The carotid circulation in seals and sea lions

The cephalic arterial pattern in pinnipeds is described on the basis of corrosion specimens. The results are discussed on an ontogenetic and phylogenetic basis, with special reference to a possible relationship between the pinniped superfamilies and recent fissipeds, especially in relation to current theories on a mono-or biphyletic origin. The cephalic arterial pattern seems to indicate a common pinniped ancestry, but unlike the general theory, from rather undifferentiated arctoids