Eotyrannus (Dawn Tyrant)

Short Info

Eotyrannus (Dawn Tyrant)

Phonetic : E-oh-ty-ran-us.

Named By : Steve Hutt et al. – 2001

Diet : Carnivore

Size : Estimated 4 – 5 meters long

Type of Dinosaur : Large Theropod

Type Species : E. lengi (type)

Found in : United Kingdom, Isle of Wight – Wessex Formation

When it Lived : Early Cretaceous, 127-121 million years ago

Eotyrannus, which means “dawn-tyrant”, is a genus of tyrannosauroid dinosaurs. It hails from the Early Cretaceous Wessex Formations, on the southwest coast of England’s Isle of Wight. Hutt and colleagues described the remains (MIWG1997.550), which include a variety of skull, axial, and appendicular elements. They were found in a clay plant debris clay bed. Hutt et al. described the remains in 2001. The generic name refers, in part, to the animal’s classification as an early-tyrannosaur (or “tyrant Lizard”) while the specific name honors its discoverer.


EotyrannusSkullEotyrannu5, CC BY-SA 4.0, via Wikimedia Commons


The holotypic specimen contains a number of unique characters that are not found elsewhere in the genus. These include the rostral end with a concave dentary containing the most mesial alveolus, and curving lateral furrows along the lateral surface.

The holotypic specimen had been disarticulated before fossilization, and many of its elements were scattered throughout the assemblage. None of the vertebral columns are preserved in articulation, and the few that are preserved contain separated neural arches, and centra. This indicates that the holotype is an immature individual.

Many pieces found were difficult to identify due to poor preservation of many skeletal elements. Eotyrannus had to be reconstructed using a longer tibiae before this fragment could be identified. This influenced early reconstructions.

Hutt and colleagues also identified many characters as being unique to the genus. These characters (2001) are actually widespread throughout Tyrannosauroidea. For example, the existence of’serrated Carinae’ on D-shaped premaxillary tooth is not unique to E. Lengi. The genus is not unique in the absence of a laterally flattened region to the maxilla or a pronounced edge to the antorbital fossa. [2]

According to estimates, the holotype Eotyrannus measured approximately 4.5m (15ft) in length and weighed between 91-227kg (200-500 lbs).

Because of its importance and the possibility that new material could be collected as the coast recedes, the exact location has not been disclosed. According to the description, the specimen was discovered on the southwest coast of the Isle of Wight between Hanover Point and Atherfield Point. Gavin Leng, a local collector, brought a claw that he found along the coast to Steve Hutt in 1995. Hutt worked at the Museum of Isle of Wight Geology at Sandown. Gavin Leng provided the exact location where the claw was found. The site was excavated over several weeks and fossils were removed from a hard matrix. The specimen was meticulously researched by scientists at the University of Portsmouth and the Natural History Museum over the next few decades.

Eotyrannus received its name and epithet in honor of Mr. Leng in 2000. Hutt and his colleagues briefly described the material in 2001. Hutt’s colleague Darren Naish created a GoFundMe campaign in July 2018 to help release a monograph. The goal was exceeded by Naish. The monograph will appear in Open Access venues.

Source: Wikipedia