Dino Family Spotlight: Coelophysidae

Though most famous for its Triassic record, the coelophysids were a greatly successful group, surviving into the Early Jurassic across North America and Africa. They were light-boned, fleet-footed predators, well-suited to a world of small prey which could run just as fast as it could. They are placed within the Theropoda, and are believed to be more primitive than the ceratosaurs and tetanurans.

Coelophysis bauri was first described by Edward Drinker Cope in 1889 from fossils found in the American Southwest, but it's unsure if these fossils even belong to the dinosaur at all. Later bones attributed to Coelophysis definitely belong to a theropod dinosaur, and as such, Coelophysis is still a valid dinosaurian genus.

Coelophysidae is also home to what is, possibly, the worst dinosaur name ever: Megapnosaurus. Once beloved by dinosaur fans as Syntarsus, the entomologists struck again: Syntarsus was taken by a beetle. In some miscarriage of justice, the entomologists who pointed this out now had the right to rename the animal. It is now Megapnosaurus - "big dead reptile". I'm not sure if this shows a twisted sense of humor on the entomologists' parts, or simply ignorance as to the true nature of dinosaurs.

This family posesses seven species across six genera.

Coelophysidae (Nopsca, 1923)

Coelophysis bauri (Cope, 1889)

Megapnosaurus rhodesiensis (Raath, 1969)

Megapnosaurus kayentakatae (Rowe, 1989)

Camposaurus arizonensis (Hunt et al., 1998)

Podokesaurus holyokensis (Talbot, 1911)

Procompsognathus triassicus (Fraas, 1913)

Segisaurus halli (Camp, 1936)

(Sorry for paragraph-fail. I blame the website!)

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)

Introducing: Dinosaur Family Spotlight!

Normally, in the spirit of the first day of April, I'd come up with something witty. But I'm rather tired today (and looking forward to my spring break!), so instead I'm announcing an upcoming segment on the blog (don't worry, Lizard Watch will be here soon). The Dino Family Spotlight!

For the benefit of those who view my page, I will go through every major grouping of dinosaurs (the families, but in some cases, subfamilies as well), and offer a summary of that group's features, and a list of species which belong in the group. The segment will begin tomorrow with the most primitive of the dinosaur families, Herrerasauridae.

Stay cool!