HOLLAND AND PETERSON: OSTEOLOGY OF THE CHALICOTHEROIDEA. 230 
CHAPTER V. THE OSTEOLOGY OF MOROPUS. 
Tue Heap. 
(Plates XLVITI-LIII.) 
The Cranium.—While an abundance of material representing the limbs and 
feet of Moropus has been recovered, and the supply of vertebree obtained from 
the quarries opened by the Carnegie Museum is not inconsiderable, crania in an 
absolutely perfect condition have not been found. The nearest approach to a 
perfect specimen is the fine cranium belonging to the mounted specimen of Moropus 
elatus, which was obtained by Mr. Peterson in the quarry on the west side of 
Carnegie Hill in the month of September, 1908, and which is catalogued as No. 
2103. The premaxillaries in this specimen are missing, and the top of the cranium, 
while preserving its contour, has been crushed downward upon the teeth. The 
line of weakness along which the crushing has taken place extends horizontally 
from a point near the posterior end of the zygomatic arch forward to the point of 
union of the premaxillaries with the maxillaries. A disarticulated and somewhat 
fragmentary cranium of an immature specimen of M. elatus was recovered in 1908 
and catalogued as No. 2104. A smaller specimen, representing Moropus petersoni 
Holland, was found in a more or less disarticulated condition and has been skill- 
fully restored by Mr. Peterson, enabling a comparative study of this cranium 
to be made. In addition to these two specimens a number of other portions of 
crania in a more or less fragmentary condition have been recovered. The speci- 
mens consist of fragments of the maxillaries with the teeth, in several cases quite 
well preserved, and dislocated parts of the occipital region. Prof. E. H. Barbour, 
as has been previously stated, secured the lower portion of a cranium of Moropus 
elatus with the premolar-molar series of teeth lacking the first premolar in a good 
state of preservation on both sides. Upon this he based a brief article published 
in the Reports of the Geological Survey of Nebraska, Vol. III, No. 2. The chief 
value of this specimen is derived from the fact that it enables a very thorough 
study of the palatal region of the skull to be made from above as well as below, 
in this respect offering some advantages which are not to be derived from the more 
complete specimen obtained by Mr. Peterson. Professor Barbour has given us 
an outline drawing of this specimen as well as some reproductions of photographs, 
which are not quite as distinct as might be desired. Through the kindness of 
Mr. Harold Cook, the writer has been allowed to study and describe the posterior 
portion of the upper surface of a cranium found by Mr. Cook, which belongs 
to Moropus petersont. This is shown in Fig. 14. 
