Fossil Songbirds (Passeriformes) from the Early Eocene of Australia

Abstract

Whether the Passeriformes, numerically the most successful extant order of birds, had a northern or southern origin has been a subject of speculation. Traditional, pre-continental drift views considered that the passerines arose in the Northern Hemisphere and colonised Australasia by a series of invasions. More recently, this opinion has been challenged by the conclusions of molecular studies and the interpretation of the fossil record, which suggest a southern origin for the songbirds. The discovery of passerine remains (carpometacarpal and tibiotarsal fragments) from the Early Eocene Tingamurra Local Fauna at Murgon, south-eastern Queensland, Australia, that are 25 million years older than the oldest northern hemisphere record, adds support for a southern origin of this order. These bones, announced previously, are herein described in detail, and the diagnostic criteria used for their ordinal identification presented.