M.
Length of first phalanx ·022
Width of first phalanx ·012
Length of second phalanx ·013
Width of second phalanx ·010
Length of ungual phalanx ·005
Width of ungual phalanx ·010
PALÆOSYOPS, Leidy.
Hayden's Geological Survey of Montana, 1871.--Proceedings
Academy Natural Sciences, Philadelphia, 1871, p.
118.--_Limnohyus._--Marsh, American Journal Science and Arts,
1872, p. 124.
_Generic characters._--The dentition is full, I. 3, C. 1, Pm. 4, M.
3; the same in lower jaw. The internal cones of the superior molars
isolated from the crescentoid crests. One inner tubercle on the
last three premolars. One internal cone on the last superior molar.
In lower jaw, true molars with four acute tubercles alternating in
pairs and connected by oblique crests. The last molar adds a fifth
posterior tubercle. The last premolar lacks the posterior inner
tubercle. The canines are in continuity with the incisors.
A broad, triangular forehead. A wide zygoma. Long, projecting nasals.
Large temporal fossæ. High sagittal crest. Prominent and nearly
vertical occiput.
Palæosyops major, Leidy.
Survey of Wyoming, 1871, p. 359.--_Limnohyus robustus._--Marsh,
American Journal Science and Arts, 1872, p. 124.
_Specific characters._--Sagittal crest short and thick. Temporal
fossæ not very deep. Frontals diverge rapidly. Occipital condyles
wide and low; the same is true of the foramen magnum. Meatus
auditorius high and deep. Glenoid cavity shallow; no internal
process. As compared with _P. Paludosus_, post-glenoid process not
so much compressed. Occipital region comparatively higher and not
so concave. The occipital condyles are more prominent. The zygomas
are lighter. Head larger than _Paludosus_, perhaps not so large as
_Vallidens_.
Description from (i) a head, complete, but distorted, with complete
dentition, upper and lower. (2) A head somewhat crushed, and lacking
some portions, with full set of upper molars and canines. (3) A great
number of fragmentary specimens of different parts of the body.
_Dentition._--In the upper jaw the incisors are arranged in a
semi-circle as in _P. paludosus_; they have long fangs and short,
conical crowns, with a decided basal ridge, which is very strong in
the third. They increase from first to third, which is very large and
pointed.
The canines have very large and long fangs (longer than the crowns).
The crowns are very stout and pointed, constituting formidable
weapons. In section they are nearly circular, with a distinct
hinder margin and a slight recurve. A rudimentary anterior margin
is sometimes present, and of the faces thus marked off, the inner
is much smaller and flatter. The general direction is forwards,
downwards, and slightly outwards. There is a diastema of about half
an inch between the incisors and canines.
_Premolars._--The first is very small, about half an inch from the
canine, simple and conical, with an obscurely marked basal ridge, and
two heavy fangs.
Further description of the upper dentition is unnecessary, owing to
the complete work of Dr. Leidy upon the subject.
The _lower incisors_ are placed in a semi-circular row, and are
somewhat procumbent, though hardly as much so as in the tapir. They
are much as in _P. paludosus_, but are relatively smaller, and have
not such distinct basal ridges; features which indicate a departure
from the carnivorous type, and a nearer approach to the herbivorous
type. The lateral incisor, though the largest of the series, is not
so large nor so pointed as in _P. paludosus_. There is no diastema.
The _canines_ are about equal in size to those of the upper jaw,
growing from stout fangs and permanent pulps. The margins of the
crowns are more decided, and are smooth, leaving a very narrow and
flat inner face. A feeble basal ridge. When the jaw was closed, the
lower canines passed inside and in front of the upper.
The _first premolar_ stands immediately behind the canine, is longer
than that of the upper jaw, consisting of a single pointed lobe
implanted by one fang, slightly recurved with a flat inner and convex
outer face. Passing in front of the first upper premolar, it leaves
a considerable diastema between this and the second premolar.
The _mandible_ approximates in form that of the tapir; the lower
border is less curved fore and aft, the alveolar border is slightly
concave antero-posteriorly. The molars converge in front, presenting
a very different arrangement from that in _Sus_. The ramus is heavy,
contracting in depth forward, and very slightly in section. Below the
alveolus, on the interior side, the ramus is greatly swollen for two
thirds of its depth, to accommodate the very long and strong molar
fangs.
