The phocid seals present an interesting puzzle within mammahan 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 detailed character analysis is also presented, including historical notes and the evolutionary pathway implied for each character from our cladogram. As well, comments regarding selected areas of cladistic methodology are also made.