Eotyrannus

Eotyrannus was a primitive relative of Tyrannosaurus rex that lived in Early Cretaceous Britain, approximately 125 million years ago. Uncovered from cliff exposures on the Isle of Wight, the holotype skeleton belonged to a subadult measuring roughly four metres in length. In stark contrast to massive, two-fingered Late Cretaceous tyrannosaurs with tiny arms, Eotyrannus was slender and possessed long, powerful forelimbs equipped with three grasping, clawed fingers. Its skull featured a small crest along the snout and serrated, recurved teeth well-suited for slicing flesh. Palaeontologists believe it was an agile, fleet-footed hunter that chased down swift prey such as hypsilophodonts and young iguanodontians. Given its evolutionary placement within Tyrannosauroidea, it may well have sported an insulative coat of simple downy feathers.

Unlike later tyrannosaurs, it retained exceptionally long arms and grasping hands with three clawed fingers.

Where and when

Eotyrannus lived in the Early Cretaceous, from 130 to 125 million years ago (Barremian age). Its remains come from United Kingdom, in the Wessex Formation.

The numbers

Length 4.3 m (estimates run from 4 to 4.5 m). Mass about 220 kg. Hip height about 1.5 m. That is 2.5 human-lengths, or 0.38 of a double-decker bus. These are estimates from partial skeleton; fields marked estimated by the site are length, mass, hip height.

Compare Eotyrannus with a bus Place on the timeline