The rami converge to the second premolar, where they expand laterally
to the canine alveolus. The symphysis is shorter relatively than
in _P. paludosus_, and the chin is regularly rounded in front. The
mental foramen is below the second premolar. The dental foramen is
small, very high up, and far behind the molars. The alveolar border
ascends rapidly behind the last molar, expanding laterally into two
ridges.
The coronoid is slender and recurved. The condyle is broad, flat
behind, inclines forward internally; there is scarcely any depression
between the condyle and the coronoid. The masseteric fossa is very
wide and deep. The angle of the ramus is broken, but evidently has no
such posterior extension as in _P. paludosus_. It thins out rapidly
behind.
_Measurements._
--------------------------------------------------+---------+----------
| P. pal. | P. major.
+---------+----------
UPPER JAW. | M. | M.
Length of entire molar series | ·147 | ·170
Length of three true molars | ·085 | ·102
Length of three premolars | ·058 | ·068
Diameter of last molar, transverse | ·039 | ·047
Diameter of last molar, antero-posterior | ·036 | ·036
Diameter of second molar, transverse | ·036 | ·040
Diameter of second molar, antero-posterior | ·033 | ·036
Length of incisor series | ···· | ·075
Fore-and-aft diameter of canine at base | ·016 | ·021
Length of crown of canine | ···· | ·033
Diastema between canines and incisors | ···· | ·013
Diastema between canines and molars | ···· | ·010
--------------------------------------------------+---------+----------
---------------------------------------------------+---------+----------
| P. pal. | P. major.
+---------+----------
LOWER JAW. | M. | M.
Incisor series | ···· | ·073
Median incisor fang, length | ···· | ·034
Median incisor crown, length | ···· | ·012
Diameter of median incisor crown, transverse | ···· | ·009
Diameter of lateral incisor crown, transverse | ···· | ·011
Diameter of lateral incisor crown, antero-posterior| ···· | ·012
Length of fang of canine | ·055 | ·052
Extreme breadth of fang of canine | ·023 | ·024
Crown of canine, length | ···· | ·034
Crown of canine, fore-and-aft diameter at base | ·019 | ·021
Diameter of first premolar, antero-posterior | ·015 | ·010
Diameter of first premolar, transverse | ·009 | ·007
Diastema between first and second premolars | ···· | ·014
Length of entire molar series | ·164 | ·186
Length of molar series, omitting first premolar | ·132 | ·163
Diameter of last molar, antero-posterior | ·017 | ·050
Diameter of last molar, transverse | ···· | ·027
Depth of jaw below last molar | ·068 | ·075
---------------------------------------------------+---------+----------
Among other specimens obtained at the divide between Henry's Fork
and Cottonwood Creek, was a nearly complete but somewhat shattered
skeleton of a _Palæosyops major_, found contiguous to the head of
the same, parts of which are just described. Portions of these are
figured on a one fourth scale in Plate II. The description is from a
nearly perfect atlas and axis, several cervical, dorsal, and lumbar
vertebræ, more or less complete, and a portion of the sacrum and
pelvis, in addition to several bones of the limbs.
The _atlas_ has a broad inferior arch, contracted antero-posteriorly,
and deeply notched for the prominent odontoid of the axis. The heavy
superior arch, inclosing a large and depressed neural canal, is
capped by a low tuberosity. It slopes into a flat, and very broad
transverse process, which thickens backwards, and is perforated by
the vertebraterial canal. Forwards the transverse process is notched
for the exit of the first spinal nerve. The anterior or condylar
faces are continuous, deeply concave from above downwards; and
slightly so from side to side; while the posterior faces are oval,
nearly flat, and directed backwards and inwards.
The _axis_ is proportionately small, with a long opisthocœlous
centrum, depressed, and produced forwards into a stout conical
odontoid process, and marked below by a strong hypapophysial keel,
which, developed on the latter half, thickens backwards. The wide
and thin pedicles inclose a high neural canal, support the posterior
zygapophyses and a prominent and peculiar neural spine. The latter
is flattened, broad, and recurved posteriorly, thinning rapidly
forwards into a prow-shaped recurved edge. The transverse processes
arising from the latter half of the centrum are undersized and widely
perforated at base. The anterior faces are very broad, directed
outwards, and slightly rounded from above downwards; they expand as
they diverge (see Fig. 2). The post-zygapophyses are small convex
faces, projecting at the base of the neural spine.
