89 



de Muizon 1982a; Wyss 1988a). This is reflected here, with most monachines (with the 

 exception of Mirounga leonina, Monachus tropicalis, and Ommatophoca) sharing the 

 derived condition (state 1). In Mirounga leonina, the middle portion of the nasal processes 

 is absent, rendering this character inapplicable (state 9), while Monachus tropicalis and 

 Ommatophoca independently revert to the primitive condition (state 0). This previously 

 undocumented occurrence in Ommatophoca may derive from the failure of the nasal 

 processes to extend fully to the nasals (see character #12). Independent origins of a 

 polymorphic condition occur in Odobenus, Enhydra, and Histriophoca. The presence of 

 the derived state in this last genus (as a synapomorphy with Pagophilus) has been noted 

 by de Muizon (1982a) and Wyss (1988a). 



7) visibility of dorsal portion of nasal processes of premaxilla along maxilla in lateral 

 view: 0 = always visible; 1 = not always visible; 9 = n/a - dorsal portion not present 

 (Wyss 1988a). 



This character apparently contains less systematic information than the other two 

 characters dealing with the visibility of the nasal processes. Most species in this study 

 display the primitive condition (state 0); only Odobenus derives the condition whereby 

 the dorsal portion is not visible. Of those taxa where the dorsal portion is not visible due 

 to its absence (Cystophora, Mirounga spp, and Ommatophoca), this condition can only be 

 considered a synapomorphy of the two elephant seals. However, this last state is really 

 more of an unavoidable consequence of character #12. 



8) shape of ventral portion of nasal processes of premaxilla along maxilla: 0 = concave; 

 1 = straight; 2 = convex (Burns & Fay 1970). 



The derivation of characters #8 to 10, dealing with the shape of the nasal processes of the 

 premaxilla, in many ways parallels that of the previous suite of characters which examined 

 their visibility from a lateral view. In their more restricted focus on the Phocini, Burns & 

 Fay (1970) initially coded the present suite of characters as "nasal processes concave 

 ventrally and convex dorsally" (for Phoca and Pusa), or "wholly concave" (for Histrio- 

 phoca and Pagophilus). During our observations, we noted that these two states were not 

 sufficient to account for the range of variation observed over the larger set of taxa 

 employed here. As well, such a coding would again exclude those previously mentioned 

 genera that lack the dorsal portion of the nasal processes. Thus, the original character was 

 again subdivided into three sections, which were examined individually. 

 In the ventral regions, most species retain the primitive condition of a concave shape of 

 the nasal processes. Independent derivations of a straight morphology occur only in Odo- 

 benus, Enhydra, and Halichoerus. The convex morphology was never consistently present 

 at the species level. 



9) shape of middle portion of nasal processes of premaxilla along maxilla: 0 - concave; 

 1 = straight; 2 = convex; 9 = n/a - middle portion not present (Burns & Fay 1970). 

 Again, most species display the primitive condition of a concave shape of the middle 

 portion of the nasal processes. The apomorphic straight morphology occurs intermittently 

 throughout the Caniformia, either by itself {Enhydra, Odobenus, Erignathus, Halichoerus, 

 and Pusa caspica), or as a polymorphism with state 0 (Martes, Lutra, Procyon, Lobodon, 

 and Pusa sibirica). This distribution is explained either entirely through independent 



