Spinosaurus

Spinosaurus was one of the largest predatory dinosaurs ever to walk the Earth, or swim its waterways. Thriving in the vast mangrove river networks of Late Cretaceous North Africa, it attained lengths of up to fifteen metres. It is instantly recognised by the magnificent sail of neural spines rising nearly two metres from its back. First described from Egyptian fossils destroyed during the Second World War, recent discoveries from Morocco have dramatically revised our understanding of the animal. It had dense bones, unusually short hind limbs, and a flexible, fin-shaped tail designed for aquatic propulsion. Its narrow jaws were filled with conical teeth, perfectly evolved for gripping enormous coelacanths, sawfish, and lungfish. While debate continues regarding whether it was an active pursuit swimmer or a shoreline wader, Spinosaurus was undeniably unique among giant theropods.

Spinosaurus possessed a paddle-like tail propelled by tall neural spines, providing evidence for a specialised semiaquatic swimming lifestyle.

Where and when

Spinosaurus lived in the Late Cretaceous, from 99 to 93.5 million years ago (Cenomanian age). Its remains come from Egypt and Morocco, in the Kem Kem Group.

The numbers

Length 15 m (estimates run from 14 to 15 m). Mass about 6.9 t. Hip height about 3 m. That is 8.5 human-lengths, or 1.29 of a double-decker bus. These are estimates from partial skeleton; fields marked estimated by the site are length, mass, hip height.

Compare Spinosaurus with a bus Place on the timeline