Of all the reptiles alive today, crocodiles and alligators may be the least changed from their prehistoric ancestors. A good example is Mystriosuchus, whose pointy, tooth-studded snout bears a remarkable resemblance to the modern gharial of central and southern Asia. Like the gharial, Mystriosuchus is believed to have been an accomplished swimmer, spearing and eating fish as it plied the ancient rivers of western Europe. Mystriosuchus is classified as a phytosaur, a type of archosaur (the family of ancient reptiles preceding the dinosaurs) that differed from primitive crocodiles in that their nostrils were positioned on top of the skull, between the eyes, rather than on the ends of their snouts. Illustration originally captioned: An Upper Triassic Phytosaur by S.W. Williston, 1914, from unidentified source.