C-H TSAIFordyce R.E.2018-09-102018-09-102018-0403036758https://doi.org/10.1098/rsos.172453http://scholars.lib.ntu.edu.tw/handle/123456789/402143Whakakai 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. http://zoobank.org/NomenclaturalActs/9D04EC04-1425-4631-9B96-3C279C51E928 http://zoobank.org/urn:lsid:zoobank.org:act:9D04EC04-1425-4631-9B96-3C279C51E928Ecology; fossil; hearing; morphology; skull; tympanoperioticjournal article10.1098/rsos.172453