« 



101 



One manifestation of the numerous defects in ossification mentioned previously for phocid 

 skulls (see character #31) apparently allows for the normally covered ethmoid to form a 

 part of the wall of the interorbital region. Howell (1928) suggests that the visibility of the 

 ethmoturbinals in Pusa hispida is due to their crowding by the extremely narrow 

 interorbital region, causing them to force their way through the overlying frontal bones. 

 In any case, this derived condition seems to be independent of the other major defect in 

 the interorbital region, the widened maxillo-frontal suture (character #31), and only occurs 

 consistently for Zalophus and Mirounga angustirostris. Lobodon is polymorphic for this 

 trait, and Erignathus, although unrecognized here, also shows a strong tendency towards 

 this trait. 



40) approach of palatine to lacrimal region: 0 = does not reach lacrimal region; 1 = reaches 

 or almost reaches lacrimal region (Wozencraft 1989). 



In most mammals (but, significantly, excluding the lutrines), the maxilla is restricted to 

 the facial region, causing the anterior orbital wall to be formed by some combination of 

 the lacrimal, frontal, palatine, and jugal (Wyss 1987). However, the unique condition of 

 a reduced lacrimal in pinnipeds allows the maxilla to expand posteriorly to contribute to 

 the medial surface of the anterior orbital wall (Wyss 1987). Together, these two features 

 reduce the contact between the lacrimal (or lacrimal region for those taxa lacking a distinct 

 lacrimal) and either the palatine or jugal (see character #54). Both states of reduced contact 

 have been described as a synapomorphies for a monophyletic Pinnipedia only (Wyss 1987; 

 Wyss & Flynn 1993), although the latter case may characterize the lutrines as well (see 

 character #54). 



The above scenario is generally echoed here, with most outgroups displaying the primitive 

 condition, in which the palatine closely approaches or reaches the lacrimal region. The 

 converse of this condition is a synapomorphy of either Martes, the lutrines, and the 

 pinnipeds, with a reversal in Enhydra (ACCTRAN optimization), or of Eutra and the 

 pinnipeds alone, with a parallel appearance in Martes (DELTRAN optimization). 



41) location of sphenopalatine vacuity: 0 = enclosed in palatine; 1 = not enclosed in 

 palatine (Wozencraft 1989) (Fig.20). 



As originally coded by Wozencraft (1989), the derived condition, shared only by the 

 otarioids, was one where the sphenopalatine vacuity was enlarged and eclipsing the 

 orbitosphenoid dorsally. This condition, he further noted, was a function of both the 

 enlargement of the orbital vacuity, including the sphenopalatine foramen (see character 

 #42), and the length of the orbitosphenoid. As we have previously dealt with the relative 

 length of the orbitosphenoid (character #38), we have employed a more generalized 

 coding, asking merely if the sphenopalatine vacuity is limited to the palatine or not. 

 Even under our modified coding, this character is still a potential synapomorphy of the 

 otarioids. Most of the taxa in this study possess the primitive morphology of an enclosed 

 sphenopalatine vacuity. The derived condition is found only in the otarioids and in most 

 of the monachines. However, there is some uncertainty as to whether this represents 

 convergence between the two groups (DELTRAN optimization), or a synapomorphy, with 

 the phocines reversing to the plesiomorphic condition (ACCTRAN optimization). It seems 

 more likely that the former situation is true. Although the sphenopalatine vacuity in all 



