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Full text of "Postilla"

A ' 1^ 



Mue. COMF. ZOOt 
LIIRARY 

iitrii 1964 

HARVARD 

yNivERsi-n; 



Peabody Museum of Natural History 
Yaee University 




Number 83 July 15, 1964 New Haven Conn. 



PSEUDODOXrONXIS AND OTHER LARGE MARINE 
BIRDS FROM THE MIOCENE OF SOUTH CAROLINA 

James A. Hopson 

Peabody Museum oi- Xati'ral History, Yai.e Uxiversity 
INTRODUCTION 

While engaged in the reorganization' of the vertebrate fossil 
collections at the Peabody Museum of Natural History, Yale 
University, the writer discovered the incomplete lower jaw ot 
a large bird from the Miocene phosphate deposits near Charles- 
ton, South Carolina. The specimen is clearly referable to the 
family Pseudodontornithidae, an extinct group of very large 
oceanic birds characterized by the presence of vertical bony 
tooth-like processes, or, as the family name implies, pseudo- 
teeth, on the margins of their jaws. This is the first record 
of a pseudotoothed bird from eastern North America. 

The only previously described bird from these deposits is 
Palaeochenoides mioceanus (Schufeldt, 1916) represented by 
a partial femur. A further search made in the collection of 
ph()s])hate beds fossils at Yale for additional avian material 
vielded negative results. Professor Bryan Patterson called my 

'Research reorganization of this eoilcction was sui)i)orte(l by National 
Science P'oundation grant GB-247 (19()2). 



2 PostUla Vale Peal)(;d_v Musuuin Xo. 83 

attention to a lai-fjc undescribed tarsonietatarsus from the 
phosphate beds which is in the Museum of Comparative Zool- 
ogy at Harvard. Dr. Pierce Brodkorb hiter informed me of a 
second undescribed tarsometatarsus from the Cooper River 
near Charleston; this specimen is in the collections of the 
United States National Museum. 

These two specimens and the recently discovered dentary 
are described in this pa]jer. The })ossibility that the two tar- 
sometatarsi and the femur described as Pidacocheno'ules might 
belong to members of the family Pseudodontornithidae is 
assessed. 

ACKXOWLEDGMEXTS 

Thanks are due Professor Bryan Patterson for bringing to 
my attention the existence of the tarsometatarsus in the Mu- 
seum of Com})arative Zoology and to Dr. Ernst Mayr for 
permission to borrow and describe it. 

Dr. Alexander Wetmore of the United States National 
Museum very generously allowed me to borrow and describe 
the tarsometatarsus from that institution. Dr. Wetmore's kind- 
ness in turning over to me his notes on this specimen, to 
which he had already devoted considerable study, is also grate- 
fully acknowledged. 

Dr. Hildegarde Howard sup})lied me with a mold of the 
foot of Osteodontornis orr'i. Dr. Howard and Dr. Pierce Brod- 
korb provided information on fossil and recent birds not avail- 
able in the literature and offered useful criticism of the manu- 
script. Dr. John H. Ostrom and Dr. Elwyn L. Simons also 
eave welcome advice and criticism. 



.\BHREVIATIOXS 

MCZ— -Museum of Comparative Zoology, Harvard Cniversity, 
Caml)ridge. 

USNM — United States National Museum, Washington. 

YPM — Peabody Museum of Natural History, Vale I'niversity, 
New Haven. 



i>tr 6 1364 

July 15, 1964 Miocene Birds from SoutliH^MAiD 3 

UNIVERSITY 

PKEviors kxowlp:i)ge of pseuuotoothed birds 

The only previously described pseudotoothed bird of definite 
North American provenance is Osteodontorms orri from the 
Upper Miocene of California (Howard, 1957). The type speci- 
men of this species consists of a crushed skull and lower jaws, 
relatively complete though crushed wing and leg bones, several 
caudal vertebrae, and the impressions of a number of wing 
feathers. It is by far the most complete pseudotoothed bird 
specimen known, but its damaged state makes many areas of its 
anatomy extremely difficult to interpret. Howard estimates the 
wingspread of the living bird to have been over 16 feet. A 
second specimen of 0. orri from California, consisting of frag- 
mentary upper and lower jaws and a partial, though uncrushed, 
atlas, was later described by Howard and White (1962). 

A closely related form, Pseudodontornis longirostris, had 
earlier been described by Spulski (1910) and redescribed by 
Lambrecht (1930). This form is known from a skull and riglit 
lower jaw which had been purchased in 190.5 by the Zoological 
Institute of Konigsberg, Germany, from a Brazilian sailor. 
Xo locality or age data were ever obtained for this specimen ; 
it is possibly from Brazil, but this is far from certain. In size, 
the type skull is only slightly larger than that of Osteodon- 
tornis orri. 

