200 



TITANOTHERES OF ANCIENT WYOMING, DAKOTA, AND NEBRASKA 

 Eometarhinus Osborn, 1919 Eometarhinus huerfanensis Osborn, 1919 



Cf. Eometarhinus, this monograph, page 419 

 Original reference. — Am. Mus. Nat. Hist. Bull., vol. 

 41, pp. 568, 569, 1919 (Osborn, 1919.494). 

 Generic characters. — Osborn writes: 



Small; ancestral to Metarhinus; with rudimentary frontonasal 

 horn; nasals elongate; overhanging premaxillaries, decurved as 



Cf. Eometarhinus huerfanensis, this monograph, page 420 



Original reference. — Am. Mus. Nat. Hist. Bull., vol. 

 41, pp. 567-569, fig. 6, 1919 (Osborn, 1919.494). 



Type locality and geologic horizon. — Huerf ano-Muddy 

 divide, 3 miles west of Gardner, Huerfano Basin, Colo.; 

 Huerfano formation, 205 feet below top (Huerfano B). 



Figure 156. — Type (holotype) skull of Eometarhinus huerfanensis 



11. Mus. 17412. After Osborn, 1919. A, Nasals, superior view; Ai, Aj, sections; B, skull, view of 

 left side; C, right upper jaw and teeth. One-half natural size. 



in Metarhinus; no infraorbital shelf; characters apparently in- 

 termediate between those of the Metarhinus and Mesatirhinus 

 phyla. 



Etymology. — rjcos, dawn; Metarhinus, a genus of the 

 middle Bridger beds; indicating an ancestral form of 

 Metarhinus. 



Present determination. — This genus appears to be 

 ancestral to the Dolichorhinus phylum. 



Type. — Anterior portion of skull (Am. Mus. 17412). 

 (See fig. 156.) 



Specific characters. — Inferior in all measurements to 

 Mesatirhinus megarhinus. Premolars with small deu- 

 terocone. p'-m', 124 millimeters ; p'-p*, 53; m'-m', 72. 



Etymology. — huerfanensis, in allusion to type locality. 



Present determination. — A valid specific stage. 



