212 



THE MERYCOIDODONTIMi 



The young skull has smaller facial vacuities and less bizygomatic width, and the temporal 

 ridges unite farther aft than in the older specimen. The latter may have been a male, as the bone is 

 much heavier and more rugose and the skull is wider, which may be interpreted either as sex char- 

 acters or as those of old age. 



The younger skull shows that this genus was easily derived from Ticholeptus in that many of its 

 features are intermediate between the two genera. 



Metoreodon cf. M. profectus Matthew and Cook 



Original Reference: In Gazin, C. L., A Miocene mammalian fauna from southeastern Oregon. 

 Carnegie Inst. Wash. Publ. No. 418, pp. 81-82, fig. 15 b, 1932 (? Ticholepus sp.). 



Locality: Twenty-eight miles south of Harper, Malheur County, Oregon, and approximately three miles 

 northwest of Skull Spring. 



Geologic Horizon: Upper Miocene (Skull Spring). 



Material: Cat. Nos. 388 and 389 U.C.M., inferior fourth premolars. 



Description: These teeth resemble closely the P 4 in M. profectus, except that the bifurcation 

 of the anterior end is more advanced. The anterior part is not so much reduced as it is in M. relictus, 

 thus resembling much more the condition seen in M. profectus. I should hesitate to refer these 

 teeth definitely to the latter species, but I do not hesitate to place them in Metoreodon. 



Fig. 154. — Metoreodon relict i, 



Matthew and Cook. Mandible and dentition. GHT. 

 Nat. size. (After Matthew and Cook, 1909.) 



Cat. No. 140 56 A.M.N.H. 



Metoreodon relictus Matthew and Cook 1909 

 Figs. 5, 1 54 



Original Reference: A Pliocene fauna from western Nebraska. Bull. Amer. Mus. Nat. Hist., XXVI, 

 Art. 27, pp. 392-393, fig. 14 (Merychyus [Metoreodon] relictus). 



Type Locality: Twenty-three miles south of Agate, Sioux County, Nebraska. 



Geologic Horizon: Upper Miocene (lower Snake Creek). 



Types: Genoholotype, Cat. No. 14056 A.M.N.H., right lower jaw, with teeth moderately worn, the part 

 posterior to M 3 as well as the canine missing, and also the incisors and M 2 . Paratypes, all in A.M.N.H., Cat. 

 Nos. 14057 and 14058, parts of lower jaws, and Cat. No. 14065, part of an upper and lower jaw. 



Mandible: The symphysis is moderately strong, with a symphysiodental angle of approxi- 

 mately 44°. The horizontal ramus is comparatively slender. 



