Deinonychus were long-clawed carnivorous dinosaurs that flourished in western North America during the Early Cretaceous Period (145.5 million to 99.6 million years ago). Paleontologist John Ostrom’s study of Deinonychusin the late 1960s lead to a dinosaur renaissance. Early scientists held the popular conception of dinosaurs being slow-moving, reptilian giants. Deinonychus had a small sleek body,...