Middle/late Miocene hoplocetine sperm whale remains (Odontoceti: Physeteridae) of North Germany with an emended classification of the Hoplocetinae

摘要

Hoplocetus ritzi n. sp. is a new hoplocetine physeterid from the Bolboforma fragorilsubfragoris Zone of the middle/late Miocene mica-clay of GroB Pampau in Schleswig-Holstein, North Germany. The Hoplocetinae are known from the early Miocene to the Pliocene. Comparative studies of cranial characters and tooth morphology allow an emended diagnosis of the Hoplocetinae Cabrera, 1926. Four genera, Diaphorocetus, Idiorophus, Scaldicetus, and Hoplocetus are included in this subfamily. The pattern of functional tooth wear deduced from the described Hoplocetus ritzi n. sp. remains is reminescent of that known from Orcinus orca. The hoplocetine physeterids possibly occupied the killer whale niche before the killer whales appeared during the middle Pliocene.