Postilla

a

e ‘ ~

\
~)

HARVARD UNIVERSITY

ish

LIBRARY

OF THE

Museum of Comparative Zoology

ostilla i

YALE PEABODY MUSEUM

oF NAaTuRAL History

Number 54 October 30, 1961 New Haven, Conn.

THE DENTITION OF OURAYIA: —ITS BEARING
ON RELATIONSHIPS OF OMOMYID PROSIMIANS

Eiwyn L. Smrons

Gazin (1958) has established for the North American
anaptomorph, or so-called ‘ttarsioid” prosimian Primates two
families: the Anaptomorphidae, containing seven early and
middle Eocene genera; and the Omomyidae, to which eleven
Eocene and one early Oligocene genera are assigned by him.
It has long been recognized that members of these two families
differ distinctly from the more clearly lJemur-like North
American prosimians of the subfamily Notharctidae, which
has been suggested, originally by Leidy (1873:90) and more
recently by W. K. Gregory (1921:220), as being plausibly the
group from which the South American platyrrhine Primates
arose. Recently, however, the candidacy of Notharctus and its
allies for such an ancestral position has been increasingly
questioned. This is because, although generalized in many
ways, notharctids already show a number of features that are
unlike Platyrrhini. The greater expression of the hypocone
and mesostyle, together with a tendency toward doubling of

the outer cusp of the fourth upper premolar all non-platyr-
thine features, but seen in the successively later species of
Notharctus—indicate a dental pattern that was diverging

from, and not approximating that which typifies the Platyr-

2 Postilla Yale Peabody Museum No. 54

rhini. Moreover, both Notharctus and Smilodectes exhibit up-
per third molars that, relative to the other cheek teeth, are
much larger and more complex than those of the earliest known
notharctine, Pelycodus, as well as of those of Oligocene-Recent
South American Monkeys.

Some current students regard omomyid prosimians as al-
ternative, or better, candidates for the ancestry of Ceboidea ;
for instance, see Gazin (1958:100). This idea appears to have
had its origin in comments by J. L. Wortman (1904:242) in
his imaginative but often overlooked studies on Eocene Pri-
mates at the Yale Peabody Museum. Probably the main reason
the case for a possible ancestor-descendant relationship be-
tween omomyids and ceboids has not previously been considered
in detail is that no really complete dentitions of members of
this prosimian family have been described. Without better
knowledge of the anterior dentition most of those acquainted
with the problem appear to have hesitated in expressing opin-
ions as to the phyletic relationships of this group. The com-
pleteness of the dentition in one omomyid, a specimen of
Ourayia uintensis, described below, largely obviates this diffi-

culty.

ACKNOWLEDGMENTS

The writer is greatly indebted to Dr. Glenn L. Jepsen of
the Department of Geology, Princeton University, who gener-
ously made available for study and description here the
unequalled specimens of Ourayia in his charge collected for
Princeton by J. B. Hatcher, O. A. Peterson [both formerly
associated with the Yale Peabody Museum], and by later
field expeditions of Princeton University. Thanks are also due
Dr. M. C. McKenna of the American Museum of Natural
History for making available for study the type specimen of
Ourayia uintensis (Osborn) and to Dr. C. L. Gazin of the
U.S. National Museum for kindly discussing with me some
problems relating to the Omomyidae. Figures were prepared
by Margaret EK. Freeman of New Haven and the early com-
pletion of this paper was facilitated by a grant from the
Wenner-Gren Foundation for Anthropological Research of

New York.

Oct. 30, 1961 The Dentition of Ourayia 3
ABBREVIATIONS

A.M.N.H.. American Museum of Natural History, New York.

