/we Universitetsforlaget, Oslo, 588
pp.

Jordan, D. S., and C. Gilbert. 1883 [1883-III].
Synopsis of the fishes of North America. Bul-
letin U.S. National Museum 16:1-1018.

Jordan. D. S., and B. W. Evermann. 1896. The
fishes of North and Middle America. Bulletin,
U.S. National Museum, 47-1:1240 pp.

Lacepede, B. G. E. 1798. Hist. Nat. des poissons,
H: 1-4 15. Chez Plasson, Paris. Imprimeur-Li-
braire, rue de Cimiticre Andre-des-Arcs, n° 10.

Lacepede, B. G. E. 1799. Naturgeschichte de Fische
als eine Fortsetzung von Buffons Naturge-
schichte Pauli, Berlin:5 19-992.

Lama, G. 1944. Observaciones hematologicas in
la especie Bdellostoma polytrema. Boletin So-
ciedad Biologia Concepcion, Chile 9:123-142
(not seen).

Lahille, F. 1915. Apuntes sobre lampreas argen-

tinas y los acraniotas. Anales Museo Nacional
de Buenos Aires 26:361-382.

Lindberg, G. V., and M. I. Legeza. 1959. Fishes
of the Sea of Japan and the adjacent areas of
the Sea of Okhotsk and the Yellow Sea. Pt. L
Amphioxi, Petromyzones, Myxini, Elasmo-
branchii, Holocephali. Translation by Israel
Program for Scientific Translations, 1967:1-
198.

Lockington, W. N. 1878. Walks around San Fran-
cisco, III — Lake Honda and Seal Rock. Amer-
ican Naturalist 12:786-793.

Mann, G. 1954. La vida de los peces en aguas
chilenas. Instituto Investicaciones Veterina-
rias, Ministario de Agricultura. Santiago, Chile:
342.

McMillan, C. B., and R. L. Wisner. 1984. Three
new species of seven-gilled hagfishes (Myxin-
idae, Eptatretiis) from the Pacific Ocean. Pro-
ceedings of the California Academy of Science
43:249-267.

Miiller, J. 1834. Vergleichende anatomic der
Myxinoiden, der Cyclostomen mit durchbohr-
tem Gaumen. Erster Theil, Osteologie und
Myologie. Abhandein der Koniglichen Aka-
demie Wissenschaften zu Berlin, Jahre, 1834,
1836:65-340.

Oliver Schneider, C. 1936. Notas sobre algunos
marsipobranquios chilenos. Comunicacion de
la Museo Concepcion 6:95-101.

Ohver Schneider, C. 1 943<3. Catalogo de los peces
marines del litoral de Concepcion y Arauco.
Boletin Sociedad de Biologia Concepcion, Chile
17:75-126.

Oliver Schneider, C. 1943/). Levantamiento bio-
logico de la provencia de Concepcion. Catalogo
de los peces marinos del litoral de Concepcion
y Arauco. Litografia Concepcion S.A.:59.

Pequeno, G. 1968. Los peces chilenos y sus
nombres vulgares. Museo Nacional Historias
Natural, Chile 12:7-10.

Pequeno, G., and M. T. Lopez. 1979. Biological
observations on organisms found on artificial
substrates in Leandro Cove, Talcahuano, Chile:
II Cyclostomi and Teleostomi. Boletin de So-
ciedad Biologia Concepcion 51:231-238.

Perez Canto, C. 1912. La fauna ictiolojicade Chile
considerada como riqueza nacional. Memorias
Cientificas y Literarias. Anales Universidad de
Chile 129:1215-1260.

Philippi.R. A. 1857. Uebereinigechilenische Vo-
gel. Archiv fiir Naturgeschite 23:262-272.

Plate, L. 1896. Uber die Eier von Bdellostoma
bischojfii Schneider. Sitzungsberichte, Gesell-
schaft naturforschender Freunde, Berlin: 1 6-2 1 .

Porter, C. E. 1900. Las especics chilenas del viaje
del buque explorador de S.M.B. "Challenger"
estractadas i adicionadas con varias notas. Re-
vista Chilena Historia Natural 4:39-42 (not
seen).
Porter, C. E. 1 903. Las especies chilenas del viaje
del buque explorador de S.M.B. "Challenger"
estractadas i adicionadas con varias notas. Re-
vista Chilena Historia Natural 7:193-194 y
230-233.
Porter, C. E. 1909. Ictiologia. Adiciones y ob-
servaciones al "Catalogo de los peces de Chile"

244

del Dr. Delfin. Revista Chilena Historia Nat-
ural 14:73-83.

Porter, C. E. 1910. Ictiologia. Adiciones y ob-
servaciones al "Catalogo de los peces de Chile"
del Dr. Delfin. Revista Chilena Historia Nat-
ural 14:73-83.

Putnam, F. W. 1874. Notes on the genus Bdel-
lostoma. Proceedings of the Boston Society of
Natural History 16:156-160.

Quijada, B. 1912. Catalogo de la coleccion de los
peces chilenos i extranjeros del Museo Na-
cional. Boletin del Museo Nacional, Chile 4:
69-109.

Quijada, B. 1913. Catalogo ilustrado i descriptivo
do los peces chilenos i extranjeros conservados
en el Museo Nacional. Boletin del Museo Na-
cional, Chile 5:7-130.

Rauther, M. 1924. Cyclostomi. Bronn's KJassen
und Ordungen des Tier-Reichs. Sechster Band.
1. Abteilung. Pisces. Akadmische Verlagsge-
sellschaft m.b.H., Leipzig, pp. 1-710.

Reed, E. 1897a. Catalogo de los peces chilenos.
Anales Universidad de Chile 98:653-673.

Reed, E. 1897^. Catalogo de los peces chilenos.
Imprenta Cervantes, Santiago, Chile:24.

Reed, E. 1901. The fisheries in Chile. Catalogue

of the fishes of Chile. The Chilean Committee
of the Buffalo Exposition. Imprenta Modema,
Santiago:33.

Regan, C. T. 1912. A synopsis of the myxinoids
of the genus Heptatretiis and Bdellostoma. An-
nals Magazine Natural History 9:534-536.

Schneider, A. 1880. Ueber die Arten von Bdel-
lostoma. Archiv fur Naturgeschichte 46:115-
116.

Shaw, G. 1804. General Zoology, Vol. 5, pt. 2,
Pisces. London:25 1-460.

Tortonese, E. 1942. Estudio di una collezione di
pesci proveniente di Valparaiso (Cile). BoUet-
tino dei Zoologia ed Anatomica Comparata
della Universita di Torino 49:227-252.

Tortonese, E. 1951. Materali per lo estudio sis-
tematico e zoogeografico dei pesci delle coste
occidentali del Sud America. Revista Chilena
Historia Natural 51-53:83-1 18.

Wolnitzky, B. 1901. The fisheries in Chile. The
coast fishery of the province of Aconcagua. The
Chilean Committee of the Buffalo Expedition.
Imprenta Moderna, Santiago:51-63.

Yaiiez, P. 1955. Peces utiles de lo costa chilena.
Revista Biologia Marina, Chile 6:29-81.

MCZ
LIBRARY TRANSACTIONS

OF THE SAN DIEGO

MAR 0 7 1988 natural history

HARVARD
UNIVERSITY

Volume 21 Number 15 pp. 245-257 24 February 1988

Two crabs, Xandaros sternbergi (Rathbun 1926) n. gen., and

Icriocarcinus xestos n. gen., n. sp., from the late Cretaceous

of San Diego County, California, USA, and Baja California Norte, Mexico

Gale A. Bishop

Institute of Arthropodology and Parasitology. Department of Geology and Geography,
Georgia Southern College, Statesboro, Georgia 30460-S149

Abstract. Two collections containing 14 specimens of late Cretaceous crabs from Carlsbad, San
Diego County, California, and Punta San Jose, Baja California Norte, Mexico, yield new data on Pacific
Slope Cretaceous decapods. Three specimens of Cretaceous decapods from Punta San Jose are preserved
in calcareous concretions from the Rosario Formation and eleven specimens associated with a diverse
molluscan fauna from Carlsbad are preserved in sandy claystone of the Point Loma Formation. Three
crabs from Punta San Jose and six specimens from Carlsbad are assigned to Xandaros sternbergi
(Rathbun 1926), n. gen. Five specimens from Carlsbad are assigned to Icriocarcinus xestos, n. gen., n.
sp. Xandaros sternbergi is a xanthid crab with a massive body and massive, spatulate chelae. Icrio-
carcinus .xestos is a carcineretid crab with a wide, flattened carapace and heterochelous, keeled claws.
One specimen of /. .xestos is preserved in a simple oblique burrow.

Introduction

Previous u'orA:. — The Cretaceous record of Pacific Slope crabs is sparse (Bishop
1986/?) consisting of rare specimens of six described species. Woodward (1896) de-
scribed the crabs Plagiolophus Vancouver ensis, Homolopsis richardsoni, and Palaeo-
corystes harveyi from British Columbia. Rathbun (1908) described Archaeopus anten-
nuatus from San Mateo County, California, and later (Rathbun 1 926) described a unique
cheliped from, "5 miles north of Carlsbad Station, Santa Fe Railway, San Diego County,"
as Zanthopsis sternbergi with the remark: "While this cheliped has the general form of
a Zanthopsis, it differs from all other species of which the cheliped is known by the
greater number and different disposition of tubercles." In 1929, Glaessner reassigned
Plagiolophus vancouverensis to Archaeopus and Palaeocorystes harveyi to Notopocor-
ystes.

Richards (1975) described Longusorbis cuniculosis from the Spray Formation (late
Campanian or early Maastrichtian) on Vancouver Island. The exquisite preservation
of 83 specimens was ascribed to their being buried and fossilized in their burrows. One
nearly complete burrow is figured (Richards 1975, fig. 6) and is differentiated from the
substrate in which it was constructed by the texture and color of the burrow fill.

Feldmann and McPherson (1980) reviewed the fossil decapod crustaceans of Can-
ada attempting to bring that scattered literature together into a revisionary paper. This
attempt was successfully completed for the lobsters but was only partly complete for
the crabs.

Bishop (1983) erected Zygastrocarcinus and reassigned Homolopsis richardsoni to
Zygastrocarcinus. Sundberg and Riney (1984) published a preliminary report on the
invertebrate fauna from the Point Loma Formation collected near Carlsbad, California,
including an illustration of an indeterminate decapod (Sundberg and Rinev 1984:105,
fig. 3.9).

The collections. —A collection of fossil crabs was made by Mr. Edward Hennessey

246

retaceous
utcrop

MEXICO

ENSENEDA

Punta San Jose

Figure 1. Geographic location of collection sites near Carlsbad (1), and Punta San Jose, Baja California
Norte (2).

of Long Beach, California, from the upper Cretaceous Rosario Formation as exposed
in the sea cUffs at Punta San Jose, Baja California Norte (Figure 1.2). Three specimens
in this collection are preserved in ovoid, calcareous concretions with portions of the
crabs exposed at the concretion surfaces. Varying portions of the carapace are exposed
giving rise to a "pseudomorphology" that could easily confuse the casual observer and
lead to false conclusions about its actual morphology.

A second collection consists of 1 1 specimens collected by Bradford Riney and
Thomas Demere, Department of Paleontology, San Diego Natural History Museum
from the Point Loma Formation, Carlsbad, CaHfomia (SDSNH Loc. 3162, Figure 1.1).
The Cretaceous section here is considered to be late Campanian or early Maastrichtian
in age (Sundberg and Riney 1984). Specimens of two species are preserved as clay-
filled exoskeletons or as exfoliated clay steinkems. The specimens received for study
had been prepared from the surrounding claystone with a pin vise. Preparation with a
needle and pin vise in Statesboro further freed several specimens from the enclosing
matrix. One specimen was preserved in situ in its shell-filled burrow. Sundberg and
Riney (1984) considered the Carlsbad invertebrate fauna to have inhabited a firm mud
bottom below wave base. This diverse fauna is characterized by Indogrammatodonl
sp., Crassatella sp., Limopsis sp., Tellinidae indet., Calva sp., Syncydonema sp., Den-
talium sp., Anchura sp., Gyrodes sp., and Volutoderma sp. The six crabs are preserved
in claystone, as articulated specimens commonly with the exoskeleton intact. The
preservation is so fine that setal pits are preserved, as are patterns attributable to color
markings.

Abbreviations used in the text include SDSNH, San Diego Natural History Mu-
seum, Department of Paleontology; EH, Edward Hennessey, private collection; and
USNM, United States National Museum, Smithsonian Institution.

247

Systematic Paleontology

Order Decapoda Latreille, 1 803

Infraorder Brachyura Latreille, 1803

Section Branchyrhyncha Borradaile, 1907

Superfamily Portunoidea Rafinesque, 1815

Family Carcineretidae Beurlen, 1930

Icriocarcinus, new genus

Type species.— Icriocarcinus xestos, new species.

Z)/a^A705/5.— Carapace pentagonal, twice as wide as long, well differentiated by
grooves into smooth, plateau-like areolations. Rostrum very narrow, downtumed, not
grooved, rounded at tip. Anterolateral margin with two small orbital spines plus large
spine at widest point Vy distance from front. Orbits large, eyestalk long and slender.
Posterolateral margins straight and steep. Posterior margin slightly concave. Areolations
on carapace raised into plateaus, small transverse ridge on protogastric region even
with distal ends of cervical groove. Anterior portion of epibranchial lobe developed as
a narrow, distal ridge behind cervical groove. Cardiac region bilobed, decreasing in
relief posteriorly until merging with intestinal region. Chelipeds long, arched upward,
keeled and slightly heterochelous. Walking legs long, P. oval, P3-P5 flattened, P5 smallest
with straight dactylus.

Etymology. —The generic name Icriocarcinus is compounded from the Greek words
"Ikrion," scaffold, bench, or platform, and "Karkinos," crab; or "platform crab."

Comparison.— T\iQ carapace shape, long and slender eyestalks, areolation, trans-
verse ridging, and heterochely typical of the Carcineretidae are well exhibited by this
species. The Carcineretidae seems to consist of two natural groups, one with straight,
lobed fronts, bilobed rostra, and a similar U-shaped carapace {Ophthalmoplax Rathbun
1935; Woodbinax Stenzel 1953; and Carcineretes Withers 1922) and another with
pentagonal or subhexagonal carapaces, spiny or lobed fronts, narrow non-bifurcated
rostra, and somewhat similar carapace areolation including more or less developed
transverse ridges {Cancrixantho Van Straelen 1934; Longusorbis Richards 1975; Icrio-
carcinus new genus; and probably Lithophylax A. Milne Edwards and Brocchi 1879).

Icriocarcinus differs from the first group {Ophthalmoplax, Woodbinax, and Car-
cineretes) by its pentagonal shape, slanted anterolateral margins, and areolation. Icrio-
carcinus is similar to members of the second group {Cancrixantho, Longusorbis, and
Lithophylax) in carapace shape, areolation, possession of a narrow rostrum, and trans-
verse ridging of the carapace. Icriocarcinus differs from Lithophylax by being much
larger, less arched, and by lacking a posterior transverse ridge on the cardiac and
mesobranchial regions. Icriocarcinus differs from Cancrixantho by being proportionally
wider; having oblique anterolateral margins; having smaller, better defined anterolateral
spines; having its widest point more posterior; lacking the posterior transverse ridge
on the epigastric and mesogastric regions; and lacking the three pronounced postero-
lateral spines oi Cancrixantho. Icriocarcinus is most similar to Longusorbis from which
it differs by being proportionally wider; having a concave front; a narrower, non-grooved
rostrum; having its widest part more posterior; having a less distinctly concave posterior
margin; having flat, rather than tumid, tuberculate areolations; having one anterior
transverse ridge across the protogastric regions on line with the distal part of the cervical
furrow; and having more elongate, upwardly arched, more keeled chelae than Lon-
gusorbis.

Icriocarcinus xestos, new species
Figures 2; 3A-D

Types. -WoXoXy^t (SDSNH 26038) and paratypes (26040, 26101, 26113, 26202)
are deposited in the Paleontology collections of the San Diego Natural History Museum.

Occurrence, sample size, and preservation.— ¥'\\e specimens were collected from
the Point Loma Formation at the Carlsbad Research Center (SDSNH Loc. 3162) and
are late Campanian or early Maastrichtian in age. The holotype (SDSNH 26038) is a

248

Figure 2. Icriocarcimis xeslos. n. sp. A, holotype, SDSNH 26038. dorsal view of carapace and appendages;
B-D, paratype, SDSNH 26202; B, ventral view of sternum, abdomen, and appendages; C, outer face of right
claw; D, outer face of left claw. Bar scales = 1 cm.

249

Figure 3. A-D, Icriocarcimis xestos, n. sp. A, paratype, SDSNH 261 13, dorsal view showing anterolateral
marginal spines on carapace and spine rows on upper surface of left claw; B, paratype, SDSNH 26 10 1 , ventral
view; C, holotype, SDSNH 26038, outer face of left claw; D, paratype, SDSNH 26040, specimen preserved
at bottom of burrow with claws exposed, burrow in claystone filled with sand and shell fragments. E-H,
Xandaros sternbergi (Rathbun 1926), E-F, topotype, SDSNH 26036, carapace and venter; G, topotype,
SDSNH 26037, carapace, both chelipeds and pereiopods; H, hypotype, EH-1, carapace in concretion showing
lateral wing. Bar scales = 1 cm.

250

Table 1 . Measurements (mm) of Icriocarcinus xestos, n. sp.

Holotype

Paratype 1

Paratype 2

Paratype 3

Paratype 4

SDSNH

26038

26101

26202

26113

26040

Carapace

Length

19.62

—

20.5

—

Width

37.13

—

36.1 +

—

Height

—

Orbital Width

(17±)

—

18.8±

—

Rostral Width

—

1.1

—

Abdomen

length

—

1.0?

—

width

—

length

—

1.0±

—

width

—

length

—

1.1

—

width

—

length

—

1.5

—

width

—

6.9

—

length

—

1.3

—

width

—

length

—

2.5

4.5

—

width

—

4.5 +

—

length

—

2.3

2.5

—

width

—

3.7

5.0

—

Chelipeds

Left/Right

Coxa

length

— /—

4.0/-

2.4/-

—/—

width

— /—

—/—

b/i

length

— / —

5.1/-

4.5/-

— / —

width

— / —

Merus

length

— / —

12.5+/-

14.3+/-

— / —

width

— /—

— / —

Carpus

length

9.1/-

—/—

— /—

width

— /—

—/—

Propodu;

; length

24.0/-

22.6+/18.3 +

28.7/33.3

22.5/26.8

31.5/34.4

width

— / —

-/5.3

-/7.3±

— / —

7.8/8.7

Dactylus

length

—/—

— /—

-/14.6

-/10.5

-/15.4

width

—/—

— /—

—/—

— /—

nearly complete steinkem (Figures 2A, 3C); paratype 2 (SDSNH 26202) preserves the
carapace, chelipeds, rostrum and anterolateral spines (Figure 2B-D); paratype 1 (SDSNH
26101, Figure 3B) and paratype 3 (SDSNH 261 13, Figure 3 A) preserve sterna, abdo-
mens, and pereiopods; paratype 4 (SDSNH 26040) is preserved in a shell-hash-filled
burrow (Figure 3D). This burrow is oriented oblique to bedding and measures 3.0 to
4.8 cm in diameter and at least 14 cm in length. The fragile, thin exoskeleton was
probably preserved on each specimen but exfoliated very rapidly due to mechanical
abrasion and humidity changes on all the specimens except paratype 2 (SDSNH 26202).

Diagnosis. — Same as for the genus.

Etymology.— The. trivial name is derived from the Greek word "xestos," scraped,
planed, or smoothed relating to the smooth plateau-like areolations on the carapace.

Description. —Carapace pentagonal, ovoid, twice as broad as long (Table 1), slightly
arched transversely, arched longitudinally, somewhat depressed in center, well differ-
entiated by grooves. Carapace front broad, sinuous. Rostrum narrow, downtumed,
ungrooved giving way laterally to broad orbital regions (50% of carapace width). An-
terolateral margins broadly rounded with three spines, one at outer angle of orbit?, one
at midpoint, and the largest forming anterolateral comer and widest part of carapace
'/3 distance from front. Posterolateral margins straight, sharply reflexed into a near
vertical surface; posterolateral angle rounded; posterior margin slightly raised into rim

251

and concave. Carapace grooves narrow, separating well delineated, plateau-like areola-
tions. Cephalic arch well differentiated; gastric region well differentiated, depressed
somewhat at center; mesogastric broadly ovoid, rounding rapidly onto very narrow
anterior tongue terminating before reaching rostrum. Protogastric lobes divided by a
distinct transverse line of flexure, forming a ridge near posterior '/3 (on line with cervical
groove) of the mesogastric region. Urogastric region transverse, convex posteriorly.
Hepatic regions transversely wide, longitudinally narrow, forming anterolateral margin
of carapace with its three marginal spines. Scapular arch moderately differentiated,
especially medially. Cardiac region raised into a bilobed level plateau anteriorly,
gradually decreasing in relief posteriorly, merging indistinguishably into the intestinal
region. Branchial regions differentiated into well-delimited epibranchial regions and
posterior meso-metabranchial regions which are broadly swollen with three short mar-
ginal ridges; one near front, the second at midpoint, and the third near posterolateral
angle. These ridges arise as small tubercles on the lateral margin of the edge of the
dorsal shield, become raised and transverse before becoming obsolete. Anterior edge
of epibranchial subdivided distally by a small, subparallel auxiliary groove posterior
to the cervical groove giving rise to a distinctive, short, distal, transverse anterior
epibranchial ridge. Two subparallel lines of muscle insertions are present, one posterior
to distal cervical groove and one subparallel to groove between epibranchial and me-
sobranchial. [The terms cephalic arch and scapular arch as used herein follow the
terminology of H. Milne Edwards (1834-40) and Bell (1858). These authors distin-
guished the anterior portion of the carapace (cepahlic arch) consisting of the frontal,
orbital, gastric, and hepatic regions from the posterior portion (scapular arch) formed
by the branchial and cardiac regions.]

Carapace evenly covered by dense, fine granulation arranged in patterns of lines
forming swirls. Exoskeleton exceedingly thin over the entire crab. Sternum transversely
ovoid, relatively flat. Anterior somites fused (1-4) with slight transverse flexure, divided
into anterior shelf and posterior sternal "plane" at same level as other somites; somites
5-7 wedge-shaped, widest distally; posterior portion of somite 5 forms widest part of
sternum; somite 6 narrower than 5 but with longer distal edge; somite 7 narrower than
6 and shorter; somite 8 barely visible beneath abdominal flap. Abdomen with at least
six segments, the penultimate being longest and those proximal being about the same
size and much shorter than either of last two segments; last three segments on males
about same width ('/3 of sternal width), the more proximal are wider (% of sternal width
and very narrow). Eyestalk long and slim, apparently folding back into long orbit
extending beneath front from rostrum to first anterolateral spine. Maxillipeds spatulate,
endognath slightly narrower than exognath, perhaps twice as long as wide; endognath
serrate on medial edge; proximal end of endognath curved beneath exognath. Chelipeds
heterochelous, long, arched upward in middle, more or less keeled, granulate between
keels, granules becoming larger and tending toward small spines on keels. Right claw
slightly larger than left, less well keeled, possessing three large button-like teeth on the
fixed finger, teeth are capped by dense enamel-like material. Left claw slightly smaller,
more keeled, possessing shearing teeth on fixed finger. Upper surface of right propodus
has three rows of spines; an inner row of four, a middle row of 7?, and an outer row
of 7. Meri of both claws have two anterior and four posterior downward facing, and
three or four forward facing, spines. Carpals have three or four longitudinal spine rows,
small spines on upper surfaces and one large forward facing spine in proximal anterior
row. Dactyli closely opposed to fixed fingers, similarly toothed, having an anterior row
of at least five spines and one proximal posterior spine on upper surfaces. Walking legs
long and flattened; P2 present only on the holotype, is largest and almost round; P3 and
P4 are very flat, similar in size, smaller than ?,, larger than P5, which is also very flat
and has a merus nearly as long as its broad carpus and propodus, and narrow dactylus.

Comparison. — Ichocarcinus xestos is the only species in the genus and is unlikely
to be confused with any other fossil carcineretid crabs as discussed in the generic
comparisons. Icriocarcimis xestos is most similar to Longusorhis cuniculosis Richards
(1975) although it differs in many significant ways: by being proportionally wider; by

252

having a concave front; by having a non-grooved, narrower rostrum, having its widest
point further back; by having a straighter hind margin; by having flat areolations; by
having an anterior transverse ridge near the posterior of the protogastric regions; and
by having more elongate upwardly arched, keeled chelae.

Remarks.— During preparation, the exceedingly thin and fragile exoskeleton was
observed over the carapace. This exoskeleton is covered by swirling patterns of fine
granules and setal pits. It is thicker on the chelae but thinner over the other pereiopods.
The thin exoskeleton is consistent with a burrowing mode of life as evidenced by
paratype 4 (26040). Longusorbis cuniculosis Richards (1975) is also a burrowing form.

Superfamily Xanthoidea Dana 1851

Family Xanthidae Dana 1851

Xandaros, new genus

Type species. — Zanthopsis sternbergi Rathbun 1926.

Diagnosis. —C2iV2LX)2LCQ slightly wider than long, transversely oval, widest at anterior
third, moderately differentiated by grooves, arched longitudinally. Rostrum short,
downturned, sulcate and bifid. Anterolateral margins tightly rounded; orbits large.
Posterolateral margins broadly rounded; posterior margin narrow, concave, slightly
upturned. Carapace transversely ridged with a gastric ridge, an epibranchial ridge, and
a mesobranchial ridge, each surmounted by low bosses. Gastric ridge with four small
anterior bosses in diamond shape on anterior tongue of mesogastric and epigastric
regions, a large boss at posterior portion of mesogastric region, and two transversely
elongate bosses across cardiac region. Abdomen large, somites increasing in length
posteriorly. Chelipeds massive, equal; merus, carpus, and propodus tuberculate; claws
strongly convex with five longitudinal rows of tubercles; fingers spatulate at tips.

EtymologyK—/K massively armored crab armed with huge claws; hence its name,
"Xandaros," Greek, meaning fabulous sea monster.

Comparison.— Xandaros exhibits the transversely oval carapace, well-developed
orbits, dentate anterolateral margins, and ambulatory fifth pereiopods of the Xanthidae
(Glaessner 1 969:R5 1 5). Xandaros is most similar to the Brazilian late Cretaceous genus
Palaeoxanthopsis Beurlen 1958 in having a convex anterior margin, large orbits, and
transverse rows of bosses on the carapace. Xandaros differs from Palaeoxanthopsis by
lacking the prominent posterolateral spines, being relatively shorter in relation to width,
and lacking carinate claws. Xandaros is much larger and more robust than Xanthilites
Bell 1858 and lacks the prominent anterolateral teeth, small, covered orbits, and smooth
claws o^ Xanthilites. Xandaros is much larger, much more robust, much more convex,
and much more areolated than the North American late Cretaceous genus Xanthias
Rathbun 1897. Xandaros somewhat resembles the genera Syphax A. Milne Edwards
1864 and Titanocarcinus A. Milne Edwards 1864 in carapace shape, possession of large
orbits, convexity, and degree of carapace areolation; but differs from them by being
relatively broader, having carapace bosses arranged in transverse rows, and having
significantly diflferent patterns of carapace areolation. Xandaros superficially resembles
Xanthopsis McCoy 1849 in carapace outline and carapace bosses; but differs greatly in
areolation, possession of transversely aligned, rather than longitudinally aligned bosses,
lack of fusion of abdominal somites 3-5 (seen in Zanthopsis; Glaessner 1969:R522),
and possession of a "greater number and different disposition of tubercles . . ." on the
claws (Rathbun 1926).

Xandaros sternbergi (Rathbun 1926)
Figures 3E-H; 4

Zanthopsis sternbergi Kz.\\\hur\ 1926, p. 54, PI. 39, figs. 1-4.
Decapoda indeterminant; Sundberg and Riney 1984, p. 105, figs. 3, 9.
Zanthopsis sternbergi Rathbun; Bishop 1986Z?, p. 128, fig. 10a, b.

253

Figure 4. Xandaros sternbergi (Ralhbun 1 926). A, topotype, SDSNH 26035, anterior view of carapace and
right claw; B, topotype, SDSNH 26034, outer face of left claw; C, topotype, SDSNH 26035, dorsal view of
carapace and right cheliped; D, topotype, SDSNH 26033, ventral view of sternum, abdomen, cheliped, and
pereiopods; E. hypotype. EH-2. anterior view of whole crab mostly encased in calcareous concretion (note
spatulate finger occlusion); F, topotype, SDSNH 26036, left oblique view of cheliped and carapace. Bar
scales = 1 cm.

254

Types.— The holotype (USNM 73390) and six specimens from the San Diego
Natural History Museum are apparently from the same general area, making the SDSNH
specimens topotypes. Thomas Demere (personal communication, 22 March 1985) has
stated "The locality description in Rathbun (1926:21, 54) is slightly in error as it states
that Kelly's Ranch is 5 miles north of Carlsbad Station. In reality, the ranch was located
east of Carlsbad. Cretaceous strata are exposed in only a small 'window' at the eastern
border of the old ranch, and I am certain that the holotype of Zanthopsis sternbergi is
from the same section as that recently exposed by grading at the Carlsbad Research
Center."

Occurrence, sample size, and preservation. —Ten specimens of Xandaros sternbergi
are known from two localities, seven from the type area and three from Punta San
Jose, Baja California (Bishop, 1986<2). The type locality is cited (Rathbun 1926) as
"California: Kelly's Ranch, 5 miles north (sic) of Carlsbad Station, Santa Fe Railway,
San Diego County. ..." A second suite of specimens was collected from the site of the
Carlsbad Research Center (SDSNH Loc. 3162) in claystones of the Point Loma For-
mation (Sundberg and Riney 1984).

