Big-mouth T.rex always picked on the little guy

Scientists think baby-eating was common for T.rex. Photo / Supplied

It was the biggest carnivore to stalk the land and with banana-sized teeth and a set of jawbones that could swallow a kitchen table, Tyrannosaurus rex earned its name as king of the dinosaurs.

But scientists may have uncovered T.rex's dirty secret - it was a prolific baby killer.

A study into the predatory habits and diet of the biggest and most ferocious of the dinosaurs has concluded that T.rex preferred to dine on juvenile prey, preferably small enough to eat whole.

The Hollywood image of T.rex, epitomised in Steven Spielberg's Jurassic Park, is of an aggressively agile giant that stalked and killed herbivorous animals of a similar or even larger size, such as the three-horned Triceratops.

But two palaeontologists believe that T.rex and the other big meat-eating dinosaurs that hunted on two legs preferred to pick on animals far smaller than themselves.

"Modern predators mainly attack vulnerable, young animals as they are inexperienced in evading predators, and this was probably the same in dinosaurs," said palaeontologist Dr David Hone, who works at the Institute of Vertebrate Palaeontology and Palaeoanthropology in Beijing.

"Young prey are easier to bring down and the risk of injury to the predator is much lower," he said.

Working with Oliver Rauhut of the Bavarian State Collection for Palaeontology and Geology in Munich, Dr Hone has reviewed the evidence suggesting that T.rex and its family went in for baby-eating in a big way. The two scientists also suggest that baby-eating was such a common behaviour among large predatory dinosaurs that it could explain why the remains of so few juvenile dinosaurs have been found in the fossil record.

"We conclude that, like modern predators, theropods preferentially hunted and ate juvenile animals leading to the absence of small, and especially young, dinosaurs in the fossil record," the scientists conclude in their study published in the journal Lethaia.

"Finds of dinosaur nesting sites indicate that dinosaurs laid large number of eggs and thus had very high numbers of offspring but little of this is reflected in the numbers of young in the fossil record," said Dr Rauhut.

The two scientists also believe that eating baby dinosaurs whole or in large pieces, digesting them with the help of their stomach acids, gave T.rex the added advantage of being able to use the minerals and nutrients stored in the bones of their small prey.

- INDEPENDENT