Friday, April 2, 2010

Dino Family Spotlight: Herrerasauridae

Herrerasaurids are among the most primitive dinosaurs, and, indeed, are primitive enough to have caused debate in the paleontological community for a couple decades. Though the general concensus is that they are a family of primitive theropods, some scientists hold them to be more basal, belonging to Saurischia incertae sedis.

The type species, Herrerasaurus ischigualastensis, was described by Osvaldo Reig in 1963 in the Ischigualasto Formation of Brazil. The specimen variously jumped around into several different placements, from prosauropods and non-dinosaurian archosaurs, to a primitive carnosaur. Since then, the classification has settled to the two options found in the previous paragraph, and the group is defined as the most inclusive clade containing Herrerasaurus ischigualastensis, but not Passer domesticus.

The family dates to the Late Triassic, from about 228 to 225 million years ago. They are most commonly found in South America (Brazil & Argentina), but specimens are also known from North America (Arizona & Texas). The possibility remains that there could be others found on other continents. The group contains at least three species across at least three genera.

Order Saurischia
Suborder Theropoda
Family Herrerasauridae (Benedetto, 1973)
Herrerasaurus ischigualastensis (Reig, 1963)
Staurikosaurus pricei (Colbert, 1970)
Chindesaurus bryansmalli (Long & Murry, 1995)

2 comments:

  1. That's a very cool illustration of Herrerasaurus! Who did it?

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  2. Sadly, I couldn't find anything on the page from which I got that stating the artist. Until my artistry improves, I'll have to use artwork from the interwebs to make my posts look less plain.

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