A teratorn (Aves: Teratornithidae) from the early late Miocene of Buenos Aires, Argentina

Abstract

We present new specimens of a teratorn (Aves, Teratornithidae) from the Chasicoan (early late Miocene) of southwestern Buenos Aires Province, Argentina. The specimens consist of an incomplete left ulna without its proximal end and two fragments of a radius. The ulna is very similar to, but larger than, Vultur, and its size and the relative slenderness of the distal shaft excludes it from Cathartidae and is diagnostic of Teratornithidae. Its length is very similar to Teratornis merriami, so its wingspan would have been around 4 m. Coming from sediments of the Barrancas Member of the Arroyo Chasicó Formation is older than Argentavis magnificens and so far the oldest record for Teratornithidae in Argentina.