Ligabueino andesi Bonaparte, 1996

Age. Hauterivian.

Occurrence. La Amarga Formation, Neuquén, Argentina.

Diagnosis. Femur with a deep longitudinal groove on its anterior side, below the lesser trochanter.

Remarks. Ligabueino, known from only a few postcranial elements (Bonaparte 1996), is one of the smallest known theropods, with a femur length of 61 mm. The articular surfaces of the femur are well formed, and the neural arch of a caudal vertebra is fused with the centrum without any visible suture, indicating that the holotype does not represent a hatchling or very young individual. Despite the fragmentary nature of the type material, it is thus of great potential interest, being one of the few small theropods known from the Cretaceous of Gondwana. The morphology of the ilium, and especially the greater and lesser trochanters on the femur, indicate that it is a non-avian theropod.