Eotyrannus

Taxobox|
name = "Eotyrannus"
fossil_range = Early Cretaceous


image width = 200 pixels
regnum = Animalia
phylum = Chordata
classis = Sauropsida
superordo = Dinosauria
ordo = Saurischia
subordo = Theropoda
superfamilia = Tyrannosauroidea
genus = "Eotyrannus"
binomial = "Eotyrannus lengi"
binomial_authority = Hutt et al., 2001

"Eotyrannus" (meaning "dawn tyrant") was a genus of tyrannosauroid theropod dinosaur hailing from the Early Cretaceous Wessex Formation beds, included in Wealden Group, located in the southwest coast of the Isle of Wight, United Kingdom. The remains (MIWG1997.550), consisting of assorted skull, axial skeleton and appendicular skeleton elements, from a juvenile or subadult, found in a plant debris clay bed, were described by Hutt "et al". in early 2001.Hutt, S., Naish, D., Martill, D.M., Barker, M.J., and Newbery, P. (2001). "A preliminary account of a new tyrannosauroid theropod from the Wessex Formation (Cretaceous) of southern England." "Cretaceous Research", 22: 227–242.]

The etymology of the generic name refers to the animal’s character as an "early tyrant", while the specific epithet is a mention to the discoverer of the fossil.

"Eotyrannus" is a 6 meter-long theropod whose tyrannosauroid character is given by serrated premaxillary teeth with a D cross section, proportionally elongate tibiae and metatarsals. Primitive characters for Tyrannosauroidea are the elongate neck vertebrae and the long well developed arms forelimbs along with the undecorated dorsal surface of the skull, unlike the more advanced tyrannosaurids. However this animal, proportionally, has one of the longest hands in Theropoda known to date.

This theropod would be a probable predator of such herbivorous dinosaurs as "Hypsilophodon" and "Iguanodon".

"E. lengi"’s find corroborates the notion that early tyrannosaurs were gracile with long forelimbs and three-fingered grasping hands, though the large size of the animal either means that early evolution for this clade was carried out at a large size or "Eotyrannus" developed large size independently.Holtz, T. R. Jr. (1994). "The phylogenetic position of the Tyrannosauridae: implications for theropod systematics." "Journal of Paleontology", 68: 1100–1117.] The find of this animal in Europe puts interesting questions to the purported Asian origin for these animals along with North American "Stokesosaurus" and European "Aviatyrannis" arguing for a more complex biogeography for tyrannosaurs.

References