154 



number of character states to account for all permutations of the relative sizes of the two 

 elements. 



The plesiomorphic condition is for the second metacarpal to be the longer of the two, a 

 situation found in all fissiped outgroups except for Enhydra and Ursus, where the 

 metacarpals are subequal in length. The pinnipeds are united by the apomorphic condition 

 whereby the first metacarpal is distinctly longer. As expected, most phocines are diagnosed 

 by having metacarpals of equal length. Cystophora retains and Pusa sibirica reverts to the 

 primitive pinniped morphology. 



168) comparative overall diameter of metacarpals I and II: 0 = I > II; 1 = I subequal to 

 II; 2 = I < II (King 1966; Wyss 1988a). 



The comparative robustness of metacarpals I and II follows much the same pattern as their 

 length, except that only scattered phocines reverse towards a more subequal arrangement. 

 An enlarged first metacarpal is a pinniped synapomorphy, with the fissipeds characterized 

 by a second metacarpal of equal (all fissiped arctoids) or greater {Cards only) diameter 

 than the first. State 0 is found universally in the otarioids and monachines, and is largely 

 retained throughout the phocines as well. Only Erignaihus, Phoca largha, and Pusa 

 caspica independently reverse to obtain the condition where the two elements are roughly 

 equal in diameter. 



169) relative degree of development of foreflipper claws: 0 = not well developed or absent; 

 1 = well developed, prominent (King 1966; Wyss 1988a). 



There is the tendency within the pinnipeds (exclusive of the phocines) to reduce both the 

 fore- and hind flipper claws (Wyss 1988a; see character #189). In the otarioids, the 

 foreflipper claws are virtually absent, remaining only as small nodules (Wyss 1988a). 

 Although only Hydrurga and Ommatophoca possess reduced foreflipper claws among 

 monachines (King 1966), Wyss (1988a) holds them to be reduced for the subfamily, thus 

 describing a pinniped synapomorphy with a reversal occurring in the phocines. For those 

 species where adequate preserved material was lacking, we supplemented our observations 

 with data from King (1966). Here the apomorphic reduction of the foreflipper claws 

 occurred independently in only the otarioids, Hydrurga, and Ommatophoca. 



Pelvis (8 characters) 



The general form of the phocid pelvis is very distinctive from that of other carnivores (de 

 Muizon 1982a), lending additional support to the monophyly of the group. However, rather 

 than concentrate on the autapomorphic features of the phocid pelvis, we have attempted 

 to examine characters that clarify either the ingroup (i.e., within the phocids) or outgroup 

 relations of the family. 



170) eversion of wing of ilium: 0 = distinctly less than 45°; 1 = roughly 45°; 2 = distinctly 

 greater than 45° (King 1966; Wyss 1988a). 



The phocids are uniquely characterized by a laterally everted ilium (King 1966; de Muizon 

 1982a; Wyss 1988a). The degree of eversion is markedly greater in phocines (exclusive 

 of Erignathus) than in monachines, often reaching 90° (Howell 1928; King 1966; Wyss 

 1988a). In the phocines especially, this eversion benefits the tremendously enlarged 

 iliocostalis portion of the back musculature which originates, at least in part, from the 



