Now for those of you who are growing bored with my ongoing discussion of the Human Powered Commuter Vehicle, something completely different, dinosaur biomechanics.
It was like being a kid again, opening Adrian Desmond’s book “Hot Blooded Dinosaurs” and seeing the picture of a sprinting dinosaur, gracefully leaning forward with tail stretched out behind. In an eye blink, the dinosaur love of my childhood (and many others as well), Tyrannosaurus Rex was replaced by this new creature, Deinonychus Antirrhopus.
Deinonychus was discovered and named by Prof. John Ostrom of the Yale-Peabody Museum in 1969. The name for this dinosaur was descriptive of the animal’s anatomy, meaning terrible claw & counter balance. Terrible claw of course referred to the sickle-shaped claw on the second digit of each foot and counter balance referred to a tail made rigid by bony extensions on the vertebrae.
Deinonychus could possibly be the most significant dinosaur discovery of the 20th Century. The reason for this was the realization that if the sickle claw was used for attacking prey, the animal needed to be very athletic and one that was more than likely warm blooded. To emphasize the point Robert T. Bakker, then a student of Prof. Ostrom drew a convincingly active restoration of Deinonychus, the image that graced Desmond’s book.
Prof. Ostrom also went on to observe strong similarities between the limb structure of Deinonychus and Archaeopteryx the famous proto-bird discovered in the 19th century. Based on Archaeopteryx, Thomas Huxley advocated that birds descended from dinosaurs and because of the similarities he observed, Ostrom resurrected the idea. Of course, because of numerous fossils indicating the presence of feathers on clearly flightless dinosaurs, the bird from dinosaur decent is now accepted as fact.
21 years would pass since its discovery and Michael Crichton through his book, “Jurassic Park” and the subsequent movie would introduce the world at large to Deinonychus. Well not exactly…
Ironically, the dinosaur mentioned in the book and movie was a misnamed species, Velociraptor Antirrhopus. An amateur paleontologist, Greg Paul, had decided, incorrectly that two raptors were of the same genus. They were Velociraptor Mongoliensis and Deinonychus Antirrhopus. Velociraptor was about 18” tall, weighed about 33lb. and had a long flat skull. Deinonychus was about 40” tall, weighed about 150lb. and had a rather deep skull. Crichton may have known the name was incorrect and used Velociraptor anyway because it conveniently shortened to “raptor”, while I don’t know how to shorten Deinonychus except to shorten it to DA. The movie took additional liberties by significantly enlarging their raptor to make it seem more fearsome, even though DA was fearsome anyway, hunting in packs like wolves. As life imitates art, a raptor was subsequently discovered about the size of the movie raptor, Utahraptor Ostrommaysorum, that weighed about 1100lb. After “Jurassic Park” the term raptor no longer referred to birds of prey like eagles, owls and vultures but instead to medium sized carnivorous dinosaurs with sickle-shaped claws on their feet.