The _remaining cervicals_, five in number, are short, all carinate,
except the seventh, and opisthocœlous; with the faces expanding
only slightly beyond the body of the centrum. A peculiar feature
is a small pit upon the convex anterior face, indicating either
a ligamentous attachment with the antecedent vertebra, or a
remnant of the notochord. This is a feature we have not noticed
elsewhere. A long and heavy transverse process supports a large and
widely-perforated inferior lamella. The pedicles are quite wide at
base, inclosing a large neural canal. The entire upper part of the
arch is unfortunately wanting.
The dorsal centra are smaller than the cervical, slightly
opisthocœlous, and carinate. They are sub-cylindrical anteriorly,
with decided costal surfaces before and behind; approaching the
lumbar region they become subtriangular. A high neural arch
supports a stout, but never very high neural spine; this projects
backwards, keeled in front, expanding and deeply grooved behind. The
zygapophyses are small and nearly vertical. There is a short and
thick transverse process.
The _lumbar_ vertebræ are long, decidedly opisthocœlous, becoming
wider and more depressed as they approach the sacrum. The first
_sacral_ vertebra presents the same characteristics as the last
lumbar, only the body of the centrum is slightly shorter. It has
a very broad pleuropophysial plate. The remaining sacral vertebræ
are broad, and very greatly depressed, rapidly decreasing in size.
The transverse processes are slender. The very low neural spines
anchylose into a long ridge. The number cannot be ascertained, owing
to the fragmentary state of the sacrum. The caudals indicate a tail
of not very great length; as the neural canal is small and persists
in only a few of the anterior vertebræ.
_Measurements of Vertebræ._ _Pal, major._
M.
Atlas, width, including transverse processes ·195
Atlas, length of inferior arch ·082
Atlas, height, including superior and inferior arches ·078
Axis, width, anterior articular faces ·110
Axis, length, excluding odontoid process ·058
Axis, height of neural spine ·096
Axis, length of odontoid process ·025
Seventh cervical, length of centrum ·037
Seventh cervical, width of posterior face ·043
Dorsals, anterior region, length ·038
Dorsals, anterior region, width, articular face ·034
Lumbar, width of posterior face ·058
Lumbar, length of centrum ·056
First sacral, width of anterior face ·059
The ribs, of which great quantities of fragments remain, were slender
and not of very great width.
The _femur_, which is figured in Plate I., has a small head,
supported by a short neck. The shaft, very broad below the head,
supports the third trochanter one third of the way down; below which
it takes a cylindrical form, and expands slightly above the trochlea.
The two condyles, separated by a wide and deep popliteal groove, are
nearly subequal in size--the internal somewhat the larger, while
the trochlea is long, narrow, and symmetrical. The great trochanter
rises slightly above the head, and overhangs a long and quite deep
digital fossa. The second trochanter is small. The popliteal space is
slightly concave.
_Tibia._--The proximal end of the tibia is very large, with massive
rugosities for muscular attachment. The two proximal faces are
subequal, slightly convex, and separated by a prominent spine, which
is grooved at the top. The shaft is long, straight, and compressed
antero-posteriorly; the anterior ridge on upper third is very high,
and expands into the tuberosity, which is enormous; while on the
posterior face is a deep fossa just below the head. The distal end of
the shaft is remarkably small, with two concave faces--the internal
the smallest--with a low oblique ridge dividing them. There is a
prominent malleolus.
The fibula (which is a distinct bone) has a small proximal end, and
expands slightly below, with a large external malleolus.
_Measurements of Limbs._
M.
Femur, total length .420
Femur, transverse diameter at distal end ·098
Tibia, length ·310
Tibia, transverse diameter, proximal articular face ·090
Tibia, transverse diameter, distal articular face ·077
The _pelvis_ is described from the right and left ilia, which
are broken as they expand towards the crest; the acetabulum is
fragmentary, but all the parts remain. The ischium and pubis are only
represented by fragments. As figured in Plate V., the acetabulum
is restored from a somewhat smaller specimen. The most striking
feature of the _ilium_ is the long and somewhat constricted neck. The
acetabular border is long and curved forward, thinning gradually as
it approaches the crest; and marked on the iliac surface, near the
acetabulum, by a slight rugosity for the rectus muscle.
The ischial border, while less arched, is probably longer; and the
sacral surface, distinctly defined, indicates that the rounded upper
border of the ilium rarely reached above the sacral spines. There
is a deep groove between the ischial and pubic borders, the latter
disappearing about half way up the iliac surface. The gluteal surface
near the acetabulum is much depressed; above it expands into a broad,
flat, thin plate.
