102 



pinnipeds (including the phocines) is enlarged as compared to fissiped carnivores (a 

 potential synapomorphy), this expansion is not as great in the phocids. In the otarioids, 

 the expansion is very great and the vacuity eclipses the bone situated dorsal to it (either 

 the frontal or the orbitosphenoid). The monachines secondarily approach the otarioid 

 condition, with the sphenopalatine vacuity generally contacting the margin of the dorsally 

 neighbouring bone, and, in a few isolated cases, eclipsing it, but never to the degree found 

 in the otarioids. 



42) relationship of sphenopalatine foramen and pterygopalatine canal: 0 = totally confluent, 

 only single foramen visible; 1 = confluent, but individually distinguishable; 2 = separate 

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



The enlarged sphenopalatine vacuity of the pinnipeds makes exact identification of 

 foramina in this area difficult. Burns & Fay (1970) state that the vacuity in this region is 

 either homologous with, or includes only a part of, the sphenopalatine foramen. Our 

 observations of an apparent intermediate state (state 1), whereby a single sphenopalatine 

 vacuity is obviously composed of two broadly confluent foramina, hints at the latter. As 

 no one to our knowledge has examined this region in detail for the pinnipeds, the 

 identification of the second foramen cannot be absolute; however, it is likely the 

 pterygopalatine canal. This conjecture is not without precedence, as Davis (1964) describes 

 the confluence of these two cavities into a single foramen in Ailuropoda (albeit not 

 enlarged into a vacuity as in the pinnipeds). As well, these two cavities are irregularly 

 confluent throughout the carnivores (Story 1951). 



Having the sphenopalatine foramen separate from the pterygopalatine canal is indeed 

 plesiomorphic among the Canifonnia, with their total confluence to a single foramen being 

 a synapomorphy of the lutrines plus the pinnipeds. (It should be noted that there is no 

 objective way to discriminate between the confluence of the cavities and merely the loss 

 of one of them.) This state is retained throughout most of the pinnipeds except for the 

 phocines, which display both the primitive pinniped (state 0) and "intermediate" (state 1) 

 states. The intermediate condition unites at least some (DELTRAN optimization), or all 

 (ACCTRAN optimization) of the phocines, with a variable number of reversals accounting 

 for state 0. It should be noted that many phocids were polymorphic for this character, and 

 that these polymorphisms included various combinations of all states, including the 

 plesiomorphic state 2. 



43) continuity of sphenopalatine vacuity and widened maxillo-frontal suture: 0 = separate; 

 1 = confluent; 9 = n/a - widened maxillo-frontal suture absent (Burns & Fay 1970; pers. 

 obs.) (Fig.20). 



The expansion of both the maxillo-frontal suture and the sphenopalatine vacuity in the 

 pinnipeds leads to the possibility of their confluence. Burns & Fay (1970) indicate that 

 this is a relatively frequent occurrence among the phocines. The distribution of this 

 character follows the major trends of either of its constituent characters (#31 or 41). The 

 lack of a widened maxillo-frontal suture in most outgroup taxa renders the "inapplicable" 

 condition (state 9) as symplesiomorphic. In phocids, a widened maxillo-frontal suture is 

 almost universally present (missing only in Pagophilus), so the distribution of the current 

 character relies more on the morphology of the sphenopalatine vacuity. The more restricted 



