Archaic baleen whale from the Kokoamu Greensand: earbones distinguish a new late Oligocene mysticete (Cetacea: Mysticeti) from New Zealand

†Whakakai waipata is a new genus and species of Mysticeti from the Kokoamu Greensand (Chattian, Late Oligocene, 25–27 Ma) of ‘The Earthquakes’, North Otago. The holotype of †Whakakai waipata is a partial skull, periotics, tympanic bulla, vertebrae and scapula. The earbone morphology of †Whakakai waipata shows a unique combination of diagnostic features including: massive periotic; flange of posterior process and caudal tympanic process flooring stapedial muscle fossa; and an elongated stylomastoid fossa that invades the robust posterior process of the periotic. The tympanoperiotic features in †Whakakai waipata suggest a different acoustic niche from other Oligocene mysticetes, and by inference different feeding habits and habitat.