Revisiting Utah

On this blog we have covered a lot of different dinosaurs over time. Nine years ago we discussed one of the largest of the dromaeosaurs, Utahraptor ostrommaysi (Kirkland, Gaston and Burge, 1993). I think it might be time to revisit this medium sized carnivorous dinosaur. It was discovered, originally, in 1975, and again in 1991 and named around the time of the release of Jurassic Park in 1993. This quieted (but of course did not silence) some discontent surrounding the "Velociraptors" in that movie. Their scientific name in the movie and the book was Velociraptor antirrhopus, which also appears in a Gregory S. Paul book (Predatory Dinosaurs of the World, 1988) as a synonym for Deinonychus antirrhopus. It appears as though Michael Crichton may have referenced this book in writing Jurassic Park. However, I digress from our main point, Utahraptor. 

Standing at a similar height to the movie 'raptors, Utahraptor, was approximately 7 m (23 ft) long and is estimated to have weighed somewhere between 230 and 500 kg (500 - 1100 lb). It is the largest dromaeosaur known at this time. Like other dromaeosaurs, Utahraptor did possess a large sickle-shaped "Killing Claw" on each foot. The claws known from Utahraptor are estimated to have been approximately 24 cm (9.4 in); actual fossilized unguals, or two claws, are slightly smaller than this.