Description.— Carapace oval; width twice length, widest at midpoint across epi-
branchial regions (Table 2); strongly arched longitudinally; slightly arched transversely.
Orbitofrontal margin large (65% of carapace width), arcuate, with a large outer fossa
and a poorly defined inner, antennal fossa; upper margin upturned with a sulcus at
intraorbital septum. Rostrum short, downtumed, sulcate and bifid. Anterolateral mar-
gins tightly rounded to widest point at epibranchial lobes; posterolateral margins rel-
atively straighter, slightly sinuous; posterior margin distinctly concave, slightly up-
turned into a shelf. Carapace furrows poorly defined by broad depressions. Cervical
depression transverse, sinuous, terminating on gastric ridge in subtle pits. A posterior
depression, subparallel to cervical depression, lies between the epibranchial-urogastric
and mesobranchial-cardiac regions. Longitudinal grooves even more subtle; those
bounding gastric ridge poorly defined anteriorly, better defined posteriorly around
posterior of mesogastric, urogastric, and cardiac-intestinal regions. Groove between
protogastric and hepatic regions obsolete.

Carapace differentiated into more or less tumid regions. Cephalic arch dominated
by discontinuous transverse ridge surmounted by a row of nine bosses; a central me-
sogastric boss on posterior of anterior tongue of mesogastric region; two on protogastric
region; and two on hepatic region, these becoming more pronounced from proximal
protogastric boss to distal hepatic boss. Mesogastric region with large posterior boss,
and smaller but pronounced medial bosses at the posterior and anterior ends of the
anterior prolongation which with small epigastric bosses form a diamond-shape. The
margin of the orbit rises from the sulcate, bifid rostrum forming prominent orbital
concavities in the anterolateral margin. Scapular arch dominated by sagittal, epigastric,
and mesogastric ridges. Sagittal ridge with depressed urogastric region and raised cardiac
region often surmounted by two low, adjacent, transversely elongated bosses. Epigastric
ridge with prominent proximal boss and two smaller but more pronounced bosses, the
distal one being extended into a long lateral spine. The epigastric ridge is interrupted
by the depressed urogastric region. A second transverse scapular ridge lies on line with
the two transverse cardiac bosses, marked by a gentle swelling on the mesobranchial
regions. Metabranchial and intestinal regions form a low, raised shelf along concave
posterior margin. Carapace ornamented by gentle unevenness, subtle bosses, and very
fine punctation.

Female abdomen broad, barely grooved longitudinally, oval; somites progressively
longer from Ab, to Ab,, widths increase to Abs then decrease to telson; segments Aba
to Abj with paired groups of setal pits (consisting of three pits each) near posteriors.
Male abdomen narrower, segments more nearly similar to one another. Pereiopods
variable; P, very large, massively chelate; P2-P5 progressively smaller, oval in cross
section. Telson of female broadly subovate in contrast to triangular telson of male.

Chelipeds very large, massive, and tuberculate, subequal, right somewhat larger.
Merus long, armed with about five ventral tubercles. Carpus equant, longitudinally

255

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256

grooved, tuberculate; four? longitudinal rows of tubercles, the uppermost row with six
small tubercles on edge of flattened crest, second row with four larger tubercles and a
single distal tubercle lies above the longitudinal groove; two rows of tubercles each lie
below the longitudinal groove which runs from the upper distal articulation to the
proximal articulation. Distal outer edge bordered by a furrow. Propodus longitudinally
convex, strongly convex transversely on outer face. Palm longer than high, covered by
five longitudinal rows of tubercles, the uppermost runs along the upper margin of the
claw, the second subparallel to the upper margin with tubercles, the third with four
tubercles, and the fourth with five tubercles form a "V" diverging distally from a
common tubercle; the fifth row runs parallel to the lower margin. The fixed fingers are
slim, extended horizontally, and spatulate at tips; left somewhat blunter than right.
The movable fingers are slim, curved and spatulate, with a row of 13 setal pits from
upper articulation to stepped-down tip.

Comparison. —Although Xandaros sternbergi resembles many other xanthid crabs
in a general way, few species are similar enough to cause confusion. Xandaros sternbergi
is perhaps most similar to Palaeoxanthopsis cretacea (Rathbun 1 902) from the Maas-
trichtian of Brazil, but differs from it by lacking the large, prominent posterolateral
spines, by being relatively shorter, by having three medial mesogastric bosses rather
than one, by having its posterior medial mesogastric tubercle and the posterior part of
the mesogastric region more anteriorly placed, by its transverse epigastric ridges with
a row of three bosses, by its transversely bilobed cardiac region, and by its lack of
"carinate" chelae. Xandaros sternbergi can easily be distinguished from Syphax crassus
A. Milne Edwards 1864, Titanocarcinus serratifrons A. Milne Edwards 1863, and
Xanthilites bowerbanki Bell 1858 by differences in carapace shape, areolation, and
surface ornamentation. Xandaros sternbergi is easily distinguished from Zanthopsis
hendersonianus Rathbun 1926 from the Oligocene of California and Zanthopsis vulgaris
Rathbun 1926 from the Oligocene of the northwestern U.S. and southwestern Canada.

Significance

The two taxa described enhance our still limited knowledge of Pacific Slope Cre-
taceous decapods. Xandaros sternbergi is now much better known with the description
of its body and its assignment to a new genus. Icriocarcinus xestos not only represents
a new taxon from the Pacific Slope but provides important insights into the possible
origin of some trace fossils in the Cretaceous. Both taxa are now relatively well known
species because of the large collections available and the completeness of the specimens.
The addition of the Baja California collection enlarges the paleobiogeographic distri-
bution of Xandaros sternbergi.

Acknowledgments

I am indebted to Edward Hennessey of Long Beach, California, for making his
collection of Baja California crabs available for study. Thomas A. Demere, Mark
Roeder, and Bradford Riney of the San Diego Natural History Museum collected and
made the Carlsbad decapod collection available to me. The Koll Construction Company
of San Diego cooperated in the conservation of the Carlsbad fossil collection. The
manuscript was strengthened by critiques provided by Thomas A. Demere and Joseph
Collins, London. The manuscript was typed by Donna Cain and Judith McQuaig.
Photographic assistance was rendered by Jeanne Amos and Frank Fortune. Indirect
support was provided by the National Science Foundation (DEB 801 1570), National
Geographic Society (2867-84), and the Georgia Southern College Faculty Research
Committee. My sincere thanks is extended to each person for his or her assistance in
the production of this paper.

257

Literature Cited

Bell, T. 1858. A monograph of the fossil mala-
costracous Crustacea of Great Britain. Pt. I,
Crustacea of the London Clay, pages 10-40.
Palaeontographical Society London.

Beurlen, K. 1958. Contribuicao a paleontologia
do estadodo Para. Crustaceos decapodos da
Formacao Pirabas 1 (Arthropoda-Crustacea).
BoUcttino del Museu Goeldi (Paraense) new
series, Geologica.

Bishop, G. A. 1983. Two new crabs. Nolopocory-
stes (Eucorystes) eichhorni and Zygastrocarci-
nus griesi (Decapoda:Brachyura) from the
Bearpaw Shale (Campanian) of north-central
Montana. Journal of Paleontology 57:900-910.

Bishop, G. A. 1986(3. Taphonomy of the North
American decapods. Journal Crustacean Bi-
ology 6:326-355.

Bishop. G. A. 1986/7. Occurrence, preservation,
and biogeography of the Cretaceous Crabs of
North America. Pp. 111-142 //; R. H. Gore
and K. L. Heck (eds.). Crustacean Biogeogra-
phy, Crustacean Issues 4. A. A. Balkema, Rot-
terdam, The Netherlands.

Feldmann, R. M., and C. B. McPherson. 1980.
Fossil decapod crustaceans of Canada. Geo-
logical Survey of Canada Paper 79-16.

Glaessner, M. F. 1929. Crustacea Decapoda: Fos-
silium Catalogus, Part 4 1 . W. Junk, Berlin, West
Germany.

Glaessner, M. F. 1969. Decapoda. Pp. 626-628
in R. C. Moore (ed.). Treatise on Invertebrate
Paleontology. Geological Society of America
and University Kansas Press, Lawrence, Kan-
sas, USA.

McCoy, F. 1849. On the classification of some
British fossil Crustacea with notices of new
forms in the University collection at Cam-
bridge. Annals and Magazine of National His-
tory 2:161-179.

Milne Edwards. A. 1862-65. Monographic des
crustaces de la famille Carcerines. Annales des
Sciences Naturelles, Zoologie. ser. 4, 1 8( 1 862):
31-85, 20(1863):273-324, ser. 5, 1(1864):31-
88, 3(1865):297-351.

Milne Edwards, A. and P. Brocchi. 1878-79. Note
sur quelques Crustaces fossiles appartenant au
groupe des Macrophthalmiens. Bulletin de la
Societe Philomathique de Paris (3):113-117.

Milne Edwards, H. 1834-40. Histoire Naturelle
des Crustaces. Paris

Rathbun, M. J. 1897. Synopsis of the American
species of fa //r(/\ Philippi ( = Cynip<)solta Roux).
Proceedings of the Biological Society of Wash-
ington 11: 109- no.

Rathbun, M. J. 1902. In J. Branner. Geology of
the northeast coast of Brazil. Bulletin Geolog-
ical Society of America 13:41-98.

Rathbun, M. J. 1908. Descriptions of fossil crabs
from California. Proceedings of the United
States National Museum 35:341-349.

Rathbun, M. J. 1926. The fossil stalk-eycd Crus-
tacea of the Pacific Slope of North America.
Bulletin of the United States National Museum
138:1-155.

Rathbun, M. J. 1935. Fossil Crustacea of the At-
lantic and Gulf Coastal Plain. Geological So-
ciety of America Special Paper 2.

Richards, B. C. 1975. Longiisorbis cuniculosis: A
new genus and species of Upper Cretaceous
crab; with comments on Spray Formation at
Shelter Point, Vancouver Island, British Co-
lumbia. Canadian Journal of Earth Science 12:
1850-1863.

Stenzel, H. B. 1953. Decapod crustaceans from
the Woodbine Formation of Texas. United
States Geological Survey Professional Paper
242:212-217.

Sundberg, F. A., and B. O. Riney. 1984. Prelim-
inary report on the Upper Cretaceous macro-
invertebrate faunas near Carlsbad, California.
Pp. 103-107 in P. L. Abbott (ed.). Upper Cre-
taceous Depositional Systems of Southern Cal-
ifornia and Northern Baja California. Pacific
Section Society of the Economic Paleontolo-
gists and Mineralogists Fieldtrip Guidebook
36.

Van Straelen, V. 1934. Contribution a letude des
crustaces decapodes fossiles de la Catalogne.
Geologique Pays Catalans 3:1-6.

Withers, T. H. 1922. On a new brachyurous crus-
tacean from the Upper Cretaceous of Jamaica.
Annals and Magazine of Natural History 10:
534-541.

Woodward, H. 1896. On some Podophthalma-
tous Crustacea from the Cretaceous Formation
of Vancouver and Queen Charlotte Islands.
Quarterly Journal of the Geological Society of
London 52:221-228.

f"^

■(^

TRANSACTIONS
IVICZ OF THE SAN DIEGO

LIBRARY SOCIETY OF

NATURAL HISTORY

FEB 2 1 1889

HARVARD
VDrOTtie' 2r RTUmbferi 6 pp. 259-273 1 5 February 1 989

A new abyssal hydrothermal verrucomorphan (Cirripedia; Sessilia):
The most primitive living sessile barnacle*

William A. Newman and Robert R. Hessler

Schpps Institution of Oceanography A-002, La Jolla, California 92093 and Natural History Museum, P.O.
Box 1390. San Diego. California 92112 USA

Abstract. A remarkable sessile barnacle, Neoverruca brachylepadoformis gen. et sp. nov., has been
discovered living near abyssal hydrothermal vents at 3600 m in the Mariana Back-Arc Basin, Western
Pacific. It has closer affinities with the earliest known sessile barnacles, the Brachylepadomorpha (?Upper
Jurassic-Miocene), than with any of the fossil or extant Balanomorpha (Upper Cretaceous-Holocene).
Thus Neoverruca, the most primitive living sessile barnacle, is a "living fossil." However, there are
subtle characteristics of its shell that are diagnostic of the asymmetrical sessile barnacles, suborder
Verrucomorpha (?Middle, Upper Cretaceous-Holocene). In having verrucomorphan specialization su-
perimposed on the brachylepadomorphan plan, Neoverruca constitutes a "missing link" between these
two suborders. As the sole surviving member of an ancient radiation, Neoverruca adds significantly to
our knowledge of the origin and evolution of sessile barnacles and the nature of their pedunculate
ancestor. Furthermore, it heightens our appreciation of the role abyssal hydrothermal environments
play in perpetuating ancient forms whose wide-ranging, predominantly shallow-water ancestors have
long been extinct.

Introduction

A little more than a decade ago communities of large clams, mussels, tube worms,
and other animals were discovered at depths of 2600 m or so, clustered around abyssal
hydrothermal vents of the Eastern Pacific, near the Galapagos Islands and at 21°N off
Mexico (Hessler and Smithey 1983, Jones 1985). The latter locality provided the first
vent barnacle, Neolepas zevinae {see Newman 1979), and '^O determinations subse-
quently confirmed that it was living in waters several degrees above ambient (Killingley
and Newman 1982).

Neolepas, a well-armored form having an apparent fossil record dating from the
?Lower Jurassic of New Caledonia (Buckeridge and Grant-Mackie 1985), is the most
primitive living scalpelloid and the sole surviving member of the Eoscalpellidae (Lower
Triassic; Buckeridge 1983). Other than its primitive arrangement of capitular plates,
Neolepas is specialized in having appendages that differ from those of all shallow-water
as well as deep-sea scalpelloids in being adapted for feeding on extremely fine suspended
material transported by gentle currents (Newman 1979).

Additional populations of the same species of Neolepas were subsequently dis-
covered by French scientists at the same depth from 13°N off Mexico (Newman 1985).
However, although recruitment on artificial substrates placed in the area has been
conspicuous (C. van Dover, personal communication), all collections have yielded little
more than a dozen adult specimens. Therefore, while Neolepas is evidently endemic
to hydrothermal vents in the East Pacific, it is a relatively inconspicuous member of
the communities found there.

The new form, Neoverruca brachylepadoformis gen. et sp. nov., differs from Neo-
lepas not only in being sessile but in being one of the most abundant and conspicuous

* Contribution of the Scripps Institution of Oceanography, new series.

260

members of the macro-fauna of the hydrothermal vents at 3600 m in the Mariana
Back-Arc Basin, Western Pacific, and this fauna differs in other ways from those seen
in the Eastern Pacific {see Hessler et al. 1988). Nonetheless, Neoverruca is ecologically
similar to Neolepas in being completely armored and provided with delicate appendages
adapted for feeding on very fine material transported by gentle currents {see Anderson
1980 and Zevina 1988, and Anderson and Southward 1987, concerning feeding in
Verruca and cirripeds in general, respectively).

Neolepas and Neoverruca are the most primitive living members of their suborders,
the Scalpellomorpha and Verrucomorpha, respectively, both of which first appear in
the Mesozoic. Thus, these genera are relics' surviving in the refugia provided by abyssal
hydrothermal springs long after their less specialized Mesozoic ancestors went extinct.

Description

Suborder Verrucomorpha Pilsbry, 1916, U. Mesozoic-Recent
(For an amendment of the suborder and a proposal for new families within it, see
the systematic section below.)

Neoverruca Newman, gen. nov.

Diagnosis. —N Qrr\xcomov^\\3. {see systematic section below) having several whorls
of small, imbricating plates surrounding the base and elevating the wall above sub-
stratum, and with a median latus interposed between scutum and tergum of the movable
side. Type: Neoverruca brachvlepadoformis. Etymology: A new {neo, G.) wart {verruca,
L.).

Neoverruca brachylepadoformis Newman, sp. nov.
Figures 1, 2, 3, and 4C-1

Diagnosis.— As for the genus, although the median latus becomes rudimentary
with growth and may be completely corroded away in old individuals. The scuta have
internal, apical teeth; the appendages are modified for feeding on extremely fine particles
{see Newman 1979), and there is a median-dorsal filamentary appendage and a pair of
ovigerous fraena, but caudal appendages are absent. Etymology: Short-shellfish {brachy-
lepas, G.) form {form, L.).

Material.— More than 100 adult hermaphrodites and 12 or so juvenile stages
attached to ferriferous crusts and vent mussels near hydrothermal springs of the Mariana
Back-Arc Basin in the Western Pacific (18°12'N; 144°42'E) at depths of approximately
3600 m. ALVIN Dives (Stations) 1822, 1840, and 1844, April 1987. Temperature field
from 5 to 15°C (Hessler et al. 1988).

Deposition of types.— Holotype U.S. National Museum of Natural History Cat.
no. 240030, and two paratypes to each of the following institutions: USNM Cat. no.
240031; British Museum (Nat. Hist.) Reg. no. 88.274-275; National Museum Nat.
Hist. Paris, Ci 2050; University of Auckland; Zool. Mus. Copenhagen; Zool. Mus.
Moscow State University; National Sci. Mus., Tokyo.

Hard parts. —Asymmetry of the shell in verrucomorphs involves ontogenetic changes
in the proportions and the arrangement of the plates, and individuals can be either
right or left sided. For ease of description and discussion both sides are illustrated as
though they were right sides (except in Fig. 2) and identified as follows: The side
supporting the movable tergum and scutum (operculum), and where the rostrum and
carina come in contact, will be called the "movable side." The opposite side, where
the gap between the rostrum and carina is filled by the fixed scutum and tergum, will
be called the "fixed side."

' The term "relic" is used here to specify a survivor of an ancient lineage, in contrast to a "relict" or
subpopulation isolated from a parent population by some vicariance event (see Udvardy 1969:208 for
discussion).

261

These designations, "movable and fixed sides," apply to all verrucomorphans and
distinguish their unique morphology from that of the symmetrical sessile barnacles.
However, if a specimen of Neovcrruca brachylepadofonnis were viewed from one side
or the other, while the nature of the opposite side remained unknown, it would be
diagnosed as a brachylepadomorphan. Furthermore, without the more detailed infor-
mation on and illustrations of the opercular parts and wall presented here, it would be
difficult to decide if a mixed sample of disarticulated plates from several individuals
of this species represented a neoverrucid or a brachylepadomorphan, as was the case
with a number of fossil shell lots assigned by Darwin to a pedunculate barnacle, Pol-
licipes, before Withers (1914a) recognized them as a new and primitive brachylepa-
domorphan, Pycnolepas. Thus, it is possible that some fossils considered brachylepa-
domorphans may actually represent neoverrucids.

The movable side, supporting the movable scutum and tergum, tends to be flattened
or slightly concave in the vertical plane, while the fixed side is somewhat rounded.
Depending on the circumstances under which an individual grew, the scuta and terga
may tilt from essentially vertical, as in Altivermca, toward the fixed side, as in Verruca.
There is no obvious shortening of the fixed scutum and tergum relative to the movable
scutum and tergum in tilted individuals of Neoverruca, although the tilt can approach
80° in crowded individuals, bringing the plane of the scuta and terga nearly parallel to
the substratum.

There are usually four whorls of relatively small imbricating plates discernible on
the movable side and two or three on the fixed side of the animal. In Brachylepas {see
Newman 1987 and Zullo et al. 1987), and perhaps in most Pycnolepas (J. S. H. Collins,
personal communication), there are more whorls of plates, and the plates of the lower
whorls possess mortises that interlock with tenons in plates of alternate lower whorls.
When viewed from within, or when disarticulated, no interlocking between imbricating
plates can be observed in Neoverruca\ to the contrary, there appears to be a tendency
for some plates of the lowermost whorl to be lost with growth and age.

At the rostral and carinal ends of the shell, the height the latera extend up the wall
diminishes. There is a subrostral and subcarinal tier of plates, and between them there
appear to be 10 to 12 tiers of latera on the movable side and 6 to 7 tiers on the fixed
side. Thus there are apparently as many as 1 8 vertical tiers of imbricating plates around
the circumference of the wall, standing two to four whorls high and supporting the
principal wall plates above the substratum. This is about the number of tiers encoun-
tered in Chionelasmus and in the basic shell of Catophragmus. On the other hand, it
is about half the number of tiers estimated for the highly derived interlocking imbri-
cation plates of Brachylepas cretacea {see Newman 1987).

The individual plates of the imbricating basal whorls in Neoverruca have much
the same shape and ornamentation: Each is a more or less equilateral triangle with a
generally faint, narrow median ridge flanked on either side by fine striations that radiate
from the apex to the base. The median tier of latera, below the median latus, covers
the rostro-carinal suture on the movable side. But it takes several tiers of latera to cover
the suture between the scutum and tergum, and the adjacent sutures between them and
the rostrum and carina, on the fixed side {see Figs. lA and B, 2B, and 4C-1).

The apically acute median latus, interposed between the movable scutum and
tergum, becomes rudimentary, badly corroded, and weakly attached with age, and it
may be lost in older individuals {see Figs. 4C-1 and 2B). A median latus in this position
is unknown in other sessile barnacles except brachylepadomorphans.

Attempts to identify individual latera in adults were confusing. Part of the con-
fusion arose because some of the marginal imbricating plates are easily lost. But the
full extent of the confusion was not understood until the ontogeny of a number of the
post-cyprid metamorphic stages was studied (Newman 1989). Some information
on the remarkable juveniles of Neoverruca is given below, under "Juvenile Stages,"
but determination of homologies and identification of the principal latera, based on
the ontogenetic analysis, are beyond the scope of this species description and will be
published separately (Newman 1989).

262

Figure 1. Neoverruca brachylepadoformis gen. et sp. nov. Large individual (2.1 cm high) from a closely
packed aggregation at ALV Sta. 1843. For ease of comparison, both sides appear as right sides. Note lack
of ferromanganese deposits on younger portions of shell of the adult and on the two juvenile individuals in
A. See Figure 4C- 1 for the form of an adult growing under uncrowded conditions (please consult Fig. 2 for
identification of plates and the caption of Fig. 4 for symbols).

A, view of the fixed (FS-FT) side. Note that R and C are moderately separated, with S and T immovably
fixed between them. The two recently settled juveniles both with movable (MS-MT) sides outward, first
attached themselves in the depression formed by the articulation between FS and FT. It can be observed
that the lower, younger juvenile appears to be basally narrower; it is a pedunculate stage with naked
peduncle and typical scalpellomorphan capitulum having a relatively narrow carina and rostrum. The upper,
older juvenile has undergone metamorphosis into the sessile mode, and it has added several more whorls of
imbricating plates to the expanded basal margin of its capitulum.

B, view of the movable (MS-MT) side. Note that R overlaps C and that the relatively narrow S and T
form a movable operculum. The median latus (L), visible on the MS-MT side of the juveniles (Fig. lA) and
the uncrowded adult (Fig. 4C-1; MS-MT), becomes vestigial with growth and, owing to corrosion, may
completely disappear in large adults as it almost has here {see Fig. 2B).

The basis is membranous. When individuals are severely crowded, the basis can
elongate to the extent that, when individuals are separated, some resemble pedunculate
barnacles. The elongation may also include the lower portion of the wall, causing some
of the lowermost plates of the imbricating whorls to separate from each other, furthering
a pecundulate semblance. Elongation of bases, both membranous and calcareous, occurs
in a number of distantly related sessile barnacles for a variety of adaptive reasons that
include crowding. We consider elongation of the basis in Neoverruca, in response to
crowding, to be without phylogenetic significance.

The scuta and terga are weakly ornamented, the terga by a more or less median
ridge and fine longitudinal ribs or striations radiating from the apex, the scuta similarly
but without a median ridge. The scutum and tergum of the fixed side are proportionately
wider than their movable counterparts {see Fig. 2C, D and E, F, respectively). The
movable pair fit within the confines of the margins of the fixed pair, and the scutum
forms the basal hinge line high up on the lateral portions of the rostrum and carina.

The rostral angle of the fixed scutum is rolled inward (Fig. 2C) to form a condyle
with the relieved rostral angle of the movable scutum (Fig. 2E). The interior of the
apical region in both scuta, above the deep depressions for the scutal adductor muscle,
is thickened; the thickening of the fixed scutum is produced into a short, longitudinal.

263

Figure 2. Neoverruca hrachylepadofonnis gen. et sp. nov. (ALV Sta. 1 843). A and B, adult viewed from
the left (fixed) and right (movable) sides, respectively. C and D, and E and F. interior views of FS and FT.
and MS and MT, respectively, but from a slightly smaller individual. Note narrowness of MS and MT (E
and F), as compared to those of the fixed side (C and D), and the unusual tooth-like structures in the apices
of the scuta (C and E). Also note contact between R and C, and vestigial L between MS and MT, on the
movable side (B).

depending tooth or ridge that comes to rest just over, or on, one or two similarly formed
ridges on the movable scutum. These ridges, the condyle, and the fit along the occludent
margins of the movable pair within the fixed pair assure alignment of the operculum
with the wall and lock it in place when closed. The relationship of the scutal adductor

264

A,C,E& F 0.25mm

Figure 3. Neoverruca brachylepadoformis gen. et sp. nov. (ALV Sta. 1 843). A, labrum flanked by mandibular
palps, setae on left palp deleted; B, crest of labrum enlarged; C, mandible; D, spines of second and third
tooth enlarged; E, first maxilla; and F, intermediate articles of sixth cirrus (some setae truncated to simplify
illustration) (note the two anomalously short articles between the two normal ones).

muscle to these ridges has not been examined, and therefore some apodemal properties
of the latter cannot be discounted, but these ridges and associated depressions are
internal and are not involved with housing complemental males. The articular margins
between the scutum and tergum of each side lack the well-developed articular ridges
and furrows seen in some scalpelloids, most verrucomorphans, and virtually all bal-
anomorphans.

The rostrum and the carina, also marked by fine ribs or striations that radiate
from apex to base, are slightly asymmetrical and perceptibly flat on the movable side.
The flattened condition could aid in their identification as "neoverrucid" when dis-
articulated. The carina is generally but not necessarily higher than the rostrum. Like
the rostrum, it has shallow depressions around its perimeter marking the positions of
the vertical tiers of imbricating plates, but the depressions are not as pronounced or
arranged in as precise a manner as in Brachylepas cretacea. The carina also has an
"alar" furrow or depression on the movable side that superficially appears to have been
formed in response to overlap by the rostrum, but when an articulated specimen is

265

viewed from within, it is seen to accommodate the carinal portions of lower latera.
Overlap between the rostrum and carina, established during ontogeny, is apparently
never marked; it is the lower latera that provide protection and strength to this suture.
Concomitantly, there is also a broad but shallow furrow on the carinal margin of the
rostrum to accommodate them.

The lateral margins of the rostrum and carina on the fixed side are provided with
narrow, smooth, articular surfaces to receive the corresponding margin of the scutum
and the basi-carinal margin of the tergum, respectively. A large latus tends to overlap
the rostro-scutal, scuto-tergal, and tergo-carinal sutures. But, for strength and protection
of the more numerous sutures found on the fixed side, there are more tiers of imbricating
latera than on the movable side. On the other hand, the movable side tends to have
more whorls than the fixed side, especially in very young individuals that are bent over.
Soft parts. —The prosoma (cephalic region supporting mouth parts) is uninflated and
blends imperceptibly into the thorax, as in Verruca. However, it bears an anteriorly
directed, median dorsal filamentary appendage containing ramifications of the testes.
The mouthparts are very similar to those of the hydrothermal scalpelloid Neolepas:
The labrum is slightly bullate; the crest is concave, without a notch, and supports a
single row of fine, sharp teeth behind a row of debris-laden bristles, and the palps are
relatively small (Fig. 3A, B). The mandibles are clothed with fine setae, and the cutting
edge consists of one strong superior spine and three low, broad teeth each supporting
a single row of fine, sharp spines along their superior margins. The fourth tooth blends
almost imperceptibly into the spiny lower margin, and the inferior angle is produced
into a fine-toothed comb of similar spines that change to fine, soft spines along the
inferior margin (Fig. 3C). The first, and second (not illustrated), pair of maxillae each
have a straight cutting edge supporting a comb of fine setae (Fig. 3E). Behind the second
maxillae, a subesophageal salivary gland apparently opens on a prominent median
papilla.

The first two pairs of cirri are modified as maxillipeds; the rami of the first pair
have inflated, heavily setose proximal articles and subequal, antenniform distal articles,
and they have about 25 articles each; the second pair are similar in appearance but
their rami, of about 14 and 34 articles each, are markedly unequal. The remaining four
pairs of cirri are ctenopod (Fig. 3F) and have long, slender rami of about 52, 70, 84,
and 75 articles per ramus, respectively; the proximal articles are wider than long and
support one or two pairs of setae, while the distal articles are three times as long as
wide and support as many as eight pairs of setae along the lesser curvature (Fig. 3F).
The probosciform penis is as long as the posterior cirri, and caudal appendages are
absent.

Approximately 100 large (0.25-0.50 mm) eggs, in a pair of saucer-shaped ovigerous
lamellae held in the bottom of the mantle cavity by a pair of ovigerous fraena, were
found in three of the five individuals examined internally; embryos from one individual
consisted of nauplii with well-developed appendages and caudal spines, but whether
they are released as feeding or non-feeding nauplii, or as cyprids, remains unknown.

Juvenile Stages

A number of ontogenetic stages following cyprid metamorphosis were found at-
tached primarily to established hermaphrodites (adults), and, as noted above, they will
be described in more detail elsewhere (Newman 1989). Juveniles found on adults
were most commonly attached along the articulation between the tergum and scutum
of either side (Fig. lA), a position where they receive protection from the adults when
crowded, and a position that could be advantageous should they develop precociously
as males {see Charnov 1987 and Klepal 1987).

Following cyprid metamorphosis, juveniles pass through several pedunculate stages,
and those developing on the surface of adults orient in the same direction as the adult
before undergoing metamorphosis into sessile juveniles. If a sessile juvenile is attached
to the right side of an adult, its movable side will be the right side, but if it settles on

266

Figure 4. Origin and radiation of the sessile barnacles. The four major radiations in this diagram are
distinguished by major evolutionary innovations: A, the development of a complex capitular armament, by
transfer of peduncular plates to the capitulum, in scalpellomorphan Pedunculata (note three latera in A-2
between R and C); A to B, advent of the Sessilia or sessile barnacles (Brachylepadomorpha) by elimination
of the peduncle and further development of a modest separation between an operculum and the remaining
capitular plates (note that three tiers of latera close the gap between rostrum and carina); B to C, divergence
of the asymmetrical sessile barnacles, Verrucomorpha, by fixation of S and T (FS and FT) between R and
C of one side, the joining of R and C to support S and T (MS and MT) of the movable side, and the subsequent

267

the left side of the aduU, its movable side will be the left side. Thus, right or left
sidedness is ecotypically determined, and this is likely the case in other verrucomor-
phans in which right and left sidedness occurs in the same species.