The _ischium_ has a stout neck and thick expansion below; the upper
border is very heavy. From what remains of the _ischium_ and _pubis_
we can infer a large elliptical obturator foramen, a short pubic
symphysis, a narrow and rather slight pubis, with a small nearly
cylindrical neck. The acetabulum is deep, with a thick well-raised
border, and a large, oblong, and very deep pit for the ligamentum
teres.
_Measurements of Pelvis._
M.
Ilium, transverse diameter above acetabulum ·062
Ilium, long diameter (estimated) ·232
Acetabulum, greatest diameter ·050
Ischium, transverse diameter below acetabulum ·041
Pubis, diameter at obturator foramen ·035
The _tarsus_ is arranged in the usual Perissodactyle order. The
_calcaneum_ is stout, of good length, tuberous, but not expanding
much at the extremity; presenting two faces for the astragalus, of
which the internal is the largest, and a large distal face for the
cuboid. The _astragalus_ is wide, with less asymmetry in the two
articular facets than is common. It articulates with both the cuboid
and navicular.
_Measurements of Tarsus._
M.
Astragalus, total width, tibial facets ·048
Astragalus, total length ·056
Astragalus, length, navicular facet ·046
Astragalus, width, navicular facet ·035
Calcaneum, total length ·120
Calcaneum, total breadth ·057
Calcaneum, length of tuber calcis ·050
All the above were found at Henry's Fork Divide. In another locality,
in connection with a fine head of _P. major_, was found the lower
half of a _humerus_.
The _shaft_ is cylindrical and twisted, expanding widely at the
distal end. Of the two condyles the external is the largest; and,
to quote from Dr. Leidy, "a deep supra-condylar fossa occupies the
front of the humerus, opposed by a deeper and more capacious anconeal
fossa." The greatest breadth between the supracondyloid eminences is
·091 m.
Palæosyops paludosus, Leidy.
Cont. to Ext. Vert. Faun, _P. lævidens_ Cope. U. S. Geol. Survey of
Terrs, 1872, p. 591.
_Specific characters._--Second superior molar has but one outer
tubercle. The cones are low as compared with _P. major_. The cingula
are much less developed. The angle of the lower ramus is much longer.
The zygoma is massive and wide. An internal process on the glenoid
cavity. Temporal fossæ very deep. Crest of occiput nearly in same
vertical line as occipital condyles.
The full details of _P. paludosus_, which follow, may seem somewhat
unnecessary, to one familiar with the comprehensive work of Dr.
Leidy upon the subject. Care has been taken not to retrace any of
his steps; and the descriptions given below are of those parts of
the animal which he did not possess at the time of writing. They
include (1) a cranium perfect posterior to the orbits; (2) a right
_ramus_ mandibuli, with full dentition, except the first premolar;
(3) portions of the fore-limbs, scapula, and pelvis, pes and manus,
and many fragments of other parts.
Among the first discoveries on Cottonwood Creek, in a stratum of
fine green sand, was a head of _P. paludosus_, complete posteriorly,
and broken off just behind the orbit. A rear view of this has been
admirably figured in Plate I.
_General appearance._--The base of the cranium is of great width;
the occiput is high, inclined very slightly backwards, and deeply
concave from side to side. The forehead is triangular and narrow.
The temporal fossa is of immense size and depth, leaving a small
intracranial cavity. The zygomas are heavy, and arching widely
outwards give this part of the head a strong resemblance to the
_Felidæ_.
_Description in detail._--The narrow but prominent _basioccipital_
segment is broadest posteriorly and tapers forwards; divided by a
median ridge, which expands anteriorly into a large tuberosity; a
feature also characteristic of the tapir. About half an inch in
advance of the condyles are the condylar foramina. The _condyles_
are formed of the exoccipitals, which are low and of great lateral
expansion. Their junction with the mastoids is marked by a large
foramen. The _par-occipitals_ are short and styliform. The
_supra-occipital_ region is very large, high, and deeply concave
from side to side, much wider than in the tapir, with a marked
interparietal suture. The _condyles_ are wide, but not very deep,
approaching each other very closely below. The _basisphenoids_ are
long and narrow, tapering forwards. The _alisphenoids_ are mutilated,
but indicate large vertical ridges joining the parietals, and heavy
pterygoid processes, perforated at the base by the alisphenoid canal.
They are again perforated by the foramen ovale three fourths of an
inch behind this. This completes the base of the skull.
