 This reformation took place following the 1964 discovery of "Deinonychus" by paleontologist John Ostrom.Ostrom's description of this nearly-complete birdlike dinosaur, published in 1969, challenged the presupposition of dinosaurs as cold-blooded, slow-moving reptiles, instead finding that many of these animals were likely reminiscent of birds, not just in evolutionary history and classification but in appearance and behavior as well.This idea had been advanced before, most notably by 1800s English biologist Thomas Huxley about the link between dinosaurs, modern birds, and the then-newly discovered "Archaeopteryx".