Eoraptor lunensis Sereno, Forster, Rogers and Monetta, 1993

Age. Camian.

Occurrence. Ischigualasto Formation, San Juan, Argentina.

Diagnosis. Strongly heterodont dentition, with leaf-shaped anterior maxillary tooth crowns; ventral process of the postorbital flexed sharply anteriorly in its lower part.

Remarks. Eoraptor (Text-fig. 4d) is one of the oldest and most primitive dinosaurs known to date, but preliminary cladistic analyses indicate that it is a member of the Theropoda (Sereno et al. 1993), although this is not yet generally accepted (Holtz 1995a; Holtz and Padian 1995; Langer 2001). The taxon is represented by two almost complete skeletons (Sereno et al. 1993; Sereno, pers. comm. 1997), and a detailed description of its anatomy is presently under way by P. Sereno.