PALEOCENE MAMMALS OF CENTRAL UTAH — GAZIN 17 



wider and the heel more basined than in Onychodectes and as with 

 other material known of the form the two teeth are intermediate be- 

 tween 0. tisonensis and C. comma in size and hypsodonty. 



The Dragon lower teeth do not exhibit the basal accessory cuspule 

 anteroexternal to the hypocone characterizing Onychodectes rams. 



Stylinodont, near Psittacotlierinin 



A single incisor tooth, No. 16204, apparently lower, seems most 

 certainly to belong to a stylinodont type of taeniodont. The tooth 

 is moderately worn but shows evidence of a conical labial portion 

 and a marked lingual shelf, and exhibits a heavy, transversely flattened 

 root. The tooth is about intermediate in size between corresponding 

 teeth in the types of the Puerco and Torre j on species, Wortmania 

 otanidens and Psittacotherium, rrmltifragum. The lingual shelf seems 

 more extended than in 'Wortma7iia but is not so prominent or so 

 broadened as in Psittacotherium^ and the enamel does not extend 

 down the labial wall of the tooth for so great a distance as in the 

 latter genus. 



The occurrence of a stylinodont in the Dragon fauna was to be 

 expected since this family is represented in both the Puerco and 

 Torrejon stages; in fact the line appears to be continuous through the 

 Paleocene, and into Eocene time where it is represented by the 

 genera Ectoganus and Stylinodon. 



CARNIVORA 

 Genus PROTOGONODON Scott 



PROTOGONODON? SPIEKERI ^ Gazin 



Protogonodon? spiekeri Gazin, 1938, p. 274. 



The species Protogonodon? s'piekeri was described from a right 

 lower jaw portion with Mi, Mg, and part of M3 in the Dragon collec- 

 tion obtained in 1937. Subsequent material includes a lower jaw 

 portion with M2 and isolated portions of lower molars. Upper 

 jaw material, including an M^ and a maxillary portion with part of 

 M^ and the root portion of M^, was referred to this species, but the 

 recognition of a second species, Protogonodon hiatheles^ from lower- 

 jaw material obtained from the Dragon horizon in 1939 makes doubt- 

 ful the reference of these upper teeth to P.? spiekeri^ in the absence 

 of any association between upper and lower teeth. 



The lower molars of Protogonodon? spieken, as represented by the 

 type, No. 15538 (fig. 9), correspond closely in size to those of P. 



' Named for Dr. Edmund M. Spieker. 

 302662—41 3 



