Deinonychus attacks Diplodocus - older model - Museum of the Rockies - 2013-07-08
Model of a Deinonychus attacking a Diplodocus, on display in the Museum of the Rockies in Bozeman, Montana.
A synonym for Deinonychus is the more familiar "velociraptor" (made famous by the Jurassic Park movies).
Deinonychus antirrhopus was first discovered in 1931 near Billings, Montana. Its name means "terible claw", because it could lift the middle toe of its heavily clawed foot and slice with it like a razor.
In the late 1960s, paleontologist John Ostrom published a series of papers about Deinonychus that completely revolutionized the way we think about dinosaurs. Previously, scientists thought of them as plodding, slow, cold-blooded creatures. But Ostrom proved that Deinonychus couldn't be cold-blooded, and was undoubtedly lightning-fast and very agile. Within just a few years, everyone accepted that dinosaurs had to be warm-blooded, and most were extremely active and mobile. This was the "Dinosaur Revolution" or "Dinosaur Renaissance", and it governs the way we think about dinos today.
Deinonychus lived 115 to 108 million years ago in western North America. It was about 11 feet in length, and tended to run with its head lowered and tail stuck straight out as a counterbalance. In this position, it was only about three feet high at the hip. It weighed no more than 160 pounds. The 16-inch-long skull had 70 curved, blade-like teeth in a very narrow snout and it had stereoscopic vision. Deinonychus had strong forelimbs, powerful and very large hands, and three claws on each hand. The middle of the three toes on each hind foot had a sickle-shaped claw. The snap-tendons on that toe permitted it to be used like a scythe!
Deinonychus was originally thought to be like most dinos -- reptilian and hairless. But since ancestors and close relatives of Deinonychus had feathers, it is bellieved that Deinonychus did as well.
Diplodocus is one of the more common dinosaur fossils, and lived about 154 to 150 million years ago. This was the age of the giant sauropods: Camarasaurus, Barosaurus, Apatosaurus and Brachiosaurus. The name means "double beam", and refers to the V-shaped bone that run down the length of its neck, spine, and tail and which reinforce the strength of the vertebrae. Diplodocus lived about 154 to 150 million years ago. It was about 110 feet long, and weighed 11 to 18 tons. It was first discovered in 1878 in Fremont County, Colorado.
This exhibit shows two model Deninychus attacking a model Diplodocus. All models are full-size. One version of Deinonychus (depicted here) shows one theory about Deinonychus skin and coloration, that is, some feathers and a lack of color. The other depicts Deinonychus via the other theory (which bright colors and feathers).