The peduncle is naked in the pedunculate juvenile stages, and, in the earliest, the
capitular plates are symmetrically arranged, all as in the early juveniles of scalpello-
morphans. Capitular asymmetry gradually becomes evident through differential ap-
pearance and growth of the plates and the heterochronous appearance of the first whorl
of latera before the median latus on the incipient movable side. When the essential
transformations heralding the verrucomorphan asymmetry are completed, the last pe-
dunculate juvenile undergoes an abrupt metamorphosis into the first sessile juvenile.
While distinct pedunculate stages are unknown in the ontogeny of other sessile bar-
nacles, Darwin (1854) noted the semblance of a peduncle during metamorphosis from
the cyprid to the first juvenile in Semibalanus balanoides.

Systematics

Subclass Cirripedia Burmeister, 1834

Superorder Thoracica Darwin, 1854, ?Cambrian, Silurian-Recent

Order Sessilia, Upper Mesozoic-Recent

Suborder Verrucomorpha Pilsbry, 1916 (amended)

Asymmetrical sessile barnacles, the primary walls of which consist of a chamber
formed by the rostrum and carina abutting on one side and a scutum and tergum
interposed and fixed between them on the opposite or "fixed" side, and closed by the
movable scutum and tergum or operculum (Darwin 1854, Verruca sensu lato, see Fig.
4C-3 herein); the wall is sometimes provided with a pair of latera (rostro- and carino-
latus) on the movable side (Withers 1914Z), Eoverruca and Proverruca, see Fig. 4C-2
herein), or it is surrounded by several basal whorls of small, imbricating plates elevating
the principal wall plates above the substratum and includes a median latus interposed
between the scutum and tergum of at least the movable side (Fig. 4C-1, Neoverruca
gen. nov.).

As can be seen from this diagnosis, and as depicted in Fig. 4C, the verrucomorphans
fall into three natural groups, beginning with the new form (superficially indistinguish-
able from the Brachylepadomorpha) and ending with the familiar and highly modified
form on which the suborder was founded {Verruca s. 1., including allied genera listed

loss of all latera, bringing the principal wall plates into contact with the substratum; B to D, divergence of
the higher symmetrical sessile barnacles, the Balanomorpha, by closing of the gap on both sides, between R
and C, with a few enlarged and specialized latera and, concomitantly, by bringing R and C and the principal
latera into contact with the substratum. The median latus (L) was known to go with the operculum in
brachylepadomorphs, it is now known to do likewise in the verrucomorphs; and it was inferred to do so in
the primitive balanomorph, Catophragmus {see Newman 1987). However, the homologies of the latera of
a very primitive balanomorphan, Chionelasmus (Fig. 4D-1) remain conjectural.

A, Pedunculata; relevant Scalpellomorpha. A-1, Neolepas zevinae from hydrothermal vents at 2600 m,
Eastern Pacific; A-2, Scillaelepas. a deep-sea amphitropical complex, 400-2000 m; and A-3, Capitulum
mitella. intertidal, ?Madagascar-Westem Pacific. B, C, and D, Sessilia. B, fBrachylepadomorpha, Europe,
North America, and Antarctica; B-1, generalized brachylepadomorphan; B-2, ■\Brachylepas cretacea,* En-
gland. C, Verrucomorpha;** C-1, Neoverruca hrachylepadoformis gen. et sp. nov., small (1.0 cm high) un-
crowded individual from 3600 m, hydrothermal springs, Mariana Back-Arc Basin (ALV Sta. 1840); C-2,
■f Eoverruca hewitti. England; and C-3, Verruca, cosmopolitan, mostly deep water to approximately 5000 m.
D, Balanomorpha; D-1, Chionelasmus darwini. deep water (approximately 500 m), islands of the Indo-West
Pacific; D-2, generalized Catophragmus s. 1.,* extant species, intertidal, Bermuda and Caribbean islands, off-
shore islands on the Pacific side of Panama and Costa Rica, and Southeast Australia and Tasmania; D-3,
Bathylasmatidae (He.xelasma), Western Atlantic and Western Pacific, deep water, 100-3000 m.

t. Extinct; *. unessential basal imbricating plates toward rostral and carinal ends omitted; **, asymmetry
in verrucomorphans can be cither right or left sided in the same population. For ease of comparison between
sides of these verrucomorphans, all side views are illustrated as though they were of the right side. C, carina;
FS, fixed scutum; FT, fixed tergum; L, median latus; MS, movable scutum; MT, movable tergum; R, rostrum;
S, scutum; and T, tergum (A, B, and D-1-2 from Newman 1987, C-2 modified from Withers 1935, C-3
modified from Pilsbry 1916. and D-3 from Hoek 1913).

268

below under the Verrucidae; see Zevina 1987^). Since this evolutionary sequence has
been achieved by reduction, it is possible that some members of Verruca s. 1. have
descended more than once from the proverrucan and/or the neoverrucan level of
organization. However, there is presently no morphological evidence for convergence
at any level within the Verrucomorpha. Therefore we propose that these three groups
be recognized at the family-group level, as follows, in order of increasing specialization:

Neoverrucidae Newman, fam. nov. The primary wall is elevated above the sub-
stratum by basal whorls of imbricating plates, and a median latus is interposed between
the movable scutum and tergum (Recent, unless some fossils, particularly some already
attributed to the Brachylepadomorpha, prove to be neoverrucids). Neoverruca gen. nov.

Proverrucidae Newman, fam. nov. The primary wall is in contact with substratum
and is provided with two overlapping latera protecting the rostro-carinal suture on the
movable side (Upper Cretaceous). Proverruca Withers, \9\4b\ family includes Eo-
v^rrwca Withers, 1935.

Verrucidae Darwin, 1854. The primary wall is in contact with the substratum and
is without latera of any sort (?Middle, Upper Cretaceous-Holocene). The genus Verruca
s. 1. proved to be species-rich with the advent of deep-sea explorations, and a number
of subgenera, presumably representing natural groups, have been erected. Zevina (1987a,
b) has proposed that the subgenera be elevated to full generic rank. To these she added
a new genus, and the six are listed below more or less in order of increasing special-
ization:

(1) Ahiverruca Pilsbry, 1916:40 (Type: V. hoeki Pilsbry, 1907; ? = F. gibbosa
Hoek, 1883; Zevina 1987/): 18 13).

(2) Verruca Schumacher, 1817:35 (Type: Lepas stroemia Miiller, 1776).

(3) Cameraverruca Pilsbry, 1916:39 (Type: V. euglypta Pilsbry, 1907).

(4) Metaverruca Pilsbry, 1916:21 (Type: V. coraliophila Pilsbry, 1916).

(5) Rostratoverruca Broch, 1922:297 (Type: V. nexa Darwin, 1854).

(6) Spongoverruca Zevina, 1987/7:1813 (Type: V. spongicola Gruwel, 1911).

While derived characters are generally used to distinguish among several of these
genera, Ahiverruca and Verruca sensu stricto are distinguished primarily on the basis
of whether the plane of the movable plates is nearly vertical or horizontal to the
substratum. In light of the variation observed in Neoverruca in this regard, the pos-
sibility that some species included in these genera express comparable ecophenotypic
variability exists, and therefore the distinction between these two otherwise unspe-
cialized genera should probably be viewed with caution.

The relationships of the Verrucomorpha to the symmetrical sessile barnacles, and
the radiation of the latter, are illustrated in Figure 4, while times of first appearance
and geologic ranges are depicted in Figure 5.

Discussion and Conclusions

Biogeographical and evolutionary significance. —Both hydrothermal barnacles,
Neolepas from the East Pacific and Neoverruca from the West Pacific, are of evolutionary
significance because they are the most primitive living members of their lineages, the
pedunculate Scalpellomorpha and sessile Verrucomorpha (Fig. 4A-1 and C-1, respec-
tively). It is also biogeographically significant that these two ancient "Mesozoic" mor-
phologies are found today as relics in the refugium provided by abyssal hydrothermal
springs. Thus, the discovery of Neoverruca not only further falsifies the hypothesis that
the Brachylepadomorpha and Verrucomorpha rose independently from scalpellomor-
phan ancestors (see Newman 1987), it further falsifies the hypothesis that vents and
cognate environments are inhabited by rapidly evolving recent immigrants (see New-
man 1985).

Neoverruca, in having a verrucomorphan facies superimposed on a brachylepa-
domorphan ground plan, represents a "missing link" as well as a "living fossil" relevant
to the early evolution of the sessile barnacles. Neoverruca is furthermore remarkable

269

Figure 5. Geological ranges of the principal sessile barnacles and their ancestral pedunculate lineage.
Of the three lineages of sessile barnacles, (1) all appear in the Cretaceous; (2) the earliest, the Brachylepa-
domorpha, went extinct, but its organization plan was central to the evolution of the higher forms; (3) the
Verrucomorpha, including the most primitive living sessile barnacle, Neovernica, is moderately diverse
although presently confined almost exclusively to the deep sea; and (4), the Balanomorpha, including the
oldest surviving members Catophragmus s. 1. and Chionelasmus, having a relict intertidal distribution and
a moderately deep-water Indo-West Pacific relic distribution, respectively, has a substantial diversity pri-
marily in shallow water (Newman and Stanley 1981).

Solid vertical bars represent the ranges of genera; the gap in the bar under Catophragmus s. 1. probably
reflects the fact that intertidal Balanomorpha are less frequently encountered in the fossil record than are
shallow-water forms. However, the Cretaceous form appears only remotely related to the Recent forms which,
in themselves, represent three morphologically very distinct and geographically isolated populations (Stanley
and Newman 1980). The dashed vertical lines indicate inferred ranges, and the extensive range for Neolepas,
initially justified on theoretical grounds, has been corroborated by a tentative identification of its morphology
in the Triassic of New Caledonia (Buckeridge and Grant-Mackie 1985). While the thoracican cirripeds may
stem from the Cambrian (Collins and Rudkin 1981; but see Briggs 1983), the oldest potential relatives of
the scalpellomorphan pedunculates are the Carboniferous praelepadids and, therefore, the dashed arrow
directed toward the earliest Mesozoic scalpellomorphs can be inferred to stem from them (Newman et al.
1969, Newman 1987).

in passing through a number of pedunculate juvenile stages during ontogeny. Therefore,
knowledge of Neoverruca provides insights not only into the affinities between sym-
metrical and asymmetrical sessile barnacles, but into their pedunculate ancestors as
well, and then beyond what analyses of extant pedunculate barnacles have been able
to provide.

The origin of symmetrical sessile barnacles.— A.s Darwin (1854) noted, the sym-
metrical sessile barnacles differ from their ancestral scalpellomorphan prototype in a
number of features, the most obvious being the conversion of the peduncle into a flat,
membranous basis extending across the perimeter of the capitulum and cementing it
to the substratum. Other more or less concomitant advances included (1) specialization
of two or more pairs of latera in closing the gap on each side between the rostrum and
carina and, ultimately, their complete integration into the wall in higher forms, (2)

270

development of a distinctly separate, movable operculum and its subsequent special-
izations, (3) eventual elimination of the remaining, undedicated basal imbricating plates
and, finally, (4) reduction of the number of latera making up the primary wall (Fig. 4B,
D-1-3).

There also were a number of changes within the mantle cavity in the course of
evolution from the pedunculate to the symmetrical mode. Two important ones involved
the loss of the ovigerous fraena, setose devices holding the eggs in place, and the loss
of filamentary appendages, strap-like organs presumably used in respiration. Filamen-
tary appendages were replaced by branchiae in balanomorphs (Darwin 1 854) and, while
higher balanomorphs have branchiae alone, Walker (1983) discovered that the primitive
balanomorph Catophragmus has both fraena and branchiae. On the other hand, while
higher verrucomorphans were presumed to have lost fraena and filamentary append-
ages, they apparently never developed branchiae. It is noteworthy that Neoverruca, the
first sessile barnacle known to have ovigerous fraena and a filamentary appendage,
satisfies this expectation; in fact, this must also have been the condition in brachyle-
padomorphans because it is the condition in some surviving members of the pedun-
culate lineage that gave rise to them.

Catophragmus (Fig. 4D-2) was the most primitive sessile barnacle known to Dar-
win (1854), and he treated it as a model elucidating transitional features between
pedunculate barnacles like Pollicipes and Capitulum and the higher sessile barnacles.
Subsequently, two extinct sessile barnacles (Brachylepas Woodward, 1901, and the
somewhat more primitive Pycnolepas Withers, 1914Z); see Fig. 4B herein) replaced
Catophragmus as the most primitive forms. However, despite Woodward's and With-
ers' considerations to the contrary, Pilsbry (1907) pronounced that the arrangement of
imbricating plates in the Brachylepas and Catophragmus was basically different and
that the two lineages had likely arisen independently from pedunculate ancestors. How-
ever, a recent study of the imbricating system in Brachylepas cretacea {see Newman
1987), including an analysis of the principal latera as viewed from within as well as
from without, revealed how the arrangement of latera seen in balanomorphs could
have been attained through loss and rearrangement of certain of the principal latera in
a Brachylepas-like ancestor. The phylogenetic inferences so derived, including the
tranfer of the median latus to the operculum in the evolution of Catophragmus, called
for rejection of polyphyly in favor of monophyly in the evolution of the symmetrical
sessile barnacles (Newman 1987). Knowledge of the basically brachylepadomorphan
organization of Neoverruca, and the presence of pedunculate stages in its ontogeny,
does much to further our understanding of how this transition took place.

The origin of the asymmetrical sessile barnacles. —Understanding of the origin of
verrucomorphans has been clouded by conjecture since Darwin (1854). He spent much
of his time on Verruca s. 1., morphologically the most specialized of the verrucomor-
phans as we know them today, in working out homologies of the plates with those of
scalpellomorphan and balanomorphan barnacles and in trying to decide whether the
unique organization plan (Fig. 4C-3) had pedunculate or sessile antecedents. While
ambivalent throughout most of his deliberations, Darwin did state that if compelled
he would with much hesitation place Verruca closer to the sessile than to the pedunculate
barnacles.

On the other hand, following the discovery of the first living representative of the
pedunculate barnacles, Scillaelepas, and the primitive verrucid having two pairs of
somewhat similarly deployed latera, Proverruca (Fig. 4A-2 and C-2, respectively), Pils-
bry (1916) accepted a pedunculate origin for the verrucids and proposed a new suborder,
the Verrucomorpha. Shortly thereafter, it was discovered that fossil material previously
thought by Darwin and others to represent Pollicipes s. 1. constituted a new sessile
genus, Pycnolepas, related to but more primitive than Brachylepas. This led to the
creation of a third independent suborder of sessile barnacles, the Brachylepadomorpha
(Withers 1923; see Fig. 4B herein) and to the notion of a triphyletic origin of the sessile
barnacles that became the dogma that all workers followed (Kriiger 1940, Withers
1953, Newman et al. 1969, Newman and Ross 1976, Newman 1982). However, as
noted above, compelling evidence for independent pedunculate origins for the Brachy-

271

lepadomorpha and Balanomorpha is lacking; to the contrary, by loss and rearrangement
of the latera it is quite apparent how the latter could have been derived from the former
(Newman 1987). And now the structure of the new form, Neoverruca, clearly illustrates
the brachylepadomorphan origin of the Verrucomorpha and falsifies the hypothesis of
even a diphyletic origin of the sessile barnacles involving these two lineages.

Neoverruca displays, in a subtle way. the profound initial morphological adjust-
ments made in the shell of a Brachy/epas-hke ancestor that led to the development of
the unique wall and operculum of the asymmetrical sessile barnacles. Such adjustments
are most readily made when the latera involved have not become an integral, dedicated
part of the primary wall, and their being readily excludable allowed one half of the
brachylepadomorphan operculum to be incorporated into the primary wall of the
verrucomorphan. This remarkable adjustment is rendered comprehensible when it is
noted that it involves the barnacle's leaning to one side or the other during ontogeny.
The adaptive value of leaning over, in an otherwise relatively high sessile barnacle,
becomes obvious if the development following settlement of a young barnacle in a
crowded colony is followed; leaning over allows young individuals to extend their cirri
upward and outward, in the same direction as those of the adults on which they settled
(Newman 1989). It is evident that this initially small adjustment, of letting the
scutum and tergum of one side come down between the rostrum and carina during
ontogeny, set the stage for the remarkable divergence of the asymmetrical from the
symmetrical forms early in the evolutionary radiation of the sessile barnacles.

Finally, it should be noted that while Withers (1914^) considered the latera of
proverrucids to be the rostro- and carino-latera (RL/CL) of a Scillaelepas-likQ ancestor,
Newman (1987) concluded they were as likely to be the rostro- and median latera (RL/
L). However, we now know that the median latus goes with the operculum in neo-
verrucids, and therefore it cannot be one of the wall latera in proverrucids. Furthermore,
from knowledge of the ontogeny of Neoverruca (Newman 1989), it is apparent that
the evolutionary transition from a neoverrucid to the proverrucid wall must have
involved progenesis (curtailment of whorl production following the formation of the
first whorl). Therefore, since it appears ontogenetically and progenetically impossible
for the latera in proverrucids to be plates from any of the subsequent whorls, they must
be RL/CL, as Withers had proposed.

Pedunculate ancestors of the sessile barnacles.— The most primitive living scal-
pellomorph is the hydrothermal barnacle Neolepas. It has simple capitular armament
including but one pair of latera (Fig. 4A-1). A more advanced form, Scillaelepas,
abundant in shallow water in the Cretaceous but presently represented by a dozen or
so species living only in the deep sea, has added two more pairs of latera, a subcarina,
and sometimes one or more subrostra (Fig. 4A-2; Newman 1980). More advanced and
ordinarily intertidal forms, the Tethyan relict Pollicipes and the Indo-West Pacific relic
Capitulum (Fig. 4A-3), have several additional whorls of smaller latera around the base
of the capitulum. There has been a long-standing consensus that the sessile barnacles
evolved from the scalpellomorph lineage represented by these genera (Darwin 1854,
Woodward 1901; Newman et al. 1969; Ghiselin and Jaffe 1973; Anderson 1983; New-
man 1982, 1987). The existence and nature of the pedunculate stages in the ontogeny
of the most primitive living sessile barnacle (Newman 1989), Neoverruca, illustrate
that the Darwinian/Woodwardian model for the pedunculate ancestry of the sessile
barnacles is well founded.

Acknowledgments

We would like to acknowledge the constructive criticism and advice of two anon-
ymous referees.

Addendum

What is apparently the most primitive living balanomorphan, fitting between B
and D-1 in Figure 4 herein, has been recently recovered by Japanese scientists from
an abyssal hydrothermal spring at approximately 2000 m in the North Fiji Basin
(Toshiyuki Yamaguchi, personal communication).

272

Literature Cited

Anderson, D. T. 1980. Cirral activity and feeding
in the verrucomorph barnacles Verruca recta
Aurivillius and V. stroemia (O. F. Miiller) (Cir-
ripedia). Journal of the Marine Biological As-
sociation of the United Kingdom 60:348-366.

Anderson, D. T. 1983. Cat omerus polymerus and
the evolution of the balanomorph form in bar-
nacles (Cirripedia). Memoirs of the Australian
Museum 18:7-20.

Anderson, D. T., and A. J. Southward. 1987. Cir-
ral activity of barnacles. Pp. 135-174 in A. J.
Southward (ed.). Barnacle Biology, Crustacean
Issues 5. Balkema, Rotterdam.

Briggs, D. E. G. 1983. Affinities and early evo-
lution of the Crustacea: The evidence of the
Cambrian fossils. Pp. 1-22 in F. R. Schram
(ed.). Crustacean Phylogeny, Crustacean Issues
1. Balkema, Rotterdam.

Broch, H. 1 922. Papers from Dr. Th. Mortensen's
Pacific Expedition, 1914-16. X. Studies on Pa-
cific Cirri pedes. Videnskabeligemeddelelserfra
Dansk Naturhistorisk Forening i Kobenhavn
73:215-358.

Buckeridge, J. S. 1983. Fossil barnacles (Cirri-
pedia: Thoracica) of New Zealand and Austra-
lia. New Zealand Geological Survey Paleon-
tological Bulletin 50:1-151 + pis. 1-13.

Buckeridge, J. S., and J. A. Grant-Mackie. 1985.
A new scalpellid barnacle (Cirripedia; Thorac-
ica) from the Lower Jurassic of New Caledonia.
Geologic de la France (1): 7 7-80.

Charnov, E. L. 1987. Sexuality and hermaphro-
ditism in barnacles: A natural selection ap-
proach. Pp. 89-104 in A. J. Southward (ed.).
Barnacle Biology, Crustacean Issues 5. Balke-
ma, Rotterdam.

Collins, D., and D. M. Rudkin. 1981. Priscan-
sermariniis barnetti, a probable lepadomorph
barnacle from the Middle Cambrian Burgess
Shale of British Columbia. Journal of Paleon-
tology 55:1006-1015.

Collins, J. S. H. 1980. A new Pycnolepas (Cirri-
pedia) from the (?) Lower Aptian of Alexander
Island. British Antarctic Survey Bulletin No.
50:21-26.

Darwin, C. R. 1854. A monograph on the sub-
class Cirripedia, with figures of all species. The
Balanidae, &C. 684 pp. + pis. 1-30. Ray So-
ciety, London.

Ghiselin, M. T., and L. JafFe. 1973. Phylogenetic
classification in Darwin's monograph on the
sub-class Cirripedia. Systematic Zoology 22:
132-140.

Hessler, R. R., and W. M. Smithey, Jr. 1983. The
distribution and community structure of mega-
fauna at the Galapagos Rift hydrothermal vents.
Pp. 735-770 in P. A. Ronds, K. Bostrom. and
K. L. Smith, Jr. (eds.). Hydrothermal Processes
at Seafloor Spreading Centers. Plenum, New
York.

Hessler, R. R., P. Lonsdale, and J. Hawkins. 1988.
Patterns on the ocean floor. New Scientist No.
1605:47-51.

Hoek, P. P. C. 1883. Report on the Cirripedia
collected by H.M.S. Challenger during the years
1873-1876. Reports on Scientific Research:
Zoology 8(25):1-169 + pis. 1-13.

Hoek, P. P. C. 1913. Cirripedia of the Siboga-
Expedition: B. Cirripedia Sessilia. Siboga-Ex-
peditie 21:129-275 + pis. 11-27. Brill, Ley-
den.
Jones, M. L. (ed.). 1985. The Hydrothermal Vents
of the Eastern Pacific: An Overview. Bulletin
of the Biological Society of Washington, No.
6, 566 pp.

Killingley, J. S., and W. A. Newman. 1982. '«0
fractionation in barnacle calcite: A barnacle
paleotemperature equation. Journal of Marine
Research 40:893-902.

Klepal, W. 1987. A review of the comparative
anatomy of the males of cirripedes. Oceanog-
raphy and Marine Biology Annual Reviews 25:
285-351.

Kruger, P. 1940. Cirripedia. H. G. Bronns Klas-
sen und Ordungen des Tierreichs 5(1,3, 3):1-
145. Leipzig.

Newman, W. A. 1979. A new scalpellid (Cirri-
pedia); a Mesozoic relic living near an abyssal
hydrothermal spring. Transactions of the San
Diego Society of Natural History 19:153-167.

Newman, W. A. 1980. A review of extant Scil-
laelepas (Cirripedia: Scalpellidae) including
recognition of new species from the North At-
lantic, Western Indian Ocean and New Zea-
land. Tethys 9:379-398.

Newman, W. A. 1982. Cirripedia. Pp. 197-221
in L. Abele (ed.). The Biology of Crustacea,
Vol. 1. Academic Press, New York.

Newman, W. A. 1985. The abyssal hydrothermal
vent invertebrate fauna: A glimpse of antiq-
uity? Pp. 231-242 in M. L. Jones (ed.). The
Hydrothermal Vents of the Eastern Pacific: An
Overview. Bulletin of the Biological Society of
Washington, No. 6.

Newman, W. A. 1987. Evolution of Cirripedes
and their major groups. Pp. 3-42 in A. J.
Southward (ed.). Barnacle Biology, Crustacean
Issues 5. Balkema, Rotterdam.

Newman, W. A. 1989. Juvenile ontogeny and
metamorphosis in the most primitive living
sessile barnacle, Neoverruca, from abyssal hy-
drothermal springs. Bulletin of Marine Sci-
ence, in press.

Newman, W. A., and A. Ross. 1976. Revision of
the balanomorph barnacles; including a cata-
logue of the species. Memoirs of the San Diego
Society of Natural History 9:1-108.

Newman, W. A., and S. M. Stanley. 1981. Com-
petition wins out overall: Reply to Paine. Pa-
leobiology 7:561-569.

Newman, W. A., V. A. Zullo, and T. H. Withers.
1 969. Cirripedia. Pp. R206-295 in R. C. Moore
(ed.). Treatise on Invertebrate Paleontology,
Part R, Arthropoda 4, Vol. 1. University of
Kansas and the Geological Society of America,
Boulder.

Pilsbry, H. A. 1907. The barnacles (Cirripedia)
contained in the collections of the U.S. Na-
tional Museum. Bulletin of the U.S. National
Museum 60:1-122 + pis. 1-11.

Pilsbry, H. A. 1916. The sessile barnacles (Cir-
ripedia) contained in the collections of the U.S.
National Museum. Bulletin of the U.S. United

273

States National Museum 93:1-366 + pis. 1-
76.

Schumacher, H. C. F. 1817. Essai d"un nouveau
systeme des habitations des Vers teslaces. &c.
287 pp. + 22 pis. Copenhagan.

Stanley, S. M.. and W. A. Newman. 1980. Com-
petitive exclusion in evolutionary time: The
case of the acorn barnacles. Paleobiology 6:
173-183.

Udvardy, M. D. F. 1969. Dynamic Zoogeography
with Special Reference to Land Animals. Van
Nostrand Reinhold, New York.

Walker, G. 1983. A study of the ovigerous fraena
of barnacles. Proceedings of the Royal Society,
London B 218:425-442.

Withers, T. H. 1914a. Some Cretaceous and Ter-
tiary cirripedes referred to Pollicipes. Annals
and Magazine of Natural History, Ser. 8, 14:
167-206 + pis. 7 and 8.

Withers, T.H. 1914/?. A remarkable new cirripede
from the chalk of Surrey and Hertfordshire.
Proceedings of the Zoological Society of Lon-
don. No. 64:945-953.

Withers, T. H. 1923. Die Cirripedien der Kreide
Riigens. Abhandlungen aus dem geologisch pa-
laeontologischen Institut der Universitat
Greifswald 3:1-54 + 3 pis.

Withers, T. H. 1935. Catalogue of Fossil Cirri-

pedia in the Department of Geology. 2 (Cre-
taceous): 1-535 ♦ pis. 1-50. British Museum
(Natural History), London.

Withers, T. H. 1953. Catalogue of Fossil Cirri-
pcdia in the Department of Geology. 3 (Ter-
tiary): 1-396 + pis. 1-64. British Museum
(Natural History), London.

Woodward, H. 1901. On "Pyrgoma cretacea" a
cirripede from the Upper Chalk of Norwich
and Margate. The Geological Magazine, New
Series, Decade IV 8:145-152 + pi. 8.

Zevina, G. B. 1987a. Abyssal Cirripcdia Verru-
comorpha (Thoracica) of the Atlantic and In-
dian Ocean. Zoologicheskv Zhurnal 66:1304-
1313.

Zevina, G. B. 1987/?. Deep-sea Verrucomorpha
(Cirripedia, Thoracica) of the Pacific: 1. The
North Pacific. Zoologichesky Zhurnal 66: 1812-
1821.

Zevina, G. B. 1988. Deep-sea Verrucomorpha
(Cirripedia, Thoracica) of the Pacific: 2. The
South Pacific. Zoologichesky Zhurnal 67:31-
40.

Zullo, V. A., E. E. Russell, and F. F. Mellen. 1987.
Brachylepas Woodward and Virgiscalpelluni
Withers (Cirripedia) from the Upper Creta-
ceous of Arkansas. Journal of Paleontology 6 1 :
101-llL

TRANSACTIONS
OF THE SAN DIEGO

^S?DV SOCIETY OF

LIBRAKT NATURAL HISTORY

MAV 1 6 1989

n. niPS

HAH*U)|ume 21 Number 17 pp. 275-282 30 April 1989

UNIV

New stratigraphic and geographic occurrences of Isognomon (Mollusca:
Bivalvia) from the Eocene of California and Oregon

Richard L. Squires

Department of Geological Sciences, California State University, Northridge, California 91330, USA

Abstract. The bivalve Isognomon (Isognomon) clarki (Effinger, 1938), previously only known from the
upper Eocene part (Galvinian Stage) of the Lincoln Creek Formation of southwestern Washington, is reported
here from five other Eocene formations. Four are in southern California: the upper Juncal Formation, the
upper Torrey Sandstone, the basal Tejon Formation, and the Coldwater Sandstone; fifth is the Keasey For-
mation of northwestern Oregon. Except in the upper Juncal Formation, the presence oi Isognomon specimens
was previously unrecorded. The geologic age range of this species is extended downward into the middle
Eocene ("Domengine Stage"). Isognomon (I.) clarki is the only species of its genus known from the Eocene
of the West Coast, and this study is the first documentation that this genus formed dense populations in
the Eocene. Most of these populations are in coarse-grained pebbly sandstone sediments that indicate near-
shore conditions. Rare specimens in the Lincoln Creek and Keasey formations are anomalous because they
are in deep-water fine-grained sediments.

Introduction

The bivalve Isognomon is rare in the fossil record of the West Coast (California, Oregon, and
Washington). Only two species are known, and their occurrence is very locaHzed. This scarcity is prob-
ably linked to the high-energy habitat of Isognomon species, which commonly inhabited intertidal
areas subject to erosion. The earliest West Coast species known is Isognomon (Isognomon) clarki
(Effinger, 1938) from the Eocene part of the Lincoln Creek Formation of Washington. In addition,
Isognomon sp. (Clark and Woodford 1927) from the Meganos Formation and Isognomon n. sp.? Givens
(1974) from the Juncal Formation have been reported from Eocene rocks of California.

