validated in 1973 with the discovery of hadrosaur fossils above the Cretaceous Canadian arctic circle by the Canadian paleontologist Dale Russell. Ostrom's reappraisal of dinosaurs as endothermic was considered radical at the time, but its ability to resolve outstanding contradictions in dinosaur physiology immediately drew many followers, and would be supported by many future discoveries. Deinonychus His 1964 discovery of additional Deinonychus fossils is considered one of the most important fossil finds in history. Deinonychus was an active predator that clearly killed its prey by leaping and slashing or stabbing with its "terrible claw", the meaning of the animal's genus name. Evidence of a truly active lifestyle included long strings of muscle running along the tail, making it a stiff counterbalance for jumping and running. The conclusion that at least some dinosaurs had a high metabolism, and were thus in some cases warm-blooded, was popularized by his student Robert T. Bakker. This helped to change the impression of dinosaurs as the sluggish, slow, cold-blooded lizards which had prevailed since the turn of the century. The implications of Deinonychus changed depictions of dinosaurs both by professional illustrators and as perceived by the public eye. The find is also credited with triggering the "dinosaur renaissance", a term coined in a 1975 issue of Scientific American by Bakker to describe the renewed debates causing an influx of interest in paleontology. The "renaissance" has lasted from the 1970s to the present and has doubled recorded dinosaur diversity. Archaeopteryx and the origin of flight Ostrom's interest in the dinosaur-bird connection started with his study of what is now known as the Haarlem Archaeopteryx. Discovered in 1855, it was actually the first specimen recovered but, incorrectly labeled as Pterodactylus crassipes, it languished in the Teylers Museum in the Netherlands, until Ostrom's 1970 paper (and 1972 description) correctly identified it as one of only eight "first birds" (counting the solitary feather). Cultural influence John Ostrom's work on the functional morphology of dinosaurs found that the claws and tendon scars in the tail would indicate a running position. And so the whole posture of bipedal dinosaurs changed to one of agile, fast-running, fearsome predators. This inspired a new generation of dinosaur movies and also museums worldwide changed their dinosaur bone displays. In 1966 John H. Ostrom was instrumental in the establishment of Dinosaur State Park in Rocky Hill, Connecticut ("because the governor was besieged by letters from schoolchildren