CRIN Bes tre. Sayre ares _... Carnegie Museum, Pittsburgh.
Raw... Princeton University, Princeton
Were. Yale Peabody Museum, New Haven

DESCRIPTION AND RELATIONSHIPS OF OURAYIA

The single species of this genus, Ourayia uintensis, 1s ap-
parently retricted to Uinta (B) horizon of the late Kocene.
It was originally described by Osborn (1895:77) as a species
of Microsyops. Later, Osborn recognized that the assignment
of this species to Microsyops was in error, remarking
(1902 :202): “Its nearer reference is either to the Anapto-
morphidae or to some member of the Notharctidae.” A further,
but incomplete, step in the direction of a more correct taxo-
nomic assignment for this prosimian species was made by
Wortman (1904:232) who referred it to the genus Omomys.
However, it remained for Gazin (1958:70) to recognize that
this species belongs to a distinct omomyid genus for which he
coined the name Ourayia, after the village of Ouray to the
north of the “White River pocket,” Utah, from which it seems
most, if not all, known specimens of this species have been
vecovered. Gazin (1958) noted that this genus is close to later
Socene omomyids such as Washakius, Hemiacodon, and
Stockia and pointed out that the species differs greatly from
any assigned to Notharctus which it resembles only in its
comparatively large size. The specimens from the Princeton
collections, described here, are much more complete than the
American Museum materials available to Gazin and further
serve to emphasize the distinctness of the dentition of Ourayia
from that of any notharctid. In view of the completeness of
the specimen P.U. 16431 it is now possible to define much
more adequately the structure and relationships of this primi-
tive prosimian.

‘b Postilla Yale Peabody Museum No. 54

Order PRIMATES Linnaeus 1758
Suborder PROSIMIT [lliger 1811
? Infraorder LEMuURIFORMES Gregory 1915
Family Omomyidae Gazin 1958

Subfamily Omomyinae Wortman 1904
OURAYIA Gazin, 1958

Type species: Ourayia uintensis (Osborn), 1895.

Included species: Ourayia uintensis.
Distribution: Late Eocene, Uintan stage; White River pocket, Uinta
Basin, Uintah County, Utah.

Generic distinctions: In addition too having lower and more anteropos-
teriorly elongated trigonids and comparatively larger talonid basins than
in Hemiacodon, as mentioned by Gazin (1958-71) for Ourayia, the hy-
poconid is less anteroposteriorly conpressed than in Hemiacodon and does
not project as far laterally from the main body of M, as it does in Stockia
and Hemiacodon. M,.. hypoconulids are not distinctly set off as in Hemi-
acodon and Washakius. Resembles HTemiacodon and differs from Washakius
in lacking molar metastylids. In Ourayia the apices of molar paraconids are
situated somewhat more internally than in Sfockia and M, hypoconulids are
comparatively smaller than in /Zemiacodon and Washakius. Second and
third molars above and below are larger compared to first molars than in
Washakius and Hemiacodon. Ourayia agrees with species of these two gen-
era in having crenulate tooth surfaces, but unlike Washakius has only a
single metaconule. Differs from Hemiacodon in having a much less sharply
broken crest between para- and metacones and no appreciable development
of P* parastylar cuspule. Anterolingual cingular region of M'* shows a
pericone variably present as is the case also in Hemiacodon and Omomys
among omomyids and in the living platyrrhine Samiri sciurea.

Discussion: One difference between Ourayia and Hemiaco-
don, noted by Gazin (1958:71), that the My paraconid of the
former is nearly obscured in the anterior trigonid crest, is now
seen to be a feature of the type specimen alone. The M, para-
conid on both sides in P.U. 11236 and P.U. 16431 shows dis-
tinctly. This difference, together with slightly smaller size and
less oval My outline in the latter two specimens might suggest a
species distinction for the Princeton materials were they not
from the same horizon and area as the type. Gazin pointed
out that the lower dentition of this primate does not resemble
Notharctus. This conclusion is amply confirmed in the upper
dentition of Ourayia where, apart from basic differences in
cheek tooth crown patterns, the upper incisors are seen to be

Oct. 30, 1961 The Dentition of Ourayia 5

comparatively huge and the canine much reduced. hese fea-

tures, together with the loss of P-, are in marked contrast to
the situation in notharctines which have small upper incisors
and long canines. The difference here is of the same order of
magnitude as that separating Malagasy lemur from loris
dental patterns and amply justifies reference of Ourayia and
Notharctus to different families.

As regards the phyletic position of Ourayia among omo-
myids I suspect that the genus may have been derived directly
from Hemiacodon, particularly since the Ms paraconid is not
as unlike that of Hemiacodon as was supposed from the type
specimen alone.

