Troodon
Mary Evans Picture Library/Deagostini Editore
Troodon ('wounding tooth') was a fast, long-legged carnivore with serrated teeth and long, slim jaws. With large eyes and probably a good sense of hearing, it is thought to have had the largest brain in proportion to its body weight of all dinosaurs. Troodon was about 3 metres long and 1 metre tall, and lived about 75 million years ago in North America.