Dino dropping yields dining clues

A king-sized lump of dinosaur excrement discovered in Canada has set palaeontologists' hearts beating faster with the news that Tyrannosaurus Rex might have been quite a dainty eater.

The fossilised faeces - known as a coprolite - was recovered from the Late Cretaceous Frenchman Formation in south-western Saskatchewan. About twice the size of previously discovered dino droppings, it excites scientists because of the secrets it yields on the beast's dining habits.

Dr Karen Chin, of the US Geological Survey, and Dr Timothy Tokaryk, of the Royal Saskatchewan Museum, examined the coprolite closely and their findings are published today in the science journal, Nature.

There are many examples of ancient mammal and avian droppings, but few from the large carnivores. The researchers believe this lump came from the biggest of them all, the T-Rex.

Their most striking finding was the large number of bone fragments, a large proportion of its total mass. The researchers were surprised because the fragments suggested that T-Rex pulverised its prey, munching on it up before swallowing.

Modern reptiles tend to swallow their prey whole or in large unchewed pieces, as T-Rex was also thought to do. Close scrutiny of the bones showed that the fragments were from young plant-eating dinosaurs. Some of the thicker pieces were thought to have come from a Tryceratops, the three-horned beast. The turd itself is 44 cm long, 16 cm across and 13 cm deep.

In an accompanying News and Views article in Nature, Drs Peter Andres and Yolanda Fernandez-Jalvo, of the Natural History Museum, London, offer much advice on 101 uses for fossilised faeces. They point out that it also gives information on the relationship between predator and prey.

It could give information about the plant life of the time seen in pollen grains, either as the stomach contents of the herbivore prey or stuck to the sticky surface of the droppings when they were fresh some 65 million years ago.

Rather startlingly, they add that one bone fragment that managed to avoid being pulverised by T-Rex was in such "pristine" condition that "it might be worth looking for DNA in it". Jurassic Park, here we come.