1922] Kellogg: Pinnipeds from Miocene and Pleistocene Deposits 63 



This skull was sent by Condon 81 to Wortman for examination. The 

 results of his observations were given by Condon as follows : 



The rapid reduction of the molars, the massiveness of the zygomatic arch, the 

 relation of the paroccipital to the mastoid, especially the large size and backward 

 projection of the former, the massive symphysis and great depth of the lower jaw, 

 the great interorbital constriction, the general aspect of the skull and the structure 

 of the fourth premolar, are all features characteristic of the creodonts especially of 

 Patriofclis. 



He adds further that "while there are certainly some strongly 

 marked creodont features it is yet far removed from any known 

 member of that group. ' ' 



It is surprising to note that the earliest known member of the 

 Otariidae on the Pacific coast possessed teeth very similar to those 

 possessed by Eumetopias jubata. The molariform teeth of Allodesmus 

 fail to throw much light on the evolution of this family. All the 

 premolars and molars referred to this form possess a haplodont crown 

 in which the main cusp is probably the paracone which has been 

 developed at the expense of the degenerating inner cusps. The second 

 lower molar, however, differs in many respects from the first lower 

 molar, owing, it may be, to degeneration or to the process of reduction. 

 The teeth of Allodesmus differ but little from those of Eumetopias 

 except that as a rule the teeth of the latter appear to be subjected to 

 much more abrasion. 



If we may judge from analogy of the teeth possessed by this 

 Temblor form to those of the existing genus Eumetopias, we may be 

 fairly certain that it was dependent upon soft shelled animals or in 

 all probability forms very similar to those eaten by the latter today, 

 such as squids and cuttlefish. The Odobenidae very likely were begin- 

 ning about this time to give up competing with forms like Allodesmus 

 for similar types of sea food, for we know that competition is most 

 severe between the nearest related species. 



The teeth of the earliest known otarids, as mentioned before, are 

 very similar to those possessed by the living species. Zalophus and 

 Eumetopias have lost the second upper molar, but it is variable in its 

 presence in both Callotaria and Arctocephalvs. On the other hand, 

 both Callotaria and Arctocephalvs appear to be more highly specialized 

 in some respects. The molariform series are simple and conical ; 

 Callotaria may possess accessory cusps, but the tendency is for them 



si Condon, T., op. oit., p. 14. 



