Aerosteon

Aerosteon is a genus of megaraptoran dinosaur from the Late Cretaceous period of Argentina. Its remains were discovered in 1996 in the Anacleto Formation, which is from the late Campanian. The type and only known species is A. riocoloradensis. Its generic name can be translated as "air bone" and derives from Greek ἀήρ and ὀστέον, whereas its specific name indicates that its remains were found 1 km north of the Río Colorado, in Mendoza Province, Argentina. The genus shows evidence of a bird-like respiratory system.