Possible relationships with the early Oligocene Macrotarsius
montanus are less certain, but direct derivation of this species
from Ourayia is not out of the question. Crenulations of the
enamel resembling those of both Hemiacodon and Ourayia,
although less pronounced, are evident in the talonid basins
of the Oligocene form. Paraconids are situated slightly more
laterally than in species of the latter two genera, but this
difference need not rule out a close relationship between them
and Macrotarsius. Present knowledge of the relative size, num-
ber and positioning of the anterior lower teeth in several omo-
myid genera, Omomys, Washakius, Chlororhysis, Hemiacodon,
and Ourayia strongly suggests that Clark (1941:562) was
correct in interpreting the lower dental formula in this Oh-
gocene omomyid as 2.1.3.3, the typical formula for the group.
If P, is lost and Ps single-rooted as in other Omomyidae, then
the small anteriormost remaining tooth in Macrotarsius must
be the base of a reduced canine (see fig. 1). This canine, how-
ever, is not less prominent than in any other omomyid as Clark
suggested, although the lateral incisors do appear to reach
an extreme of reduction, judging from the alveolus. In Oura-
yia, moreover, the lower incisors are more procumbent. To
the extent that the species of Hemiacodon, Ourayia, and
Macrotarsius are in, or close to, a single progressing phylum,
the suggested trends, apart from size increase, were toward
deepening and shortening of the ramus mandibuli, together
with a size reduction and more vertical implacement of the
lower incisors. Perhaps the latter changes are to be correlated

6 Postilla Yale Peabody Museum No. 54

with increasing use of the hands in feeding and with facial
foreshortening.

OURAYIA UINTENSIS (Osborn), 1895
Figures 1, 2, 3.

Microsyops uintensis Osborn 1895, Bull. Amer. Mus. Nat. Hist. No. 7, pp.

(Us kes Ie
Omomys uintensis Wortman 1904, Amer. Jour. Sci. 4th Ser., Vol. 17, pp.

134, 135.
Ourayia uintensis Gazin, 1958, Smithsonian Mise. Coll. Vol. 136, No. 1, pp.

70-72, pl. 13, fig. 8.

Type of genotypic species: A.M.N.H. No. 1899; left mandibular ramus
with P,-M..

Type locality: Late Eocene, Uinta (B), White River, Utah.

Hyopdigm: Type and A.M.N.H. 1900, mandibular fragment with right
M,; P.U. 11236, left and right mandibular rami with left P,;-M, (lacking
trigonid of M., alveoli of P.; right P,-M, (trigon of M, missing), alveoli
of I,-P,; P.U. 11288, edentulous right mandibular ramus; P.U. 16431, max-
illae with upper dentition excepting left P*, mandibular fragments with
left I,, P;-,, damaged M,, M.-M;; right I,, damaged P,, M,-M., trigonid
of M3.

Horizon and locality: Lower Uinta [B], upper Eocene, White River
Pocket, Utah. P.U. 16413, Section 2, T. 9 S., R. 20 EK. Uintah County, Utah;
P.U. 11236, 11288 Uinta [B], Kennedy’s Hole, White River, Utah.

Specific diagnosis and description:! A moderate sized prosimian; com-
parable parts approximately within the size range of the living Perodicticus
potto. Dental formula 2.1.3.3; I, spatulate, and somewhat procumbent,

2.1.3.3
posteriorly with median vertical ridge and basal cingulum rising internally
halfway toward crown; I, smaller than I, (alveolus) ; c probably smaller
than I, (root), no diastema; P. single-rooted; P, with internal cingulum
lacking on P,; P;-, of equal height, paraconid, metaconid, and external cin-
gulum present in P,, -lacking in P,, heel of P;., with single cusp situated
laterally. Surfaces of cheek teeth, particularly, bearing wrinkled or crenu-
late patterns. M. slightly larger and more oval in outline than M,. Molar
paraconids distinct (except in M, of type), situated only slightly less
laterally than metaconids and connected with protoconids by an arcuate
crest. Hypoconulids not sharply set off on M,... M; hypoconulid not as

‘T fail to grasp fully the logic behind the increasingly popular practice
of neglecting to distinguish between generic and specific diagnoses in
treatments of monospecific genera. Generic characters, in this case, are
those features which prevent reference of such species to other genera;
the specific, those attributes which, combined, characterize a given, and
no other, species. The two suites of features are not indistinguishable,
although I suspect that the failure to see that they are not may be one
prime contributor to the production of unnecessary or invalid genera.