The only West Coast Oligocene species is Isognomon panzana (Loel and Corey, 1932) from the
upper Oligocene through lower Miocene Vaqueros Formation, California. The cooler conditions that
predominated from middle Miocene through Recent times are the inferred cause of the elimination
of Isognomon from the West Coast's higher latitudes. Today in western North America, there are
only two species of Isognomon, extending north only as far as Baja California, primarily in warm
lagoons (Keen 1971).

Four previously unknown stratigraphic occurrences of West Coast Paleogene Isognomon can now
be added. These are the upper Torrey Sandstone, San Diego County, southern California; the basal
Tejon Formation, Kern County, south-central California; the Coldwater Sandstone, Ventura County,
southern California; and the upper Keasey Formation, Columbia County, northwestern Oregon
(Figure 1). In all these Eocene formations, except the Meganos Formation, I believe the specimens
represent /. (/.) clarki (Effinger). The Meganos Formation occurrence is not included at this time
because there is not enough material to allow a conclusive determination.

Methods

During field investigations of the Tejon Formation, I collected abundant specimens of Isognomon.
The other three previously unknown stratigraphic occurrences are based on museum material I iden-
tified while examining collections in museums. The primary type specimens of /. (/.) clarki and the
hypotypes from the Juncal Formation were borrowed from museums.

276

^45''

Type Locality
Keasy Formation

^40**

PACIFIC OCEAN

35'

Tejon Formation
Juncal Formation •

Coldwater Sandstone

30"

0 200 400 600 800 km

L 1 1 1 1 1 I I I

Torrey Sandstone — A*

120

Figure 1. Stratigraphic occurrences of Isognomon (Isognomon) clarki (Effinger, 1938).

277

Observations on the height of the Hgamental area and number of Hgamental grooves of modern
Isognomon were made on specimens in the malacological collections of the San Diego Society of
Natural History.

The usage of molluscan provincial Eocene stages for California is based on Clark and Yokes (1936)
with modifications by Givens (1974). The ages of these stages follow Saul (1983) and Squires (1984,
1987). The usage and ages of molluscan Eocene stages for northwestern Oregon and Washington follow
Armentrout (1975, 1981).

Abbreviations used for catalog and/or locality numbers are CSUN, California State University,
Northridge; LACMIP, Natural History Museum of Los Angeles County, Invertebrate Paleontology
Section; SDSNH, San Diego Society of Natural History; UCR, University of Cahfornia, Riverside;
UCMP, University of Cahfornia Museum of Paleontology, Berkeley.

Stratigraphic Occurrences

Type Locality.— Effinger (1938) named and reported Isognomon (Isognomon) clarki [= F^dalion
clarki] from the Gries Ranch beds, just east of Vader, Lewis County, southwestern Washington. Only
two valves were found, at locality UCMP 3607. Mainly on the basis of the abundance of sessile near-
shore invertebrates, he interpreted the environment to have been nearshore or littoral. C. S. Hickman
(personal communication, 1988), however, believes the shallow-water invertebrates were transported
into a deep-water environment. Durham (1944:112, fig. 7) assigned the Gries Ranch beds to his
Molopophorus stephensoni megafaunal Zone. Armentrout (1975) assigned the M. stephensoni Zone
to the Echinophoria dalli Zone in the lower part of the Lincoln Creek Formation and in the middle
of his Galvinian Molluscan Stage of late Eocene age.

California. — Givens (1974) reported the first occurrence of Isognomon from the Eocene of Cali-
fornia. His specimens were from the upper half of the Juncal Formation, Pine Mountain area, Ventura
County, southern California, at a single locality (UCR 4752) in a lens of calcareous sandy conglomerate.
He identifed these specimens as Isognomon n. sp.? pending the discovery of more complete material.
Givens' material consists of three large (up to 14 cm in height) articulated and two fragmentary
specimens. From the presence of Isognomon and associated moUusks he interpreted this Isognomon-
bearing bed as having formed in a shallow-water (inner sublittoral) environment at the seaward margin
of a delta. The bed lies within the Tiirritella uvasana applinae fauna of the Juncal Formation, and
this fauna is equivalent to the West Coast megainvertebrate provincial middle Eocene "Domengine
Stage."

The new stratigraphic occurrence of /. (/.) clarki in the Torrey Sandstone is near the top of the
formation, east of the city of Del Mar, in a new development called North City West, San Diego
County, southern California. A 20-m-thick section of the Torrey was exposed in 1985 by bulldozing
during construction. A 15-m-thick section of Ardath Shale was also exposed. The contact between
the two units was sharp, and locally the claystone of the Ardath draped over cobbles at the top of
the Torrey Sandstone. Overlying the Ardath was 10 m of the Scripps Formation. A housing tract now
covers most of the entire section.

Specimens of /. (/.) clarki were found near the top of the 20-m-thick section of the Torrey Sand-
stone. The collecting site was a 30- to 60-cm-thick pebbly sandstone bed at locality SDSNH 3282.
Thirty-three specimens were collected, of which 15 were right valves and 17 were left valves. Only
a single articulated specimen was found. Most of the specimens are fragmentary, but preservation
of the shell material is excellent. Only one complete left valve 12.5 cm in height (hypotype SDSHN
35235) (Figures 2.1, 2.2) was found. No complete right valves were found, but the best example is
hypotype SDSNH 35236 (Figures 2.3, 2.4).

Mollusks in the Torrey Sandstone are rare. Previously, only two species were reported by Givens
and Kennedy (1979:85). Associated shallow-water mollusks at locahty 3282, however, are common.
Other taxa include a solitary coral, a bryozoan, a brachiopod, barnacle fragments, a brachyuran,
four shark species, a ray, a turtle, a glyptosaurine lizard, and a rodent (T. A. Demere, personal com-
munication, 1988).

A nearshore environment for locality 3282 is indicated by the mixing of marine and nonmarine
fauna. According to Givens and Kennedy (1979), a middle Eocene age ("Domengine Stage") for the
Torrey Sandstone is indicated by that formation's interdigitating with the lower part of the more readily
dated middle Eocene Ardath Shale.

278

Figure 2. Isognomon (Isognomon) clarki (Effinger, 1938), middle Eocene ("Domengine Stage") upper Torrey Sand-
stone, locality SDSNH 3282. 1-2, SDSNH hypotype 35235, left valve, xO.6, height 12.5 cm, width 10.8 cm. 1,
exterior. 2, interior. 3-4, SDSNH hypotype 35236, partial right valve, xO.7, height 9 cm, width 9.7 cm. 3, exterior.
4, interior.

The new stratigraphic occurrence of /. (/.) clarki in the Tejon Formation is in the basal part of
the formation, Tehachapi Mountains, Kern County, south-central California. This part of the for-
mation is rarely exposed because it is normally covered by extensive landslides and/or slope wash.
A road cut made in 1971 along the east side of the Edmonston Pumping Plant, however, exposed
a 122-m-thick section. The lowest 27 m consists of shoreline-associated deposits laid down as a trans-
gressing sea advanced over an irregular surface of gneissic bedrock. Channel-lag storm accumula-
tions of oyster hash and other mollusks indicate a rocky nearshore environment (Squires 1989).

At locality CSUN 1201, 13 m above the base of the section, numerous Isognomon valves (up to
9 cm in height) were found in closely packed layers. TXventy-four specimens were collected, three of
which are articulated and range in height from 6 to 8 cm. They indicate that the distance of post-
mortem transport was short. The other specimens consist of six right valves and 12 left valves, all

279

poorly preserved and consisting of only partial shells (chalky) or internal molds. Above 27 m, mollusk-
bearing channels are scarcer, and mollusks indicating subtidal environment increase (Squires 1989).
Single fragmentary specimens of /. (/.) clarki were found at localities CSUN 1202 and 1203, 19 and
63 m, respectively, above the base.

Nilsen (1987:90-92, fig. 58) listed mollusk species from a few beds in the Edmonston Pumping
Plant section and diagrammed the section. Isognomon was not Usted; neither was it found by early
workers (Gabb 1864; Dickerson 1915, 1916; Anderson and Hanna 1925) who described molluscan
faunas from the Tejon Formation in the Tehachapi Mountains and the adjacent San Emigdio
Mountains.

The lower 63 m of the Edmonston Pumping Plant section is of middle Eocene age ("Transition
Stage"), as indicated by the overlapping of Turritella uvasana uvasana and Ficopsis remondii crescentensis.
The remaining 59 m is of middle Eocene age ("Tejon Stage"), as indicated by the presence of Tur-
ritella uvasana sargeanti (Squires 1989).

The new stratigraphic occurrence of/. (/.) clarki in the Coldwater Sandstone, upper Sespe Creek,
Ventura County, southern Cahfornia, is at locality CSUN 252. The formation in this area has received
very little geologic study. Four large (up to 12 cm in height) articulated specimens were found in well-
sorted fine-grained sandstone. Associated mollusks include abundant very large (up to 18 cm in height)
articulated oysters and a few articulated Venericardia sp. Sturdy-shelled oysters and Venericardia remain-
ing in situ indicates nearshore shallow water. The well-sorted nature of the sandstone supports this
interpretation and suggests a sand-bar environment.

Oregon. — ^The new stratigraphic occurrence of /. (/.) clarki in the Keasey Formation is in the upper
part of the middle member of the formation at the Smithwick Haydite quarry, south of Vernonia,
Columbia County, northwestern Oregon. An articulated partial specimen was found in siltstone at
locality LACMIP 5806. C. S. Hickman {personal communication, 1988) collected two additional
specimens from this quarry. Both are articulated and one is complete. Hickman (1976) interpreted
the environment of the Keasey Formation to be bathyal. The articulated specimen of Isognomon is
anomalous in this deep-water assemblage. Isognomon today may attach itself to roots of mangrove
trees (Emerson and Jacobson 1976). Its occurrence in the Keasey may have resulted from individuals
being attached to floating wood that eventually sank in deep water.

The Keasey Formation is of late Eocene age (Hickman 1976, 1980; Armentrout et al. 1983). The
/. (/.) clarki specimen from locality LACMIP 5806, therefore, is of the same geologic age as those
from the type locality found by Effinger (1938).

Systematic Paleontology

Class Bivalvia Linne, 1758

Subclass Pteriomorphia Beurlen, 1944

Order Pterioida Newell, 1965

Suborder Pteriina Newell, 1965

Super family Pteriacea Gray, 1847

Family Isognomonidae Woodring, 1925

Genus Isognomon Solander in Lightfoot, 1786

Type Species. — By monotypy, Ostrea perna Linne, 1767, Recent, Indo-Pacific.

Subgenus Isognomon s.s.

Isognomon {Isognomon) clarki Effinger, 1938

Figure 2.1-2.4

Pedalion clarki Effinger, 1938:367-368, pi. 45, figs. 9-10. Weaver, 1943:77, pi. 13, fig. 9.

Isognomon n. sp.? Givens, 1974:43-44, pi. 2, fig. 6.

Isognomon {Isognomon) n. sp.? Givens. Moore, 1983:85, pi. 26, fig. 1.

The Torrey Sandstone specimens are better preserved than the primary type specimens, warrant-
ing the following supplementary description: equivalved, inequilateral, subquadrate, moderately
inflated, and large (up to 14 cm in height); prosogyrate beaks somewhat extended anteriorly; anterior
margin nearly straight, becoming concave near beak and reflected and forming a ridge in byssal gape
area below beak, reflection more pronounced on left valve; angle between hinge line and anterior

280

margin about 65°; posterior and ventral margins evenly rounded; hinge line straight with up to 21
ligamental grooves that are about half as wide as the interspaces, posteriorly the interspaces become
wider; ligamental area flat and broad to very broad, depending on the particular specimen; very narrow
byssal gape below beaks; pallial line near anterior margin marked by small nodes and pits; shell surface
with closely spaced growth Hnes; holotype height 12.5 cm, length 11 cm, (h/l = 1.14), width of both
valves together 3 cm.

Discussion .—The use of the subgenus Isognomon in this present report follows Cox (1969).

All the West Coast Eocene isognomonid specimens are judged to be /. (/.) clarki because they
are morphologically inseparable. The only differences are minor and fall within Umits of normal varia-
tion seen in comparably sized modern species oi Isognomon. The two adult specimens of/. (/.) clarlii
shown in Figure 2 differ in the height of the ligamental area and number of hgamental grooves. This
kind of variation is also present in adult specimens of /. recognitus from Kino Bay, Sonora, Mexico,
with a few specimens having ligamental area heights 25 percent greater than that of the average
specimen. Similary, the height of the ligamental area in adult specimens of/, isognomum from Manila,
PhiUppine Islands, varies from specimen to specimen, with a few specimens having heights 50 percent
greater than the average. In addition, there are 19 ligamental grooves in young adults versus 23 ligamental
grooves in mature adult specimens of this species.

The specimen shown in Figures 2.1 and 2.2 is the widest known specimen of / (/) clarki because
it is the most complete specimen of this species.

Isognomon (I.) clarki is most similar to Isognomon (/) panzana (Loel and Corey, 1932:187, pi.
9, figs, la-b, 2-6) from the upper Oligocene and Miocene Vaqueros Formation, California. Moore
(1983:84, pi. 25, figs. 3 and 6) also figured this species. Isognomon (/) clarki differs from / {I.) panzana
in the following features: much wider, h/l = 1.1 rather than 1.8, angle between hinge line and anterior
margin about 65° rather than about 75°, 12 rather than 9 ligamental grooves in specimens about 9
cm high, irregular divaricate-radial plications on the exterior absent, and posterior ventral margin
not crenulate.

A specimen from the lower Eocene Meganos Formation of north-central CaUfornia, referred to
as Pedalion sp. by Clark and Woodford (1927:88, pi. 14, fig. 8), may be an Isognomon and may be
conspecific with / (/) clarki. Moore (1983:84-85, pi. 26, fig. 3) identified this specimen as Isognomon
sp. My examination of this tiny (height 12 mm) fragmentary specimen revealed that it does have a
straight hinge line, but the view is of the exterior and no ligamental grooves can be seen. More mate-
rial of this species is needed for an identification to genus.

Material. — Sixty-six specimens.

Occw/reAZce.— ^'Domengine Stage" through Galvanian Stage, equivalent to the upper lower through
upper Eocene (upper Ypresian through Priabonian stages of Europe).

"Domengine Stage": Upper Torrey Sandstone, northern San Diego County, southern California
(locality SDNHM 3282); upper Juncal Formation, Turritella uvasana applinae fauna, Pine Mountain
area, Ventura County, southern CaUfornia (locality UCR 4752).

"Transition Stage": Lower Tejon Formation, Kern County, south-central Cahfornia (localities CSUN
1201, 1202, 1203).

"Tejon Stage": Coldwater Sandstone, upper Sespe Creek, southern Cahfornia (locality CSUN 252).

Galvanian Stage (equivalent to the "Tejon Stage"): Upper part of the middle member of the Keasey
Formation, Smithwick Haydite quarry, Columbia County, northwestern Oregon, (locality LACMIP
5806); lower Lincoln Creek Formation, near Vader, Lewis County, southwestern Washington (locality
UCMP 3607).

Repositories.— Holotype, UCMP 33513. Paratype, UCMP 33514. Hypotypes, UCR 4752/61;
SDSNH 35235 and 35236.

Acknowledgments

T. A. Demere, San Diego Natural History Museum, D. R. Lindberg and L. Bryant, University
of California, Berkeley, M. A. Kooser, University of Cahfornia, Riverside, and E. C. Wilson, Natural
History Museum of Los Angeles County, provided loans. T. A. Demere also provided a macro faunal
hst for locality SDSNH 3282. B. O. Riney, San Diego Natural History Museum, found the Torrey
Sandstone specimens and kindly gave detailed locality information. M. A. Roeder, San Diego Natural
History Museum, screened sediment from locaUty SDSNH 3282 and sorted out the vertebrate material.

281

A. E. Fritsche, California State University, Northridge, found the Coldwater Sandstone specimens.
C. S. Hickman, University of California, Berkeley, showed me additional specimens of Isognomon
from the Keasey Formation.

C. L. Powell, II, U.S. Geological Survey, Menlo Park, arranged loans of mollusks associated with
the Isognomon from the basal Tejon Formation. R. C. Brusca, San Diego Natural History Museum,
allowed access to the malacological collections.

Al Grmela, Department of Water Resources, Bakersfield, granted permission to enter and collect
specimens at the Edmonston Pumping Plant. Mildred Wiebe, Tejon Ranch, granted permission for
paleontologic investigations on the Tejon Ranch area west of the Edmonston Pumping Plant.

The manuscript benefited from comments by two anonymous reviewers. California State Univer-
sity, Northridge, kindly funded page changes.

Localities

All the quadrangle maps listed below are 7.5-minute, unless otherwise specified.

CSUN 252. Just north of upper Sespe Creek, NW 1/4, SW 1/4, SW 1/4 of section 35, T 6 N,
R 22 W, Lion Canyon quadrangle, California (1943).

CSUN 1201. Roadcut exposure about 20 m east of the eastern side of Edmonston Pumping Plant,
13 m above base of Tejon Formation, Pastoria Creek quadrangle, California (photorevised 1974).
Equivalent to U.S. Geological Survey, Menlo Park, Cenozoic collection locality M4631, given in Nilsen
(1987:90).

CSUN 1202. Roadcut exposure about 20 m east of the eastern side of Edmonston Pumping Plant,
19 m above base of Tejon Formation, Pastoria Creek quadrangle, CaUfornia (photorevised 1974).

CSUN 1203. Roadcut exposure about 60 m N5 E of the northeast corner of Edmonston Pumping
Plant, 63 m above base of Tejon Formation, Pastoria Creek quadrangle, California (photorevised
1974). Equivalent to U.S. Geological Survey, Menlo Park, Cenozoic collection locality M4633, given
in Nilsen (1987:91).

LACMIP 5806. Smithwick Haydite Quarry, 0.4 km north of the high trestle across Oregon Highway
47, 13.6 km south of Vernonia, Washington County, Oregon.

SDNHM 3282. Hillside exposure (now mostly covered), 330 m north and 330 m east of southwest
corner of section 8, T 14 S, R 3 W, Del Mar quadrangle, California (1967).

UCMP 3607. In south bank of Cowlitz River at the old Gries Ranch in the NW 1/4 of section
25, T 11 N, R 2 W, Castle Rock 15-minute quadrangle, Washington (1953).

UCR 4752. On the crest of a southwest-trending ridge northeast of the main fork of Piru Creek,
525 m south and 735 m east of the northwest corner of section 29, T 7 N, R 21 W, San Guillermo
quadrangle, California (1943).

Literature Cited

Armentrout, J. M. 1975. Molluscan biostratigraphy
of the Lincoln Creek Formation, southwest
Washington. Pp. 14-28 in D. E. Weaver, G. R.
Hornaday, and A. Tipton (eds.). Future energy
horizons of the Pacific Coast; Paleogene sym-
posium and selected technical papers. Pacific
Section, Society of Economic Paleontologists and
Mineralogists, Los Angeles.

Armentrout, J. M. 1981. Correlation and ages of
Cenozoic chronostratigraphic units in Oregon and
Washington. Pp. 137-148 in J. M. Armentrout
(ed.). Pacific Northwest Cenozoic biostratigraphy.
Geological Society of America Special Paper 184.

Armentrout, J. M., D. A. Hull, J. D. Beaulieu, and
W. W. Rau. 1983. Correlation of Cenozoic
stratigraphic units of western Oregon and
Washington. Oregon Department of Geology and
Mineral Industries, Oil and Gas Investigation
7:1-90.

Anderson, F. M., and G. D. Hanna. 1925. Fauna
and stratigraphic relations of the Tejon Eocene
at the type locality in Kern County, California.

California Academy of Sciences, Occasional
Papers 11:1-249.

Clark, B. L., and H. E. Yokes. 1936. Summary of
marine Eocene sequences of western North
America. Geological Society of America, Bulletin
47:851-878.

Clark, B. L., and A. O. Woodford. 1927. The geology
and paleontology of the type section of the
Meganos Formation (lower middle Eocene) of
California. University of California Publications,
Department of Geological Sciences Bulletin
17(2):63-142.

Cox, L. R. et al. 1969. Systematic descriptions. Part
N, Mollusca 6, Bivalvia, vols. 1 and 2, pp. 225-952
in R. C. Moore (ed.). Treatise on invertebrate
paleontology. University of Kansas Press,
Lawrence.

Dickerson, R. E. 1915. Fauna of the type Tejon: its
relation to the Cowlitz phase of the Tejon Group
of Washington. California Academy of Sciences,
Proceedings, series 4, 5(3):33-98.

. 1916. Stratigraphy and fauna of the Tejon

282

Eocene of California. University of California
Publications, Department of Geology Bulletin
9(17):363-524.

Durham, J. W. 1944. Megafaunal zones of the
Oligocene of northwestern Washington. Univer-
sity of California Publications, Department of
Geological Sciences Bulletin 27(5):101-212.

Effinger, W. L. 1938. The Gries Ranch fauna
(Oligocene) of western Washington. Journal of
Paleontology 12(4):355-390.

Emerson, W. K., and M. K. Jacobson. 1976. The
American Museum of Natural History guide to
shells. A. A. Knopf, New York.

Gabb, W. M. 1864. Description of the Cretaceous
fossils. Pp. 55-243 in F. B. Meek and W. M. Gabb.
Palaeontology of California. Geological Survey
of California, vol. 1, Palaeontology. Caxton Press,
Philadelphia.

Givens, C. R. 1974. Eocene molluscan biostratigraphy
of the Pine Mountain area, Ventura County, Cali-
fornia. University of California, Publications in
Geological Sciences 109:1-107.

Givens, C. R., and M. P. Kennedy. 1979. Eocene
molluscan stages and their correlation, San Diego
area, California. Pp. 81-95 in P. L. Abbott (ed.).
Eocene depositional systems, San Diego, Cali-
fornia. Pacific Section, Society of Economic
Paleontologists and Mineralogists, Field Trip
Guide, Geological Society of America Annual
Meeting.

Hickman, C. S. 1976. Bathyal gastropods of the family
Turridae in the early Oligocene Keasey Formation
in Oregon, with a review of some deep-water
genera in the Paleogene of the eastern Pacific.
Bulletins of American Paleontology 70(292): 1-1 19.

Hickman, C. S. 1980. Paleogene marine gastropods
of the Keasey Formation in Oregon. Bulletins of
American Paleontology 78(310):1-112.

Keen, A. M. 1971. Sea shells of tropical west America
(marine mollusks from Baja California to Peru).
Stanford University Press, Stanford, California.

Loel, W, and W. H. Corey. 1932. The Vaqueros For-
mation, lower Miocene of California. I. Paleon-
tology. University of California Publications,
Bulletin of the Department of Geological Sciences
22(3):3 1-410.

Moore, E. J. 1983. Teritary marine pelecypods of Cali-
fornia and Baja California: Nuculidae through
Malleidae. United States Geological Survey, Pro-
fessional Paper i228-A:l-108.

Nilsen, T. H. 1987. Stratigraphy and sedimentology
of the Eocene Tejon Formation, western
Tehachapi and San Emigdio Mountains, Cali-
fornia. U. S. Geological Survey Professional Paper
1268:1-110.

Saul, L. R. 1983. Notes on Paleogene turritellas,
venericardias, and molluscan stages of the Simi
Valley area, southern California. Pp. 71-80 in R.
L. Squires and M. V. Filewicz (eds.). Cenozoic
geology of the Simi Valley area, southern Cali-
fornia. Pacific Section, Society of Economic
Paleontologists and Mineralogists, Los Angeles.

Squires, R. L. 1984. Megapaleontology of the Eocene
Llajas Formation, Simi Valley, California. Natural
History Museum of Los Angeles County, Con-
tributions in Science 350:1-76.

. 1987. Eocene molluscan paleontology of the

Whitaker Peak area, Los Angeles and Ventura
Counties, Cahfornia. Natural History Museum
of Los Angeles County, Contributions in Science
388:1-93.

1989. Middle Eocene rocky nearshore molluscs.

Tejon Formation, Tehachapi Mountains, Cali-
fornia. The Western Society of Malacologists,
Annual Report for 1988 [abstract] 21:18.
Weaver, C. E. 1943. Paleontology of the marine Ter-
tiary formations of Oregon and Washington. Uni-
versity of Washington, Publications in Geology
5(l-3):l-789.

IVIQ2 TRANSACTIONS

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SOCIETY OF
JAN 2 9 1990 NATURAL HISTORY

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UNIVERSITY

Volume 21 Number 1 8 pp. 283-290 1 5 October 1 989

Homology and terminology of higher teleost postcleithral elements

Michael D. Gottfried

Museum of Natural History and Department of Systematics and Ecoloi^y, Dyche Hall, University of Kansas. Lawrence,
Kansas 66045-2454: Field Associate. San Diego Natural History Museum. P.O. Bo.x 1390. San Dici^o. California
92112. USA

Abstract. Primitively, actinopterygians have a single postcleithrum, which is not homologous to the
anocleithrum of sarcopterygians. The possession of multiple postcleithra is a shared derived feature of leleosts.
Three to five postcleithra are typically found in lower teleosts; as many as seven are present in primitive fossil
forms. Consideration of the positional relationships of postcleithra in primitive teleosts provides criteria for
homoiogizing and naming teleost postcleithra. Ctenosquamate teleosts (myctophiforms and acanthomorphs)
typically possess two postcleithra; on the basis of positional relationships these are interpreted as postcleithra two
and three (not "one and two," "upper and lower," "dorsal and ventral," or "proximal and distal" as in previous
interpretations). Ctenosquamates are therefore derived in having lost postcleithrum one. which is considered here
to be the homologue of the single postcleithrum of primitive actinopterygians.

Introduction

The postcleithral elements of actinopterygian fishes are small dermal bones that lie along
the posterior border of the pectoral girdle. Primitively, actinopterygians have a single,
relatively small postcleithrum located at and extending dorsal to the juncture between the
supracleithrum and cleithrum and lying medial to those two bones. This single postcleithrum
can be seen in the Devonian genus Cheirolepis (Pearson and Westoll 1979), which is the most
primitive actinopterygian according to recent analyses (Lauder and Liem 1983. Gardiner
1984). It is also present in the following lower actinopterygian groups: Cladistia [Polypterus,
Jollie 1984b), Chondrostei {Polyodon, Gregory 1933), Ginglymodi {Lepisosteus, Jollie 1984a),
and Halecomorphi {Amia, Figure 1 A); the last is the sister taxon of the Teleostei (Schultze and
Wiley 1984).

Extant lower teleosts typically have three postcleithra (Gosline 1980). with the most
dorsal occupying the same relative position as the single postcleithrum of lower
actinopterygians and the additional postcleithra a more ventral position. As many as six
(possibly seven) postcleithra have been described by Arratia (1984, 1987) in the unusual
Jurassic teleost Vavasichthys, while five are known in several other Jurassic forms including
Bohhichthys, Protoclupea, and Domeykos (Arratia 1987) and in juvenile Salmi) (Arratia and
Schultze 1987). Five postcleithra are also found in extant Elops (Figure IB); Gosline (1980)
referred to the two most ventral postcleithral elements in Elops as axillary scales, but Arratia
(1984) considered them to be true postcleithra on the basis of their structure and lack of scale-
like ornamentation.

While the exact number of postcleithra primitive for teleosts is not certain (because of
poor phylogenetic resolution at the base of the Teleostei). and reduction in number or complete
loss of postcleithra has occurred within different teleost groups (Gosline 1980). it is most
parsimonious to hypothesize multiple postcleithra (probably five) as a teleost synapomorphy.

The ctenosquamate teleosts (myctophiforms and acanthomorphs; Rosen 1973)
characteristically possess two postcleithra. The intent of this paper is to provide positional and
phylogenetic criteria for homoiogizing teleost postcleithra and to detennine which elements are
represented in ctenosquamates.

284

Figure 1. A, lateral view of the pectoral girdle in a lower actinopterygian, Amia calva, KU 1798 (note single
postcleithruin positioned at supracleithrum/cleithrum juncture). B, lateral view of the pectoral girdle of a primitive
teleost, Elops saiinis (note multiple postcleithra); after Arratia and Schultze (1987). Scale bars = 5 mm. Abbreviations:
cl, cleithrum: pel, postcleithrum; scl, supracleithrum. Numbers 2-5 in B indicate postcleithra 2-5.

POSTCLEITHRAL TERMINOLOGY

The multiple postcleithra of teleosts have been subjected to a variety of different
terminologies based on their relative positions, have been referred to as a "postcleithrum plus
postpectorals" (Jollie 1986), or have been numbered. The numbering approach is preferable for
three reasons: it allows for reference to multiple postcleithra without resort to awkward names
(e. g., the "upper middle postcleithrum" or "middle ventral postcleithrum"), it permits a less
ambiguous terminology that facilitates comparisons between the postcleithra of different
forms, and it avoids using another name (the "postpectorals" of Jollie) for elements that in the
past have consistently been called postcleithra.

The following positional relationships and suggested terminology are based on the
location of the postcleithral elements in primitive teleosts such as the Jurassic forms discussed
by Arratia (1987) and extant Elops (Figure IB). The most dorsal postcleithrum in teleosts,
which is interpreted here as homologous to the single postcleithrum of lower actinopterygians,
is most appropriately referred to as postcleithrum 1. It lies at the level of and extends dorsal to
the juncture between the supracleithrum and cleithrum and, depending on the taxon, extends
ventrally to a variable degree. It is usually overlapped by a portion of the cleithrum and the
most ventral part of the supracleithrum. Postcleithrum 2 articulates dorsally with the
ventromedial margin of postcleithrum 1 and lies at approximately the level of the middle
region of the cleithrum, medial to the scapula and coracoid. It does not extend as far dorsally as
the juncture between the cleithrum and supracleithrum. In some forms a gap separates
postcleithra 1 and 2 (Gosline 1980). Postcleithrum 3 characteristically forms a slender spinous
process that angles posteroventrally, medial to the pectoral fin. Its somewhat stouter dorsal
portion articulates with the anteromedial surface of postcleithrum 2. Postcleithrum 3 is a useful
landmark element and can generally be distinguished by its spinelike appearance and
posteroventrally angled orientation; in contrast, the other postcleithral elements are more
flattened and scalelike and often have a crenulated surface .

