Fossil discovery of new strong-handed dinosaur to change past notions

Washington, Oct 7 (ANI): Scientists have discovered fossils of an intriguing new species of dinosaur that had a powerful hand- a feat that could reveal an edgier side of some supposedly peaceful, plant-munching dinosaurs, says a new study.

The discovery of Sarahsaurus aurifontanalis, which roamed North America about 190 million years ago, also boosts the idea that at least some dinosaurs became masters of their domain less by dominance than by opportunistic behaviour and a bit of good luck.

A remarkably complete Sarahsaurus skeleton, found in Arizona, shows that the early Jurassic herbivore was, at 14 feet (4.3 meters) long and 250 pounds (113 kilograms), smaller than its enormous sauropod cousins such as Apatosaurus, which arose later. (See a sauropod picture.)

Like the sauropods-the largest animals to walk Earth-Sarahsaurus featured a long neck and small head.

But the newly identified creature also boasted strong teeth and an unusual clawed hand, that, while only human size, was clearly built for enormous power and leverage, according to palaeontologists.

"The dogma is that these animals were herbivores, but these hands and massive claws reopen the door to what they might have been doing with them," National Geographic News quoted study leader Tim Rowe, a palaeontologist at the University of Texas, as saying.

"Looking at the teeth, I think they could have eaten anything that they wanted, so they may have also been scavengers and not pure herbivores," he added.

Beyond its bizarre appearance, the new species lends support to the relatively new view that dinosaurs came to dominate North America by being opportunistic, not necessarily by overpowering their competitors.

By dating bones of Sarahsaurus and two other previously described species, scientists suggest that sauropodomorphs migrated to North America in several waves after the Triassic-Jurassic mass extinction killed off the dinosaurs' North American competition 200 million years ago.

"It's not as if they stormed the beaches. They had to wait for this natural catastrophe to empty the neighborhood. So they were opportunists, not completely superior invaders. The poignant story to me is that of recovery after a great extinction," noted Rowe.

The Sarahsaurus skeleton also spurred a reanalysis of existing fossil fragments in other species, Rowe said.

For instance, the team now asserts that sauropods were completely absent in North America prior to the Triassic-Jurassic extinction that wiped out more than half of the planet's species. (ANI)