Pinniped

A suborder of the order Carnivora that includes the families:

1. Otariidae, the "eared seals" or "walking seals" (sea lions and fur seals)
2. Phocidae, the "true seals" or "earless seals"
3. Odobenidae, the walruses

There has been some debate in taxonomic circles about whether seals, sea lions, and walruses share a common land ancestor or are the products of convergent evolution. If the latter is the case, "Pinnipedia" would be a nonphyletic grouping with no taxonomic meaning. Recent studies of mitochondrial DNA, however, have lent credence to the monophyletic hypothesis: that is, the evidence is currently on the side of a single-ancestor theory.