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systematic opinion. Ideally, the whole area of phocid biogeography needs to be re- 

 examined, with an eye not only to paleontological and systematic data, but also to other 

 historical lines of evidence (e.g., oceanic currents, potential migration routes, glaciation 

 events, competition from other organisms). In the near future, however, any hypotheses 

 will continue to be hindered by the poor fossil record of the family and that of the 

 pinnipeds as a whole. Fortunately, interest in pinniped paleontology has increased in recent 

 years, leading to many new finds, particularly in the southern hemisphere. We would 

 suggest that additional effort should also be focused around the region of Central America 

 to test the hypotheses of the initial eastward migration of the phocid ancestors through 

 the Central American Seaway and the subsequent return migration of the ancestors of 

 Monachus schauinslandi. Once all this new material is properly described and analyzed, 

 a more comprehensive attempt at explaining the biogeographic distribution of the phocids 

 can truly be made. 



ABSTRACT 



The phocid seals present an interesting puzzle within mammalian systematics. The undue 

 attention focused on their contentious ancestral affinities (together with the ongoing debate 

 over pinniped origins) has contributed, in part, to their internal phylogeny remaining 

 reasonably poorly studied. Therefore, a species-level cladistic analysis was undertaken to 

 resolve the overall phylogeny of this family. All recent phocid species were examined 

 (including Monachus tropicalis), using representatives of all major extant caniform 

 lineages as outgroups. 168 morphological characters (primarily osteological, and primarily 

 those of the head skeleton) were examined. 



A parsimony analysis using PAUP 3.1.1 revealed two equally most parsimonious solutions, 

 each with a consistency index (corrected for uninformative characters) of 0.456. The recent 

 supposition of a monophyletic Pinnipedia was upheld, albeit with lutrine, and not ursid 

 affinities. However, this latter point may be an unnatural resolution of a real polytomy 

 within the evolutionary history of the arctoids. A monophyletic Otarioidea formed the 

 immediate sister group to the phocids. Within the phocids, reasonable support for both 

 traditional subfamilies was found, albeit with novel relationships within each, particularly 

 for their basal taxa. Both Monachus spp. and Erignathus, which have universally been 

 viewed as the most primitive members of their subfamilies (Monachinae and Phocinae 

 respectively), are held here to hold more derived positions (with strong support for a 

 monophyletic Monachus as well), rendering the Antarctic Lobodontini and Arctic Phocini 

 paraphyletic respectively. We suggest that perhaps undue attention has been focussed on 

 the admittedly primitive features of both genera at the expense of other apparently more 

 derived ones. Instead, the basal positions within each subfamily are suggested to be 

 occupied by Mirounga spp. and Cystophora respectively, leading to the possibility that 

 the diagnostic features of the now abandoned subfamily Cystophorinae may be based, to 

 some degree, on phocid symplesiomorphies. Together with various statistical tests and 

 comparative tools, reasonable support was indicated for this pattern of phylogenetic 