A third, more distantly related, "toothed" bird, about half 
the size of the above forms, has long been known from the 
Eocene London Clay. This is Odontopteryx toliapica, described 
by Sir Richard Owen in 1873 from an incomplete skull and jaws. 
It is currently placed in the monotypic family Odontopterygidae. 
The most obvious distinguishing feature between Odontopteryx 
and the pseudodontorns is that the "teeth" in the former slant 
forward, while those in the latter stand perpendicular to the 
margin of the jaw. The three genera are usually grouped as the 
suborder Odontopterygia of the Order Pelecaniformes (Brod- 
korb, 1968), though Howard (19.57) believes they merit sep- 
arate ordinal rank. 

AGE OF THE PHOSPHATE BEDS BIRDS 

In the nineteenth century, abundant vertebrate fossils were 
dredged from the beds of coastal rivers in the vicinity of Charles- 



4 PostiUa Yale l^eabody Museum No. 83 

ton, South Carolina, during' the course of commercial phos- 
phate digging. The phos])hate de})osits have long been recog- 
nized to contain a mixture of fossils ranging from Miocene to 
Pleistocene ages. Tiie remains of lantl mannnals are almost 
wholly from the Pleistocene, though a few are clearly of Pliocene 
and even Miocene ages (Allen, 1926; Simpson, 1932). The 
marine fossils — cetaceans, sirenians, bony fishes, and sharks — 
seem to be mainly Miocene in aspect, though mixing here too 
cannot be ruled out. One sirenian, HaVdherinm ciUeni, is referred 
to a genus which is not known above the Lower Miocene in 
Europe (Simpson, 1932). 

That part of the phosphate deposits which is of Miocene age 
is now considered to be a northern extension of the Hawthorne 
Formation of Florida (Wilmarth, 1938). Brodkorb (1963a) 
summarizes the evidence for considering the Hawthorne For- 
mation to be of late Early Miocene age. The phosphate beds 
marine fauna is not known to cast doubt on this age determina- 
tion. The birds described here are almost certain!}" part of 
this fauna and, therefore, may be considered at least tentatively 
to be of late Early Miocene age. 

descriptiox and discussiox of material 

Family PSEUDODONTORNITHIDAE Lambrecht 

Pseudodoiitoruis long'irostris (Spulski) 
Figure lA 

Odontaptcrii.r loiu/irostiis S])ulski. 15)10, p. 507. 
l^scudodoiiidni'is loiu/iro.st ris, I.ainhreclit. 1J).'30. p. 1. 

This specimen (VPM 4(517) consists of a j)nrHon of the 
anterior half of a right dentai'v bearing three prominent 
teeth" and the renuiants of several smaller ones. It is from 
the large C\ A. Scanlon collection cf j)h()spjiate beds fossils 
which was ac(|uire(l by Yale l*eal)ody Museum in 1913. No 
locality data on the Scanlon collection exists in Peabody 

- Altlioiifjli tlicsc tnotli-llkc jiroj'cssfs aro not true teeth, tlie (luotatioii marks 
will lie oinitteil in Hie rest of tlu' (iiscussioii. 



July 1-5, 1964< Miocene Birds from Soutli Carolina 



5 



Museum records other than tlic very general: "Phosphate dig- 
gings about Charleston, S.C." However, Shufeldt (1916, p. 
3-14"), with reference to the type locality of Palaeochenoides, 
quotes a letter from Dr. Earle Sloan of Charleston which states, 
"The Scanlon collection was in the main taken from the rock 
dredged from the bed of the Stono River near its source." 





rijrurt' 1. Lateral views of right dentaries of Fxeudvdoiiturnin lotiffirostris. 
A. YPM 4617. B. Type, from Lambrecht, 1930. Both X 1. 



Howard (1957) cites as distinguishing features between the 
denhiries of the two larger genera of pseudotoothed birds the 
following characteristics: in Osteodoiitorms there are "two or 
three smaller 'teeth' between each large one on [the | lower 
jaw"; in Fscndodontornis there is "only one smaller 'tooth' 
between large ones on [the] lower jaw." In number and 
arrangement of teeth, the Hawthorne dentary c()rres})()nds 
more closely to Howard's ciiaracteri/ation of O. orri, but I 
believe the "dental" distinctions which she cites are not valid. 



