100 



*35) degree of invagination of maxillary (anteroventral) edge of widened maxillo-frontal 

 suture: 0 = none to slight; 1 = medium or greater; 9 = n/a - maxilla and frontal in contact 

 (pers. obs.) (Fig.20). 



With recoding, this character was included in character #3 1 . 



*36) degree of invagination of frontal (posterodorsal) edge of widened maxillo-frontal 

 suture: 0 = none to slight; 1 = medium or greater; 9 = n/a - maxilla and frontal in contact 

 (pers. obs.) (Fig.20). 



With recoding, this character was included in character #3 1 . 



*37) anterior process of orbitosphenoid: 0 = absent / barely extends onto palatine; 1 = 

 present (pers. obs.) (Fig.20). 



With recoding, this character was included in character #38. 



38) degree of anterior extension of orbitosphenoid: 0 = extends to distinctly less than one- 

 half length of palatine; 1 = extends to about one-half length of palatine; 2 = extends to 

 distinctly greater than one-half length of palatine; 9 = absent / barely extends onto palatine 

 (Wozencraft 1989; pers. obs.) (Fig.20). 



In attempting to determine the relative position and size of the sphenopalatine foramen, 

 we noticed that the length of the orbitosphenoid (with respect to the palatine) varied 

 among, but was more or less constant within the different phocid species. To our 

 knowledge, this has only been reported briefly for the otarioids (Wozencraft 1989), but 

 never fully examined in a systematic context. The primitive condition is one in which the 

 orbitosphenoid extends into the anterior half of the palatine, a condition found in most of 

 the outgroups. (This assessment of state 1 for Odobenus is somewhat tentative due to the 

 tremendous compression of the interorbital region that characterizes this genus, obscuring 

 and modifying the exact relationships between the orbitosphenoid and palatine bones.) 

 This plesiomorphic condition is retained primitively in the phocids and characterizes nearly 

 all phocines. In contrast, the monachines derive state 1 ancestrally. The terminal branches 

 of this subfamily (Lobodon plus Monachus spp.) display a tendency to reduce the 

 orbitosphenoid further, but only Monachus tropicalis (and independently in Erignathus) 

 essentially lack any anterior extension (state 9). 



The above distribution of this character could be related to the length of the interorbital 

 region. A relatively short orbitosphenoid could arise through either a truly shortened 

 orbitosphenoid, a lengthened interorbital region filled in dorsally by the frontal, or a 

 combination of these two factors. The relatively shorter orbitosphenoid of the phocids is 

 due at least in part to their proportionately larger orbits as compared to the remaining 

 caniforms (King 1972). Although this may explain the relatively reduced phocid 

 orbitosphenoid, it does not appear to apply specifically within the phocids, as the phocids 

 with the largest orbits - Cystophora, Leptonychotes, Mirounga spp., and Ommatophoca 

 (King 1972) - do not possess the shortest orbitosphenoids. Likewise, Lobodon, which 

 possesses a relatively small orbit (King 1972), does not have the predicted relatively long 

 orbitosphenoid. 



39) ethmoid / turbinal bones in wall of interorbital region: 0 = absent; 1 = present (pers. 

 obs.). 



