Neobalaenidae


Neobalaenidae is a family of baleen whales including the extant pygmy right whale. Although traditionally considered related to balaenids, a recent phylogenetic study by Fordyce and Marx recovered the living pygmy right whale as a member of Cetotheriidae, making it the only extant cetotheriid, but not all authors agree with this argument.

Taxonomy

The family Neobalaenidae was long restricted to the pygmy right whale from the Southern Hemisphere due to the unusual skeletal form of the species relative to other extant mysticetes. Until the early 2010s Neobalaenidae was unknown from the fossil record despite a study by Sasaki et al. placing the divergence date of Neobalaenidae from other living baleen whales at 23 mya.
Fordyce and Marx found that the pygmy right whale formed a well-supported clade with Eschrichtiidae and Balaenopteridae based on molecular data, and that, within 'cetotheres', it was most closely related to the herpetocetines, rendering the pygmy right whale the only living species of Cetotheriidae. For his part, Bisconti described the first pygmy right whale from the fossil record, Miocaperea, from the Pisco Formation of Peru. Bisconti et al., however, found, based on morphological data, it to be more closely related to Balaenidae, but added that additional specimens are expected to resolve these conflicting results within a few years. Cladistic analyses by Gol'din & Steeman and Gol'din partly agreed with Fordyce and Marx in recovering neobalaenids as closer to cetotheres than to Balaenidae, but disagreed with their recovery of the pygmy right whale as a herpetocetine, instead recovering Neobalaenidae outside Cetotheriidae.

Fossil record

Examples of Neobalaenidae in the fossil record include Miocaperea, a couple of indeterminate earbones from Australia, and specimens from Pleistocene localities in the Northern Hemisphere.