The morphology and systematics of New Zealand fossil cetacea [article]

R. Ewan Fordyce, University Of Canterbury
Previous work on New Zealand fossil Cetacea is reviewed. The formally described specimens of Kekenodon onamata, Squalodon serratus, a protosqualodontid, Austrosqualodon trirhizodonta, Prosqualodon hamiltoni, Prosqualodon marplesi, Squalodon andrewi, Microcetus hectori, Tangaroasaurus kakanuiensis, Phocaenopsis mantelli, an "archaeocete" braincast, an odontocete braincast, Mauicetus parki, M. brevicollis, M. lophocephalus, and M. waitakiensis are redescribed and/or reappraised. Other New Zealand
more » ... . Other New Zealand fossil Cetacea, predominantly Oligocene in age, are redescribed. Three Late Eocene specimens include aff. Dorudon, and indicate 1 the early presence of archaeocetes in New Zealand. Four Early Oligocene Cetacea comprise one Cetacea incertae sedis, the earliest recorded odontocete, and. the two earliest recorded mysticetes. Evolution of odontocetes and mysticetesin southern oceans at this time reflects the advent of new feeding strategies triggered by changes in oceanic trophic regimes. Mid Oligocene Cetacea include archaeocetes {Kekenodon}, odontocetes {e.g. squalodonts} and mysticetes {e.g. "Mauicetus"}. Mysticete radiation was influenced further by trophic resource changes. The Late Oligocene fauna is diverse. Archaeocetes are not recorded in New Zealand, but occur in Australia {Mammalodon}. Squalodontid odontocetes include Prosqualodon s. s., "P." hamil toni, "P." marplesi, a Phoberodon-like form, and indeterminate taxa. Nonsqualodonts include eurhinodelphinids{?} and platanistoids{?}, and mysticetes include Mauicetus parki {Cetotheriidae} and an uncertain number of other cetotheres. Late Oligocene Cetacea are more abundant than their antecedents, and similarities with those from elsewhere suggest a diverse and cosmopolitan global fauna. The relatively poorly studied Neogene fauna comprises squalodonts, platanistoids?, ziphioids, delphinoids, indeterminate odontocetes, and indeterminate mysticetes. Amongst more recent forms are mysticetes and delphinids of modern appearance. Some phases of cetacean evolution were saltato [...]
doi:10.26021/6300 fatcat:yw7nkbjsrrcwbhhplhvnn7rgqe