Deinonychus antirrhopus – A Ferocious Member of the Dromaeosauridae

It was the great American dinosaur hunter, Barnum Brown who discovered the fossilised bones of a fast-running, fearsome looking dinosaur at an excavation in Wyoming (United States), in 1931.  The animal, although clearly a new species of predatory dinosaur was not formally studied, this prehistoric animal was not properly studied or described by Brown.  It was the influential and highly respected John Ostrom who found more fossils of this dinosaur in the 1960s and it was Ostrom who went on to name and describe Deinonychus (D. antirrhopus).


Standing around 2.5 metres tall and with a length of 3-4 metres, Deinonychus was a new type of meat-eating dinosaur.  It inspired Ostrom and his contemporaries to depict dinosaurs not as sluggish, slow-witted beasts but as dynamic animals as active as warm-blooded mammals and birds.  Indeed, much of Ostom’s work on the Dromaeosauridae was directed at challenging the accepted doctrine that the Dinosauria were all cold-blooded.

An Illustration of Deinonychus by a Young Dinosaur Fan

Fast-running, active, warm-blooded dinosaurs

Fast-running, active, warm-blooded dinosaurs

Picture credit: Everything Dinosaur

Intriguingly, a number of highly curved teeth, obviously the teeth of a predator, have been excavated from time to time from strata of the famous Hell Creek Formation of Montana.  It has been speculated that these are the teeth of a new type of dromaeosaurid dinosaur whose fossils have yet to be found.  It has also been suggested these are the teeth of young tyrannosaurs (T. rex) as Tyrannosaurus rex fossil material is also associated with the member of the Hell Creek Formation.

Everything Dinosaur stocks the Safari Ltd Wild Safari Prehistoric World range of models and figures that includes a replica of Deinonychus: Wild Safari Prehistoric World Models and Figures.

This post has been put up in response to a question received at a recent dinosaur workshop in a school organised by Everything Dinosaur, as part of the company’s work in educational establishments teaching about dinosaurs and fossils in schools.  We used a number of dromaeosaurid fossils and casts to illustrate the size of some predatory dinosaurs.  The term dromaeosaur means “swift lizard” an apt title for these fast, active dinosaurs.