Herrerasaurus ischigualastensis (Reig 1963) Ladinian, middle Triassic ~230 mya, 3m in length was much larger than its sister Marasuchus. Phylogenetically Herrerrasaurussucceeded Trialestes and Turfanosuchus. Herrerrasaurus preceded members of the Dinosauromorpha, including Pisanosaurus and Coelophysis.
Distinct from its sisters and predecessors, the skull of Herrerrasaurus had a deep robust rostrum. The antorbital fossa was not as apparent. The postorbital portion of the skull was shorter. The lateral temporal fenstra was more open as the quadrate and squamosal retreated. The mandible had a larger fenestra.
The neural spines were taller, especially near the pelvis.
The scapula was greatly reduced. Manual digits IV and V were vestiges.
The pubis is deeper and angled posteriorly with a large "boot." The hind limb was more robust. |