The _parietals_ are very large, they form nearly the whole of the
temporal fossil; which, deep and wide, enclosing a small cranial
cavity, contrast strongly with the long and shallow temporal fossæ
of the tapir. The parietal crest is very broad, and grooved at the
top. This high crest and deep adjacent temporal fossæ we at first
mistook as pointing to an exclusively carnivorous type. The forehead
has a triangular appearance, from the divergence of the two side
ridges of the sagittal crest. The _postorbital_ processes are very
large, but do not reach the opposing processes of the _malar_. The
orbit is thus left incomplete posteriorly, while in form it greatly
resembles that of the _Sus_. The _squamosal_ encroaches considerably
upon the temporal; and sends outwards and downwards a great zygomatic
process, which arches outwards from the skull as in the _Felidæ_,
and is more powerful than in any living carnivore (Leidy.) A strong
downward direction is especially characteristic, the whole describing
a sigmoid curve. The _mastoids_ are of great size vertically, and
transversely they are confluent with the par-occipitals. A low, thick
process on the internal side of the glenoid cavity prevents lateral
motion.
The _nasals_ are long, broad, and thick, convex from side to side,
narrowing slightly anteriorly. They are straight, as in _Sus_, which
they resemble more than they do either tapir or rhinoceros. The
anterior borders are rounded, and do not reach as far forward as
the symphysis of the premaxillary. The _malar_ is broad and thick,
probably forming but little of the face, being directed downwards
and backwards to meet the zygoma. The postorbital process is short,
and rather larger than Dr. Leidy has indicated. The _maxillaries_,
smaller proportionately than in _Sus_, form posteriorly the floor of
the orbit; while the infraorbital foramen is situated over the last
premolar. The premaxillaries fail to reach the nasals.
_Comparative Measurements of Head._
----------------------------------------+----------+---------+-------
| P. | P. |
|paludosus.| major. | Tapir.
----------------------------------------+----------+---------+-------
| M. | M. | M.
Height of occiput | ·122 | ·148 | ·120
Breadth of occiput at post tympanic | | |
processes | ·160 | ·166 | ·110
Breadth of cranium at ends of | | |
post-glenoid processes | ·172 | ·210 | ·126
Transverse diameter of occipital foramen| ·031 | ·049 | ·040
Vertical diameter of occipital foramen | ·027 | ·033 | ·027
Depth of occipital condyles | ·033 | ·039 | ·029
Breadth of occipital condyles | ·040 | ·049 | ·041
Breadth at occipital condyles together | ·082 | ·100 | ·082
Width of basioccipital at anterior | | |
condyloid foramina | ·038 | ·039 | ·028
Width of basioccipital at junction with | | |
basisphenoid | ·025 | ·032 | ·020
Width of crest dividing the temporal | | |
fossæ posteriorly | ·011 | ·020 | ·011
Breadth of cranium outside of zygomata | ·262 | ·280 | ·180
Depth of zygoma | ·046 | ···· | ·036
----------------------------------------+----------+---------+-------
_Lower jaw_ of _P. paludosus_ described from another specimen.
The peculiar feature of this jaw is its remarkable extension back of
the molar series (a feature which has not been noticed heretofore),
the distance from the last tooth to the angle being greater than the
length of the entire molar series. From beneath the last molar, the
lower margin curves gently up to the symphysis. The alveolar border
is but slightly curved. Behind the last molar the lower margin forms
a sigmoid curve, much more decided than in _P. major_ (first upwards
and then downwards), and the ramus thins out rapidly to the angle,
where it has a slightly raised border; at the diastema the ramus
curves outwards so as to throw the canines out of the line of the
molars. The symphysis is long.
_Dentition._--The incisors, three in number, from length and shape
indicate a semi-circular arrangement, as in most Perissodactyles.
They increase from first to third. The crown of the first resembles
very much that of the ruminants, but has a straight posterior
basal ridge. Its forward edge is worn so as to expose a small tract
of dentine. The second is larger, but very much like the first in
conformation; while the third has an acute conical crown with a
strong basal ridge.
Of the _premolars_ the first is wanting in this specimen. The second
is bilobed, the anterior lobe much the larger. It has a small
accessory tubercle on its anterior slope. The outer face is rounded,
the inner nearly flat. The posterior lobe is very small and obtuse,
and with the inner face slightly grooved. In third and fourth the
valley between the lobes and the groove on their faces enlarge; while
the anterior lobe becomes relatively smaller.
_Measurements of Lower Jaw._
M.
Diastema between canine and first premolar ·024
Length of entire molar series ·143
Distance between last molar and extremity of angle ·147
Depth of jaw at last molar ·070
Among the first discoveries on Cottonwood Creek, in connection with
the lower jaw of _P. paludosus_ just described, were an ulna and
radius, and part of the manus and scapula of the same. These have
been figured, together with other fragments belonging to the same
species, in Plate III., and form an interesting complement to the
nearly complete hind limb of _P. major_ previously described.