Postcleithra 4 through 6 (or 7) form an additional series of sequentially overlapping
elements that extend back from the lower posterior corner of the cleithrum, lateral to
postcleithra 2 and 3. Postcleithra 4 and 5 are found in Elops {Figure IB), in juvenile Salmo

285

(Arratia and Schullze 1987). and in several Jurassic forms discussed by Arraiia (1987); as
many as six (possibly seven) are known only in the Jurassic genus Varasichtliys.

Results and Discussion

As noted above, ctenosquamate teleosts generally possess two postcleithral elements.
Exceptions to this exist; e. g., among acanthomorph ctenosquamates some gobioids may lack
either of the two elements or lack postcleithra entirely (Springer 1983). and some acanthurids
have only a single postcleithrum (Johnson and Washington 1987). Previous literature shows
that there has been confusion and a lack of consistency as to which postcleithra these are and
what they should be called. Some authors (Patterson 1964. Zehren 1979, both referring to
beryciforms; Springer 1983. referring to gobioids) call these two bones the "dorsal and
ventral" postcleithra. while others refer to them as "upper and lower" postcleithra (Rosen and
Patterson 1969, referring to "paracanthopterygians"), "postcleithra 1 and 2" (e. g.. Greenwood
1976, 1985, Braga and Azpelicueta 1982, Arratia 1982, Kong 1985, all referring to various
acanthopterygians), or "proximal and distal" postcleithra (KuUander 1988, referring to
cichlids).

Examination of the pectoral girdle in a variety of acanthomorph ctenosquamates (see
"Materials Examined" and Figure 2) confirms that two postcleithra are typical in the group, as
noted by Gosline (1980). In addition, non-acanthomorph ctenosquamates typically have two
postcleithra; these include Polymixia (Zehren 1979), the sister taxon of the Acanthomorpha
according to Rosen (1985) and Stiassny (1986), and myctophiforms (Goody 1969, Paxton
1972), the sister group oi Polymixia plus the Acanthomorpha (Rosen 1985, Stiassny 1986).

The two postcleithra in the various ctenosquamates generally occupy the same relative
positions and have comparable proportions. The more dorsal of the elements is flattened and
platelike, lies at approximately the level of the middle region of the cleithrum (and medial to
the scapula and coracoid), is overlapped (to varying degrees) by the cleithrum, and does not lie
as far dorsally as the most dorsal postcleithrum in primitive teleosts. The more ventral element
is generally narrower, posteroventrally directed, medial to the pectoral fin, and terminates in a
pointed process. It articulates dorsally with the anteromedial surface of the postcleithrum
above it. In some forms, for example. Prionotus (Triglidae. Percomorpha) and Coitus
(Cottidae. Percomorpha; Figure 2C). the more dorsal postcleithrum is also relatively narrow
and spinelike.

The positional relationships described earlier indicate that the two postcleithral elements
in ctenosquamates are best interpreted as postcleithra 2 and 3. This means that the other
terminologies are unneccessarily imprecise. More important, it follows from this interpretation
that postcleithrum 1 (the teleost homologue of the single postcleithrum of lower
actinopterygians) has been lost in ctenosquamates. and the "postcleithra 1 and 2" terminology
is therefore inappropriate for the group.

Although the determination of the elements in ctenosquamates as postcleithra 2 and 3 is
relatively straightforward, it is neccessary to add one cautionary note. I observed ontogenetic
fusion in the postcleithra of a cleared and stained series (// = 17) of Cichlasoma citrinellum
(Percomorpha. Cichlidae); specimens ranged from small juveniles to large adults (35 mm to
145 mm total length). Juveniles and sub-adults of C. citrinellum have two distinctly separate
postcleithral elements up to approximately 70-90 mm in total length (Figure 3A). The more
dorsal of these (postcleithrum 2) is flattened and has a semikmale shape. A thickened spinelike
ridge runs along the anterior edge of the element, terminating dorsally in a sharp point.
Posterior to the ridge the bone is thin and has a crenulated surface similar to that of elements in
the opercular series. The ventrally positioned element (postcleithrum 3) is more robust and
tapers ventrally to a sharp point. The two bones articulate by means of a shallow depression on
the dorsolateral surface of postcleithrum 3 into which fits the rounded lower corner of
postcleithrum 2.

In contrast, adults of C. citrinellum have what appears to be a single postcleithrum
(Figure 3B). In these larger fish, the anteriorly positioned ridge of postcleithrum 2 has grown
down onto postcleithrum 3. and there is no longer any indication of an articulation or that the

286

pel 2

pel 3

pel 2

pel 3

Figure 2. Lateral views of the pectoral girdles of ctenosquamate teleosts. A, Percopsis omiscomaycus, KU 11337
("Paracanthopterygii," Percopsiformes, Percopsidae). B, Gooclea atripinnis, KU 16998 (Acanthopterygii,
Atherinomorpha, Atherinidae). C, Cottus hairdi. KU 17151: note reduced pel 2 (Acanthopterygii, Percomorpha,
Cottidae). D, Lepomis gihhosus, KU 13983 (Acanthopterygii, Percomorpha, Centrarchidae). Scale bars = 2 mm.
Abbreviations: cl, cleithrum; co, coracoid; pel 2, 3, postcleithrum 2, 3; ra, pectoral fin radials: sc, scapula: scl,
supracleithrum.

two elements were once separate. Similar ontogenetic fusion of postcleithra 2 and 3 has been
observed in the acanthuroid percomorph Zanclus cornutus (Johnson and Washington 1987).

The most parsimonious interpretation of the loss of postcleithrum 1 in ctenosquamates is
that it represents an additional synapomorphy corroborating monophyly of the group [see
Lauder and Liem (1983) and Stiassny (1986) for additional ctenosquamate synapomorphies].

287

pel 2

2+3

Figure 3. Left lateral views of postcleithra (pel) of Cichlusoina cifriiie/liiin (Acanthopterygii, Pereomorpha.
Cichlidae). A, from a juvenile (37 mm total length) in which pel 2 and 3 are separate (KU 21916). B. from an adult
(118 mm total length) in which pel 2 and 3 are fused (KU 21915). Scale bars = 1 mm.

The primitive condition relative to that in ctenosquamates is possession of postcleithra 1. 2,
and 3. Postcleithra 1 through 3 are present in close ctenosquamate outgroups, including the
order Aulopiformes (Sulak 1977, Gosline 1980), which is the sister group of the
ctenosquamates according to Lauder and Liem (1983), Rosen (1985). and Hartel and Stiassny
(1986). Sulak (1977) did describe two synodontid aulopiforms (Synodus and
Trachinocephalus) as having two postcleithra, which occupy the positions of postcleithra 2 and
3 by my interpretation. However, Sulak (1977, p. 68) suggested that three postcleithra are
typical for the group, and basal aulopiforms (e. g., Aidopus) have three postcleithra, so the loss
of a postcleithrum in some aulopiforms can be interpreted as independent of the loss in
ctenosquamates. Postcleithra 1 through 3 are also present in further outgroups, including
salmoniforms, clupeomorphs (Gosline 1980), and characiforms (c. c.. Brxcon. Weitzman
1962).

Mapping postcleithral conditions on to an existing hypothesis of actinopterygian
interrelationships (Figure 4) indicates that the interpretation here is consistent with the
phylogenetic concept of homology as discussed by Ax (1987). Remane (1952) considered a
positional relationship such as I have used to be the strongest criterion for establishing
homology.

Gosline (1980) interpreted the most dorsal postcleithrum of lower teleosts and the single
postcleithrum of lower actinopterygians as homologues of the anocleilhrum of sarcopterygians
(lungfishes, coelacanths, and crossopterygians). I agree with Gardiner (1984) that the single
postcleithrum of lower actinopterygians should not be considered homologous to the
anocleithrum. the possession of which has been interpreted as a sarcopterygian synapomorphy

288

Actinopterygii

anocleithnim

Figure 4. Phylogenetic diagram of the major groups of actinopterygians, with postcleithral conditions specified at the
appropriate levels. A, single postcleithrum present at juncture of supracleithrum and cleithrum (the primitive
actinopterygian condition): B, multiple postcleithra (1 through 5), hypothesized here as a teleost synapomorphy, with
postcleithrum 1 the homologue of the single postcleithrum of lower actinopterygians and 2-5 in a more ventral
position; C, reduction to postcleithra 1-3: D, reduction to postcleithra 2-3, with loss of postcleithrum 1 interpreted as a
ctenosquamate synapomorphy; X, independent reduction to a single postcleithrum in the Osteoglossomorpha. ?,
primitive condition unknown for the Osteichthyes (Actinopterygii plus Sarcopterygii); 0. postcleithra absent. Lower
right, postcleithra present at the stem of each indicated node within the Actinopterygii. Note presence of anocleithrum
(here considered nonhomologous to postcleithrum 1) in Sarcopterygii. t. taxa represented by fossils only. Sequence of
taxa primarily based on Lauder and Liem (1983) and Arratia (in press) for the lower teleo.stean groups.

(Long 1989). In sarcopterygians, the anocleithrum lies fully within the arcade of pectoral girdle
elements, articulating dorsally with the supracleithrum and ventrally with the cleithrum and
preventing those two elements from contacting one another. In the most primitve
actinopterygians, Cheirolepis (Pearson and Westoll 1979) and Cladistia (Jollie 1984b), the
postcleithrum has a different position; it lies along the posterior edge of the pectoral girdle,
where it is overlapped by the supracleithrum and cleithrum, which are in contact. The
distinction between the anocleithrum and postcleithrum is further clarified by Jollie's (1984a)
observations on the developmental osteology of the extant ginglymodian Lepisosteus, in which
the postcleithrum (in juveniles) first forms as a dermal ossification separate from and posterior
to the pectoral girdle and only later in development contacts and is overlapped by (but does not
separate) the supracleithrum and cleithrum. The primitive condition for the Osteichthyes
(Actinopterygii plus Sarcopterygii) is not known because of lack of information on the
osteichthyan sister group, the Acanthodii (Figure 4).

Finally, teleost groups other than ctenosquamates reduce the number of postcleithra.
Siluriforms, mormyrids, anguillids, and engraulids lack postcleithra entirely (Gosline 1980);
most osteoglossomorphs (Taverne 1977, 1978) and some cyprinids (Gosline 1980) have a
single postcleithrum. These reductions can best be interpreted as independent losses within
each lineage.

289

Materials Examined
The following specimens were examined for this study. Except where noted, specimens
are cleared and stained (for cartilage and bone); they are in the Ichthyology Division of the
University of Kansas Museum of Natural History (KU). Numbers in parentheses indicate
number of individuals per lot.

Actinopterygii, Halecomorphi;

Amia calva, KU 1798 ( 1; skull only)
Teleostei, Percopsiformes, Aphredoderidae;

Aphredoderus sayanits, KU 12390 ( I; cleared only)
Percopsiformes, Percopsida

For apsis omiscomaycus, KU 1 1337 (1; in alcohol)
Gadiformes, Gadidae;

Microgadus proximus, KU 12150 (I; in alcohol)
Atherinomorpha, Atherinidae;

Basilichthys aiistralis. KU 19278 (7)

Goodea atripinnis, KU 16998 (5)

Lahidesthes siccidus. K\J 17621 (7)
Atherinomorpha, Cyprinodontidae;

Fundulus catenatus, KU 17616 (7)

Crenichthys halleyi. KU 1 1862 ( 11 )
Percomorpha, Percidae;

Stizostedion canadense, KU 1 7920 ( 1 )
Percomorpha, Percichthyidae;

Morone chrysops, KU 18024 (5)
Percomorpha, Sciaenidae;

Aplodinotiis grunniens, KU 21461 (8)
Percomorpha, Cottidae;

Cottusbairdi,KV 17151 (7)
Percomorpha, Triglidae;

Prionotiis evolans, KU 21435 (2)
Percomorpha, Centrarchidae;

Elassoma zonatum, KU 20307 (5)

MIcropterus salmoides, KU 15939 (2)

Lepomis gibbosus, KU 13983 (4)
Percomorpha, Cichlidae;

Cichlasoma citrinelliim, KU 21915 (1), 21916 (1), 21917 (15)

Acknowledgments

I am very grateful to G. Arratia (University of Kansas) for her generous advice and many
discussions on this topic. F. Cross and J. Collins (University of Kansas) allowed free access to
the KU fish collections; G. Barlow (University of California, Berkeley) supplied the cichlid
specimens mentioned in this study. P. Mabee (Smithsonian Institution) and an anonymous
reviewer provided valuable criticisms and comments. H.-P. Schultze and P. Rasmussen
(University of Kansas) made helpful suggestions on an earlier version of this paper. Financial
support was given by the University of Kansas Department of Systematics and Ecology.

Literature Cited

Arratia, G. 1982. A review of freshwater percoids Zeitschrift ."^8: 149-163.

from South America (Pisces. Osteichthyes, . 1987. Jurassic fishes from Chile and critical

Perciformes, Percichthyidae, and Percilidae). comments. Pp. 257-286 /// W. Volkheimer and E.

Abhandlungen der Senckenbergischen Naturfor- A Musacchio (eds.). Bicstratigrafia de los Sistemos

schenden Gesellschaft .540:1-52. Rcgionalcs del Jurasico y Cretacico en America

. 1984. Some osteological tealures of del Sur, Tomo 1. Jurasico anterior a los

Varasichthys ariasi Arratia (Pi.sces, Teleostei) from movimientos malmicos. Mendoza, Argentina;

the Late Jurassic of Chile. Paliiontologischc Comitc Sudamericano del Jurasico y Cretacico.

290

. In press. The caudal skeleton of Jurassic

teleosts; a phylogentic analysis. Special
Symposium Volume. Early Vertebrates and Related
Problems in Evolutionary Biology. Academia
Sinica, Beijing.

Arratia, G., and H.-P. Schultze. 1987. A new
halecostome fish (Actinopterygii, Osteichthyes)
from the Late Jurassic of Chile and its
relationships. Dakoterra 3:1-13.

Ax, P. 1987. The Phylogentic System. The
Systematization of Organisms on the Basis of
Their Phylogenesis. Wiley, New York.

Braga, L., and M. Azpelicueta. 1982. Estudio sobre
Plagioscion ternetzi Boulenger, 1895. (Perci-
formes, Sciaenidae). Parte II. Neotropica
28:103-116.

Gardiner, B. G. 1984. The relationships of the
palaeoniscid fishes, a review based on new
specimens of Mimia and Moythomasia from the
Upper Devonian of Western Australia. Bulletin
British Museum of Natural History (Geology)
37:173-428.

Goody, P. C. 1969. The relationships of certain Upper
Cretaceous teleosts with special reference to the
myctophoids. Bulletin British Museum of Natural
History (Geology), Supplement 7:1-255.

Gosline, W. A. 1980. The evolution of some structural
systems with reference to the interrelationships of
modern lower teleostean fish groups. Japanese
Journal of Ichthyology 27:1-28.

Greenwood, P. H. 1976. A review of the family
Centropomidae (Pisces, Perciformes). Bulletin of
the British Museum (Natural History, Zoology)
29:1-81.

. 1985. Notes on the anatomy and phyletic

relationships of Hemicliromis Peters 1858. Bulletin
of the British Museum (Natural History,
Zoology) 48:131-171.

Gregory, W. K. 1933. Fish skulls. A study of the
evolution of natural mechanisms. Transactions of
the American Philosophical Society 23:75-481.

Hartel, K. E., and M. L. J. Stiassny. 1986. The
identification of larval Parasudis (Teleostei,
Chlorophthalmidae); with notes on the anatomy
and relationships of aulopiform fishes. Breviora
487:1-23.

Johnson, G. D., and B. B. Washington. 1987. Larvae of
the Moorish idol, Zanclits cornutiis, including a
comparison with other larval acanthuroids. Bulletin
of Marine Science 40:494-5 1 1 .

Jollie, M. 1984a. Development of cranial and pectoral
girdle bones of Lepisosteiis with a note on scales.
Copeia (1984): 476-502.

. 1984b. Development of the head and pectoral

skeleton of Polyptenis with a note on scales
(Pisces, Actinopterygii). Journal of Zoology
(London) 204:469-507.

1986. A primer of bone names for the

understanding of the actinopterygian head and

pectoral girdle skeletons. Canadian Journal of

Zoology 64:365-379.
Kong, I. 1985. Revision de las especies chilenas de

Sebastes (Osteichthyes, Scorpaeniformes,

Scorpaenidae). Estudios Oceanologfa 4:2 1-75.
KuUander, S. O. 1988. Teleocichla. a new genus of

South American rheophilic cichlid fishes with six

new species. Copeia (1988): 196-230.
Lauder, G. V, and K. F. Liem. 1983. The evolution

and interrelationships of the actinopterygian fishes.

Bulletin Museum of Comparative Zoology

150:95-197.
Long, J. A. 1989. A new rhizodontiform fish from the

Early Carboniferous of Victoria, Australia, with

remarks on the phylogenetic position of the group.

Journal of Vertebrate Paleontology 9: 1-17.
Patterson, C. 1964. A review of Mesozoic

acanthopterygian fishes, with special reference to

those of the English Chalk. Philosophical

Transactions of the Royal Society (B)

247:213-482.
Paxton, J. R. 1972. Osteology and relationships of the

lanternfishes (family Myctophidae). Bulletin Los

Angeles County Museum of Science 13:1-81.
Pearson, D. M., and T. S. Westoll. 1979. The Devonian

actinopterygian Cheiwlepis Agassiz. Transactions

of the Royal Society of Edinburgh 70:337-399.
Remane, A. 1952. Die Griindlagen des naturlichen

Systems, der vergleichende Anatomie und der

phylogenetik. Akademische Verlagsgesellschaft

Geest & Portig, K.-G., Leipzig.
Rosen, D. E. 1973. Interrelationships of higher

euteleostean fishes. Pp. 397-513 in P. H.

Greenwood, R. S. Miles, and C. Patterson (eds.).

Interrelationships in Fishes. Academic Press,

London.
. 1985. An essay on euteleostean classification.

American Museum Novitates 2827: 1^5.
, and C. Patterson. 1969. The structure and

relationships of the paracanthopterygian fishes.

Bulletin American Museum of Natural History

141:357^74.
Schultze, H.-P., and E. O. Wiley. 1984. The

neopterygian Amia as a living fossil. Pp. 153-159

in N. Eldredge and S. M. Stanley (eds.). Living

Fossils. Springer Verlag, New York.
Springer, V. 1983. Tyson belos, new genus and species

of western Pacific fish (Gobiidae, Xenisthminae),

with discussions of gobioid osteology and

classification. Smithsonian Contributions to

Zoology 390:1^0.
Stiassny, M. L. J. 1986. The limits and relationships of

the acanthomorph teleosts. Journal of Zoology

(London) B (1) : 411-460.
Sulak, K. J. 1977. The systematics and biology of

Bathypterois (Pisces, Chlorophthalmidae) with a

revised classification of benthic myctophiform

fishes. Galathea Report 14:49-108.
Taverne, L. 1977. Osteologie, phylogenese, et

systematique des Teleosteens fossiles et actuels du

super-ordre des Osteoglossomorphes. Premiere

partie. Academic Royale de Belgique, Memoires

de la Classe des Sciences 42: 1-235.
. 1978. Osteologie, phylogenese, et

systematique des Teleosteens fossiles et actuels du

super-ordre des Osteoglossomorphes. Deuxieme

partie. Academic Royale de Belgique, Memoires de

la Classe des Sciences 43:1-168.
Weitzman, S. H. 1962. The osteology of Brycon ineeki,

a generalized characid fish, with an osteological

definition of the family. Stanford Ichthyological

Bulletin 8:1-77.
Zehren, S. J. 1979. The comparative osteology and

phylogeny of the Beryciformes (Pisces: Teleostei).

Evolutionary Monographs 1:1-389.

|y/|QZ TRANSACTIONS

LIBRARY OF THE SAN DIEGO

SOCIETY OF
JAN 29 1990 NATURAL HISTORY

HARVARD
UNIVERSITY

Volume 21 Number 19 pp. 291-316 15 October 1989

Ranges of offshore decapod crustaceans in the eastern Pacific Ocean

Mary K. Wicksten

Department of Biology, Texas A&M University, College Station, Texas 77843, USA

Abstract. Distributions of offshore decapods in the eastern Pacific fall into a pattern of at least five
clusters: the Aleutian Islands to Washington, Washington or Oregon to southern California, Baja California and
the Gulf of California to central America, Panama or Colombia to Peru, and Chile to Cape Horn. These clusters
are supported by distributional data at all depths considered, although there is more blurring of provincial
boundaries at depths greater than 1500 m than at lesser depths. There is a sharp break in faunal distributions
between that of northern Baja California and all areas to the south, largely due to the replacement of species of
Pandalus to the north by species of Heterocarpits to the south. The northeastern Pacific is particularly rich in
species of hippolytid shrimps and lithodid crabs and contains endemic genera of the families Crangonidae and
Majidae. Species in these and other groups probably underwent extensive radiation in the late Cenozoic and
dispersed from the northern Pacific into the northern Atlantic and less readily into the southern hemisphere.
Compared to the northeastern Pacific, the western coast of South America is poor in the total number of species
and the degree of endemism in decapods. Except for a few cosmopolitan species of the lower continental slopes,
North and South America have no species in common.

Introduction

The coast of the Americas constitutes the longest continuous north-south ocean margin in
the world. In shallow and intertidal regions, the distributions of co-occuring invertebrate
species have been used to define at least six zoogeographic provinces. From north to south,
these are the Aleutian (the Bering Sea to Puget Sound), the Oregonian (Puget Sound to Point
Conception, California), the Califomian (Point Conception to approximately Bahia Magdalena,
Baja California, Mexico), the Panamic (Bahia Magdalena to the Gulf of Guayaquil, including
the Gulf of California), the Peru-Chilean (northern Peru to approximately Isla Chiloe, Chile),
and the Magellanic (Isla Chiloe to Cape Horn) (Dana 1853, Keen 1937, Ekman 1967,
Valentine 1966, Briggs 1974).

Different interpretations have been offered for designations of provinces. For example,
Brusca and Wallerstein (1979) referred to all of the coastal warm-water (subtropical/tropical)
area as the Eastern Pacific Zoogeographic Region, noting Briggs' subdivisions of four
provinces: the Cortez, Mexican, Panamic, and Galapagos. They also recognized the west coast
of Baja California between Punta Eugenia and Bahia Magdalena as a broad transition zone
between the Califomian and Cortez provinces. Keen (1937) designated subprovinces of the
Oregonian province. Garth (1955) considered the fauna of the outer coast of Baja California
to belong to a province separate from that of the Gulf of California, but Briggs (1974) included
both faunas in a common province. All of these interpretations were based on species living
no deeper than the continental shelf.

There are very few studies of wide-scale distributional patterns of invertebrates of
offshore areas, at depths of 50 m or more. Menzies et al. ( 1 973) defined offshore provinces by
depth, sorting invertebrate species into a Shelf Province (about 246 m or less), an
Archibenthal Zone of transition (to 1000 m), and a deeper Abyssal Province. Their study did
not consider distributions by latitude. However, Cutler (1975) noted that the region of Cape
Lookout, North Carolina, constitutes a zoogeographical barrier to sipunculid and
pogonophoran worms not only of shallow waters, but also to species living on the continental
slope. Parker (1963) reported the distributions of decapods of the eastern Pacific by latitude.

292

but based his work strictly on published literature and made no distinction between species
living inside the Gulf of California and those on the open Pacific coast.

Work on moUusks in the eastern Pacific suggests that latitudinal distribution patterns in
this group change with depth. Reports by Jackson (1974) and Jablonski and Valentine (1981)
indicate that species living in very shallow water tend to have broader latitudinal distributions
than those living deeper on the continental shelf, but the trend in decreasing range with
decreasing depth reverses itself near the shelf-slope break, below which species tend to have
increasingly wider ranges. The wider latitudinal ranges of species living below the shelf break
was attributed by Jackson to the damping of environmental fluctuations with greater depth.
Jablonski and Valentine (1981) noted that western American molluscan provincial boundaries
are well defined down to 100 m and can be detected across the continental shelf.

Data for any group of offshore invertebrates in the eastern Pacific are scanty. Decapod
crustaceans, however, are reasonably well studied, identified, and collected. Being among the
larger invertebrates, they can be taken with trawls, dredges, traps, and nets, as well as
identified at times from bottom photographs. Hence, data for this group are more abundant
than for others.

Published records of ranges of decapod crustaceans are scattered through expedition
reports, monographs, systematic papers, and short notes. The earliest major deep-sea
expedition to visit the eastern Pacific was that of the H.M.S. Challenger, which made
collections in 1875 off Chile and Juan Fernandez Islands. Bate (1888) reported on many of
the decapods taken during this trip. The U.S. Fisheries Steamer Albatross collected
extensively off the Galapagos, Central America, and the coast of the United States from
southern California to Alaska from 1888 to 1914. Information on decapods taken during its
cruises can be found in the works of Benedict (1902), Faxon (1895), Rathbun (1904, 1918,
1925, 1930, and 1937) and Schmitt (1921).

Only two papers have attempted to describe assemblages of offshore eastern Pacific
decapods quantitatively by depth. Pereyra and Alton (1972) reported on crustaceans and other
invertebrates taken by trawls at 91-2103 m and grabs and dredges to 411 m off the Columbia
River. They provided charts and diagrams of the relative abundance of species at various
depths and divided the invertebrate groups into an outer sublittoral assemablage (at 91-183 m),
a bathyal assemblage (at 185-914 m, subdivided into an upper bathyal assemblage at 185^57
m and a lower bathyal assemblage at 457-914 m), and a bathyal-abyssal assemblage (at
917-1554 m). Wicksten (1980), using published and unpublished records of decapods taken
by a variety of methods off southern California, divided the fauna into mainland and insular
assemblages, providing numbers of specimens and stations per species at depths of 185 m or
less, 185-923 m, and 923-1846 m.

Records and ranges of offshore decapods have been presented in works discussing the
faunas of particular countries, states, or regions. Offshore species of Chile have been reported
by Baez and Andrade (1979), of the Peru-Chile Trench and its vicinity by Haig (1955, 1974b),
Garth and Haig (1971), and Garth (1973), of Peru by Mendez (1981), of California and
western Mexico by Haig and Wicksten (1975) and Wicksten (1980, 1982a, 1987), of Oregon
by Pereyra and Alton (1972) and McCauley (1972), and of British Columbia by Butler (1980)
and Hart (1982). Records of species that cross the northern Pacific, ranging from Alaska to the
Siberian coast, can be found in the work on fauna of the Kurile-Kamchatka Trench by
Birshtein and Zarenkov ( 1972).

Ranges of many eastern Pacific decapods are included in wide-scale systematic works and
short notes. Offshore peneids are discussed by Faxon (1895) and Mendez (1981). Information
on carideans is included in works by de Man (1920), Holthuis (1971), Crosnier and Forest
(1973), Wenner (1979). Wicksten (1977, 1978, 1979a,b, 1984), Wicksten and Mendez (1982,
1983, 1985), and Zarenkov (1976). Records of stenopodids are given by Goy (1980) and
Wicksten (1982b). Lobster-like decapods are treated in the works of Manning (1970), Firth
and Pequegnat (1971), Wicksten (1981), and Williams (1986). Anomurans are considered in
notes and works by Bouvier (1896), Haig (1956, 1968, 1974a,b), Anderson and Cailliet (1974),
and Ambler (1980). The works by Garth (1958 and 1973) provide information on
brachyurans.

293

Methods

Large collections of eastern Pacific decapods are maintained at the U.S. National Museum
of Natural History, California Academy of Sciences. Allan Hancock Foundation (University of
Southern California and Los Angeles County Museum), and Scripps Institution of
Oceanography. While identifying and cataloguing specimens from these collections. 1
analyzed the localities and depths of collection of over 5000 specimens of offshore decapods
from nearly 500 eastern Pacific stations. Previously unpublished records found while
examining these collections were published in a short note (Wicksten 1987) as well as in
previous papers (Wicksten, 1977, 1978, 1979a,b,c, 1980, 1981, 1982a,b, and 1984). I also
accumulated records of depth distribution and ranges from the published literature.

For this study, I defined an offshore species as one for which the majority of records of
occurrence are at 50 m or deeper. I considered only benthic species or those that normally can
be collected on the bottom despite their limited abilities to swim. (Although the galatheid crab
Pleiironcodes planipes can be abundant at 23-103 m off western Baja California, [Rowe,
1985], it was excluded from this study because most of the records in collections and the
literature did not distinguish between specimens taken on the bottom and those cast ashore or
swimming in the water column). Species from deep-sea hydrothermal vents and seeps were not
included. See Jones (1985) for papers discussing the decapod faunas of these areas.

The area covered by this study is from the westernmost tip of the Aleutian Lslands
(excluding the Bering Sea) to Cape Horn, including the Galapagos Islands, Juan Fernandez
Islands, and their immediate surroundings. The area was arbitrarily divided into 5° "squares"
of latitude and longitude (Figures 1-6), numbered at 1 for the tip of the Aleutians and running
to 66 at Cape Horn (including offshore banks and nearshore islands), with 67-70 assigned to
the Galapagos Islands and 71-72 to the Juan Fernandez Islands. The square bounded by
25-30°N and 1 10-1 15°W (Figure 3) was arbitrarily divided into two parts so that ranges from
the outer coast of Baja California (28) could be separated from those within the Gulf of
California (31). Square 8 (Figure 1) is considered to contain only the Pacific side of the
Alaska Peninsula.

One hundred eighty-three species of offshore decapods are reported from the eastern
Pacific (Appendix 1). In this study, endemic subspecies of widespread species {Parapagiints
pilosimanus henedicti, Pontophilus gracilis occidentalism and Stereomastis sculpta pacifica) are
treated as eastern Pacific species. Ranges are treated as continuous for all species: if, for
example, a species is reported only from squares 1 and 10, it is considered to occur also in
squares 2-9. (No disjunct amphitropical distributions are known for any offshore eastern
Pacific decapods). All species are included, including those known only from single
specimens.

The interested reader can find published records of exact latitude, longitude, and depth of
occurrence of individual specimens by referring to the works given for each species in
Appendix 1 . Records of the decapods in the collections of Scripps Institution of Oceanography
have been published by Luke (1977). The decapods of the Allan Hancock collections have
been card-catalogued by species and partially by station or collection site, but these data have
not been published or entered into a computer. Specimens at the California Academy of
Sciences are being catalogued by species.