6 Postilla Yale Peabody Museum No. 83 

Neither Spulsky (1910) nor Lambrecht (1930) made any 
reference to more than a single tooth between the large teeth 
in the type of P. longirostris, but I.ambrecht's photograph of 
the type dentary (PI. II, Fig. 2), which is redrawn in Fig. IB, 
shows a very low rounded protuberance midway between the first 
and second teeth and another between the third and fourth teeth. 
These protuberances are identical in appearance to the broken 
bases of similarly placed small teeth in the Hawthorne speci- 
men and presumably represent the remnants of formerly com- 
plete tooth-like projections. It seems likely that in a well- 
preserved jaw of Pseudodontornis the luunber and distribution 
of teeth would probably be very similar to that which Howard 
(1957) believes to be diagnostic of Osieodontornis. Therefore, 
in identifying the Hawthorne jaw I have utilized as diagnostic 
characters only the gross size of the specimen and the sizes of 
and distances between the preserved teeth. 

The anterior tip of the dentary is unfortunately not pre- 
served in either described specimen of 0. orri. Howard's meas- 
urements on the more posterior portions of the type mandibles 
show that: (1) large teeth are spaced 30-4iO mm apart; (2) 
large teeth range from 7.5 to 13 mm in height and 7.5 to 10 nun 
in basal length; and (3) the largest tooth is the third from 
the back (Howard, 1957, }). 12). The measurements of the 
Hawthorne jaw are given in Table 1. The two large teeth arc 
comparable in size to the largest tooth in 0. orri but are about 
5 mm higher and longer than the smallest tooth of the large 
size class. The distance between the two large teeth in the Haw- 
thorne jaw is almost 12 mm greater than the maxinuun distance 
in O. orri. 

Examinatir.n of Lambrecht's figure (1930, PI. II, Fig. 2) as 
redrawn in Fig. IB, indicates that the teeth of P. longirostris 
are, on the average, larger than those of (). orri. Also, the dis- 
tance between the teeth is gieatei- (by abuut 10 niin), though 
Howard (1957, ]). 12) states that the distance is about the 
same in the two species. A com})aris(;n of the Hawtiiorne jaw 
(P'ig. lA) and the coinparable region of the type dentary of 
/*. longirosiiis (Fig. Hi) indic.ites that tiiey are remarkably 
siinilai', especiallv in the distances between the ])reserved teeth. 
On this basis, Vl'M 4(517 is referred to this genus and s})ecies. 



July 15, IdGi Miocene Birds from South Carolina 



Table 1 
measurements os ypm 4617 in 3im 



Preserved Length 






68.1 


Maximum Depth 






20.4 


Width: 








Below Anterior ' 


"Tooth" 




9.0 


Below Posterior 


"Tooth" 




10.1 


Distance Between Two Largest 


"Teeth" 


51.9 


Distance Between Middle and Posterior "Teeth" 


24.5 


Anterior "Tooth": 








Height 






12.5 


Length at Base 






12.0 


Posterior "Tooth": 








Height 






12.2 


Length at Base 






12.8 


Middle "Tooth": 








Height 






5.4 


Length at Base 






6.8 



The discovery of Pseudodontornis longirostris in the Haw- 
thorne Formation of South Carolina establishes a Miocene age 
for this species and strengthens the supposition that the type 
specimen came from the Western Hemisphere. It does not, how- 
ever, demonstrate that the type was necessarily from North 
America, for a large oceanic bird of tliis sort was probably 
widely distributed. 

The fragmentary Hawthorne specimen is undoubtedly from 
near the anterior end of the jaw for it is dorsoventrally very 
shallow. Low on its lateral surface is a shallow longitudinal 
sulcus which is characteristic of the three known s})ecies of 
"toothed" birds. In cross section the outer surface of the ja\\ 
is straight and vertical, the inner surface smoothly convex. 
The three largest teetli have straight sides which are continuous 
with the sides of the jaw. They are inclined somewhat laterally 
so that their tips are directly above the outer margin of the 
jaw. The bases of tlie smaller teeth are restricted to the lateral 
half of the jaw margin. 

The ])reserved "dentition" consists of two large teeth 51.9 
mm apart and a single smaller tooth about midway between 



8 Postilla Yale Peabody Museum No. 83 

them (actually 24'. 5 mm from the posterior large tooth). Half- 
way between the middle tooth and each of the larger teeth are 
the broken bases of two even smaller teeth. Finally, in each of 
the spaces between these five teeth are shiny oval patches, flush 
with the jaw margin, which are the bases of four very tiny 
teeth of which no remnant is preserved. These teeth correspond 
to the "narrow spinelike ridges" in the lower jaw of the second 
specimen of Osteodontornis (Howard and White, 1902). 

