July 1969

There are a number of events turning 50 this year. Paleontology is not left out of 50 year old events. One of the most important, in my opinion, is Bulletin 30 of the Yale Peabody Museum of Natural History. Bulletin 30 included one of the most iconic scientific illustrations of my childhood (see below), drawn by Robert Bakker, and accompanying the description by John Ostrom of an "unusual theropod" found in Montana known now as Deinonychus antirrhopus (discovered in 1964). The inspiration for Jurassic Park's Velociraptor antagonists, Deinonychus was a small to medium sized bipedal dinosaur approximately 3.4 m (11 ft) long that lived 115 - 108 million years ago. Hypotheses of Deinonychus behavior and the 172 page description of its osteology by Ostrom have fueled comparisons to birds and produced images of an intelligent, pack-hunting dinosaur. The 120 mm (4.7 in) toe claw reconstructed from YPM 5205 by Ostrom was enough to inspire nightmares even before that annoying kid spoke up in Jurassic Park. Estimated to weigh in at 100 kg (220 lbs) Deinonychus was beefy and adding strength and a giant claw to an animal that was likely rather fast for its size only adds to the nightmarish qualities of this Cretaceous predator.

Happy 50th naming month to one of my favorite, and one of the most frightening, dinosaurs that we know of, Deinonychus antirrhopus!

Deinonychus antirrhopus ©Robert Bakker