Protohadros

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Protohadros
Fossil range: Late Cretaceous

Scientific classification

Kingdom:	Animalia
Phylum:	Chordata
Class:	Sauropsida
Superorder:	Dinosauria
Order:	Ornithischia
Suborder:	Ornithopoda
Infraorder:	Iguanodontia
Superfamily:	Hadrosauroidea
Genus:	Protohadros Head, 1998

Binomial name

Protohadros byrdi
Head, 1998

Protohadros (meaning "first hadrosaur") was a genus of dinosaur from the Late Cretaceous (Cenomanian). It was an Iguanodont, specifically a late-surviving primitive hadrosaur (hence the name). Its fossils were found in Texas. The type species is Protohadros byrdi, described by Head in 1998.

Gary Byrd, a part-time palaeontologist, discovered fossils of this duckbill dinosaur in 1994 at Flower Mound, Denton County, north-central Texas. The creature was described and named in 1998 by Jason Head of the Dedman College of Humanities and Science, Southern Methodist University. It lived about 95 million years ago, much earlier than most other hadrosaurs, making it one of the oldest known duckbills and an often-quoted candidate for the ancestry of the group. Before the discovery of Protohadros, the ancestry of the hadrosaurs, which probably developed from Iguanodon-like predecessors, was thought to lie in Asia. This new find has has moved the focus of attention to North America, though there are still disputes about which was the first hadrosaur.

Since the remains of Protohadros include just a partial skull and possibly pieces of ribs and foot bones, much of the reconstruction of this dinosaur is speculative. Protohadros reached 6 m (19.5 ft) in length and had many duckbill features. It probably had a large, deep set of jaws, with the typical toothless "beak" at the front of the mouth, and, in its cheeks, extensive rows or "batteries" of chewing teeth which it used to crush tough vegetation. As with later members of the group, its rear legs were probably longer than the front pair, and it could move on all fours, especially when feeding from ground plants and low shrubs, or walk and run on its hind legs only. During the early Late Cretaceous Period, the region where Protohadros lived was a low-lying mix of woods and marshes, and the climate was warm and humid, providing plenty of vegetation.

[edit] References

http://www.users.qwest.net/~jstweet1/iguanodontia.htm
Head J., 1998, "A new species of basal hadrosaurid (Dinosauria, Ornithopoda) from the Cenomanian of Texas", J. of Vertebrate Paleontology 18 (4); 718 - 738 (1998).