Protohadros

Taxobox
name = "Protohadros"
fossil_range = Late Cretaceous
regnum = Animalia
phylum = Chordata
classis = Sauropsida
superordo = Dinosauria
ordo = Ornithischia
subordo = Ornithopoda
infraordo = Iguanodontia
superfamilia = Hadrosauroidea
genus = "Protohadros"
genus_authority = Head, 1998
subdivision_ranks=Species
subdivision=
*"P. byrdi" Head, 1998 (type)

"Protohadros" (meaning "first hadrosaur") is a genus of dinosaur from the Late Cretaceous (Cenomanian stage), 95 million years ago.

Gary Byrd, a part-time palaeontologist, discovered fossils of this ornithopod 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 was first described as the most primitive hadrosaurid, hence its name. However scientific opinion has since changed and it is now regarded as a non-hadrosaurid iguanodontian. The dinosaur's discovery conflicted with the idea that hadrosaurs evolved in Asia; however, the reassessment of "Protohadros" as a less-derived iguanodontian has rendered this discrepancy less problematic.

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 hadrosaur-like features. It had a large, deep set of jaws, and the snout was turned down at the front, which suggests a habit of grazing on low-growing plants, rather than browsing from bushes or overhanging branches. It did not have the cranial joint system that produced the food-grinding action seen in hadrosaurids. Its diet would have consisted of the plants which grew in the delta streams in its habitat, scooped up by the broad, down-turned mouth.

"Protohadros"' rear legs were probably longer than the front pair, and it could move on all fours or walk and run on its hind legs only.

References

* Head J., 1998, "A new species of basal hadrosaurid (Dinosauria, Ornithopoda) from the Cenomanian of Texas", "Journal of Vertebrate Paleontology" 18 (4); 718 - 738 (1998).

Links

* [http://www.nhm.ac.uk/jdsml/nature-online/dino-directory/detail.dsml?Genus=Protohadros "Protohadros" in the Dino Directory]
* [http://www.users.qwest.net/~jstweet1/iguanodontia.htm Iguanodontia]