100 million years ago, the Sahara Desert was wet. Animals included the pterosaur "Alanqa", types of giant crocodiles, and theropod predators the size of "T. rex". The largest predator was "Spinosaurus". In the past, it was thought that Spinosaurus aegyptiacus was bipedal. In 2014, scientists believed that "Spinosaurus aegyptiacus" was quadrupedal because it is front-heavy. If "Spinosaurus aegyptiacus" were to walk on two legs, it would topple. "Spinosaurus" probably walked on its knuckles. Spinosaurus's legs were short. "Spinosaurus"'s jaws were designed to catch slippery prey like fish. Scientists say that "Spinosaurus" spent most of its time in the water and it was a semi-aquatic dinosaur. 