Named By: Agustín G. Martinelli & Ezequiel I. Vera - 2007.
Classification: Chordata, Reptilia, Dinosauria, Saurischia, Theropoda, Alvarezsauroidea, Alvarezsauridae.
Species: A. manazzonei (type).
Known locations: Argentina, Rio Negro Province - Bajo de la Carpa Formation.
Time period: Santonian of the Cretaceous.
Fossil representation: Partial post cranial skeleton.
Achillesaurus has been identified as a basal alvarezsaur that lived in Argentina during the late Cretaceous, but there is now some question to its validity. Achillesaurus was thought to have lived alongside the type genus of the alvarezsauridae, Alvarezsaurus. A 2012 study by Makovicky et al. however has raised the notion that Achillesaurus and Alvarezsaurus may in fact be one and the same dinosaur. If so then Achillesaurus would become a synonym of Alvarezsaurus.
- Achillesaurus manazzonei, a new alvarezsaurid theropod (Dinosauria) from the Late Cretaceous Bajo de la Carpa Formation, Río Negro Province, Argentina - Agustín G. Martinelli & Ezequiel I. Vera - 2007.
- A New Coelurosaurian Theropod from the La Buitrera Fossil Locality of Río Negro, Argentina - P. J. Makovicky, S. N. Apesteguía, F. A. Gianechini - 2012.