Oct. 30, 1961 The Dentition of Ourayia 7

large as in most earlier omomyids. Upper incisors large, I>* sub-equal in
size, spatulate; upper canine reduced, premolariform, smaller than P?; P?
small, lacking lingual cusp; P** with s‘ngle inner and outer cusps. M'*
with para- and metaconules, varying expression of cuspules on lingual pro-
tocone cingulum in positions of hypocone and pericone, pronounced labial
cingula with cuspule not seen in Hemiacodon in position of mesostyle.

Discussion: Ourayia uintensis is of greater size than are
other known omomyids except for the considerably younger
species Macrotarsius montanus of Chadronian age, which is
about ten percent larger in comparable parts. Among omo-
myids earlier or contemporary with Owrayia, Hemiacodon
gracilis most nearly rivals it in size, being about eighty-five
percent as large in most measurements. The remote possibility
that canines were lost in O. wintensis and that there were
actually four premolars above and below in this species has
been considered but rejected. In spite of its premolariform
appearance, the upper canine apex is directed forward while
that of P® has a distinct backward tilt which can hardly be
due to crushing. Moreover, occlusion of the teeth in P.U.
16431 shows that the lower canine (which has a larger root
than the teeth adjacent to it) lies in front of the upper canine,
as would be expected.

The maxillae of P.U. 16431 are crushed, but some features
of interest are still to be observed (see fig. 2). Much of the
premaxilla of the right side is preserved, and a wavy suture
just in front of the canine and arching backward is indicated
on both sides. Both narial margins of the premaxillae are
evident anteriorly. The thin, fairly long right nasal has drop-
ped down between the premaxillae. In the orbital region the
jugal is missing and the orbital border of the right maxilla
much eroded, so that it is not possible to determine whether
the malar contacted the lachrymal. However, it is difficult to
avoid the conclusion that the orbit was quite large relative to
the size of the rostrum. This possibility is also indicated by
a specimen of Hemiacodon figured by Gazin (1958: pl. 4, fig.
4) in which the supraorbital border of both orbits is preserved.
Since this specimen and P.U. 16431 are the only individuals of
any species of omomyid primate which preserve part of the
skull other than mavxillae or dentaries, they deserve special
comment. It appears that in Ourayia the depth of the rostrum

8 Postilla Yale Peabody Museum No. 54

above the canine was greater than the horizontal distance from
the narial to orbital borders, so that this primate shows the
progressive feature of being comparatively short snouted,
evidently much more so than in Smilodectes or Notharctus.
On the other hand, this “advanced” omomyid feature is
balanced by the presence of a metopic suture between the
frontals in Hemiacodon figured by Gazin as is generally the
case in “‘primitive” or non-tarsioid prosimians.

The reduced upper canine of O. uintensis, taken together
with possession of a lower canine root that is hardly larger
than P. in cross-sectional area, indicates a small, premolari-
form lower canine. Both Matthew and Granger (1915: fig. 24)
and Gazin (1958: pl. 8) illustrated specimens of the closely
related Hemiacodon gracilis which preserve broken lower
canines that are indeterminate as to the height of this tooth.
A specimen of H. gracilis recently located in the Yale collec-
tions, Y.P.M. 16253 from Henry’s Fork, Wyoming, shows
that the entire tooth was extremely premolariform and only
barely higher than Ps (see fig. 1). In view of an overall simi-
larity in general size and proportions of the other teeth
between O. wintensis and H. gracilis, the reduced upper canine
of the former almost certainly opposed a premolariform tooth
below. In earlier omomyids, Omomys and Chlororhysis, the
lower canine is relatively larger (fig 1). Such canine reduction
in the later omomyids practically eliminates them from con-
sideration as being ancestors of any Ceboidea.

Although O. wintensis may be derived from H. gracilis, ref-
erence of the former species to the genus Hemiacodon seems
out of the question. The primary distinctions between these
two genera have been cited in the diagnosis given above (page
4), and they are considerably greater than those which have
been proposed as separating the genera Omomys, Loveina, and
Chlororhysis. No doubt, known omomyid species could be
lumped under fewer genera, but in the fragmentary state of
present knowledge concerning them, limited almost entirely
to dentitions, this would serve no useful purpose and in any
event cannot be attempted here.

