Spinosaurus is named after the great row of spines down its back. These spines were 2m long! All of the spines were covered in skin, just as your backbone is covered in skin, and in the case of Spinosaurus it would have made the animal appear to have a great flap, called a sail, on its back. This sail might have had blood vessels in it, and if so it would have been a warm-blooded dinosaur.

It lived in Africa from 100 to 93 million years ago. It was 18m long and weighed 9 tonnes, making it probably the largest hunting dinosaur that ever lived. It had one of the longest skulls – about 2m – of any hunting dinosaur. The skull had a narrow snout filled with straight conical teeth as you can see in the illustration.

It may well have been a fishing dinosaur because its nostrils are high up on its nose (compare this to a crocodile), but again, like a crocodile, it would have eaten anything that came within reach.