Cetotheriidae

The Pygmy ( Caperea marginata ), the only extant species of Cetotheriidae.

Worldwide

The Cetotheriidae are a family from the suborder of baleen whales ( Mysticeti ). The family appeared in the late Oligocene and it was assumed that they disappeared with the early Pliocene again, until recently the smallest of all extant baleen whales, the only 6 feet long expectant and occurring in temperate and cold seas of the southern hemisphere Pygmy ( Caperea marginata ) as member of the Cetotheriidae was identified.

Features

From other baleen whales, the Cetotheriidae be a combination of the following anatomical skull characteristics were different (list not exhaustive):

The interface between the upper jaw bone ( maxilla ) and prefrontal ( frontal ) is slightly concave and obliquely to the back pages. The rear portions of the nose bone ( Rostrum ) form a V-shaped wedge between the orbits. The upper parts of the maxillary bones have contact with each other or are close together. The premaxillary bone ( premaxilla ) is close to the back, along the nasal bone ( nasal ) and does not extend to the rear portions of the maxilla. The nasal bone is triangular and wedge-shaped. At its dorsal apex of the frontal bone is reduced or completely overgrown by Rostralknochen. The joint socket of the leg scales ( squamosal ) is indented not deep. Like all other baleen whales are the Cetotheriidae toothless.

A feature shared by both the Cetotheriidae with the furrows whales ( Balaenopteridae ), is the strong integration of the Rostralknochen with the rest of the skull bones and the maxilla.

Outer systematics

The Cetotheriidae are the sister group of the rorqual, both families together, united as a family Balaenopteroidea, in turn, the sister group of right whales are ( Balaenidae ).

Right whales ( Balaenidae )

Cetotheriidae

Rorqual ( Balaenopteridae )