Curiously, wear on M— of O. wintensis, P.U. 16431, is dis-

tinctly less than on M-.. That this could be due to misinter-

Oct. 30, 1961 The Dentition of Ourayta

7)

pretation of the dental formula, with molariform P——and loss
of one of the molars seems impossible, particularly because in
the closely related H. gracilis the normal sequence of molar
wear can be established for numerous specimens.

MEASUREMENTS IN MILLIMETERS OF OURAYIA UINTENSIS

Length I.— My,
Length P.,—M,
Length P., — M.

Depth of jaw below M,

Transverse diameters:

Anteroposterior diameters:

LOWER DENTITION
P.U: Jeae
No. No.
16431 11236
eee ee 27.6
eS 8.0 18.8
13.0 14.6
6.2 6.8
ee ee 2.0 1.9
Tt tie, Arerperes
CAS ae aE: :
Pipers: Ole oe. LAG eran
[Day epee ie 2.0 2.3
it ew eee Zui 2d
M, (trigonid) 3.0 2.8
Misne fete 2 i eae enol Pel
IVI ee ees ree 2.9 3.0
M, (talonid) 3.5 3.3
M; 3.6 3.3
M., 3.2 3.0
| Ep ee at 2.3 2.1
ie eye ;
Ps 1 Si(Ga) ee
Pe 2.9 3.1
P, “aed | 3.7
M, 4.0 4.2
M. 4.2 4.2
IVER tee 9: 5.2 4.6

2.3
2.6
2.9

3.4

3.6
3.8

10 Postilla Yale Peabody Museum No. 54

UPPER DENTITION

P.U
No.
16431
Wenig ile Ne ——— Ne a Sgn ees 28.9
Bengt hee ANE eee oe eee ies
Transverse diameters: I? ......... V3
| opie herent ir
Coe 1.4
| at ae eS ae 1.4
| PEED eae oe ok
Pee Oe aie 3.8
1 (oo 4.8
1 Cee ead 5.2
M? 4.8
Anteroposterior diameters:
een 5 eels. 3.4
iy els Roe. Sal
Gi Sk hey eae
Rees Saran De
Pe eo Be en Sell
Ps geese. 3.0
Mea eer. oe 3.8
Mies Seay eee 4.1
1, Geo 3.8

Measurements for a possibly associated right P, of P.U.
16431 have been given above. Although there is no definite
contact between this tooth and the right mandibular fragment,
it is the proper size and shape for an omomyid P,, judging
from morphology of Ps in Omomys and Hemiacodon.

RELATIONSHIPS OF THE OMOMYIDAE

The hypothesis that omomyid prosimians may be near the
ancestry of the platyrrhine monkeys is based on several points
of direct and indirect evidence, most of which are rather

Oct. 30, 1961 The Dentition of Ourayia aU |

equivocal, as is often the case with such phyletic conjec-
tures. For those who do not favor a notharctid derivation for
platyrrhines these small Primates remain as the only other
group now known in North America which contains mem-
bers that are early and generalized enough to admit of
such a relationship. Other early Cenozoic families of North
American Primates including Plesiadapidae, Carpolestidae,
Anaptomorphidae, Phenacolemuridae, and Paromomyidae (if
the latter two are regarded as distinct) exhibit extreme tooth
specialization or reduction which entirely eliminates their
known members from any ancestral relation to the South
American Monkeys. It is clear, however, that if the dental
form and arrangement of Ourayia uintensis was at all typical
of the later Omomyidae as a whole, it would require a reversal
of the trend toward reduction of the canines, seen in this
species in order to reach the condition typical of the ceboid
monkeys. Such a possibility seems at best rather unlikely.

