Spinosaurus was a large carnivorous saurischian (lizard hipped) theropod type dinosaur that lived about 95 million years ago during the middle of the Cretaceous period. The front arms were slightly shorter than the muscular back legs so it was probably bipedal but walked on all fours when it needed to.

Spinosaurus prints

Its main feature was a large sail on its back that may have been used for regulating its temperature; during cold parts of the day Spinosaurus could lie in the sun collecting its warmth; during the hotter parts of the day Spinosaurus could lie in the shade, when the sail would act as a radiator giving off excess heat. The sail may also have been used to attract a mate.

Spinosaurus' diet was meat and fish. It had a large crocodilian shaped head with powerful jaws full of long sharp teeth that had few or no serrations (unlike the much heavier T-Rex, whose teeth had lots). Given the opportunity it may also have been a scavenger.

The first Spinosaurus fossils were found by a German palaeontologist called Ernst Stromer in Egypt in 1912. This specimen was destroyed during an air raid on Munich in the Second World War. Other fossils have been found in the Sahara desert, Morocco and South America but none have been so complete as the first. During the early Cretaceous, about 95 million years ago, the climate in this area of the world was much more tropical with abundant lakes, rivers and wetlands.