Dinosaur - Eotyrannus lengi

Introduction

Pronounced Ee-o-tie-ran-us leng-ee

Eotyrannus means ‘dawn tyrant’ in Greek and lengi honours its discoverer Gavin Leng.

The relatively small tyrannosaur Eotyrannus lived about 60 million years before its more famous relative Tyrannosaurus rex.

Identification

Aside from some fragmentary fossils from Portugal, Eotyrannus was the first tyrannosaur described from Europe and one of the first early tyrannosaurs known. The only known specimen is a subadult (teenager), represented by a partial skull, vertebrae, shoulder, forelimb, partial pelvis and hindlimb.

As a tyrannosauroid Eotyrannus shares the following characteristics with other tyrannosaurs: serrated premaxillary teeth with a D-shaped cross section, and proportionally elongate tibiae (shine bones) and metatarsals (foot bones). As a primitive tyrannosaur, it has long neck vertebrae and long, well-developed forelimbs with three fingers on each long, slender hand.

Habitat

The Isle of Wight, where Eotyrannus was found, has produced rich plant and animal life from the earliest Cretaceous (including the first ever dinosaur described as such, the plant-eating Iguanodon). Eotyrannus was found near the remains of a plant-eating ornithopod, in amongst plant debris.

Distribution

Eotyrannus lived in what is now England, Europe, during the Early Cretaceous, about 131-126 million years ago.

Feeding and diet

Eotyrannus had the teeth and build of a predator and was probably fast and agile, with unusually long legs. Its prey may have included plant-eating dinosaurs such as Hypsilophodon and Iguanodon, along with other small- to medium-sized mammals and reptiles.

Fossils description

The first fossils were found in 1995 and named and described in 2001.

The only known specimen is a subadult ('teenager'), represented by a partial skull, vertebrae, shoulder, forelimb, partial pelvis and hindlimb.

Some of the fossil bones were articulated (which means they were still attached to each other), whilst others were jumbled in new positions. This suggests the animal may have been partially scavenged before it was buried. The rock containing the fossils also includes bones from two other dinosaurs. .

Evolutionary relationships

Eotyrannus has yet to be placed into one of the two known tyrannosaur families. Its closest relatives are Juratyrant and Stokesosaurus.

References

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.