The question of the ancestry of the platyrrhine monkeys
bears rather crucially on the interpretation of a number of
more general assumptions inherent to the currently accepted
higher categories of Primates, particularly the concept of the
suborder Anthropoidea, as well as to the widely accepted
succession of grades, from lemuroid to tarsioid, to monkey
and etc., through which the ancestors of man and the other
Higher Primates are commonly supposed to have passed.
Perhaps the problem is largely semantic, resulting from the
all too human tendency to superimpose an idealistically sub-
divided terminology on what are actually continua of evolving
lineages. Nevertheless, most of the various named higher
-ategories of Primates have been, and presumably will continue
to be, useful in talking about evolutionary relationhips within
the order. One possible reaction might be to suspend judge-
ment or discussion of relationships between early and late
Cenozoic Primates in view of the partial and fragmentary
evidence now available, but within the framework that has
been set up by previous research it seems advisable to follow
out some earlier suggestions to their logical conclusion. For
instance, if platyrrhine monkeys were actually derived from
anything like the Notharctus group or even from the omomyid

12 Postilla Yale Peabody Museum No. 54

prosimians, it is difficult to see how they could have passed
through a grade of organization that need be qualified as
tarsioid. If either of these groups are actually ancestral to the
South American Monkeys, but not to the Old World Higher
Primates, then it is also necessary to conclude that those
features which are shared by Old and New World Higher
Primates are the result of parallel evolution and that these
two groups were independently derived from the Prosimu.

In the latter case the taxon Anthropoidea consists of a
grade in the sense of Huxley (1958) rather than a clade, in
which the common ancestor of subsequent derivative stocks
shares something of the definition which justifies the associa-
tion of such subsequent groups within a single taxon. If Catar-
rhini and Platyrrhini were derived from independent stocks of
Prosimii, then Anthropoidea have a polyphyletic origin, even if
such stocks belonged to the same major division of prosimians.

When considering the various alternatives for the derivation
of the Platyrrhini it may be noted that latest species of the
genus Notharctus, and of Smilodectes as well, are rather large
prosimians, having approximately the body size range seen in
species of the living Malagasy genus Lemur or in the domestic
cat. It seems implausible, although not impossible, that forms
such as the pigmy marmoset could have descended from ances-
tors of the size range of known notharctids. The smallest
notharctids, species of the early Eocene genus Pelycodus, in
comparable parts, have about twice the linear dimensions of
the smaller species of Callithriv and are even larger compared
to Cebuella, should the latter genus be sustained as distinct
from Callithrix [Hapale|. Inasmuch as known species of Pely-
codus give every evidence of being close to the origin of the
taxon Notharctidae, there is little reason to posit that there
ever were unknown smaller members of this subfamily from
which marmosets such as Cebuella might more plausibly have
been derived without marked size decrease at some intermediate
period. One is therefore faced with the supposition that, if
Notharctidae are in or near the ancestry of platyrrhines, mar-
mosets have undergone a size reduction since their initial dif-
ferentiation. This view has sometimes been put forward, but
to date there is no paleontological evidence for it.

Oct. 30, 1961 The Dentition of Ourayia 13

In conclusion, it is possible to say that in spite of the fact
that late Eocene and Oligocene omomyids were specializing
along distinct lines of their own, not foreshadowing Platyrrhini,
it seems probable that Omomys and its immediate forebears are
the most likely early Cenozoic prosimians to have a direct
relationship to the rise of the South American Monkeys.
Among principal evidences supporting this view are the obser-
vations that Omomys, or one or more forms allied to it, was
smaller than any known ceboids, had suitably unspecialized
molar crown patterns together with small third molars, shared
with some ceboids the otherwise nearly unique possession of a
pericone cusp, and belongs to a group showing trends away
from the primitive prosimian condition toward foreshortening
of the rostrum, orbital enlargement, and vertical incisor em-
placement. Moreover, Omomyidae are the only known family
of ancient and undoubted Primates now known which possessed
exactly the same dental formula as do the living Cebidae.
Nevertheless, only in earliest omomyids are relative sizes of
respective tooth types reasonably satisfactory for derivation
of the tooth morphology characteristic of Oligocene-Recent
South American Monkeys.

14 Postilla Yale Peabody Museum No. 54

Figure 1.

Diagrammatic reconstructions of a sequence of representative omomyid
species, approx. x 3. Dotted outlines hypothetical.

These species may not represent a single phylum, but each is typical of
the successive Epoch substage to which it belongs. Specimens on which
this chart is based are as follows: Macrotarsius montanus (type) C. M.
9592 (reversed) ; Ourayia uintensis, P.U. 16431 (P, and M, reversed from
right ramus): Hemiacodon gracilis (composite), part A—A.M.N.H.
12037, part B—Y.P.M. 16253, part C—Y.P.M. 12987-1; Omomys carteri
(composite), part A—A.M.N.H. 12600, part B—Y.P.M. 16287 (reversed),
part C—Y.P.M. 13219-2 (reversed).

