Spinosaurus or "spiny lizard" is one of the longest known dinosaurs, measuring up to 59 feet long, 20 feet high and up to 9 tons. Easily recognizable by its very large dorsal spines, it is supposed that it possessed a veil fulfilling the function of thermal regulator. The Spinosaurus, which lived in the Cretaceous Period, was both carnivorous and piscivorous. Long, narrow and with many straight teeth, the skull of Spinosaurus is shaped like crocodiles.