Modern reconstruction of spinosaurus - stock illustration

Spinosaurus (meaning 'spine lizard') was arguably the largest known meat-eating dinosaur at, according to one estimate, up to 18m in length. Named for the elongated spinal bones that make up the curious sail on its back, spinosaurus was probably a fish-eater. Its head was narrow like that of a crocodile and, like that animal, might have spent its life on land and in water. It lived towards the end of the Cretaceous period, in what is now northern Africa. There have been suggestions that the animal may have had a quadrupedal gait when on land, as shown here, but this is currently contested.