Sanjuansaurus gordilloi, Alcober, Oscar A. & Martinez, Ricardo N., 2010

Alcober, Oscar A. & Martinez, Ricardo N., 2010, A new herrerasaurid (Dinosauria, Saurischia) from the Upper Triassic Ischigualasto Formation of northwestern Argentina, ZooKeys 63, pp. 55-81 : 57-58

Sanjuansaurus gordilloi sp. n.

Etymology:

gordilloi, in honor of Raul Gordillo, head fossil preparator and artist in the laboratory of the San Juan Museum and team member during many years of excavation.

Holotype:

PVSJ 605, an incomplete skeleton including left maxilla, partial axial column, from the axis to the twelfth caudal vertebra, lacking the third, fourth, and anterior half of the fifth dorsal vertebrae, both scapulae, left ulna, ungual phalanx of left? digit III, preacetabular portion of the left ilium, proximal end of left and complete right pubis, both femora and tibiae, right fibula, right astragalus and calcaneum, and left metatarsal II.

Type locality:

The specimen was found in the Cancha de Bochas Member ( Currie et al. 2009), 40 m above the base of Ischigualasto Formation. The type locality, informally called "Herrera de la base", is located 3 km northwestern of "Cancha de Bochas" locality, Ischigualasto Provincial Park, San Juan, Argentina (Figure 1).

Horizon and age:

40 m above the base of the Ischigualasto Formation, Late Triassic, Carnian (ca. 231.4 Ma), Ischigualasto–Villa Unión Basin ( Rogers et al. 1993; Renne et al. 2010). The type horizon lies at approximately the same level as the dated ash, which implies a late Carnian age for the specimen.

Diagnosis:

Diagnosed bythe followingautapomorphies: shelf-like, posterolaterally directed transverse processes on the posterior cervical vertebrae; neural spines of the sixth to eighth dorsal vertebrae, at least, bearing acute anterior and posterior processes; everted lateral margins of the glenoid; short pubis (63% of the femoral length); and pronounced, rugose scar on the medial surface of the femur at the level of the fourth trochanter.

These features distinguish Sanjuansaurus gordilloi from the previously described herrerasaurids, such as Herrerasaurus ischigualastensis and Staurikosaurus pricei , as well as other basal saurischians from Ischigualasto Formation, such as Eoraptor lunensis ( Sereno et al. 1993), Panphagia protos ( Martinez and Alcober 2009), and Chromogisaurus novasi ( Ezcurra 2008, 2010)