An early Miocene diversity of parrots (Aves, Strigopidae, Nestorinae) from New Zealand

Abstract

A new genus and three species of parrot (Psittaciformes, Strigopidae, Nestorinae) are described from the early Miocene (19–16 Ma) St Bathans Fauna of Otago, New Zealand, based on 85 fossils as follows: Nelepsittacus minimus (17), N. donmertoni (60), and N. daphneleeae (6), with two additional fossils representing a fourth unnamed taxon. These taxa range from small parrots approximately the size of Cyanoramphus species to one as large as the living Nestor notabilis. Apomorphies in the coracoid, humerus, tibiotarsus, and tarsometatarsus ally Nelepsittacus with Nestor and exclude a close relationship with Strigops, the other endemic genus assumed to have had a long history in New Zealand. With only nestorine parrots represented, the St Bathans Fauna has nothing in common with the Australian psittaciform fauna, in which cacatuids and a diversity of psittacid genera exist. These data add to the growing body of evidence that the New Zealand terrestrial vertebrate fauna, at a time minimally 3 Ma after the maximal marine inundation of Zealandia in the late Oligocene, was highly endemic, with no close relationship to the closest faunas in Australia. This high degree of endemism strongly suggests that the Zealandian terrestrial biota persisted, at least in part, through the Oligocene highstand in sea level.