Weird dinosaur was "cow of the Mesozoic"

By Maggie Fox, Health and Science Editor

WASHINGTON (Reuters) - A strange-looking dinosaur with rows of tiny teeth crammed into the very front of its jaws and fragile air-filled bones may have been the "cow of the Mesozoic," and far more common than better-known dinosaurs, scientists said on Thursday.

Its shovel-shaped jaws and tightly packed teeth -- up to 10 rows of teeth -- allowed Nigersaurus taqueti to vacuum through ferns and other ground cover, a team led by Paul Sereno at the University of Chicago reported.

The researchers used a combination of computer modelling, X-rays and good old-fashioned digging to build a model of an elephant-sized animal that lived 110 million years ago in what is now the Sahara desert in Niger.

And they argue that their work calls into question some of the standard models of other related dinosaurs such as Diplodocus that show the creatures standing and browsing in the treetops.

Such creatures, known as diplodocids, more likely grazed, Sereno writes in his report, published in the Public Library of Science journal PLoS ONE here

Enough bone was found to show the orientation of the semicircular canals -- the organ of equilibrium. What they found astonished the researchers.

"In everyday life this animal had its nose pointed towards the ground," Sereno told a news conference at the National Geographic Society, which helped pay for his 10-year study of the 30-foot-long (10 meter) Nigersaurus.

What this says, argues Sereno, is that experts have long mistakenly believed that many herbivore dinosaurs behaved like living long-necked animals such as giraffes.