Physeteridae

Evolution

The close relationship between extant Physeteridae and Kogiidae is confirmed in recent molecular studies using mitochondrial cytochrome b,; on the basis of these analyses, their nearest relatives appear to be the Ziphiidae on one hand, and the Mysticeti and Platanistidae on the other. The last cited paper also favours the grouping of Physeteridae and Kogiidae in a single superfamily, Physeteroidea, as has sometimes previously been suggested. Bianucci & Landini, 2006 suggest that Diaphorocetus, Zygophyseter, Naganocetus, and Aulophyseter antedate the inferred split of the Kogiidae and Physeteridae, thus would restrict the family Physeteridae to those genera that postdate this split (a cladistic view).