Herrerasaurus

Herrerasaurus (meaning "Herrera's lizard", after the name of the rancher who discovered the first fossil of the animal) was one of the earliest dinosaurs. All known specimens of this carnivore have been discovered in rocks of late Ladinian age (middle Triassic according to the ICS, dated to 231.4 million years ago) in northwestern Argentina. The type species, Herrerasaurus ischigualastensis, was described by Osvaldo Reig in 1963 and is the only species assigned to the genus. The names Ischisaurus and Frenguellisaurus are synonymous with Herrerasaurus.

For many years, the classification of Herrerasaurus was unclear, as the animal was initially known from very fragmentary remains; it has been hypothesized to be a basal theropod, a basal sauropodomorph, a basal saurischian, or not a dinosaur at all. However, with the discovery of a mostly complete skeleton and skull in 1988, Herrerasaurus has been classified as either an early theropod or an early saurischian in at least five recent reviews of theropod evolution, with many researchers treating it at least tentatively as the most primitive member of Theropoda. It was a member of the Herrerasauridae, a group of similar animals which were among the earliest of the dinosaurian evolutionary radiation.

Read more about Herrerasaurus:  Description, Classification, History, Paleoecology, Paleobiology

Other articles related to "herrerasaurus":

Herrerasauridae - Classification
2009, have found Herrerasaurus and its relatives in Herrerasauridae to be very basal theropods, while others (such as Ezcurra 2010) have found them to be basal ... Sanjuansaurus from the same Ischigualasto Formation of Argentina as Herrerasaurus, Staurikosaurus from the Santa Maria Formation of southern Brazil, Chindesaurus from the Upper ... Novas (1992) defined Herrerasauridae as Herrerasaurus, Staurikosaurus, and their most recent common ancestor ...
Staurikosaurus - Classification
... (2011) supports that Staurikosaurus and the related genus Herrerasaurus are theropods and evolved after the sauropod line had split from the Theropoda ... first to recognize that Staurikosaurus and Herrerasaurus were more closely related to each other than to sauropodomorphs or avepods, placing them both in the Herrerasauridae and Herrerasauria ... Staurikosaurus differs from Herrerasaurus because of its considerably smaller size (femur length of 23cm vs ...
Herrerasaurus - Paleobiology - Paleopathology
... paleontologists, 12 hand bones and 20 foot bones referred to Herrerasaurus were examined for signs of stress fracture, but none were found ... PVSJ 407, a Herrerasaurus ischigualastensis had a pit in a skull bone attributed to a bite by Paul Sereno and Novas ... the size and angles of the wound, its likely that they were obtained in a fight with another Herrerasaurus ...
Pisanosaurus - Paleoecology - Fauna and Habitat
... Herrerasaurus remains appear to have been the most common among the carnivores of the Ischigualasto Formation ... rauisuchians, archosaurs, Saurosuchus and the dinosaurs Herrerasaurus and Eoraptor, all of whom lived it its paleoenvironment ... The large carnivore Herrerasaurus may have fed upon Pisanosaurus ...
Staurikosaurus - Classification - Related Genera
... Herrerasauridae also includes Herrerasaurus ischigualastensis and Eoraptor lunesis, both small predatory animals that were either dinosaurs or precursors ... exclude Eoraptor, and include Chindesaurus along with Herrerasaurus as more derived than Staurikosaurus ... the same Ischigualasto Formation of Argentina as Herrerasaurus, and possibly Caseosaurus from the Dockum Formation of Texas, although the relationships of these animals are not fully understood, and not all ...