Eotyrannus: Prehistoric Animal of the Week

This week we will be taking a look at a predator that once called the United Kingdom home.  Check out Eotyrannus lengi!  Eotyrannus came from what is now called the Isle of Wight, off of the southern coast of England, during the Early Cretaceous, about 130 million years ago.  When alive it would have coexisted with several other dinosaurs known from that place and time, like Baryonyx, Hypsilophodon, and Mantellisaurus.  Eotyrannus is known from a partial skeleton from an individual that would have measured roughly thirteen feet long from snout to tail, but this specimen may be a juvenile and could have grown to be larger.  The genus name, Eotyrannus, translates to "dawn tyrant" because at the time of its discovery, Eotyrannus was the earliest known member of the tyrannosauroid superfamily. (Much older tyrannosauroids have been discovered since.)

Eotyrannus life reconstruction by Christopher DiPiazza.

Eotyrannus was a tyrannosauroid which means that it belongs to the same group as large, two-fingered tyrannosaurids like Tyrannosaurus, Tarbosaurus, Lythronax, and Teratophoneus.  Like them, it had curved, serrated teeth with a D-shaped cross section.  However, Eotyrannus was more basal than these later predators and shares more in common with its closer, more basal relatives, like Dryptosaurus and Guanlong. Like them it had proportionally longer arms with three fingers on each hand, each tipped with a curved claw.  It also had long legs and overall gracile build, implying that it was a fast runner.

Eotyrannus hand claw on display at the Isle of Wight Museum.  Photo courtesy of Marc Vincent.

When alive, Eotyrannus may have relied on its speed and probably specialized in hunting smaller prey, like the small ornithopod dinosaurs it shared its habitat with.  It also would have needed to use its speed and agility to avoid the larger predators it coexisted with like Baryonyx, the spinosaurid, and Neovenator, the allosauroid.

Eotyrannus lower jaw fragment and tooth on display at the Isle of Wight Museum.  Photo Courtesy of Marc Vincent.

That is all for this week!  As always feel free to comment below or on our facebook page!

References

Brusatte, S. L. and Benson, R. B. J. and Norell, M. A. (2011) The Anatomy of Dryptosaurus aquilunguis (Dinosauria: Theropoda) and a Review of its Tyrannosauroid Affinities. American Museum Novitates, 3717 . pp. 1-53. ISSN 0003-0082

 Loewen, M.A.; Irmis, R.B.; Sertich, J.J.W.; Currie, P. J.; Sampson, S. D. (2013). Evans, David C, ed. "Tyrant Dinosaur Evolution Tracks the Rise and Fall of Late Cretaceous Oceans". PLoS ONE 8 (11): e79420. doi:10.1371/journal.pone.0079420.

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.