The outer surfaces of the teeth bear longitudinal striations 
and small foramina. The foramina undoubtedly represent Volk- 
man canals, seen in the thin sections of a tooth of 0. orri 
(Howard, 1957, p. 10, fig. 5). 

A transverse break at midheight across the anterior large 
tooth shows that this structure is hollow, with walls about 1.0 
mm in thickness. Several thin bony trabeculae extend into the 
central cavity from the walls and the break cuts across one 
trabecula in the center of the cavity. This conflicts with the 
findings of Lambrecht (1930) who states that X rays showed 
that the teeth in the type of P. longirosiris are not hollow but 
are composed of sj^ongy bone. The teeth of 0. orri are hollow 
and much like the one describi.d here (Howard, 19.57). and in 
Odontopterifx certain teeth are described as being hollow 
(Owen, 1873). Inasmuch as I^ambrecht did not examine sec- 
tions across the teeth of Psciulodoiitorn'is, his statement that 
the teeth in this form are not hollow retjuires further confirma- 
tion before it can be accepted. 

Family CYPHORNT^rHH:)AK? Wktmork 

'^P<d(U()(hi ii'j'idvs inioccd/i/is Shufcldt 
Figure 2 

This well-})reserve(l distal ) oitioii ( f a left tarsometatarsus 
(MCZ 2514) is from the W'illiani Priiigle Frost collectiim of 
j;hosphate beds fossils which is now in the .Museuiu of Comj^ara- 
tive Zoology at Harvard. A numbtr (;f fossil mauHHals from 
the Frost collection wti-e described 1)\ Allen (192(5). He states 
that this collection is from the Ashlt y River. The marine forms, 
including the present spi'cinien. are almost certainly from tlie 
Hawthorne P'oi-niation. 



July 15, 1964; Miocene Birds from Soutli Carolina 9 

With the exception of the above-described specimen of Pseu- 
dodontornis, the only bii'd previously known from the Haw- 
thorne Formation of South Carolina is Polaeocheuoides viio- 
ceainis, described by Schufeldt (1916) from the distal end of 
a right femur. Shufeldt believed the affinities of this species to 
be with the anseriforms, but Wetmore (1917) subsequently 
pointed out that the type femur is distinctly jjelccaniform in 
morphology. This element indicates that Palaeochenoides was 
a very large bird, being, according to Wetmore, somewhat 
larger than the living Pelecanus onocrofalus or P. erythrorhyn- 
chus. Wetmore (1928) later allied Palaeochenoides Avith Cy- 
phornis, a gigantic Lower Miocene bird, known only from the 
proximal end of a tarsometatarsus from Vancouver Island, in 
the family Cyphornithidae. 

The dimensions of the MCZ tarsometatarsus are commensu- 
rate with the expected dimensions of this bone in a bird with a 
femur the size of the type specimen of Palaeochenoides mio- 
ceanus and with limb ])rop()rtions approximating those of 
Pelecanus or Diomedea. Both. fossil limb bones have very thin- 
walled shafts indicating that they were highly pneumatic. With 
the exception of the pseudodontorns, with which they cannot 
be compared in any detail because of the lack of comparable 
well-preserved parts, no other volant bird of this size is known 
from the Miocene of North America (Cyphornis is much 
larger). Therefore, it is extremely likely that the MCZ speci- 
men is referable to Palaeochenoides mioceanus. Were it to show 
distinctly pelecaniform features, this assignment would be a 
virtual certainty ; as it docs not, I have qualified its reference 
to this species with a question mark. Further discussion of its 
relationships is left until the end of this paper. 

The shaft of the tarsometatarsus is broadly oval in cross 
section, and is almost completely smooth except for a promi- 
nent, though damaged, longitudinal ridge on the anterior sur- 
face. This ridge terminates ventrally 17.5 mm above the inner 
edge of the middle trochlea. At its lower border, the shaft is 
22.3 nnn wide. The possible function of this structure is dis- 
cussed below in connection with the second tarsometatarsus. 

In anterior view the shaft is r.ioderately expanded distally; 
in profile its sides are only slightly concave above the trochleae. 



10 



Postilla Vale Peabodv Museum 



No. 83 




Figure 2. ?P<il<(( nrliinoiilcs luiorduwix MC"/ 2514, left tarsoiiictatarsus. 
A. Acrotarsial view. B. IMantar view. (". M((lial view. D. Lateral 
view. E. Distal view. X 1. 



