A New Specimen of Sinosaurus triassicus (Dinosauria: Theropoda) from the Early Jurassic of Lufeng, Yunnan, China

The holotype of Sinosaurus triassicus is poorly preserved, and no previous research has focused exclusively on its anatomy. This research reports a new specimen recovered near the locality of the holotype of S. triassicus including a complete skull with mandible and 11 cervical vertebrae. Three newly identified traits are proposed to be unique of the species – (1) a vertical crest developed dorsoventrally from the ventral portion of the maxilla to the nasal crest; (2) ventral border of the antorbital fenestra formed mostly by the anterior process of the jugal; and (3) a fenestra between the nasal, the lacrimal and the prefrontal. This research provides new information on the cranial anatomy of this species as well as the genus Sinosaurus, offering more accessibility for later research concerning the evolution of early deriving neotheropods.