Oct. 30, 1961

EARLY OLIGOCENE

EVOIGREINIE

EVA E

WwW
=
WW
oO
(oe)
WwW

MIDDLE

The Dentition of Ourayia

MACROTARSIUS

OMOMYS

16 Postilla Yale Peabody Museum No. 54

Figure 2.

Occlusal views of right upper, and left lower dentitions of Ouwrayia win-

tensis, P.U. 16431, (M, reversed from right side), approx. x 5.5.

Oct. 30, 1961 The Dentition of Ourayia il

18 Postilla Yale Peabody Museum No. 54

Figure 3.

lateral view of right maxilla of Ourayia uintensis, P.U. 16431, approx.

NGOs

Oct. 30, 1961

Ss

a

_. The Dentition of Ourayia

i]

20 Postilla Yale Peabody Museum No. 54

REFERENCES

Clark, J., 1941. An anaptomorphid primate from the Oligocene of Montana.
Journ. Paleo., v. 14, no. 5, pp. 562-563, 1 fig.

Gazin, C. L., 1958. A review of the Middle and Upper Eocene Primates of
North America. Smiths. Mise. Coll. v. 136, no. 1, pp. 1-112, 14 pl.

Gregory, W. K., 1921. On the structure and relations of Notharctus, an
American Eocene primate. Mem. Amer. Mus. Nat. Hist., v. 3, pt. 2,
pp. 49-243, 84 fig., 36 pl.

Huxley, J. S., 1958. Evolutionary processes and taxonomy with special
reference to grades. Uppsala Univ. Arsskrift, No. 6, pp. 21-39.

Leidy, J., 1873. Contributions to the extinct vertebrate fauna of the
western territories. Rep. U.S. Geol. Surv. Terr. (Hayden), v. 1, pp.
1-358, 33 fig., 37 pl.

Matthew, W. D. and W. Granger, 1915. A revision of lower Eocene Wasatch

and Wind River Faunas. Part IV., Bull. Amer. Mus. Nat. Hist., v.
34, pp. 429-483, 52 fig., 1 pl.

Osborn, H. F., 1895. Fossil mammals of the Uinta Basin. Expedition of
1694. Bull. Amer. Mus. Nat. Hist., v. 7, pp. 71-105, 17 fig.

, 1902. American Eocene Primates, and the supposed rodent
family Mixodectidae. Bull. Amer. Mus. Nat. Hist., v. 16, pp. 169-214,
40 fig.

Wortman, J L., 1903-1904. Studies of Eocene Mammalia in the Marsh Col-
lection, Peabody Museum. Part 2. Primates. Amer. Journ. Sci., 4th Ser.,
v. 15, pp. 163-176, 399-414, 419-436, v. 16, pp. 345-368, v. 17, pp. 23-33,
132-140, 203-214, 48 fig., 2 pl.

wwe

3 2044 066 305 236

Date Due

ALE HS

oe PI

Pr

= Sige a
Ae eee

——
Sn OP
Spawn Pom ERTS ROOTES TSS
or A ITAA ALR

ee amend

6A a ne
a eee

~~

er paPrDnrae ra eX

a

ne
a

pr en - .
Seer PTL EEE

<r rete ae : me

- ey : en ay Sin inlet oS ae Ci TT a a eel

ee TT petal TT eC EN ae igh mn rene

Sere t Oa ON a et eet ee a

eS OLE PES Re ete eli

pepernenss

aad

PLEA

one em
ete pate

eee
ee aeeietind
ee aa

a teat
ge

lA
ee aie

ee

ett gp mathy
Se anes
Cheer faeyew ’ a4 -
nt ‘. — : ep IT x r a bee
wanes _ , iO eet
~ LO OS a epee ti SLe aenn - -
CO gee OOF aN a ae EE OO OTL
ee aacalae —,
pie ntl Rae en

I eee P-So
ST eee a aa tc Pie a Oe

OT Se ae eee OT eae Att” FOI eile atl

i Pep PPP POOL. ee - ee eo

se iccaane_ eee PLEO IAI ene ore a8

PE pen OO

nde ela ”