Recognizing Certain Species of Beaked Whales of the Pacific Ocean

Abstract

The distinguishing characteristics of beaked whales of the family Ziphiidae, genus Mesoplodon, which have born the species names bowdoini and stejnegeri, are here re-examined from greater numbers of specimens and in greater morphological detail of the skull than has been attempted by any previous investigator. The specimens personally examined are of species limited, as presently known, to the Pacific Ocean, and they sort out morphologically and geographically into: 1. a boreal or subarctic sample of nine animals (of 13 known) which is now demonstrated by several characters of the skull to be a distinct species, properly bearing the species name stejnegeri True, 1885; 2. a South Temperate sample of one (of two known) observed also to be distinct at the species level and properly bearing the name bowdoini Andrews, 1908; and, 3. a North Temperate sample of four (five known) is shown to be morphologically distinct and is recognized as a new species, M. carlhubbsi. A diagnosis of the new species distinguishes it from all the congeneric Pacific species-bowdoini, ginkgodens, stejnegeri, layardi, grayi, and densirostris-that are enough like M. carlhubbsi to have the tooth of the male rise high above the alveolus, by at least four characters of the skull each.