Fossil songbirds (Passeriformes) from the Early Eocene of Australia

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, southeastern 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.