109 



With recoding, this character was included in characters #58 to 61. 



58) size of incisive foramina: 0 = small; 1 = medium; 2 = large; 9 = absent (pers. obs.). 

 To our knowledge, the incisive foramina have never been used to help resolve phocid 

 phylogeny, despite readily apparent differences in size, general location, and even in their 

 presence or absence. Size, perhaps, is the most obvious character, although the functional 

 significance of any size differences is unknown. We divided the foramina roughly into 

 size classes based on the size of the foramina relative to the size of the anterior end of 

 the hard palate. Increased emphasis for assigning foramina to their appropriate size class 

 was given to their width (rather than their length; see the following character), due to its 

 greater range of variation. 



In moving towards the pinnipeds, the general trend is for a stepwise reduction in the size 

 of the incisive foramina. Canis and Ursus possess the plesiomorphic condition of large 

 foramina, with medium-sized and small foramina describing successive synapomoiphies 

 for the remaining fissipeds (excluding Lutra) and the pinnipeds respectively. Within the 

 pinnipeds, the otarioids retain small foramina, as do the two phocid subfamilies ancestrally. 

 The phocines are characterized by a reversal back to larger incisive foramina: large 

 foramina for Halichoerus and Phoca largha, and medium-sized foramina in the remaining 

 species, excluding Cystophora. The monachines largely retain small foramina. Mirounga 

 spp. (although M. leonina is polymorphic for this character) and Monachus schauinslandi 

 continue the trend to smaller foramina by losing them outright (see character #61). In 

 contrast, the remaining monk seals show a tendency to revert to larger foramina, as does 

 Hydrurga. 



59) posterior extension of incisive foramina: 0 = enclosed within premaxilla; 1 = contact 

 premaxillary-maxilla suture; 2 = extend into maxilla; 9 = incisive foramina absent 

 (Chapskii 1955a). 



In some ways, this character overlaps the previous one, as the posterior extension of the 

 foramina is a function of their size. However, whereas the previous character was more 

 a function of their width, this character deals more with their length. Our observations 

 revealed two distinct morphologies (state 0 and 2), with a somewhat arbitrary intermediate 

 (state 1). This latter state is likely not truly intermediary, but rather a modification of one 

 of the two more extreme conditions. 



The plesiomorphic state for the Caniformia is uncertain for this character. In most of the 

 basal outgroups the incisive foramina are restricted to the premaxilla, but in Canis, the 

 foramina extend well into the maxilla. In any case, the lutrines, otarioids, and the phocids 

 are all united by the possession of foramina that extend into the maxilla to varying degrees. 

 Both phocid subfamilies retain this condition primitively, before showing parallel 

 derivations of foramina that only contact the premaxillary-maxilla suture, again hinting 

 that state 1 is not a true intermediate condition. Mirounga spp. and Monachus schauins- 

 landi convergently lack incisive foramina, while Zalophus and Cystophora independently 

 re-obtain state 0. 



60) number of incisive foramina: 0 = one; 1 = two; 9 = absent (pers. obs.). 

 Surprisingly, our observations revealed that the incisive foramina are not always paired 

 (the plesiomorphic condition). Other than those forms that lack the foramina, or show 