The _scapula_ has a shallow oval glenoid cavity, which is concave
longitudinally. Separated from it by a narrow notch is a strongly
recurved coracoid, placed on the inner side of the bone. Above the
coracoid the border is thin, and arches inwards and then forwards;
while the glenoid border is much straighter, rising from a slight
tuberosity. The spine rises gradually from the glenoid, and does not
bear any indication of an acromion.
The _humerus_ is represented by proximal and distal extremities. The
latter presents the same characters on a smaller scale as in _P.
major_. Upon the proximal end there is a deep bicipital groove. The
greater tuberosity has a hooked anterior projection, and runs back
into a ridge behind. (See Fig 7, Plate III.)
The proximal end of the _ulna_ (of median breadth anteriorly) narrows
into a prominent ridge behind. This gives a trihedral character to
the shaft. This is persistent, but is less marked as the fore-and-aft
diameter decreases. The remaining features of note are a high
tuberous olecranon expanding behind; a shallow sigmoid, divided by a
deep fossa into two long divergent articular faces; a trihedral shaft
tapering slightly, but distinct from the radius; a narrow distal
extremity, with a small irregular face for the cuneiform.
The _radius_ has a rather short shaft, curved forwards, expanding
below, and placed immediately in front of the ulna. A strong ridge
runs from the external tuberosity up the posterior face of the shaft,
disappearing two inches from the top. The proximal end, fitting
against the ulna by two small faces, forms the greater part of the
elbow-joint, a strong median ridge dividing the proximal face into
two subequal surfaces with well-raised borders. The distal end of
the shaft is rugose, and more prominent than the proximal. It has an
oblong transverse face, which is slightly concave fore and aft. The
position of the radius, immediately in front of the ulna, and its
manner of articulation, remove any possibility of rotation, a feature
in strong contrast with what we should expect from the character of
the head.
_Measurements of Ulna and Radius._
M.
Ulna, length, excluding olecranon ·224
Ulna, length of olecranon ·080
Ulna, transverse diameter, proximal surfaces ·041
Ulna, diameter of shaft at median line ·038
Ulna, fore-and-aft diameter, distal face ·025
Ulna, transverse diameter, distal face ·017
Radius, proximal face, transverse ·048
Radius, proximal lace, fore-and-aft ·030
Radius, median diameter, shaft ·019
Radius, median diameter distal face, transverse ·043
Radius, median diameter distal face, fore-and-aft ·016
The _manus_ is described from the third and fourth metatarsals, with
three phalanges. The metatarsals are short, with a wide, stout shaft,
flat in front and slightly arched forwards behind. The proximal ends
unite and form a continuous articular face, concave from side to
side; while upon the exposed sides are smooth facets, indicating the
presence of two additional toes of less size. (See Plate III.) The
convex distal faces are marked behind by a slight groove.
The _phalanges_ are very short and broad, the lower facets marked by
a shallow median groove. The ungual phalanx is wide and short, with a
crescentic outline.
_Measurements._
M.
Third metatarsal, total length ·090
Third metatarsal, transverse diameter, proximal face ·017
Third metatarsal, transverse diameter, distal end ·019
Second phalanx, length ·024
Third phalanx ·014
Total estimated length of manus (6 inches) ·155
Palæosyops vallidens, Cope.
Proceedings Am. Phil. Society, 1872, p. 487; Hayden's Survey, 1872,
p. 572.
_Specific characters._--Founded on details of dental structure.
Superior size. In the upper molars two strong transverse ridges
connect the inner tubercle with the outer crescents, inclosing a pit
between them. In the premolars the outer crescents fuse almost into
a single ridge. These united crescents are relatively narrower. The
inner molars are also narrower, and the posterior tubercle of the
last is an elevated cone.
Fragment of a lower jaw containing the two posterior molars. The
measurements of the teeth are identical with those given by Professor
Cope. The depth of the ramus below the last molar is three and one
third inches, and it is slightly heavier below than in _P. major_.
_Restoration of Palæosyops._--The elevation of _Palæosyops major_,
which is taken as a type, was approximately the same as that of
_Palæotherium magnum_ as restored by Cuvier.
The nearly complete ilium, femur, tibia, and tarsus of _P. major_
in our possession, enable us to make the following estimate of the
elevation of the hind quarters.