A large cracticine passerine (Aves, Artamidae, Cracticinae) from the Early Miocene, St Bathans Fauna of New Zealand

Abstract A large fossil passerine (Aves, Artamidae, Cracticinae, Miostrepera canora gen. et sp. nov.), of Early Miocene (19–16 Ma) age, is described based on a proximal and a distal humerus from the lower Bannockburn Formation near St Bathans in Otago, New Zealand. Referred material includes a previously reported scapula and, tentatively so, a distal tibiotarsus. This taxon is the largest passerine in the St Bathans Fauna, in which the total passerine diversity may include up to 17 species. The only other named passerine in this fauna is a tiny acanthisittid wren, Kuiornis indicator . Cracticines (currawongs, magpies and butcherbirds) were absent in the native avifauna of New Zealand during the late Quaternary but are represented by the introduced Australian Magpie Gymnorhina tibicen now. The group is widespread in Australia with a fossil record extending to the Early Miocene. The presence of a Strepera -like cracticine in the Early Miocene in New Zealand indicates overwater dispersal to and colonisation of Zealandia from Australia that we suggest was facilitated by the diverse flora in the subtropical environments of Zealandia at the time. The subsequent loss of cracticines from the Zealandian avifauna is correlated with the marked loss in floral diversity following the climate cooling in the Middle Miocene and during the subsequent Pleistocene glacial oscillations. Furthermore, we show that the osteological correlates of the origin of musculus humerotriceps pars dorsalis are shown to be more complex than presence or absence of a dorsal fossa on the humerus.