Seven theories that are also extinct

The asteroid theory might be closest to the truth about how the dinosaurs were wiped out but other hypotheses are far more entertaining.

The undisputed rulers of the planet lost their sex drive and failed to reproduce enough offspring to continue the family lines, some believe.

They were smitten by a plague of cataracts and went blind, say others.

They were wiped out by fierce competition for food and water from other mammals or even armies of hungry caterpillars, who also started to devour their giant eggs.

So successful and voracious were the carnivores that they massacred their vegetarian peers and then, presumably, ate each other.

They may have become extinct after an enormous burst of radiation which hit the Earth after two neutron stars collided in our galaxy.

One more recent theory was that they all dropped dead from a form of dinosaur Aids, spread by their uncontrollable promiscuity.

Other theories put forward over the years have included intense volcanic activity, food poisoning, slipped discs in the dinosaurs' backs and general stupidity.