For analysis of co-occurring species, presence-absence data were used. Each species was
assigned a number, then its occurrence was entered for each 5° square in its range. Initially, I
experimented with three methods of determining similarity of species composition: simple
matching, Jaccard's coefficient, and the method of Rogers and Tanimoto (1960). (See Sneath
and Sokal [ 1973 J for a discussion of similarity coefficients). Of the three methods, only the last
produced a phenogram that seemed to show distinguishable patterns related to geography.

Using the method of Rogers and Tanimoto (1960), 1 compared the squares for similarity
of species composition at five depth ranges: all depths, range number 1 (0-500 m), number 2
(500-1000 m), number 3 (1000-1500 m), and number 4 (1500 m and deeper). Comparisons
were done by cluster analysis with the UPGMA (unweighted pair-group analysis) clustering
algorithm. A phenogram of co-occurrences was produced, with a cophenetic correlation

294

Figure 1. Location of 5° X 5° map coordinates across the North Pacific from the Aleutian Islands to the Gulf of
Alaska.

Figure 2. Location of 5° X 5° map coordinates along the west coast of North America from Alaska to Baja California
Norte.

295

Nicaragua

Figure 3. Location of 5° X 5° map coordinates along the west coast of Mexico and Central America. Note that
numbers 28 and 31 share the same 5° X 5° square.

Figure 4. Location of 5° X 5° map coordinates from the Isthmus of Panama to central Peru.

296

Chile

Figure 5. Location of 5° X 5° map coordinates from southern Peru to central Chile.

Cape Horn

60°- 70»

Figure 6. Location of 5° x 5° map coordinates from central Chile to Cape Horn.

297

coefficient of 0.96.

Each phenogram shows clusters of squares according to similarities. In comparing the
clusters with the geography of the coast, north-south patterns appear most consistently at a
similarity of approximately 0.75. Therefore, the 0.75 level of similarity was chosen arbitrarily
for discussion of the clusters.

Results

Figures 7-11 are phenograms of similarities in species composition by squares. For
species at all depths taken together, there are seven sets of squares at levels of similarity of
0.75 or more (Figure 7). From north to south, these include squares 1-18 and 20 (Aleutian
Islands to Washington), squares 22-25 (Oregon to offshore southern California), squares 27^1
(Baja California to Isla del Coco), squares 42 and 43 (Gulf of Panama), squares 44^6 and
48-53 (Colombia to Peru), and squares 54-72 (mostly from Chile) plus the northern squares
19, 21, and 47. Square 26 (coastal southern California) constitutes a single-member group
because its similarities to other squares are at levels below 0.75.

At depth range number 1 (0-500 m), there are seven clusters of squares with a similarity
of 0.75 or more (Figure 8). The clusters define the following groups by geographic position:
the westernmost Aleutian Islands, the Aleutians to Washington; Oregon to central California:
southern California, northern Baja California, and part of the Gulf of California: the southern
Gulf of California to Peru, and all others. At depth range number 2 (500-1000 m), the squares
clustered at the 0.75 level follow a similar pattern (Figure 9): Aleutians to Washington, Oregon
to California, square 26 alone, Baja California to Isla del Coco, Costa Rica to Ecuador. Peru,
and all others. The patterns for depth ranges 3 and 4 differ slightly: at range 3 (1000-1500 m),
there are eight clusters (Figure 10), and at range 4 (greater than 1500 m), there are ten (Figure
1 1 ). Those at range 3 include the following areas: the Aleutians to Washington, Oregon to
California, square 26 alone, northern Baja California and part of the Gulf of California,
southern Baja California to Nicaragua, Isla del Coco to Ecuador, Peru, and all others. Those at
range 4 are from the Aleutians to Washington; offshore of Washington and Oregon; central
and southern California; southern California, northern Baja California, and the Gulf of
California; southern Baja California to Nicaragua; square 42 alone; Panama to Peru; Peru to
Chile; and the rest of Chile with all remaining squares.

Regardless of the depth range considered, there is a cluster of squares that primarily
represents the area off southern Chile, the Juan Fernandez Islands, and the Tufts and Cascade
abyssal plains. These groupings almost surely are an artifact of the use of presence-absence
data. Examination of the species composition of these squares indicates that they have almost
nothing in common except for ubiquitous species such as Parapagurus pilosimaiius henedicti.

In examining distributions at all depths, one finds taxa characteristic of particular regions.
Table 1 presents examples of endemic species and species reaching either their northern or
southern limits in particular regions. Refer to Appendix 1 for details of ranges and depth
distributions of the species.

Comparisons of patterns of ranges at different depths reveal only slight differences. At
any depth, there is a sharp break between species that range from northern Baja California
northward and those that range from there southward. The area from the Aleutians to
Washington seems to remain distinct in its fauna regardless of depth. At all depths, however,
patterns of clustering can be seen.

In comparing distributions of eastern Pacific offshore species with those of shallow water,
one sees similar north-south changes in species composition. The Aleutian Province seems to
retain its identity into deeper water. The area from Washington to central California seems to
contain a mixture of more northerly and southerly ranging species. Square 26 (Point
Conception to San Quintin Bay, Baja California, hereafter called the Californian Province) is
distinct at all depths. This area includes marked zoogeographic boundaries for shallow-water
species: Point Conception is the northern boundary of the Californian Province, while San
Quintin Bay is the beginning of a region of transition between the temperate Californian
Province and tropical regions to the south. The fauna of southwestern Baja California and
much of the Gulf of California either forms a unit of its own or shows similarity to faunas

298

I-"

0.518 0.588 0.658 0.728 0.798 0.868 0.938 1 008
--^ ^ r-T-^ . < ^59

— 65

r 66

J 47

58
57
62
60
63
64
67
70
68
69
54
55
56
27
28
30
31
32
29
33
34
35
36
37
39
40
38
41
42
43
44
45
46
48
49
50
51
52
53
01
02
03
04
05
06
07
11

Chile,

Galapagos,

other

Baja California

to
Isia del Coco

p5Z
-J — S3 I—

Costa Rica to Panama
Gulf of Panama

Colombia

Peru

-i-

-L-

15
08
16
17
09
18
20
23
22
24
25
26 —

Aleutians

Washington

0.51 8 0.588 0.658 0.728 0.798 0.868 0.938 1 .008

0.750

Oregon

Point Conception

Southern California

Figure 7. Phenogram of similarities between all squares in Figures 1-6 by presence or absence of all species at all
depths. General geographic locations of the squares are given at right. Comparisons done by the methods of Rogers
and Tanimoto (1960) with UPGMA cluster analysis. Clusters defined at the 0.750 level of similarity.

299

0.120 0.270 0.420 0.570 0.720 0 870 1 020 1 170

I ' ^ 111 1 , ' I 21

— - 35

— - 10

Peru

Chile,

other

Baja California,
Gulf of California

Gulf of California

Peru

Aleutians

Washington

-4-

" r Oregon to
24 L California

26 C Southern California

0.120 0.270 0.420 0.570 0.720 0.870 1.020 1.170
I
0.750

Figure 8. Phenogram of similarities between all squares in Figures 1-6 at depth range I (O-f^Ofl m). All species found
at the particular depth range are used in delemiining similarities, including species found at other depth ranges. All
squares are assumed to contain all depth ranges. Comparisons done by the methods of Rogers and Tanimoto (1960)
with UPGMA cluster analysis. Clusters defined at the O.V.'SO level of similarity.

300

0.448 0.528 0.608 0.688 0.768 0.848 0.928 1.008
> — ~-i 1 1 n 1 1 1 -.

- 19

r-54
-I F.K 1—

IL'

J- 14
-^ 1£

r16
-^ 17

Peru

to
Chile,
other

Baja California

to
Isia del Coco

Costa Rica

Ecuador

Peru

Aleutians

Washington

ii r

22 Oregon to

24 California
?s I—

26 — Southern California

0.448 0.528 0.608 0.688 0.768 0.848 0.928 1.008
I
0.750

Figure 9. Phenogram of similarities between squares at depth range 2 (500-1000 m). All species found at the
particular depth range are used in detennining similarities, including species found at other depth ranges. All squares
are assumed to contain all depth ranges. Comparisons done by the methods of Rogers and Tanimoto (1960) with
UPGMA cluster analysis. Clusters defined at the 0.750 level of similarity.

301

0.448 0.528 0,608 0.688 0 768 0.848 0.928

I 1 . T p , 1

roo8
59 r-

47
66
21
72
71
19
61
65
58
57
r62
63
64
60
67
70
69

— 68
r54

p"- 55
^ 56

— ■- 28

— 30

— 31

— 32

— 29

— 33

07
10
11
12
13
14
15
08
09
16
17
18
20
23
22
24
25

Peru
to

Chile,

other

Baja California
Gulf of California

Baja California
to

Nicaragua

Isia del Coco

Ecuador

Peru

Aleutians

Washington

[

Oregon to
California

J4-

26 — Southern California

0.448 0.528 0.608 0.688 0.768 0.848 0.928 1 008

I
0.750

FiGURH 10. Phenogram of similarities between squares at depth range 3 (1 ()()(>- 1500 ni). All species t'ound at the
particular depth range are used in detennining similarities, including species t'ound at other depth ranges. All squares
are assumed to contain all depth ranges. Comparisons done by the methods of Rogers and Tanimoto (1960) with
UPGMA cluster analysis. Clusters defined at the 0.750 level of similarity.

302

0.408 0.493 0.578 0.663 0.748 0.833 0.918 1.003
' ' ' ' "^ ' ' ',66

Chile,
others

Peru to Chile

06
15
07
10
11
12
13
16
14
17
06
09
23
20
18
22
24
25
26
27
28
30
31
32
I — 29
35

Aleutians

Washington

Q Washington, Oregon
Q California

Southern California

Gulf of California

Baja California

Nicaragua

36
37
39
40
33
34
■41
38

42 — Costa Rica

43
I 44
I 45

-i-

I 46

48
49
50
51
52
53

Gulf of Panama

Peru

-I

0.408 0.493 0.578 0.663 0.748 0.833 0.918 1.003
0.750

Figure 11. Phenogram of similarities between squares at depth range 4 (1500 m and deeper). All species found at the
particular depth range are used in determining similarities, including species found at other depth ranges. All squares
are assumed to contain all depth ranges. Comparisons done by the methods of Rogers and Tanimoto {I960) with
UPGMA clu.ster analysis. Clusters defined at the 0.750 level of similarity.

303

Table 1. Characteristic taxa of particular geographic regions.

Aleutian Islands and Bering Sea to Oregon:

Endemics: Eiialus hiiinguis, E. piisloliis, /■.. siicklcyi. E. townsencli, Heptcnarpus nioseri, Pandalopsis dispar, PaiuUihis
goniiiriis, P. hypsinotiis. P. stcnolcpis. P. tridetts. Argis ovifer. Pugunts confiagosus, P. cornulu.s, Lithodes
aequispinci. Chirosryliis sp., Miinidopsis hcringana, Hyas lyratiis.

Northern range limits: Axiopsis spiiuilicuuda, Cahistacus stillrostris, Callicinassu goniophthalma, Eiiulus haihatus, E.
macrophthulmus. Heptacarpus fle.xus. Lehheiis washingtonianits, Spirontocaris holmesi, S. sica, Pandalopsis
ampla, Paiiduhis jordani, P. platyccros. Mctacrangon varlahilis. Pugiirislcs mrgidiis. Pugiirtts caplllalus. P
taiiiwri, Lopholithodes foraminatus, Paralomis miilti spina, Mitnida c/uadrispina. Miinidopsis c/iiadrala, M. scahra.
M. verrilli, M. verrucosus, Chorilia I. longipes, C. longipes turgida.

Southern range limits: Pandalus horealis, Pagurus aleiiticus, Chionoecetes angulalus angidaius. C. hairdi, Oregonia
bifurca. (Species ranging into northwestern Pacific).

Central-Southern California, Northern Baja California:

Endemics: Argis californiensis. Crangon lomac. Paralithodes californiensis, P. rathhuni. Cliirostyliis pcrarmatus.
Upogehia lepta.

Northern range limits: Benthesicymus altus, B. tanneri, Stereomastis sculpta pacifica, Pontophilus gracilis
occidentalis. Glyphocrangon spinulosa, G. vicaria, Parapagurus liaigae, Glyplolitliodes cristaiipes, Gulathea
californiensis, Munida hispida, M. depressa, M. diomedeae, Munidopsis hystrix.

Southern range limits: Callianassa goniophthalma, Eualus barhatus, Lebbeus washingtonianus, Spirontocaris
holmesi, S. sica, Pandalus jordani, P. platyceros, P. tridens, Crangon abyssorum, Metacrangon variabilis, Pagurus
caplllalus, P. tanneri. Paguristes turgidus, Lithodes couesi, Lopholithodes foraminatus, Paralomis multispina. P.
verrilli, Munida quadrispina, Munidopsis aspera, M. verrilli, Chionoecetes tanneri. Chorilia longipes, C. longipes
turgida.

West Coast of Baja California, Gulf of California:

Endemics: Processa pippinae, Munida perlata.

Northern range limits: Plesionika heehei, Heterocarpus vicarius, Metacrangon procax, Nephropsis occidentalis.
Upogebia jonesi, Paralomis papillata. Munidopsis hamata.

Southern range limits: Calocaris quinc/ueseriatus, Lebbeus vicinus montereyensis, Pandalopsis ampla, Galathea
californiensis.

Southwestern Mexico:

Endemic: Heptacarpus yaldwyni.

Northern range limits: Nematocarcinus agassizii, Heterocarpus affinis, Paracrangon areolata, Sclerocrangon atrox,
Glyphocrangon alata, Munida refulgens, Ethusinafaxonii, Trachycarcinus corallinus.

Southern range limits: Munidopsis depressa, M. quadrata;.

Gulf of Panama:

Endemics: Glyphocrangon sicaria, Uroptychus nitidus occidentalis. Munida gracilipes, Munidopsis agassizi. M.
crinita. M. hendersoniana. M. sericea, M. tanneri. Ethusa ciliatifrons, Cympolia tuberculata.

Northern range limits: Polychelcs tanneri. Heterocarpus hostilis. Lithodes panatnensis. Lopholithodes diomedeae,
Paralomis aspera, P. longipes, Munida propinqua. Munidopsis villosa.

Southern range limits: Upogebia jonesi, Parapagurus haigae, Munidopsis hamata.

Galapagos:

Endemics: Spongicoloides galapagensis, Chirostylus defensus, Uroptychus granulatus, Munidopsis margarita. M.
ornata, Rochinia cornuta, Rochinia occidentalis.

Northern range limit: Glyphocrangon loricata.

Southern range limits: Benthesicymus altus, Polychelcs tanneri. Glyphocrangon vicariu. Munida hispuhi. Munidopsis
rostrata.

Peru:

Endemics: Bathypalaemonella delsolari. Lebbeus carinatus, L. curvirostris. L. splendidus. Pagurus imarpe. Lithodes
wiracocha, Paralomis inca, Cymonomus menziesi. Honu)lodromia robertsi. Acanthocarpus delsolari, Trizocarciniis
peruvianus.

Northern range limit: Lophorochinia parabranchia.

304

Southern range limits: Calastacus stilirosfris, Nematocarcinus agassizii, Heterocarpiis affinis, H. Iiosfilis, H. vicariiis,
Plesionika beebei, P. trispinus. Metacrangon procax, Paracrangon areolata, Sclerocrangon atrox. Glyphocrangon
loricata, Pwbeebei mirabilis, Lithodes panamensis, Lopholithodes diomedeae, Paralomis aspera, P. longipes, P.
papillata, Munida propinqua. Munidopsis hystrix, M. scabra. Ethusina faxonii, Trachycarciniis coralliiuis.

Southern Peru to Chile:

Endemics: Nematocarcinus pwximatus, Leontocaris pacificus, Heterocarpiis reedi. Polycheles chilensis. Willemoesia
challengeri, W. pacifica. Lebbeus scrippsi, Pagiirus delsolari. Trachycarciniis hystricosus.

Northern range limit: Pagiirits forceps.

Southern range limits: Benthesicymus tanneri. Nephropsis occidentalis. Stereomastis sciilpta pacifica, Pontophilus
gracilis occidentalis. Glyphocrangon alata, Glyptolithodes crislatipes. Munidopsis dioniedae, M. verrucosus. M.
villosa, Lophorochinia parahranchia.

Southern Chile to Cape Horn:

Endemics: Campylonotus semistriatus, Steromastis suhmi. Neolithodes diomedeae. Chirostylus niilneedwardsi,
Munida curvipes. Munidopsis opalescens. M. trifida.

Southern range limits: Haliporoides diomedeae, Pagurus forceps, Munidopsis aspera.

farther south. From western Mexico to Peru, species appear to have greater latitudinal range in
shallow water than in deeper water. The fauna of the Galapagos Islands does not appear
distinct from that of the coast of tropical western America, but this may be an artifact of
limited sampling: Munidopsis margarita and M. ornata, for example, are known only from
specimens taken by the Albatross in 1891 (Faxon 1895).

Two genera of spot prawns (family Pandalidae) show allopatric distributions in the eastern
Pacific. In the northeastern Pacific, species of the shrimp Pandalus range from Alaska to
northern Baja California. From the Gulf of California south to Chile, species of Heterocarpus
are found. Both are relatively large epibenthic shrimp of sand, mud, or gravel bottoms. Being
easily recognized to genus and of commercial importance, these shrimp have been studied
better than have many other decapods. The allopatric distributional pattern, therefore, is not
likely to be an artifact of sampling or data analysis.

Only 25 decapod species have been reported exclusively from 1500 m or deeper in the
eastern Pacific (Table 2). Of the species living at depths of 500 m or deeper, 18 are
widespread: the hermit crab Parapagunis pilosimanus heneclicti seems to be ubiquitous at its
depth range (414-2200 m), being reported from the Kurile Islands south to the Juan Fernandez
Islands (Birshtein and Zarenkov 1972, Haig 1955). Pontophilus gracilis occidentalis,
Benthesicymus tanneri, Stereomastis sculpta pacifica, and Glyptolithodes cristatipes range
from southern California to Chile (Wicksten 1976. 1979b, 1982, Mendez 1981).
Glyphocrangon vicaria ranges from southern California to the Galapagos; G. spinulosa, from
southern California to the Gulf of Panama (Wicksten 1979a). Benthesicymus altus is
widespread in the Atlantic and Pacific (Schmitt 1921). Pandalopsis ampla ranges in the
eastern Pacific from Washington state to the Gulf of California (Schmitt 1921, Wicksten 1987),
but also has been reported in the southern Atlantic off Argentina and Uruguay (Takeda and
Hatanaka 1984). Takeda and Hatanaka (1984) suspected that the Atlantic and Pacific
populations may in fact be separate species. Munidopsis latirostris and Axius acutifrons range
from the eastern Pacific into the Indo-West Pacific, while Munidopsis hairdii, M. ciliata, M.
suhsquamosa, Stereomastis nana, Nematocarcinus ensifer, Parapagurus ahyssorum and
Ethusina rohusta are reported to be cosmopolitan at their respective depth ranges (Faxon 1895,
Firth and Pequegnat 1971, Ambler 1980).

Discussion

In interpreting patterns of ranges of offshore decapods, one should bear in mind the
limitations of the data base. Data for many groups of offshore crustaceans are frustratingly
sparse. Sixty of the species here analyzed are known from five or fewer specimens, many
collected only once at the type locality. Species living on hard bottoms, such as members of
the families Stenopodidae and Chirostylidae. are difficult to collect. Other seemingly

305

Table 2. Species found at 1500 m and deeper.

Polyvhcles chilcnsis Sund: 2500 m.
Stereonuistis nana (Smith): 1544-2412 ni.
Willemoesia challengeri Sund: 2520-4000 m.
Wlllemocsia pacifica Sund: 2520 m.
Ncmatcicairiinis pro.xinuitus Bate: 2516-2654 m.
Lchheits carinatiis Zarenkov: 1850 m.
Lehheiis ctirvirostris Zarenkov: 1680-1860 m.
Pontophihis i^racill.s occidentalis Faxon: 1789^082 m.
Glyphocrangon rimapes Bate: 2500 m.
Neolithodes diomedcac (Benedict): 1923-2478 m.
Munidu ciirvipcs Benedict: 1924 m.
Miinida pciiata Benedict: 1920-3292 m.
Mnnldnpsis antoni (Milne Edwards): 2519-3676 m.
Miinidopsis aries (Milne Edwards): 2912-3025 m.
Miinidopsis heringana Benedict: 2800-3276 m.
Miinidopsis cascadia Ambler: 2743-2926 m.
Miinidopsis ciliala Wood-Mason: 2030-2875 m.
Miinidopsis hendersoniana Faxon: 1869 m.
Miinidopsis lostrata (Milne Edwards): 2153-2492 m.
Miinidopsis tiiftsi Ambler: 3500-3858 m.
Miinidopsis verrucosus Khodkina: 3932—4880 m.
Miinidopsis vicina Faxon: 3063-3885 m.
Miinidopsis yaquinensis Ambler: llb'i-lZll m.
Etinisinafa.xonii Rathbun: 2999^081 m.
Ethusina rohusta (Miers): 1618-3334 m.

widespread families, such as the armored shrimps CGlyphocrangonidae) and blind lobsters
(Polychelidae) live only on the lower slope at depths (1000 m or more) that have not been
sampled in many areas. (There are no published reports of either family, for example, north of
Point Conception, yet both probably occur along the northern Pacific slope — related species
so occur in the North Atlantic and off northern Japan). Many species from off Central
America, the Galapagos, and the Juan Fernandez Islands are known only from the collections
of the Albatross and ChaUeni>ei\ not having been collected since then. It can be difficult to
judge from only a few records whether or not an offshore species has a continuous or
discontinuous distribution. (The lack of any amphitropical distributions among deeper
decapods, for example, may be an artifact of sampling.) However, data for commercial species,
such as species of Pandalus, are more abundant than for other decapods and may bias the
analysis. Records may be misleadingly abundant in well-studied areas such as the Californian
Province, where the University of California, Santa Barbara, the University of Southern
California, and Scripps Institution of Oceanography are studying the benthic fauna.

If deeper waters contain a more homogeneous environment than those of the continental
shelf, why can one see clusters of squares by latitude at all depth ranges? Topographic barriers,
such as the trenches off Central America, Peru, and Chile and the basins and ridges of
southern California may limit some benthic species, while subsurface regimes of temperature,
salinity, and oxygen may limit others. Biological factors, either current or past, may be
involved — little is known about dispersal abilities, predator-prey relationships, or competitive
interactions of offshore decapods.

The abundance of lithodid crabs and hippolytid shrimps in the northeastern Pacific
suggests that there has been evolutionary radiation of species in the area. Ekman (1967)
speculated that elements of the North Atlantic fauna were derived from the North Pacific
through "temporary and difficult communication." Menzies ct al. (1973) accounted for
amphiboreal distributions by dispersal of species during a Pliocene trans-Arctic sea connection
between the Pacific and Atlantic. During this connection, groups previously endemic to the
Pacific colonized the Atlantic. Colonization ended during the unstable glacial conditions of
the Pleistocene. Such a faunal exchange across the Arctic enabled species of certain genera
(such as Spirontocaris) to colonize the Atlantic, while others (such as species of Heptacarpus)

306

were unable to cross the "filter bridge."

Ekman (1967) noted the abundance of cold-water caridean shrimps of the family
Hippolytidae in the northern Pacific, referring to these shrimps as various species of
Spirontocaris. Holthuis (1947) split the genus into four genera, Spirontocaris sensu stricto,
Heptacarpus, Eualus, and Lebbeus. Ekman's observation still has merit — species of
Spirontocaris are far more abundant in the northern Pacific than in the northern Atlantic, the
only other place where they occur. Species of Heptacarpus are confined to the northern
Pacific, from Japan across the Aleutians to off Oaxaca, southern Mexico. More species of
Eualus and Lebbeus are known from the northern Pacific than from anywhere else, although
species of each occur off western South America and elsewhere; species of Lebbeus also occur
at bathyal depths in the Indo-Pacific, the Arctic, and boreal Atlantic, while species of Eualus
live off Europe and South Africa (Holthuis 1947, Noel 1978, Wicksten 1979c, 1984, Mendez
1981, Wicksten and Mendez 1982).

A cladistic analysis of the Hippolytidae by Christoffersen (1987) indicates that members
of Lebbeus, Heptacarpus, Spirontocaris, Eualus, and the mostly tropical genera Thor,
Thoralus, and Birulia are closely related and perhaps should be split off from the old family
Hippolytidae into a new family, the Thoridae. Distributional patterns of these genera suggest
origin and radiation in the Pacific with subsequent spread into the Atlantic. The patterns of
distribution of the four cold-water genera resemble that of the rock crabs, genus Cancer, which
are most abundant in the Pacific but also occur across the northern Atlantic Ocean. The
patterns differ, however, in the lack of any records of the four hippolytid genera from Australia
and New Zealand, where one species of Cancer occurs. Fossils of Cancer spp. suggest that
these crabs originated at latest in the Miocene in the northern Pacific and dispersed from there,
following cold-water regimes, in the Pliocene and Pleistocene (Nations 1975). Although there
are no fossils to provide evidence of past distributions of the hippolytids, at least the four cold-
water genera seem to follow much the same pattern as the species of Cancer.

Bouvier (1896) noted that there are many species of the king crab family (Lithodidae) in
the northern Pacific: there are more in the area from the Aleutian Islands to northwestern Baja
California, from the intertidal zone to bathyal depths, than elsewhere. Of those found
elsewhere, species of Lithodes and Paralomis live offshore in both the northern and southern
hemispheres. Glyptolithodes cristatipes ranges from Chile to southern California.

In two other decapod families there are genera endemic to offshore waters of the northern
hemisphere. Among the bay shrimps (family Crangonidae), the genera Argis, Crangon, and
Metacrangon live in the North Atlantic and Pacific. Of the spider crabs (Majidae). species of
Chionecetes and Hyas live in the North Atlantic and Pacific, while species of Chorilia and
Oregonia are found only in the northern Pacific. One majid genus, Lophorochinia, seems to be
endemic to the Peru-Chile Trench (Garth and Haig 1971).

Decapods are not the only organisms showing relatively high diversity of species or
endemism of genera in the northern Pacific. The west coast of North America is second only
to Australia and New Zealand in numbers of unique algal species and is noted for such large
endemic genera of brown algae as Nereocystis and Postelsia (Abbott and Hollenberg 1976).
Estes and Steinberg (1987) hypothesized that the larger algae of the order Laminariales
radiated in the northern Pacific following the onset of late Cenozoic polar cooling. These
characteristic cold-water plants are not found in tropical regions and cannot tolerate warm
ocean water. Evidence from molluscan fossils and other material suggests that the polar
cooling trend could have begun in the middle to late Miocene, allowing spreading of cold-
water groups. The kelps apparently spread across the northern hemisphere into the Atlantic,
then later colonized the southern hemisphere after closure of the Panamic seaway halted the
westward flow of warm water from the Caribbean region into the eastern Pacific. Kelps may
have spread into the southern hemisphere as late as the Pleistocene, when glacial periods
narrowed the distance between cold-water regions of the northern and southern hemispheres.
Northern Pacific decapods may have followed a similar pattern of diversification and dispersal,
but could have spread more easily than algae because of their ability to survive in cold water
at greater depths. Kelps require sunlight for photosynthesis and cannot survive at depths of 50
m or more. Decapods may have spread by equatorial submergence — remaining in the same

307

temperature regimes in the tropics as in temperate regions by moving into deeper water.

The northern Pacific contains many other examples of species-rich cold-water groups. Of
the living species of chitons (MoUusca: Polyplacophora), more can be found along the
northwestern coast of North America than on any other coast of comparable length in the
world. Conspicuous species such as Cryptochiton stellerl and Katherina tunicata have wide
ranges in the northern Pacific (Haderlie and Abbott 1980). Two families of fishes, the
Embiotocidae and Hexagrammidae. are found only in the northern Pacific, from Japan to
western Mexico, while species of the families Stichaeidae and Cottidae as well as of Ihc genus
Sehastodes (family Scorpaenidae), although also occuring in the northern Atlantic, are by far
more diverse in the northern Pacific (Herald 1961).

Except for the examples given in the families Pandalidae, Hippolytidae, Crangonidae,
Lithodidae, and Majidae, offshore decapods of the eastern Pacific belong to widespread genera
found at characteristic depths or temperatures. Menzies ct al. (1973) refer to these widespread
groups as the Tethyan fauna, implying that their distributions could be related to the Tethyan
Seaway of tropical regions in the early Mesozoic. Latitudinal ranges of the species vary from
extensive to seemingly small, but the paucity of data for many groups makes family-by-family
comparison of ranges difficult.

Manning and Reaka (1987) related differences in rates of evolutionary change of
stomatopod crustaceans to differences in larval dispersal ability, habitat, and body size in
different lineages. Evolutionary changes in stomatopods generally are inversely related to the
size of the postlarvae. Lineages of small body size seem to have the most rapid rates of
evolutionary change. The degree of species endemism is associated with substrate type,
speciation being seemingly more common for species inhabiting coarse rather than level
bottom habitats. Larger species of temperate habitats tend to have broad ranges: for example,
Hemisquilla ensigera can be found in California, Chile, New Zealand, and Australia.

Because of the scarcity of information on the distributions, habitats, and life histories of
offshore decapods, it is difficult to compare their evolutionary rates to those of stomatopods.
Stomatopods are rare in cold deep water, being represented by only a few species. As a
general rule, small decapods seem to be more common and diverse in shallow rather than deep
waters: most offshore decapods measure at least 1 cm in largest dimension. Decapods of
deeper hard substrates are rarely collected, so the degree of species endemism among them is
difficult to determine.

It is interesting that among eastern Pacific decapods living at 50-1500 m. there are no
examples of strictly amphitropical (occurring in both northern and southern temperate regions
but not in the tropics) genera or species. Some of the typically cold-water families and genera
live at greater depths in tropical regions than in temperate and boreal areas — species of
Lehheus, for example, can be found almost in the intertidal zone in California, but tropical
representatives of the genus are found on the continental slopes or deeper.

The fauna of western South America has fewer species and genera of decapods than does
North America and has only one reported offshore endemic genus (Lophorochinia). While
many of the species found from Peru south to Chile are endemic to the area, they belong to
genera with widespread distributions.