July 15, 1964 Miocene Birds from Soulh Carolina 11 

The width through the trochleae is 3-t.7 mm. The middle 
trochlea is the longest of the three. It is relatively broad ; the 
rims of the articular facets are relatively low with a broad 
shallow sulcus between them. The outer trochlea is 4 mm shorter 
than the middle one. Its inner rim extends well below its outer. 
Viewed laterally, its plantar wing extends slightly be\'ond, and 
its acrotarsial edge slightly below, the corresponding edges of 
the middle trochlea. The inner trochlea is elevated above the 
others and is thrust relatively strongly backward and slightly 
inward. The inner intertrochlear notch is about 2 mm deeper 
than the outer. In side view the acrotarsial edges of the middle 
and outer trochleae are raised only slightly above the level of 
the shaft. 

Posteriorly, no articular facet for digit I is visible; there- 
fore, this toe was absent or greatly reduced. The plantar sur- 
face of the shaft is slightly concave between the bases of the 
trochleae. Some 9 mm above the center of the middle trochlea, 
and -i mm dorsomedial to the distal foramen, is a relatively 
large subtriangular pit, about i mm in maximum diameter, 
which passes obliquely dorsally into the shaft. It does not seem 
to be a pneumatic foramen for no comparable foramen was 
seen in any of those birds with pneumatic tarsometatarsi. The 
closest approximation to such a structure were one or more 
much smaller foramina in the same location seen in numerous 
members of a variety of orders. These foramina presumably 
mark the attachment areas of stout ligaments binding sesamoid 
bones in the living species, and perhaps the foramen in the fossil 
had a similar function. 

Immediately below this foramen is a low ridge which passes 
ventromedially on to the lateral surface of the inner trochlea. 
This ridge forms the upjier boundary of a pitted depression on 
the })lantar surface of the intertrochlear space and the postero- 
medial surface of the base of the middle troclilea. A roughened 
scar on the outer half of the latter, which terminates distally at 
a pair of well-developed pits just above the articular surface, 
bounds the de])ression laterally. I'his rather })r()ininent depres- 
sion ])robablv held a large sesamoid whicli was anchored in 
place by strong ligaments. A similar de})ressi()n is described by 
Brodkorb (19(i8c) in the Cretaceous gaviiform Lonchodytes. 



12 Post ilia Yale Peabody Museum No. 83 

The distal foramen is low, the ventral margin of its acrotar- 
sial opening being -i mm above the articular surface of the 
middle trochlea. It is oval, of moderately large size, and ori- 
ented at a distinct angle to the axis of the shaft. Its plantar 
opening is between the bases of the middle and outer trochleae. 
The small foramen for extensor brevis digiti quarti passes from 
just inside the anteroventral end of the distal foramen to open 
distally between the middle and outer trochleae. A short faint 
groove for the extensor tendon passes upward from the outer 
half of the distal foramen for about 4". 5 mm and merges into 
the surface of the shaft. 

By far the greatest similarity of this specimen is to the pro- 
cellariiforms. However, as Palaeochcnoides was believed by 
Shufeldt (1916) to be allied to the anseriforms and by Wet- 
more (1917) to the pelecaniforms, it is also compared with 
members of these orders. 

The rather broad, somewhat anteroposteriorly compressed, 
and smoothly rounded shaft is similar to that of Diomedea, and 
unlike either the similarly shaped but strongly ridged and 
grooved shaft of Pelccanus or the smooth but more slender and 
rounded shafts of the anseriforms. It is quite distinct from the 
extremely flattened shaft of Sida. The relative lengths of the 
trochleae arc most nearly duplicated in the smaller procel- 
lariiforms, especially Fnlmarus. In Diomedea the inner trochlea 
is nearly as long as the outer, while in the ducks it is generally 
quite short and very high on the shaft. In the pelecaniforms the 
inner trochlea is longer than the outer, and may, as in Sula, 
be the longest of the three. The alignment of the outer and 
middle trochleae in a transverse plane is seen only in the smaller 
procellariiforms ; in Diomedea and in the other orders examined 
the outer trochlea has a moderate thrust toward the i)lantar 
surface. 

In most features of the individual trochleae the fossil is very 
different from the pelecaniforms and most resembles the procel- 
lariiforms. The middle trochlea is l)roader than in Diomedea, 
and nuich bi'oader than in the othei' members of the order, bui 
tlir low rims of the articular facet separated by a broad groove 
are virtually identical to these features in the })rocellariif()rms. 
Ill the pelecaniforms this articular facet is ([uite different. 



July 15, 1964 Miocene Birds frcin South Carolina 13 

having high swollen rims and a deep median groove. A distinctly 
grooved inner trochlea is also like the procellariiforms, and 
unlike the pelocaniforms in which the articular surface is 
rounded or very feebly grooved. 

