The Evidence

Fragmentary dentary, vertebrae, hindlimb elements, teeth [destroyed]
Neck vertebra, fragmentary dentaries, dorsal neural arch

Spinosaurus was originally described in 1915 from a discovery made in North Africa by Stromer's German team. Sadly, an attack by allied forces in World War II destroyed this excellent specimen.

It it generally felt that the the known Spinosaur material is from a sub-adult. It is for this reason that the estimates of its size vary but generally suggest that it was the same length as T rex.

A large Spinosaurus skull, rumoured to be eight feet long, has turned up more recently. If the measurement is correct, this would suggest that the complete animal was longer than any known Giganotosaurus or T. rex, but there are no reliable sources yet.

What was Spinosaurus like?

Spinosaurus was thought to be as long as Tyrannosaurus rex but with a more slender body. Its most striking feature was its tall skin "sail" down its back, held aloft by bony spines. These were about 1.6 metres tall.

The new evidence and the records of the original find suggest that the animal had a long, low skull with a kinked snout very similar to Baryonxy.

The spines of the animal were very flat and bladelike. To this day, no other dinosaur specimen has been found with such extremely tall neural spines.

What was the function of Spinosaurus' Sail?

Although classically thought to be a device for regulating body temperature I, personally, don't subscribe to this theory. As a means for heating the blood its very clumsy. It also implies that this dinosaur was cold-blooded and would have had to carefully position itself in the sunlight. If this was true it might have severely overheated if it fell asleep in the afternoon sun!

My belief is that, as with all known peripheral adornments, it was sexual. It would have been used to make the animal look bigger both for attracting a mate and frightening opponents. Perhaps the skin across the surface had such a profusion of blood vessels that it could "flush" its colour, creating vivid patterns that were alluring to the females. A Peacock's tail plume is a modern-day comparison.

Many thanks to Steve Coombs

(c) 2001-2005