The relative paucity of offshore decapods off western South America, in both numbers of
species and degree of species endemism, is difficult to explain. The coast is geologically
active, but so is that of western North and Central America. It is possible that gradual cooling
of the coastal waters since the Mesozoic eliminated many elements of the fauna over time:
Menzies et al. (1973) noted that cooling, which extended from the Mesozoic until glaciation in
the Miocene, resulted in a progressive loss of invertebrate groups from the Antarctic. Tropical
waters to the north may have inhibited colonization by the common cold-water families of the
northeastern Pacific. Members of genera that inhabit bathyal zones (such as Lehheus and
Lithodes) seem more likely to co-occur in the northern and southern Pacific than do groups that
live in shallower areas. The slope region off Peru and Chile, however, contains extensive areas
of low oxygen concentrations, inhabited by bacterial mats and not by larger invertebrates
(Rowe and Haedrich 1979). Perhaps a combination of historical elimination or decrease in
faunal diversity and modem conditions that inhibit decapod life has resulted in the paucity of

308

species in this area relative to the coast of North America.

Between the fauna of the eastern Pacific and that of other offshore regions there are
puzzling differences. The northern Pacific is rich in cold-water caridean shrimps of the
families Pandalidae and Hippolytidae. Crabs of the family Lithodidae are more diverse than in
other areas. However, the abundant red crabs, Geryon spp., found on the slopes of the Atlantic
and Indo-West Pacific region, are entirely absent, while members of the family Goneplacidae,
widespread in the warmer parts of the Atlantic, seem to be relatively uncommon on eastern
Pacific slopes. No species of antlered crabs, family Latreilliidae, have been reported from the
eastern Pacific, although they occur in the Atlantic, Indo-West Pacific, and Mediterranean.
Giant isopods {Bathynomus spp.), conspicuous inhabitants of the continental slopes of the
tropical western Atlantic and Indo-Pacific regions, also are absent from the eastern Pacific.

Reaka and Manning (1987) noted gaps in the distributions of otherwise worldwide groups
of stomatopods. For example, the species of Alima, are found in tropical waters worldwide
except in the eastern Pacific. They speculated that such groups have undergone extinction.
Such apparent extinctions in stomatopods have been more numerous in the eastern Pacific than
in the western Atlantic. Perhaps such local extinctions have occurred in decapods as well as
stomatopods.

The sharp break seen at all depths between the fauna of southern California and northern
Baja California combined and all areas to the south is due largely to the allopatry of Paudalus
and Heterocarpus. Changes in the species composition within the family Hippolytidae also
contribute to the break.

Systematic treatments of eastern Pacific decapods for the most part have considered
intertidal and shallow-water species, not animals living at depths of 50 m or more. Much of
the information on offshore species consists of basic descriptions and accounts of where
specimens were collected without comparison of records of related species. More analysis of
the evolutionary relationships of the taxa might shed light on the historical biogeography of the
eastern Pacific.

Acknowledgments

I thank Janet Haig, Allan Hancock Foundation, Spencer Luke, Scripps Institution of
Oceanography, and Dustin Chivers and Robert van Syoc, California Academy of Sciences, for
their assistance in finding records of species, and Steve Taylor, Russ Souchek, and Terrence
Walters, Texas A&M University, for help with the analysis of data. Richard Brusca, San Diego
Natural History Museum, and Gilbert Rowe, Texas A&M University, provided valuable
criticism of early drafts.

Literature Cited

Abbott, I. A., and G.J. HoUenberg. 1976. Marine
Algae of California. Stanford University Press,
Stanford, California.

Ambler, J. W. 1980. Species of A////;/c/o/7.y/5 (Crustacea,
Galatheidae) occurring off Oregon and in adjacent
waters. U.S. Department of the Interior Fishery
Bulletin 78:13-34.

Anderson, M. E., and G. M. Cailliet. 1974.
Coastwatch: California. Underwater Naturalist
8:29-31.

Baez, P., and H. Andrade. 1979. Crustaceos decapodos
arquibentonicos frecuentes frente a la costa de
Chile central. Anales del Museo de Historia
Natural Valparaiso 12:219-231.

Bate, C. S. 1888. Report on the Crustacea Macrura
collected by H.M.S. Challenger during the years
1873-1876. Reports of the Voyage of H.M.S.
Challenger Zoology, Vol. 24.

Benedict, J. E. 1894. Descriptions of new genera and
species of crabs of the family Lithodidae, with
notes on the young of Lithodes caintschaticits and
Lithodes brevipes. Proceedings of the United

States National Museum 17:479-488.

. 1902. Descriptions of a new genus and forty-
six new species of crustaceans of the family
Galatheidae, with a list of the known marine
species. Proceedings of the United States National
Museum 26:243-334.

Birshtein, Y. A., and N. A. Zarenkov. 1972. Bottom
decapods (Crustacea Decapoda) of the
Kurile-Kamchatka Trench area. Pp. 439—447 in
V. G. Bogorov (ed.) Fauna of the Kurile-Kamchatka
Trench and Its Environment. Akademiya Nauk
SSSR — Trudy Instituta Okeanologii Vol. 86. Israel
Program for Scientific Translations, Jerusalem.

Bouvier, E. L. 1896. Sur la classification des
Lithodines et sur leur distribution dans les oceans.
Annales des Sciences Naturelles 8: 1—46.

Briggs, J. C. 1974. Marine Zoogeography. McGraw-
Hill, New York.

Brusca, R. C, and B. R. Wallerstein. 1979.
Zoogeographic patterns of idoteid isopods in the
northeast Pacific, with a review of shallow water
zoogeography of the area. Bulletin of the

309

Biological Society of Washington 3:67-105.

Butler. T, H. 19S0. Shrimps ot the Pacific coast of
Canada. Canadian Bulletin of Fisheries and
Aquatic Sciences 202.

Chace. F. A. Jr. 1984. The carulean shrimps
(Crustacea: Decapoda) of the Albatross Philippine
Expedition. 1907-1910. Part 2: Families
Glyphocrangonidae and Crangonidae. Smith-
sonian Contributions to Zoology 397.

Christoffersen. M. L. 1987. Phylogenetic relationships
of hippolytid genera, with an assignment of new
families for the Crangonoidea and Alpheoidea
(Crustacea. Decapoda. Caridca). Cladistics
3:348-362.

Crosnier. A., and J. Forest. 1973. Les crevettes pro-
fondes de I'Atlantique oriental tropical. Faune
tropicale. XIX. Office de la Recherche
Scientifique el Technique Outre-Mer, Paris.

Cutler, E. B. 1975. Zoogeographical barrier on the
continental slope off Cape Lookout. North
Carolina. Deep-Sea Research 22:893-901.

Dana, J. D. 1853. On the geographical distribution of
Crustacea. In United States exploring expedition
during the years 1838-1842, under the command
of Charles Wilkes, U.S.N. Vol. 14, No. 2.
Crustacea, pp. 696-805.

Ekman. S. 1967. Zoogeography of the Sea. Sidgwick
and Jackson. London.

Estes. J. A., and P. D. Steinberg. 1987. Predation. her-
bivory and kelp evolution. Paleobiology
14:19-36.

Faxon. W. 1895. Reports on an exploration off the
west coasts of Mexico, Central and South
America, and off the Galapagos Islands, in charge
of Alexander Agassiz, by the U.S. Fish
Commission steamer "Albatross" during 1891,
Lieut. Commander Z. L. Tanner, U.S.N., com-
manding. 15. The stalk- eyed Crustacea.
Harvard University Museum of Comparative
Zoology Memoir 18.

Firth, R. W. Jr.. and W. E. Pequegnat. 1971. Deep-sea
lobsters of the families Polychelidae and
Nephropidae (Crustacea. Decapoda) in the Gulf of
Mexico and Caribbean Sea. Texas A&M
University Department of Oceanography. A&M
Project 700- 1 5 Reference 7 1 - 1 1 T.

Garth, J. S. 1955. The case for a warm-temperate
marine fauna on the west coast of North America.
Pp. 19-27 ill Essays in Natural Sciences in Honor
of Captain Allan Hancock. University of
Southern California Press, Los Angeles.

. 1958. Brachyura of the Pacific coast of

America: Oxyrhyncha. Allan Hancock Pacific
Expeditions Vol. 21, Part 1.

. 1973. New taxa of brachyuran crabs from

deep water off western Peru and Costa Rica.
Bulletin of the Southern California Academy of
Sciences 72:1-12.
-, and J. Haig. 1971. Decapod Crustacea

The chitons. Pp. 412-428 (/; R. H. Morris, D. P
Abbott, and E. C. Haderlie (eds.). intertidal
Invertebrates of California. Stanford University
Press, Stanford. California.

Haig, J. 1955. The Crustacea Anomura of Chile.
Reports of the Lund University Chile Expedition
1948^9. No. 20. Lunds Univcrsitcts Arsskrift N.
F. Avd. 2, Bd. 51.No. 12.

. 1956. Notes on two anomuran crustaceans

new to California waters. Bulletin of the .Southern
California Academy of Sciences 55:79-8 1 .

. 1968. First report of the crab family

Chirostylidae of California, and description of a
new species of Chin>sr\liis. Calilornia Fish and
Game 54:270-277.

. 1974a. Observations on the lithodid crabs of

Peru, with description of two new species.
Bulletin of the Southern California Academy of
Sciences 73:152-164.

. 1974b. Two new species of Pui^itnis from

deep water off Peru and Chile (Decapoda,
Anomura, Paguridae). Crustaceana 27:1 19-130.

, and M. K. Wicksten. 1975. First records and

(Anomura and Brachyura) of the Peru-Chile
Trench. Anton Bruun Report 6:6.3-6.20.

Goy. J. W. 1980. Spongicoloides fialapagenls. a new
shrimp representing the first record of the genus
from the Pacific Ocean (Crustacea: Decapoda:
Stenopodidea). Proceedings of the Biological
Society of Washington 93:760-770.

Haderlie. E. C. and D. P. Abbott. 1980. Polyplacophora:

range extensions of crabs in California waters.
Bulletin of the Southern California Academy of
Sciences 74:100-104.

Hart. J. F. L. 1982. Crabs and their relatives of British
Columbia. British Columbia Provincial Museum
Handbook 40.

Herald, E. S. 1961. Living Fishes of the World.
Doubleday, New York.

Holthuis, L. B. 1947. The Decapoda of the Siboga
Expedition. Part 10. The Hippolytidae and
Rhynchocinetidae. Siboga Expeditie 39a8.

, 1971. The Atlantic shrimps of the deep-sea

genus Glypliocrani^on A. Milne Edwards, 1881.
Bulletin of Marine Science 21:267-373.

Jablonski. D., and J. W. Valentine. 1981.
Onshore-offshore gradients in recent eastern
Pacific shelf faunas and their paleobiogeographic
significance. In G. E. E. Scudder and J. C. Reveal
(eds.). Evolution Today. Proceedings of the
Second International Congress of Systematic and
Evolutionary Biology, pp. 441-^53.

Jack.son, J. B. C. 1974. Bit>geographic consequences
of eurytopy and stenotopy among marine bivalves
and their evolutionary significance. American
Naturalist 108:541-560.

Jones, M. L. (ed.). 1985. Hydrolhennal vents of the
eastern Pacific: an overview. Bulletin of the
Biological Society of Washington 6.

Keen, A. M. 1937. An Abridged Check List and
Bibliography of West North American Marine
Mollusca. Stanford University Press. Stanford.
Calitbrnia.

Khodkina, I. V. 1973. New species of the genus
Miiniclopsis (Decapoda. Anomura) from the east
Pacific. Zoologicheskii Zhurnal 52:1156-1167.

Luke, S. R. 1977. Catalog of the benthic invertebrate
collections. I. Decapod Crustacea and
Stomalopoda. Scripps Institution of Oceanog-
raphy Reference No. 77-9.

McCauley,, J. E. 1972. A preliminary checklist of
selected groups of invertebrates Irom ottcr-lrawl
and dredge collections off Oregon. Pp. 409^43
/// A. T. Pruter and D. L. Alverson (eds.). The
Columbia River Estuary and Adjacent Ocean

310

Waters. Bioenvironmental Studies. University of
Washington Press, Seattle.

de Man, J. G. 1920. The Decapoda of the Siboga
Expedition. Part IV. Families Pasiphaeidae,
Stylodactylidae, Hoplophoridae, Nemato-
carcinidae, Thalassocaridae, Pandalidae,
Psalidopodidae, Gnathophyllidae, Processidae,
Glyphocrangonidae, and Crangonidae. Siboga
Expeditie 39a3.

Manning, R. B. 1970. Notes on the west American
nephropidean lobster Nephrops occidentalis
Faxon. Proceedings of the Biological Society of
Washington 82:865-870.

Mendez, M. 1981. Claves de identificacion y dis-
tribucion de los langostinos y camarones
(Crustacea: Decapoda) del mar y rios de la costa
del Peru. Instituto del Mar del Peru Boletin 5.

Menzies, R. J., R. Y. George, and G. T. Rowe. 1973.
Abyssal Environment and Ecology of World
Oceans. Wiley, New York.

Nations, J. D. 1975. The genus Cancer (Crustacea:
Brachyura): Systematics, biogeography and fossil
record. Los Angeles County Natural History
Museum Science Bulletin 23.

Noel, P. 1978. Eualus drachi nov. sp. (Crustacea,
Caridea, Hippolytidae) des cotes fran^aises de la
Mediterranee. Archives de Zoologie
Experimentale et Generale 1 19:21-28.

Parker, R. H. 1963. Zoogeography and ecology of
macro-invertebrates, particularly mollusks, in the
Gulf of California and the continental slope off
Mexico. Videnskabelige Meddelser fra Dansk
Naturhistorisk Forening i Kobenhavn 126:1-1178.

Pereyra, W. T, and M. S. Alton. 1972. Distribution
and relative abundance of invertebrates off the
northern Oregon coast. Pp. 444-474 //; A. T.
Pruter and D. L. Alverson (eds.). The Columbia
River Estuary and Adjacent Ocean Waters.
Bioenvironmental Studies. University of
Washington Press, Seattle.

Rathbun, M. J. 1904. Decapod crustaceans of the
northwest coast of North America. Harriman
Alaska Expedition Report 10:1-210.

. 1918. The grapsoid crabs of America.

Bulletin of the United States National Museum 97.

. 1925. The spider crabs of America. Bulletin

of the United States National Museum 129.

. 1930. The cancroid crabs of America of the

families Euryalidae, Portunidae, Atelecyclidae,
Cancridae, and Xanthidae. Bulletin of the United
States National Museum 152.

. 1937. The oxystomatous and allied crabs of

America. Bulletin of the United States National
Museum 166.

Reaka, M. L., and R. B. Manning. 1987. The signifi-
cance of body size, dispersal potential, and habi-
tat for rates of morphological evolution in
stomatopod Crustacea. Smithsonian Contributions
to Zoology 448.

Rogers, D. J., and T T Tanimoto. 1960. A computer
program for classifying plants. Science
132:1115-1118.

Rowe, G. T. 1985. Benthic production and processes
off Baja California, northwest Africa and Peru: A
classification of benthic subsystems in upwelling
ecosystems. Pp. 589-612 in Simposio
Internacional sobre las Areas de Afloramiento

Mas Importantes del Oeste Africano (Cabo
Blanco y Benguela). Instituto de Investigaciones
Pesqueras, Barcelona.
— , and R. L. Haedrich. 1979. The biota and bio-

logical processes of the continental slope.
Society of Economic Palaentologists and
Mineralogists Special Publicaton 27:49-59.

de Saint Laurent, M. 1972. Sur la famille des
Parapaguridae Smith, 1882. Description de
Typhlopagnnts foresri gen. nov., sp. nov., et de
quinze especes ou sous-especes nouvelles de
Parapagurus Smith (Crustacea, Decapoda).
Bijdragen Tot de Dierkunde 42:97-123.

Schmitt, W. L. 1921. The marine decapod Crustacea
of California. University of California
Publications in Zoology 23:1^70.

Sneath, P. A., and R. R. Sokal. 1973. Numerical
Taxonomy. Freeman, San Francisco.

Takeda, M., and H. Hatanaka. 1984. Records of deca-
pod crustaceans from the southwestern Atlantic
collected by the Japanese fisheries research
trawlers. Bulletin of the National Science
Museum, Tokyo. Series A (Zoology), 10:7-24.

Valentine, J. W. 1966. Numerical analysis of marine
molluscan ranges of the extratropical northeastern
Pacific shelf. Limnology and Oceanography
11:198-211.

Wenner, E. L. 1979. Distribution and reproduction of
nematocarcinid shrimp (Decapoda: Caridea) from
the northwestern north Atlantic. Bulletin of
Marine Science 29:380-393.

Wicksten, M. K. 1977. Range extensions of four
species of crangonid shrimps from California and
Baja California, with a key to the genera
(Natantia: Crangonidae). Proceedings of the
Biological Society of Washington 90:963-967.

. 1978. The species of Plesionika from

California and western Mexico (Natantia:
Pandalidae). Bulletin of the Southern California
Academy of Sciences 77:84—87.

. 1979a. New records of the species of

Glyphocrangon in the northeastern Pacific Ocean
(Caridea: Glyphocrangonidae). Proceedings of
the Biological Society of Washington
92:217-224.

. 1979b. Range extensions of four species of

crangonid shrimps in the eastern Pacific Ocean
(Decapoda: Crangonidae). Bulletin of the
Southern California Academy of Sciences
79:38-41.

. 1979c. Zoogeographical affinities of the bro-
ken back shrimp (Caridea: Hippolytidae) of west-
ern South America. //; Proceedings of the
International Symposium on Marine
Biogeography and Evolution in the Southern
Hemisphere. New Zealand Department of
Scientific and Industrial Research Information
Series 137, Vol. 2: 627-634.

. 1980. Mainland and insular assemblages of

benthic decapod crustaceans of southern
California. Pp. 357-367 in D. M. Power (ed.).
The California Islands: Proceedings of a
Multidisciplinary Symposium. Santa Barbara
Museum of Natural History, Santa Barbara,
California.

. 1981. New records of Stereoniastis sculpta

pacifica (Faxon) (Decapoda: Polychelidae) in the

311

eastern Pacific Ocean. Proceedings of the

Biological Society of Washington 93:914-919.
— . 1982a. Crustaceans from baited traps and gill

nets off southern California. California Fish and

Game 68:244-248.
. 1982b. Two species of Odontozoini

(Decapoda: Stenopodidae) from the eastern

Pacific. Journal of Crustacean Biology

2:130-135.
— . 1984. New records and a new species of hip-

polytid shrimp from the northeastern Pacific.

Crustaceana 46:241-248.
— . 1987. Range extensions of offshore decapod

crustaceans from California and western Mexico.

California Fish and Game 73:54-56.
— , and M. Mendez. 1982. New records and new

species of the genus Lebbeus (Caridea:

Hippolytidae) in the eastern Pacific Ocean.

Bulletin of the Southern California Academy of
Sciences 81:106-120.

, and . 1983. Bathypalaemonella delso-

Iciri, a new species of shrimp from Peru
(Decapoda, Caridea, Campy lonotidae). Crus-
taceana 45:225-231.

. and . 1985. Processa pippinae: A new

species of deep-sea shrimp from the Gulf of
California. Crustaceana 49: 1 6-2 1 .

Williams, A. B. 1986. Mud shrimps, Upogebia. from
the eastern Pacific (Thalassinoidea: Upoge-
biidae). San Diego Society of Natural History
Memoir 14.

Zarenkov, N. A. 1976. K faune desyatinogikh rakoo-
braznykh priamerikanskikh yuzhnugo polushariya.
Biologiya Morya 5:8-18.

APPENDIX 1 : Species List of Offshore Decapod Crustaceans of the

Eastern Pacific Ocean

D = depth category. 1 = 0-500 m, 2 = 500-1000 m, 3 = 1000-1500 m, 4 = 1500 m and deeper. S = square (see Figs.
1-6). References for distribution are given in parentheses after depth range.

Suborder Dendrobranchiata

Family Penaeidae

Bentheskymus alius Bate, 1881: San Nicolas Is., California to Galapagos, 916-4089 m (Schmitt 1921). D 3, 4; S 26,

27. 28, 29, 33, 34, 35, 37, 39, 40, 41, 42, 43, 44, 45, 46, 67, 68, 69, 70.

Benthesicvmus tanneri Faxon, 1893: San Diego, California, to Peru-Chile border, 606-2422 m (Schmitt 1921, Mendez

1981). D 2, 3, 4; S 26, 27, 28, 29, 30, 31, 33, 34, 35, 37, 39. 40, 41. 42, 43, 44, 45, 46, 47. 48. 49. 50, 51, 52, 53, 54,

55, 67. 68, 69, 70.

Halipowides diomedeae (Faxon, 1893): Gulf of Panama to S. Chile, 440-3455 m (Mendez 1981 ). D 2, 3, 4; S 42, 43,

44, 45, 46, 47, 48, 49, 50, 51. 52, 53. 54. 55. 56, 57, 58, 59, 60.

Hymenopenaeus doris (Faxon, 1893): Mexico to northern Peru, 549^802 m (Mendez 1981). D 2, 3, 4; S 33. 34. 35.

36. 37. 39, 40, 41, 42, 43. 44. 45. 46. 47. 48, 49.

Hxmenopenaeits nereus (Faxon, 1893): Costa Rica to Ecuador, 330-1300 m (Mendez 1981). D 3, 4; S 42, 43, 44, 45,

46, 67, 68, 69. 70.

Suborder Pleocyemata

Infraorder Stenopodidea

Family Stenopodidae

Odontozom Ispongicola (Alcock and Anderson. 1899): off Santa Catalina Island. California. 609 m (Wicksten 1982).

D 2; S 26.

Spongicoloides galapagensis Goy. 1980: Galapagos Islands, 717 m. D 2; S 69.

Infraorder Astacidea

Family Nephropidae

Nephropsis occidentalis Faxon, 1893: west coast of Baja California to Chile, 550-1238 m (Manning 1970). D 2, 3: S

27, 28, 29, 33. 34. 35, 36, 37, 39, 40, 41, 42, 43. 44, 45. 46. 47. 48. 49. 50. 51, 52. 53. 54. 55. 56.

Infraorder Palinura

Family Polychelidae

Polycheles chilensis Sund, 1920: west of Valparaiso. Chile. 2500 m (Holthuis 1952). D 4; S 56.

Polvcheles tanneri FsLXon, 1893: Gulf of Panama to off Galapagos. 1079-1411 m (Faxon 1893). D 3. S 41, 42, 43. 44.

45.68.

Stereomastis nana (S. Smith, 1884): cosmopolitan, 1544-2412 m (Firth and Pequegnat 1971). D 3, 4; S 1, 2. 3. 4. 5, 6,

7,8.9. 10, 11. 12. 13, 15, 16, 17. 18, 19,20,21,22.23.24.25.26.27.28.29.30.31,33,34,35,36,37,39,40.41.42.

43, 44', 45. 46, 47', 48, 49, 50, 5 1 , 52, 53, 54, 55, 56, 57, 58, 59, 60, 62, 63, 65, 66, 67, 68, 69. 70. 7 1 . 72.

Stereomastis sculpta pacifica (Faxon, 1893): San Clemente Island. California, to off Valparaiso. Chile; 1000-3692 m

(Faxon 1893, Schmitt 1921. Wicksten 1981 ). D 3, 4; S 26, 27, 28, 29, 30, 31, 33, 34, 35, 36, 37. 39, 40, 41. 42. 43. 44.

45, 46, 47, 48, 49, 50, 51. 52, 53, 54, 55. 56.

Stereomastis suhmi (Bate. 1878): off Valparaiso, Chile; circum-Antarctic. 293-2220 m (Firth and Pequegnat 1971). D

2. 3. 4; S 55. 56, 57, 58, 59, 60. 62. 63. 65, 66.

312

Willemoesia challengeri Sund, 1920: off Valparaiso, Chile, 2520-4000 m (Holthuis 1952). D 4; S 56.
Willemoesia pacifica Sund, 1920: off Valparaiso, Chile, 2520 m (Holthuis 1952). D 4; S 56.

Infraorder Thalassinidea

Family Axiidae

Axiopsis spinulicauda (Rathbun, 1902): Vancouver Island. Canada, to Bodega Head, California, 59-256 m (Hart

1982). D 1,2; S 17, 18,20,23,24.

Axius acutifrons (Bate, 1888): off San Clemente Island, California; off Mariato Point, Panama; 595-2310 m (Wicksten

1982). D 2, 3. 4; S 26, 27, 28, 29, 33, 34, 35, 36, 37, 39, 40, 41, 42.

Axius cristagalU Faxon, 1893: off Mariato Point, Panama, 852 m (Faxon 1895). D 2; S 42.

Calastacus stilirostris Faxon, 1893: southwest of Vancouver Island, Canada, to Peru, 700-1208 m (Hart 1982). D 2, 3;

S 18, 20, 23, 24, 25, 26, 27, 28, 29, 33, 34, 35, 36, 37, 39, 40, 41, 42, 43, 44, 45, 46, 48.

Calocaris investigatoris (Anderson, 1896): Aleutian Islands to San Diego, California, 549-1733 m (McCauley 1972,

Pereyra and Alton 1972, Hart 1982). D 2, 3; S 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 20, 22, 23, 24,

25, 26.

Calocaris quinquesehatus (Rathbun, 1902): Sea of Okhotsk to Gulf of California, 288-220 m (Hart 1982). D 1, 2, 3; S

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 20, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 33.

Uroptychus bellus Faxon, 1893: off Mariato Point, Panama, 333-599 m (Faxon 1895). D 2; S 42.

Uroptychus nitidus occidentalis Faxon, 1893: Gulf of Panama, 839 m (Faxon 1895). D 2; S 43.

Uroptychus pubescens Faxon, 1893: off Mariato Point, Panama, 333-590 m (Faxon 1895). D 2; S 42.

Family Callianassidae

Callianassa goniophthalma Rathbun, 1902: Alaska to southern California, 483-651 m (Wicksten 1987). D 2; S 1, 2, 3,
4, 5, 6, 7, 8, 9, 10, 1 1, 12, 13. 14, 16, 17, 18, 20, 22, 23, 24, 25, 26.

Family Upogebiidae

Upogebia jonesi Williams, 1986: northern Gulf of California to Panama, 20-74 m. D 1, S 30, 31, 32, 33, 34, 35, 36,

38,39,40,41,42,43.

Upogebia lepta Williams, 1986: off Santa Catalina Island, California, to Islas Coronados, Mexico, 73-103 m. D 1; S

26.

Infraorder Caridea

Family Nematocarcinidae

Nematocarcinus agassizi Faxon, 1893: Mexico to Peru, 41-900 m (Mendez 1981 ). D 1, 2; S 36, 37, 39, 40, 41, 42, 43,

44,45, 46,48, 49,'5 1,52.

Nematocarcinus ensifer Smith, 1882: Gulf of California to off Ecuador, 1218-3212 m (Wenner 1979). D 2, 3; S 31, 33,

34, 35, 36, 37, 39, 40, 41, 42, 43, 44, 45.

Nematocarcinus proximatus Bate, 1888: off Valpariaso and Valdivia, Chile, 2516-2654 m (Holthuis 1952). D 4; S 56,

58.

Family Campylonotidae

Bathypalaemonella delsolari Wicksten and Mendez, 1983: off Peru, 1\2-1AA m. D 2; S 48.

Campvlonotus semistriatus Bate, 1888: southern Chile to Cape Horn, 30-816 m (Mendez 1981). D 1, 2; S 58, 59, 60,

61,62,63,64,65,66.

Family Hippolytidae

Eualus barbatus (Rathbun, 1899): Pribilof Islands to Santa Monica Bay, California, 82-507 m (Butler 1980, Wicksten

1984). D 1,2;S 1,2.3,4,5,6,7,8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,20,23,24,25,26.

Eualus biunguis (Rathbun, 1902): Kurile Islands and Bering Sea to Oregon, 90-2090 m (Birshtein and Zarenkov 1970,

Butler 1980). D 1, 2, 3, 4; S 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1, 12, 13, 14, 15, 16, 17, 18, 20, 22, 23.

Eualus macrophthalmus (Rathbun, 1902): Unalaska to Point Sur, California, 1 10-1 163 m (Butler 1980). D 1, 2, 3; S 5,

6, 7, 8, 9, 10, 1 1, 12, 13, 14, 16, 17, 18, 20, 22, 23, 24.

Eualus pusiolus (Kroyer, 1841): Bering Sea to British Columbia, 0-138 m (Butler 1980). D 1, 2, 3; S 1, 2, 3, 4, 5, 6, 7,

8,9, 10, 11, 12, 13, 14, 16, 17, 18,20.

Eualus suckleyi (Stimpson, 1864): Bering Sea to Washington, 11-1025 m (Birshtein and Zarenkov 1970, Butler 1980).

Dl,2, 3;S 1,'2, 3,4, 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 16, 17. 18.20.

Eualus townsendi (Rathbun, 1902): Pribilof Islands to Puget Sound, 38-630 m (Butler 1980). D 1, 2; S 1, 2, 3, 4, 5, 6,

7, 8, 9, 10, 11, 12, 13, 14, 16, 17, 18, 20.

Heptacarpusflexus (Rathbun, 1902): Bering Sea to Drake's Bay, California, 37-1189 m (Schmitt 1921). D 1, 2, 3; S 1,

2,3,4,5,6,7,8,9, 10, 11, 12, 13, 14, 16, 17, 18,20,23,24.

Heptacarpus moseri (Rathbun, 1902): Bering Sea to off Oregon, 108-1100 m (Butler 1980). D 1, 2, 3; S 1, 2, 3, 4, 5,

6, 7, 8, 9, 10, 11, 12, 13, 14, 16, 17, 18, 20.

Heptacarpus yaldwyni Wicksten, 1984: off Salina Cruz, Mexico, 1052-1145 m. D 3; S 37.

Lebbeus bidentatus Zarenkov, 1976: off Peru, 1680 m. D 3; S 51.

Lebbeus carinatus Zarenkov, 1976: off Peru, 1850 m. D 3; S 48.

Lebbeus curvirostris Zarenkov, 1976: off Peru, 1680-1860 m. D 3, S 48, 49, 50, 5 1 .

