But Currie felt he had an answer to this. These tyrannosaurs were rare dinosaurs.
They would have made up only five per cent of the animal life in this area. The chances that 12 unrelated tyrannosaurs died separately and were washed together to this spot were minute. To find 12 tyrannosaurs by chance, at this level, in this bone bed. The chances of that happening are about one in 64 million. It really isn't very likely that it's going to happen by chance. But there could be an even more dramatic reason why the bones of Currie's tyrannosaurs were all in one place. They could all have been caught in a predator trap. This is a predator trap. In this strange swamp-like place, molten tar has bubbled up from deep within the Earth for tens of thousands of years.