The absence of a facet for the first digit is like Diomedea, 
and unlike the pelecaniforms in which the facet is generally 
strongly developed. The strong ridge on the anterior face of 
the shaft is not found in any living form examined, though, as 
Dr. Alexander Wetmore (in litt.) has pointed out, a similar 
structure is faintly indicated in Diomedea. 

The distal foramen is less like that of either the ])rocel- 
lariiforms or the pelecaniforms than it is like that of the 
anseriforms, being very low, <)bli({ue, and opening posteriorly 
between the outer and middle trochleae. In general, it is lower 
in the pelecaniforms than in the procellariiforms, but it is more 
obliquely oriented in the latter. It differs from that of anseri- 
forms in being flush with the anterior surface of the shaft, as 
it is in Diomedea, rather than being depressed in a shallow 
sulcus. 

To summarize these facts, the MCZ tarsometatarsus is 
matched most closely in geiieral shape and surface features by 
the comparable element in Diomedea, though in relative propor- 
tions of the trochleae it is almost identical to Fidmarns. It 
shows no distinctly ])elecaniform, as opposed to procellariiform, 
features except an ap})arcntly strong })neumaticity. The only 
feature in which it most nearly resembles the anseriforms is the 
low. oblique distal foramen. 

In addition, the s})ecimen luis several characters either com- 
pletely^ lacking or only feebly developed in any of the above 
orders. These are: (1) the strong ridge on the anterior face of 
the shaft; (2) the prominent foramen on the plantar surface; 
and (3) the pitted depression between the plantar faces of the 
middle and inner trochleae. All of these features, apparently 
related as they are to tendons and sesamoids of the foot, sug- 
gest that the living bird had ])owerfully (Icvelojji'd toes. 

The possible relationshi]) of PalaeoeJieiioides to the pseu- 
dodontorns will be discussed in a final section after the descrip- 
tion of the second tarsometatai-sus fi-om the phosj)hate beds. 



14 Posiilla Yale Peabody Museum No. 83 

Family CYPHORXITHIDAE? 

Tympanonesiotes wetmorei^* new genus and species 

Figure 3 

Type: Distal portion of right tarsometatarsus, USNM 
16809. 

Horizon and Locality: Hawthorne Formation. From the 
Cooper River, near Drum Ishmd, Charleston, South Carolina. 

Diagnosis: Tentatively referred to the family Cyphorni- 
thidae on the basis of its similarity to the ?Palaeochenoides 
mioceanus tarsometatarsus (MCZ 2514), which it resembles in: 
its relatively broad flat shaft expanding gradually into bases 
of trochleae; relative proportions of its trochleae (as pre- 
served) ; its low distal foramen opening posteriorly between 
bases of trochleae III and IV ; short ridge on anterior surface 
of its shaft ; pronounced hollow on plantar surface between 
trochleae II and III. 

It is distinguished from Palaeochenoides? in: being about one 
fourth smaller in size; having distal foramen lower and con- 
tained in deep sulcus ; having anterior surface of trochleae III 
and IV raised more abruptly and to a greater height above 
level of shaft. It is distinguished from Cyphornis by its much 
smaller size, from Osfeodonforuis and Pseudodontornis, less 
certainl}', by its smaller size. 

The specimen consists of the anterior face of the distal end 
of the tarsometatarsus with the basal sections of the three 
trochleae. The posterior surface with the exception of the base 
of the middle trochlea is missing. 

The very thin wall of the shaft indicates that this element 
was pneumatic. The lower end of the shaft is relatively flat with 
the lateral portions gently rounded toward the back. Inside 
the median line of the shaft, about 15 nun above the upper 

■''From Greek tympauon ((Iruiii) and iicniotcs (t\-miniiu'. islander). 
' Named in honor of Dr. Alexander Wetmore. 



July 15, 196-1 Miocene Birds from South Carolina 



15 





Figure 3. T ympanonesiotcs xcetmorei gen. et sj). nov., USXM 16809, right 
tarsometatarsus. A. Acrotarsial view. B. Medial view. X 1. 



edge of the middle trochlea, are a pair of short ridges which 
form a narrow sulcus between them. The more medial is a 
heavy ridge some 8 mm long which corresponds to the similar 
raised area on the shaft of the Palaeochenoides? tarsometa- 
tarsus. The outer raised line is very faint in T ympanonesiotes 
and is not evident at all in the larger specimen. The sulcus, 
according to Dr. Wetmore (in lift.), "evidently guided a ten- 
don that controlled the inner toe. The indication, therefore, 
is that the rather elevated second toe was capable of active 
movement." The width of the shaft at the base of the heavier 
ridge is 16.1 mm. 

