The Spinosaurus or "spiny lizard" is one of the longest known dinosaurs measuring up to 18 m in length, 6 m in height and weighing up to 9 tonnes. It is recognizable for its large back spines, which lead us to suppose that it had a sail used as a temperature regulator. The Spinosaurus, which lived in the Cretaceous period, was both a carnivore and a fish eater. Both long and narrow, and equipped with numerous straight teeth, the Spinosaurus skull is a similar shape to that of crocodiles.