Lebbeus scrippsi Wicksten and Mendez, 1982: Peru to Chile, 768-1 164 m. D 2, 3; S 51, 52, 53.

Lebbeus splendidus Wicksten and Mendez, 1982: off Peru, 712-1 100 m. D 2, 3; S48.

313

Lebheits vicinus monterexensis Wicksten and Mendez. 1982: Monterey Bay, California, to Gulf of California,

954-2086 m. D 3, 4; S 24,25. 26. 27. 28, 29, 33.

Lehheiis vicinus vicinus (Rathbun, 1902): north of Unalaska, 556-730 m (Rathbun 1904). D 2; S 5.

Lehheus washiniitonianus (Rathbun. 1902): Queen Charlotte Islands to off San Clemente Island, California, 820-1808

m (Butler 1980). D 3; S 16. 17. 18, 20, 23, 24, 25. 26.

Leontocaris pacificus Zarenkov, 1976: off Chile, 600-700 m. D 2. S 51.

Spiwntociiris holmesi Holthuis. 1947: Yes Bay. Alaska, to San Diego, California. 24-386 m (Butler 1980). D 1. 2; S

14, 16, 17, 18,20,23.24.25.26.

Spirontocaris sica Rathbun, 1902: Restoration Bay, British Columbia, to off Cedros Island, Baja California, 88-849 m

(Butler 1980, Wicksten 1987). D 2, 3; S 16. 17. 18, 20, 23, 24, 25, 26, 27.

Family Processidae

Pwcessa pippinae Wicksten and Mendez. 1985: Gulf of California. 265-644 m. D 2, 3; S 31.

Family Pandalidae

Heterocarpus ajfinis Faxon, 1893: Islas Tres Marias, Mexico, to Peru, 660-800 m (Mendez 1981). D 2; S 33, 34, 35,

36, 37, 38, 39, 40, 41. 42, 43, 44, 45, 46, 48, 49.

Heterocarpus hostilis Faxon, 1893: Gulf of Panama to Peru. 187-1000 m (Mendez 1981 ). D 1.2,3; S 44, 45, 46.

Heterocarpus reedi Bahamonde, 1955: off Chile, 200-500 m (Mendez 1981 ). D 2; S 54, 55, 56, 58.

Heterocarpus vicarius Faxon, 1893: Gulf of California to Peru, 73-800 m (Mendez 1981). D 1, 2; S 30, 31. 32, 33, 34,

35, 36, 37, 38, 39. 40. 41. 42. 43. 44. 45. 46. 48, 49. 51.

Pandalopsis ampla Bate, 1888: Washington to Gulf of California, 553-1986 m (Schmitt 1921, Wicksten 1987). D 3; S

20, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33.

Pandalopsis dispar Rathbun. 1902: Bering Sea to Oregon, 46-649 m (Butler 1980). D 1, 2; S 1, 2, 33, 4. 5. 6, 7. 8. 9.

10, 11, 12, 13, 14, 16, 17, 18,20.

Pandalus borealis Kroyer, 1838: Bering Sea to off Columbia River, 16-1380 m (Butler 1980). D 1, 2, 3; S 1, 2. 3. 4. 5.

6. 7, 8, 9, 10. 1 1. 12. 13. 14. 15. 16. 17, 18. 20.

Pandalus goniurus Stimpson, 1860: Bering Sea to Puget Sound, 5^50 m (Butler 1980). D 1, 2; S 1, 2, 3, 4, 5, 6, 7, 8,

9, 10, 11, 12, 13. 14, 16, 17, 18,20.

Pandalus fnpsinotus Brandt. 1851: Norton Sound. Alaska to Puget Sound. 5^60 m (Butler 1980). D 1. 2: S 1. 2. 3. 4,

5.6.7.8,9, 10, 11. 12, 13, 14, 16, 17, 18,20.

Pandalus jordani Rathbun, 1902: Unalaska Island to San Nicolas Island, California, 36^57 m (Butler 1980). D 1, 2: S

5,6,7.8,9. 10. 11, 12, 13, 14, 16, 17, 18,20.23,24.25.26.

Pandalus platvceros Brandt, 1851: Unalaska Island to San Diego, 0-1846 m (Butler, 1980). D 1, 2, 3; S 5, 6, 7, 8, 9,

10, 11, 12, 13,' 14, 16, 17, 18,20,23,24,25,26.

Pandalus stenolepis Rathbun. 1902: Unalaska Island to Hecata Bank, Oregon, 49-229 m (Butler 1980). D 1. 2: S 5. 6.

7,8,9, 10, 11, 12, 13, 14, 16, 17, 18,20,23.

Pandalus tridens Rathbun, 1902: Pribilof Islands to San Nicolas Island, 5-1984 m (Butler 1980). D 1, 2, 3; S 1, 2. 3, 4.

5,6,7,8,9. 10, 11, 12, 13, 14, 15, 16, 17, 18,20,22,23,24,25.26.

Plesionika heehei Chace, 1937: Gulf of California to Peru, 73-916 m (Mendez 1981). D 1. 2, 3; S 33, 34, 35, 36, 37,

39,40,41,42,43,44.45,46.

Plesionika trispinus Squires and Barragan, 1976: Colombia to Peru, 140-430 m (Mendez 1981). D 2: S 44. 45. 46, 48.

Family Crangonidae

Argis californiensis (Rathbun. 1902): Port Hueneme, California, to Punta Banda, Baja California. 20-286 m (Wicksten

1977). D 1,2;S26.

Argis ovifer (Rathbun, 1902): Bering Sea to Queen Charlotte Sound, 102-673 m (Butler 1980). D 1. 2; S 1, 2, 3, 4, 5,

6,7,8,9, 10, 11, 12. 13, 14, 16, 17.

Crangon ahyssorum Rathbun, 1902: Bering Sea to Cortez Bank, California, 97-2975 m (Birshtein and Zarenkov 1970.

Butler 1980). D 1,2, 3,4; S 1,2,3,4,5.6.7,8,9, 10, 11, 12, 13, 14, 15, 16, 17. 18.20.23,24,25,26.

Crangon Inmae (Schmitt. 1921): San Miguel Island to San Diego, California, 830-1182 m (Wicksten 1980). D 2, 3; S

25, 26.

Metacrangon procax (Faxon, 1893): Gulf of California to southern Peru, 1209-1658 m (Mendez 1981). D 3; S 31. 32.

33, 34, 35, 36, 37, 39, 40, 41, 42. 43, 44, 45, 46, 48. 49, 51. 52.

Metacrangon variabilis (Rathbun. 1902): Bering Sea to San Nicolas Island, California, 92-1271 m (Birshtein and

Zarenkov'l970. Butler 1980). D 1.2. 3; S 1,2,3,4,5,6,7,8,9, 10, 11, 12, 13, 14. 15, 16, 17,20,23.24,25,26.

Paracrangon areolala Faxon, 1893: Islas Tres Marias to Peru, 1238-1246 m (Mendez 1981). D 3; S ii, 34, 35, 36, 37,

39, 40, 41 , 42, 43, 44, 45, 46, 48, 49, 50, 51, 52.

Sclerocrangon atrox Faxon, 1893: Islas Tres Marias to Peru, 1209-1238 m (Mendez 1981 ). D 3: S 33, 34, 35, .36, 37,

39, 40, 41, 42, 43, 44, 45, 46, 48, 49, 50, 5 1 , 52.

Pontophilus gracilis occidentalis Faxon, 1893: off San Clemente Island, California to Peru. 1789-4082 m (Faxon

1895, Zarenkov 1976. Wicksten 1977, Chace 1984). D 1, 2. 3. 4; S 26. 27. 28. 29, 33, 34, 35, .36, 37, .39. 40. 41. 42. 43.

44, 45, 46, 48, 49, 50, 51,52,53, 54.

Family Glyphocrangonidae

Glyphocrangon alata Faxon, 1893: Off Acapulco, Mexico, to off Valparaiso, Chile. 600-1300 m (Wicksten 1979.

Mendez 1981). D 2, 3; S 40, 41, 42, 43, 44, 45, 46, 48, 49, 50, 51, 52, 53, .54, 55. 56.

Ghphocrangon loricata Faxon. 1895: Galapagos Islands to Peru. 605-769 m (Mendez 1981 ). D 2; S 46, 48, 67, 68, 69, 70.

314

Glyphocrangon rimapes Bate, 1888: near Islas Juan Fernandez, 2500 m (Holthuis 1952). D 4; S 71, 72.

Glyphocrangon sicaria Faxon, 1893: Costa Rica and Gulf of Panama, 1454-3310 m (Faxon 1895, Wicksten 1979). D

3; S 41, 42, 43.

Glyphocrangon spinulosa Faxon, 1893: Cortez Basin, California, to off Mariato Point, Panama, 1218-1374 m (Faxon

1895. Wicksten 1979). D 3; S 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 39, 40, 41, 42.

Glyphocrangon vicaria Faxon, 1893: San Clemente Basin, California, to Galapagos Islands, 1374—2441 m (Faxon

1895, Wicksten 1981). D 3, 4; S 26, 27, 28, 29, 33, 34, 35, 36, 37, 39, 40, 41, 42, 43, 44, 45, 46, 67, 68, 69, 70.

Infraorder Anomura

Family Diogenidae

Paguristes turgidus (Stimpson, 1857): Chukchi Sea to San Diego, 5-465 m (Hart 1982). D 1, 2, 3; S 1, 2, 3, 4, 5, 6, 7,
8,9, 10, 11, 12, 13, 14, 16, 17, 18,20,23,24,25,26.

Family Paguridae

Catapagurus diomedeae Faxon, 1893: off Mariato Point, Panama, 333 m (Faxon 1895). D 3; S 42.

Pagurus aleuticus (Benedict, 1892): Japan, Bering Sea to off Eureka, California, 208-283 m (Haig and Wicksten

1975). D 1,2;S 1,2,3,4,5,6,7,8,9, 10, 11, 12, 13. 14, 16, 17, 18,20,23.

Pagurus capillatus (Benedict, 1892): Bering Sea to off Santa Cruz, California, 4-1189 m (Hart 1982). D 1,2, 3; S 1,2,

3, 4, 5, 6, 7, 8, 9, 10, 1 1. 12, 13, 14, 16, 17, 18, 20, 23, 24.

Pagurus confragosus (Benedict, 1892): Alaska to off Columbia River, 55-435 m (Hart 1982). D 1, 2; S 5, 6, 7, 8, 9,

10, 11, 12, 13, 14, 15, 16, 17, 18,20.

Pagurus cornutus (Benedict, 1892): Bering Sea to off Oregon, 160-830 m (Hart 1982). D 2; S 1, 2, 3, 4, 5, 6. 7, 8, 9,

10, 11, 12, 13, 14, 16, 17, 18,20.

Pagurus delsolari Haig, 1974: Peru to off Valparaiso, Chile, 275-650 m. D 2; S 53, 54, 55, 56.

Pagurus forceps (A. Milne Edwards, 1836): Coquimbo, Chile, to Straits of Magellan, 660 m (Haig 1955). D 2; S 55,

56, 57, 58, 60, 62, 63, 64, 65, 66.

Pagurus imarpe Haig, 1974: Banco de Mancora and off Punta Aguja, Peru, 570-980 m. D 2; S 46.

Pagurus tanner! (Benedict, 1892): Bering Sea to off San Diego, California, 91-1372 m (Hart 1982; USNM unpubl.

record). D 1,2, 3; S 1,2,3,4,5,6,7,8,9, 10, 11, 12, 13, 14. 16, 17, 18,20,23,24,25,26.

Family Parapaguridae

Parapagurus abyssorum Henderson, 1888: Gulf of California to Chile, 1410-3340 m (Garth and Haig 1971). D 3, 4; S

33, 34, 35, 37, 39, 40, 41 , 42, 43, 44, 45, 46, 48, 49, 50, 5 1 , 52, 53, 54, 55.

Parapagurus haigae de St. Laurent, 1972: off Santa Rosa Island, California, to Gulf of California, 55-923 m

(Wicksten 1987). D 2, 3; S 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43.

Parapagurus mertensii (Brandt, 1851): Kodiak Island, Alaska, to San Nicolas Island, California, 42-2012 m (Schmitt

1921). b 1,2, 3; S 10. 11. 12, 13, 14, 16, 17, 18,20,23,24,25,26.

Parapagurus pilosimanus benedicti de St. Laurent, 1972: Alaska to off Islas Juan Fernandez, 415-2200 m (Haig 1955,

Hart 1982). D 2, 3, 4; S 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15. 16, 17. 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28,

29, 30, 31, 32, 33, 34, 35. 36, 37, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51. 52, 53, 54, 55, 56, 57, 58, 59, 62, 63,

64,65,66,67,68,69,70,71,72.

Probeebei mirabilis Boone, 1926: Costa Rica to Peru, 1 145-3995 m (Garth and Haig 1971). D 3, 4; S 41. 42, 43, 44,

45,46,48,49,50.51.

Family Lithodidae

Glyptolithodes cristatipes (Faxon, 1893): Palos Verdes Peninsula, California, to Chile, 183-800 m (Wicksten 1982). D

2; S 26, 27, 28, 29, 33, 34, 35, 36, 37, 38, 39. 40, 41, 42, 43, 44, 45, 46, 48, 49, 51, 52, 53, 54, 55.

Lithodes aequispina Benedict, 1894: Bering Sea to Vancouver Island, 275-366 m (Birshtein and Zarenkov 1970, Hart

1982). D 2; S 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 16, 17, 18, 20.

Lithodes couesi Benedict, 1894: Japan and Alaska to San Diego, California, 384-1 125 m (Hart 1982). D 2, 3; S 1, 2, 3,

4,5.6,7,8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18,20,23.24,25.26.

Lithodes panamensis Faxon, 1893: off Panama to Peru, 760-850 m (Haig 1974). D 2; S43. 44, 45, 46, 49, 51, 52, 53.

Lithodes wiracocha Haig, 1974: off Peru, 620-800 m. D 2; S 46, 48. 49.

Lopholithodes diomedeae Faxon. 1893: off Panama to Peru. 830-935 m (Haig 1974). D 2; S 43. 44, 45, 46, 48, 49, 51.

Lopholithodes foraminatus (Stimpson, 1859): British Columbia to San Diego, California, 0-547 m (Hart 1982). D 1, 2,

3;S 16, 17, 18,20,23,24,25,26.

Neolithodes diomedeae (Benedict, 1894): off Chonos Archipelago and Chiloe Island. Chile. 1923-2459 m. D 3. 4; S

33. 34. 35, 36, 37, 39, 40, 41, 42, 43, 44, 45, 48, 499, 50, 51, 52, 53, 54, 55, 56, 58. 59.

Paralithodes californiensis (Benedict. 1894): Monterey Bay to San Diego. California, 148-306 m (Schmitt 1921,

Anderson and Cailliet 1974). D 1. 2; S 24. 25. 26.

Paralithodes rathbuni (Benedict, 1894): Cordell Bank to San Diego, California, 165-500 m (Schmitt 1921, Wicksten

1987). D 1,2;S24, 25, 26.

Paralomis aspera Faxon, 1893: off Panama to Peru, 560-1270 m (Haig 1974). D 2, 3; S 42, 43, 44, 45, 46.

Paralomis inca Haig, 1974: off Peru, 620-744 m. D 2; S 48, 49.

Paralomis longipes Faxon, 1893: 760-1410 m (Haig 1974). D 2. 3; S 41. 42, 43. 44, 45, 46,48, 49, 50, 51, 52.

Paralomis multispina (Benedict, 1894): Alaska to San Diego, California, 500-1665 m (Hart 1982). D 2,.3; S 1, 2, 3, 4,

5.6.7,8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18,20,23,24,25,26.

Paralomis papillata (Benedict. 1895): off Baja California. Mexico, to Peru. 712-744 m (Haig 1974). D 2; S 29, 33, 34,

315

35, 36. 37, 39, 40, 41, 42. 43, 44, 45, 46, 48.

Paralomis \r/777// (Benedict, 1SM4): Sea of Okhotsk to Cortez Bank, California, 1238-2379 m (Harl 1982). D 3, 4; S 1,

2,3,4,5,6,7, 8,9, 10. II, 12. 13. 14. 15. 16. 17. 18.20,23.24.25.26.

Family Chirostylidae

Chiwstyliis dcfcnsits (Benedict. 1902): off Galapagos Islands. 214 m (Haig 1968). D 2; S 67.

Chirostylus inilnccdwunlsi (Henderson. 1885): southern Chile to Magellanic region, 733 m (Haig 1968). D 2; S 63, 64.

Chirostylus perarmatus Haig, 1968: north of Anacapa Island, California, 229 m. D 2; S 26.

Chiwstyhis sp.: southwest of Vancouver Island to off Columbia River, 914-951 m (Hart 1982). D 3; S 18, 20.

Uroptychiis iiianukmis Benedict, 1902: off Galapagos Islands, 724 m. D 2; S 67.

Family Galatheidae

Galathea califomiensis Benedict, 1902: Monterey Bay, California, to Gulf of California, 104-3998 m (Schmitt 1921,

Wicksten 1987). D 1, 2, 3, 4; S 24, 25, 26, 27, 28, 29, 31, 32, 33.

Munida ciinipes Benedict, 1902: off Archipelago de los Chonos, Chile, 1924 m. D 3; S 59, 60.

Munida f^racilipes Faxon, 1893: Gulf of Panama, 280 m (Faxon 1895). D 2; S 43.

Munida hispida Benedict. 1902: Monterey Bay. California, to off Galapagos Islands, 165-500 m (Schmitt 1921,

Wicksten 1982). D 2; S 26, 27, 28, 29, 33, 34, 35, 36, 37, 39, 40, 41, 42, 43, 44, 45, 46, 67, 68, 69, 70.

Munida Imicropthalma A. Milne Edwards, 1880: off Cocos Island, 245 m (Faxon 1895). D 2; S 41.

Munida ohesa Faxon, 1893: Gulf of Panama, 385 m (Faxon 1895). D 2; S 42, 43.

Munida perkua Benedict, 1902: southern Gulf of California, 3292-1920 m (Luke 1977). D 3, 4; S 33.

Munida piopinqua Faxon, 1893: Gulf of Panama to Peru, 1290-1713 m (Garth and Haig 1971). D 3; S 43, 44, 45, 46.

48.49,51.

Munida quadrispina Benedict, 1902: Alaska to off Baja California, Mexico, 22-1463 m (Hart 1982, AHF unpubl.

data). D 1, 2, 3: S 13, 14, 16, 17, 18, 20, 23, 24, 25, 26, 27, 28.

Munida refulgens Faxon, 1893: near Islas Tres Marias, Mexico, to off Isla Malpelo, Colombia, 95-183 m. D 1; S 33,

34, 35, 36, 37, 39, 40, 41, 42, 43, 44.

Munidopsis aculeata Henderson. 1888: southern California to Chile, 2519-3285 m (Faxon 1895). D 4; S 26, 27, 28,

29, 33, 34, 35, 36, 37, 39, 40, 41, 42, 43, 44. 45, 46, 48, 49, 50, 51. 52, 53, 54, 55.

Munidopsis agassizi Faxon, 1893: Gulf of Panama, 385 m (Faxon 1895). D 2; S 43.

Munidopsis antoni (A. Milne Edwards, 1884): cosmopolitan, Baja California, Peru, off Islas Juan Fernandez,

2519-3676 m (Luke 1977). D 4; S 27, 28, 299, 33, 34, 35, 37, 39, 40, 41, 42, 43, 44, 45. 46, 48. 49, 50, 51. 52. 53. 54.

55,56,71,72.

Munidopsis aries (A. Milne Edwards, 1880): off Oregon, 2850 m (Ambler 1980). D 4; S 22.

Munidopsis aspera (Henderson, 1885): Santa Catalina Island, California, to Straits of Magellan, 104—2748 m (Haig

1955). D 1, 2, 3, 4; S 26, 27, 28, 29, 33, 34, 35, 36, 37, 39, 40, 41, 42, 43, 44, 45, 46, 48, 49, 50, 51, 52, 53, 54, 56, 58,

59, 60, 62, 63, 64, 65, 66.

Munidopsis hairdii (Smith, 1884): Oregon to Panama, cosmoplitan, 1920-3292 m (Ambler 1980). D 3, 4; S 22, 24, 25,

26, 27, 28, 29, 33, 34, 35, 37, 39, 40, 41, 42, 43.

Munidopsis heringana Benedict, 1902: Bering Sea to Oregon, 2800-3276 m (Ambler 1980). D 4; S 1,2, 3, 4, 5, 6, 7,

8,9, 10, 11, 12, 13, 15, 16, 17, 18.

Munidopsis carinipes Faxon, 1893: off Mariato Point, Panama, 1273 m (Faxon 1895). D 3; S 42.

Munidopsis cascadia Ambler, 1980: Cascadia Basin, off Oregon, 2743-2926 m. D 4; S 18, 22.

Munidopsis ciliata Wood-Mason, 1891: Oregon to Panama, 2030-2875 m (Ambler 1980). D 4; S 18, 22, 24, 25, 26,

27, 28, 29, 33, 34, 35, 37, 39, 40, 41, 42, 43.

Munidopsis crinita Faxon, 1893: Gulf of Panama. 839 m (Faxon 1895). D 2; S 43.

Munidopsis depressa Faxon. 1893: Santa Catalina Island. California, to off Islas Tres Marias, Mexico, 185-1255 m

(Haig 1955). D 1, 2, 3, 4; S 26, 27, 28, 29, 33.

Munidopsis diomedae (Faxon, 1893): San Clemente Island, California, to Chile, 768-3790 m (Haig and Wicksten

1975, Luke 1977). D 2, 3, 4; S 26, 27, 28, 29, 33, 34, 35, 37, 39, 40, 41, 42, 43, 44, 45, 46, 48, 49. .50. 51. 52. 53.

Munidopsis hamata Faxon, 1893: off Baja California and Gulf of Panama, 936-1337 m (Faxon 1895, Luke 1977). D 3;

S 29, 43.

Munidopsis hcndeisoniana Faxon, 1893: Gulf of Panama, 1869 m (Faxon 1895). D 3; S 43.

Munidopsis Instrix Faxon, 1893: Anacapa Island, California, to Peru, 552-1243 m (Garth and Haig 1971). D 2, 3; S

26, 27, 28, 29, 33, 34, 35, 36, 37, 39, 40, 41, 42, 43, 44, 45, 46, 48, 49, 50, 5 1 .

Munidopsis incrmis Faxon, 1893: off Mariato Point, Panama, 590 m (Faxon 1895). D 2; S 42.

Munidopsis latiwstris (Henderson, 1895): Cascadia Plain, off Oregon, to off Panama, 280-3243 m (Ambler 1980). D

2, 3, 4; S 22, 24, 25, 26, 27, 28, 29, 33, 34, 35, 37, 39, 40, 41, 42, 44.

Munidopsis margarita Faxon, 1893: off Galapagos Islands. 705 m (Faxon 1895). D 2; S 69.

Munidopsis opalescens Benedict. 1902: southern Chile, 638-823 m (Haig 1955). D 2; S 63, 64.

Munidopsis ornata Faxon, 1893: off Galapagos Islands, 705 m (Faxon 1895). D 2; S 68.

Munidopsis quadrata Faxon. 1893: Queen Charlotte Islands, Canada, to off Islas Tres Marias, Mexico, 245-1574 m

(Hart 1982). D 2, 3; S 16, 17, 18, 20, 23, 24, 25, 26, 27, 28, 29, 33.

Munidopsis rostrata (A. Milne Edwards, 1880): off Acapulco, Mexico, to off Galapagos Islands, 2153-2492 m (Faxon

1895). D 4: S 67, 68, 69. 70.

Munidopsis scahra Faxon, 1893: off Oregon to Peru, 567-1243 m (Pereyra and Alton 1972, Haig and Wicksten 1975).

D 2, 3; S 22, 23, 24, 25, 26, 27, 28, 29, 33, 34, 35, 37, 39, 40, 4 1 . 42, 43, 44, 45, 46, 48, 49, 5 1 .

316

Mimidopsis sericea Faxon, 1893: Gulf of Panama, 936 m (Faxon 1 895). D 3; S 43.

Munidopsis subsquamosa Henderson, 1885: off Oregon to off Chile, 1097-3000 m (Luke 1977, Ambler 1980). D 3, 4;

S 22, 24, 25, 26, 27, 28, 29, 33, 34, 35, 37, 39, 40, 41. 42, 43, 44, 45, 46, 48, 49, 50, 51, 52, 53.

Mimidopsis tanneri Faxon, 1893: Gulf of Panama, 156-415 m (Faxon 1895). D 1, 2; S 43.

Mimidopsis trifida Henderson, 1885: southern Chile, 638-823 m (Haig 1955). D 2; S 63, 64.

Munidopsis tuftsi Ambler, 1980: Tufts Abyssal Plain, northern Pacific, 3500-3858 m. D 4; S 18, 19, 21, 22.

Munidopsis veirilli Benedict, 1902: off Oregon to off Cedros Island, Baja California, Mexico, 1253-1986 m (Schmitt

1921, McCauley 1972). D 3; S 18, 20, 22, 23, 24, 25, 26, 27.

Munidopsis verrucosus Khodkina. 1973: Oregon to off Antofagasta, Chile, 3932^880 m (Ambler 1980). D 4; S 18,

19, 21, 22, 24, 25, 26, 27, 28. 29, 33, 34, 35, 37. 39, 40, 41, 42. 44, 46, 48, 50, 51, 52. 53. 54.

Munidopsis vicina Faxon, 1893: Gulf of Panama and off Cocos Island, 3063-3885 m (Faxon 1895). D 4; S 42.
Munidopsis villosa Faxon, 1893: Gulf of Panama and off Arica, Chile, 936-1773 m (Faxon 1895, Luke 1977). D 3; S
44, 53.
Munidopsis yaquinensis Ambler, 1980: off Oregon, 2763-2377 m. D 4; S 18, 19, 21, 22.

Infraorder Brachyura

Family Homolodromiidae

Homolodromia robertsi Garth, 1973: off Peru, 800 m. D 2; S 46, 48.

Family Calappidae

Acanthocarpus delsolari Garth, 1973: off Peru, 250 m. D 1; S 46.

Family Dorippidae

Ethusa ciliatifrons Faxon, 1893: Gulf of Panama. 280-475 m (Faxon 1895). D 1, 2; S 43.

Ethusa lata Rathbun. 1893: off Cocos Island, 183 m (Faxon 1895). D 1; S 41.

Ethusina fa.xonii Rathbun, 1933: western Mexico to Peru, 2999^081 m (Garth and Haig 1971). D 3; S 36. 37. 39. 40.

41,42,44.46.48.

Ethusina robusta (Miers. 1886): Bay of Panama to Galapagos Islands and Ecuador. 1618-3334 m (Garth and Haig

1971). D 3, 4; S 42, 44, 46, 48, 65, 67, 69, 70.

Ethusina smithiana Faxon, 1893: off Cocos and Malpelo Islands, 245-1647 m (Faxon 1895). D 2, 3; S 41, 42, 44.

Family Cymonomidae

Cymonomus menziesi Garth, 1971: Peru. 1005-1 124 m (Garth and Haig 1971). D 3; S 48.

Family Majidae

Chionoecetes angulatus angulatus Rathbun. 1924: Bering Sea to Oregon. 90-3330 m (Garth 1958, Birshtein and

Zarenkov 1970, Hart 1982). D 1,2, 3,4; S 1.2,3.4.5.6,7.8.9, 10, 11, 12, 13, 14, 16. 17, 18,20.

Chionoecetes bairdi Rathbun. 1924: Bering Sea to Oregon, 6-475 m (Garth 1958, Hart 1982). D 1, 2; S 1. 2, 3, 4, 5, 6,

7,8.9, 10, 11, 12, 13, 14. 16, 17. 18,20.

Chionoecetes tanneri Rathbun, 1893: E of Kamchatka to Cortez Bank, California, 29-1944 m (Garth 1958, Hart

1982). D 1,2, 3,4; S 1,2,3.4.5.6,7,8,9. 10. 11. 12. 13, 14, 15, 16, 17, 18,20,23,24,25,26.

Chorilia longipes Dana, 1851: Alaska to Cortez Bank, California, 22-1 190 m (Garth 1958, Hart 1982). D 1, 2, 3; S 1.

2, 3, 4. 5, 6. 7, 8, 9. 10. 1 1. 12. 13. 14. 16. 17, 18. 20, 23. 24. 25, 26.

Chorilia longipes turgida Rathbun, 1924: Oregon to off San Diego, California, 66-1169 m (Garth 1958). D 1. 2. 3; S

20, 23, 24, 25, 26.

Hyas lyratus Dana, 1851: Bering Sea to Puget Sound, 9-640 m (Garth 1958, Hart 1982). D 1, 2; S 1, 2, 3. 4. 5. 6, 7. 8,

9, 10, 11. 12. 13. 14. 16. 17. 18.20.

Lophorochinia parabranchia Garth. 1969: northern Peru to off Valparaiso. Chile, 128-509 m (Garth and Haig 1971).

D1,2;S51,52, 53, 54.

Oregonia hifurca Rathbun, 1902: Bering Sea to off Columbia River, Oregon, 494-1463 m (Garth 1958. Hart 1982). D

2. 3;S 1,2.3.4.5.6,7,8.9. 10. 11. 12. 13. 14. 15. 16. 17.20.

Rochinia cornuta (Rathbun. 1898): off Galapagos Islands, 718-1160 m (Garth 1958). D 2, 3; S 69.

Rochinia occidentalis (Faxon, 1893): off Galapagos Islands. 705 m (Garth 1958). D 2; S 69.

Family Atelecyclidae

Trachycarcinus corallinus Faxon. 1893: off Acapulco. Mexico, to Peru. 834-1280 m (Garth and Haig 1971). D 2. 3; S

35, 36, 37, 39, 40, 41. 42, 43, 44, 45, 46, 48.

Trachycarcinus hvstricosus Garth, 1971: Peru to Chile, 907-935 m (Garth and Haig 1971). D 1, 2, 3; S 46, 48, 49, 50,

51,52,53,54,55,56.

Family Palicidae

Cympolia tuberculata Faxon, 1893: Bay of Panama, 333 m (Rathbun 1918). D 2; S 42.

Family Goneplacidae

Trizocarcinus peruvianus Garth. 1973: off Paita. Peru, 144 m (Garth 1973). D 1, S 48.

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