Eoraptor lunensis Sereno et al., 1993

Nesbitt, Sterling J., 2011, The Early Evolution Of Archosaurs: Relationships And The Origin Of Major Clades, Bulletin of the American Museum of Natural History 2011 (352), pp. 1-292 : 54

Eoraptor lunensis Sereno et al., 1993

(fig. 12D)

AGE: Late Carnian, Late Triassic ( Rogers et al., 1993, adjusted for the new Triassic timescale of Muttoni et al., 2004).

OCCURRENCE: Ischigualasto Formation, San Juan, Argentina.

HOLOTYPE: PVSJ 512, essentially complete skeleton lacking only the distal caudal vertebrae.

REMARKS: Eoraptor remains one of the most controversial basal dinosaurs discovered. It is known from an entire articulated skeleton. Nevertheless, the poor preservation of the surface of the bone, missing details of the skull, crushing of the some of the elements, and covered elements led to conflicting interpretations (compare Sereno et al., 1993, to Langer and Benton, 2006).

Sereno et al. (1993) found Eoraptor as the basalmost theropod sister taxon to Herrerasaurus + Neotheropoda. Other studies focused on the interrelationships of theropods (e.g., Rauhut, 2003) found Eoraptor as the sister taxon to Herrerasaurus + Neotheropoda. Most recently, Langer and Benton (2006) found Eoraptor as the sister taxon to Eusaurischia. A detailed description of the taxon is currently in progress.

Eoraptor possesses two potential autapomorphies: a leaf-shaped premaxillary and anterior maxillary crowns, and a ventral process of the postorbital flexed sharply anteriorly in the ventral portion (from Rauhut, 2003).

KEY REFERENCES: Sereno et al., 1993; Langer and Benton, 2006; Sereno 2007.