The outer two trochleae lie in the plane of the shaft. The 
inner is inflected slightly posteriorly, and is elevated above the 
level of the other two, its upper margin being on a line with the 
upper margin of the distal foramen. Details of the trochleae, 
insofar as they are prcsei'A'ed, are nearly identical to these 
parts in the MCZ specimen. In T yvipanonesiotes the anterior 
surface of the middle and outer trochleae are raised more 
sharply above the level of the shaft. The preserved width 
through the trochleae is 2-}<.5 nnn. 

The distal foramen is contained in a shallow sulcus with a 
short groove presumal)ly for extensor brevis digiti quarti, 
extending upward for 5 nnn to merge with the surface of the 



16 PostiUa Yale Peabody Museum Xo. 83 

shaft. Below the distal foramen the sulcus deepens, extending 
between the middle and outer trochleae. Possibly the extensor 
tendon lay in this sulcus rather than having been enclosed in a 
distinct foramen, the presence or absence of which cannot be 
tletermined in this specimen. 

Enough of the plantar surface is preserved to show that the 
distal foramen o})ens posteriorly between the bases of the mid- 
dle and outer trochleae. On the inner half of the middle troch- 
lea, continuing into the intertrochlear space, is a roughened 
depression like that seen in Falaeochenoides? . It is bounded 
above by a shelf passing upward and outward from the inner 
trochlea to tlie extreme base of tiie middle trochlea. 

In his notes Dr. Wetmore writes : "The only hint of possible 
relationship that has come from this latest study is a faint 
resemblance to what is found in the albatrosses." Mainly on 
the basis of the more com})lete MCZ specimen I had also arrived 
at the similar conclusion that the closest resemblance of these 
two tarsometatarsi is to Diomedca. The Palaeochenoides? bone, 
however, is in general less specialized and more albatross-like 
than is that of T ym panonesiot es . 

RELATIONSHIPS OF THE PHOSPHATE BEDS BIRDS 

With regard to the possible ordinal relationshi})s of the two 
tarsometatarsi described above, the following conclusions may 
be drawn: (1) they show definite resemblances to the Procel- 
lariiformes except for being highly pneumatic ; (2) they show no 
definite resemblances to the Pelecaniformes, with tiie excej)tion 
of an apparently high degree of pneumaticity ; (3) tiie larger 
specimen resembles in size and pneumatic character a femur, 
the ty})e of Palofocht'fwide.s tuioccdfiiis, from the sanu' forma- 
tion and a nearby locality, which, however, is distinctly pele- 
caniform and not procellariiform in mor})hologv ; and (4) 
Pseiulodontonih longirostris, a large bii-d comparable in size 
to P. miociunius and a mumber of a family which sliows a com- 
bination of })elecanif()rm and proccllaiMifoiMu features also oc- 
curs in the same beds as all of the above-mentioned specimens. It 
tlierefore seems j)robablc that Ptildcoclicno'idis and Psfudodon- 
toniis are synonymous (the former name having priority). 



July 15, 1964 Miocene Birds from South Carolina 17 

I'nfcrtunately, confirmation of this hypothesis by comparing 
the Hawthorne Hnib bones with the type skeleton of Osteodont- 
ornis cannot yield conchisive results for the leg bones of that 
specimen are so crushed that none but the grossest features can 
be made out with any certainty. However, Howai'd (1957) does 
note the probable absence of digit I in this specimen, a point of 
similarity to ?F. inioceanus and a distinct difference from the 
pelecaniform birds. Inasmuch as the evidence suggesting the 
identity of Palaeochenoides and Pseudodontornis is as yet by 
no means conclusive, I await further knowledge of well-pre- 
served associated skeletal parts before proposing formal nomen- 
clatural changes. 

In recent classifications (Wetmore, 1960; Brodkorb, 1963b) 
the pseudotoothed birds have been placed as a suborder of the 
order Pelecaniformes. Howard (1957), however, as a result of 
her study of the relatively complete skeleton of Osteodontornis 
concluded that the three genera of "toothed" birds show enough 
similarities to both the Pelecaniformes and Procellariiformes 
in combination with quite distiiictive characteristics of their own 
to merit placement in a separate order Odontopterygiformes 
(proposed by Spulski, 1910, as Odontopterygia). Wetmore 
(1960), on the basis of a restudy of the skull of Odontopteryx, 
prefers to retain the group in the Pelecaniformes. If the 
Hawthorne tarsometatarsi do pertain to pseudodontorns they 
strengthen Howard's argument that the odontopterygians show 
enough non-pelecaniform features to require being placed in 
an order of their own. 

