Ornithocheirus was a large pterosaur with a long slender skull and a bony crest on its snout (though some specimens lack this). It had sharp teeth set in a long, tapering jaw designed for catching fish.

Ornithocheirus had the wing area of a small aeroplane, yet because of its hollow bones, its body probably weighed less than a human. Its wings were made of skin stretched between an enormous elongated finger and its ankle.

Using rising air currents, or 'thermals' to soar into the air, Ornithocheirus may have been able to fly hundreds of kilometres without flapping its wings. This could account for the worldwide distribution of its fossil remains.

As a fish-eater, Ornithocheirus' hunting technique would probably have involved swooping down from high up and then flying very low across the water's surface. When parallel with the fish the beak would be momentarily dipped under the surface and the jaws would close around it. The fish would probably be swallowed whole.