Before the mid-1960s, it was widely believed that all dinosaurs were cold-blooded, slow-moving animals. But in the summer of 1964, a team of paleontologists led by John Ostrom discovered Deinonychus, a dinosaur equipped with large, sickle-shaped claws; a lightweight body; and strong legs. The fossil suggested the animal was fast and agile.
The discovery showed that some dinosaurs were active and nimble. And so began the "dinosaur renaissance" — a scientific shift that redefined our understanding of dinosaurs by showing that many were faster than previously assumed.