Whether or not the Odontopterygia should be raised to the 
status of order, I suggest that the family Cyphornithidae be 
added to its included families (see Brodkorb, 1968b, for the 
most recent classification of this group). This allocation of the 
Cyphornithidae, in which I would include Cyphorn'is, Palaeo- 
chenoides, and, less certainly, Tijinptniottctiiotes, is necessarily 
provisional, but it is })referable to that of Brodkorb (1963b), 
in whose classification this family is })laced in the sul)or(ler 
Cladornithes. This jjossibly pelecaniform suborder was erected 
by Wetmore (1960) to contain Cladoniis pachifpitH Ameghino 
(1895), a peculiar broad, antero})osteriorly compressed tar- 



18 Posfilla Yale Peabody Museum No. 83 

sometatarsus from the Oligocene of Patagonia. Brodkorb's rea- 
son for including the Cyphornithidae in the suborder Clador- 
nithes was the presence in the same beds with Palaeochenoides 
of the tarsometatarsus described herein as Tympanonesiotes 
wetmorei (USNM 16809), which he believed bore a resemblance 
to Ameghino's figure of Cladornis (Brodkorb, pers. comm.). 
With additional preparation and with the more complete MCZ 
tarsometatarsus taken into account, it is clear that Tympano- 
nesiotes is quite different from Cladornis and sheds no light 
whatsoever on the possible affinities of the Patagonian fossil. 
The suborder Cladornithes is best returned to its uncertain 
position at the end of the order Pelecaniformes, where it was 
placed by Wetmore (19(30). 



Referencpis 

Allen, G. M., 1926. Fossil mammals from South Carolina. Bull. Mus. Comp. 

Zool., V. 67, no. 14, p. 447-467, .5 pi. 
Ameghino, F., 189.5. Sur les oiseaux fosslles de Patagonie. Boletin del 

Institute Geografico Argentine, tome 1.5, cahiers 11-12, ji. 1-104, 44 fig. 
Brodkorb, P., 1963a. Miocene birds from the Hawthorne Formation. Quart. 

Jour. Florida Acad. Sci., v. 26, no. 2, \\. 159-167, 1 pi. 
, 1963b. Catalogue of fossil birds: Part 1 ( Archaeopterygi- 

formes through Ardeiformes). Bull. Florida State Mus., v. 7, no. 4, p. 

179-293. 

-, 1963c. Birds from the Ui)i)er Cretaceous of Wyoming. Proc. 



Xlllth Internat. Ornith. Congr. Ithaca, p. 55-70, 10 ^i- 
Howard, H., 1957. A gigantic "toothed" marine bird from the Miocene of 

California. Bull. Dept. Geol., Santa Barbara Mus. Xat. Hist., no. 1, p. 

1-23, 8 fig. 
, and J. A. White, 1962. A second record of Osteodontornii, 

Miocene "toothed" bird. Los Angeles County Mus. Contr. in Science, 

no. 52, p. 1-12, 5 fig. 
Lambrecht, K., 1930. Studien iiber fossile Riesenvogel; I Pneiidodoiitoniis 

n.g. Geol. Hungarica, ser. pal., fasc. 7, ]). 1-17, 6 fig., 2 {)1. 
Owen, R., 1873. Descri])tion of the skull of a dentigerous bird {Odonfop- 

teryx toVuiiilca ()w.) from tlie London Clay of Shejijiey. Quart. Jour. 

Geol. Soc. London, v. 29, p. 511-522, 2 jil. 
Shufeldt, R. W., 1916. New extinct bird from Soutii Carolina. Geol. Mag., 

U.S., V. 3, p. 348-347, 1 ])1. 
Sim])son, G. G., 1932. Fossil Sirenia of Florida and the evolution of the 

Sirenia. Bull. Amer. Mus. Xat. Hist., v. 59, p. 419-503, 23 fig. 
Sjjulski, B., 1910. Od<)ii)()i>t('ri/.v loiu/irostris n. s]). 'Zcitsciir. d. Deutsch Geol. 

Ges. Monatsber., p. 507-521, 7 fig. 



July 15, 1964 Miocene Birds from South Carolina 19 

Wetmore, A., 1917. The relationships of the fossil bird PalacochcnoUh'x 

mioceaniis. Jour. Geol., v. 2.5, p. .5.55-.557, 1 fig. 
, 1928. The systematic position of the fossil bird Cyphorniti 

iiiaf/iui.'i. Geol. Surv. Canada Mus. Bull., no. 49, ]). 1-4, 1 fig. 
, 1960. A classification for the birds of tlie world. Smithsonian 



Misc. Coll., V. 139, no. 11, p. 1-87. 



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