Saurischian dinosaurs

Spinosaurids

Spinosaurids belong to the family Spinosauridae, a group that lived from the Late Jurassic through to the Late Cretaceous periods, and was fairly closely related to the carnosaurs . Spinosaurid remains have been found in north Africa, Europe and Asia. These huge two-legged carnivores were 30-50ft long and had straight sharp teeth. Spinosaurus means 'thorn lizard', and this dinosaur was a large two-legged carnivore up to 50ft long: remains of its huge jaw and backbone have been found in Egypt and Niger. Spinosaurus was an unusual carnivorous dinosaur because it had a sail on its back, possibly to control body temperature.

Since the discovery of Spinosaurus, two other related dinosaurs have been found. The first of these was Baryonyx, a large Cretaceous dinosaur that seems to have eaten fish. The curve of the jaw of this dinosaur is very similar to the jaw of the fish-eating crocodiles, and fossil scales and teeth of prehistoric fish were found in the area where the dinosaur's stomach would have been.

Suchomimus (the name means 'crocodile mimic') was another long-jawed fish-eating dinosaur, and it lived in what is now north Africa in the mid-Cretaceous period. Suchomimus was discovered in 1997, and it lived in the same waters as 50ft long crocodiles. Both dinosaur and crocodile seemed to hunt in the same way, using their teeth to hook prey rather than slash it - the two types of creature seem to have evolved similar feeding mechanisms independently, and they do not seem to have been closely related. Suchomimus had three-clawed hands, each of which had an elongated thumb that may have been used to spear fish.