MERYCOIDODON 51 



Scott (1890B, pp. 322 et seq.) described very fully the skeleton of this genus, and the following 

 excerpts I have translated freely from his work. 



The atlas resembles more that of the swine than that of the ruminants in that it is short, with widely 

 expanded transverse processes; the neural canal is short and flattened and has a rudimentary neural spine; the 

 lower surface is deeply excavated between the somewhat flat articular fossa: and has a definite hypapophysis. The 

 upper surface is pierced by foramina for the two branches of the first cervical nerve, and the transverse process is 

 carried out from the canal for the vertebral artery. . . . The axis is very peculiar and in many respects occupies a 

 middle position between that of the swine and that of the ruminants. The body is short and wide, and on the 

 lower side there is a strong ridge, with a tubercle aft; the centrum is much more opisthocoelous than in the 

 swine; the odontoid process is very characteristic and for the most part resembles that of Anoplotherium ; it is 

 short and very wide, and the lower side is very convex and the upper mostly flat, although in some specimens this 

 side is somewhat excavated; the anterior border is rounded. The articular surfaces for the atlas are wide and 

 very low and extend upward scarcely more than the height of the bottom of the spinal canal, and the two surfaces 

 do not touch below the odontoid process, while in the ruminants these surfaces almost entirely surround the 

 canal. The transverse processes are short and slender and originate at the vertebrarterial canal; the roots of the 

 neural arch are not pierced by the second spinal nerve, which is a deviation from most of the living artiodactyls, 

 although this condition is present in Anoplotherium ; the neural spine is very large and ax-like in shape. The 

 remaining cervical vertebra; resemble in general those of the ruminants; the bodies are fairly short and opistho- 

 coelous and possess a strong inferior ridge having a posterior tubercle (with the exception of the sixth and 

 seventh); in all anterior to the seventh the transverse processes are pierced; the inferior lamella is very large in 

 the sixth and small in the third, fourth, and fifth; the transverse processes of the seventh are long and slender 

 and extend directly outward. The neural arches are elongated fore and aft and are not pierced by foramina for 

 the spinal nerves. The spinal processes are differently developed; the third vertebra has simply a low ridge; 

 the fourth, fifth, and sixth have short laterally compressed spines; while in the seventh the process is longer and 

 stronger. . . . 



The centra of the dorsal vertebra: are small, and the spinal processes are fairly small and slender. They 

 number 14 vertebra-. 



The lumbars are large and have massive, somewhat opisthoccelous centra, which in the posterior vertebra 

 become very low; the spinal processes are fairly low but are expanded fore and aft; the transverse processes are 

 wide and of moderate length. . . . Although the cervicals and dorsals of Orcodon have many similarities with those 

 of Tragulina, the lumbars are very different in the two groups. . . . The number of the sacral vertebra: is different 

 according to the age of the individual; in young specimens it is four, in older ones five. . . . 



Although no examples of Oreodon known to me possess a completely preserved tail, yet the many vertebra: 

 still present prove that the animal did have a very long tail, even as long apparently as in Anoplotherium. The 

 anterior caudals are proportionately short and wide and have all the processes well developed. Next there follows 

 a long row, with elongated bodies and reduced processes, while the posterior vertebra: are composed of simple bony 

 rods. I have up to now been able to find no trace of inferior arches. . . . 



The ribs show many characteristics similar to those of Hyrax and the Tragulida:. The four anterior ribs 

 are flattened and wider than those following; the other ribs are long and slender and oval in cross section. . . . 



The sternum is more like that of the Tragulid.x than like that of the true ruminants. The manubrium is 

 long, narrow, and rounded, is not laterally compressed and is furnished with a keel. The second section of the 

 sternum is shorter and wider than the first, but otherwise similar; the third section is short and flattened. 



The scapula is high, narrow, and triangular; the glenoid cavity is flat and nearly circular, and the coracoid 

 is small, even less developed than in Tragulus. The neck is long, slender, and rounded, and above it the anterior 

 border extends in an almost straight line but curves gradually to pass over into the roughened suprascapular 

 border; the posterior border is also almost straight and forms a right angle with the suprascapular border. The 

 spine rises abruptly to form a high, but only slightly projecting acromion, much as in Traguha. The position of 

 the spine is that customary in the older artiodactyls (for example, Anoplotherium and Hyopottimus) in that the 

 anterior and posterior fossae are almost equal in size, while in nearly all of the living artiodactyls the spine is moved 

 toward the front. . . . To summarize, the scapula of Oreodon has assumed the slender, triangular form char- 

 acteristic of the living selenodonts, while at the same time retaining many older characteristics. 



The humerus differs from that of all living artiodactyls. This bone is short and heavy; the shaft is strong 

 and shows well developed edges and ridges serving for muscle attachments; the head is large and fairly flat and 

 curves strongly behind; the external protuberance is very massive and rises much above the head; its upper 

 border is simply arched. The process which overhangs the biceps groove is almost entirely lacking in the external 

 tuberosity. The internal tuberosity is very small and hook-like in shape; the biceps groove is very wide and 



