November 15, 2007—This bizarre-looking dinosaur "mowed" through ground vegetation using its vacuum cleaner-shaped mouth more than a hundred million years ago, a new study has found.

New CT scans of the dinosaur, Nigersaurus taqueti, first discovered in the 1950s in the Sahara region of Africa, shows that the species had an extremely delicate skull and brain construction. (Read full story.)

That forced the dinosaur to keep its head low to the ground at all times, as seen in this artist's rendering.

The unusual posture suggests that similar dinosaurs, called sauropods—such the well known North American Diplodocus—also typically ate with their heads lowered, the authors write in today's issue of PLoS ONE.

The researchers also found that Nigersaurus had 500 teeth, with up to eight replacements stacked up behind each tooth. The 50 columns of teeth, lined tightly along a squared-off jaw, made the dinosaur's mouth essentially a foot-long (0.3-meter) pair of scissors.

"Among dinosaurs, Nigersaurus sets the Guinness record for tooth replacement," study lead author Paul Sereno, a paleontologist at the University of Chicago said in a statement.

Sereno, who named the odd plant-eater in 1999, is a National Geographic Society Explorer-in-Residence. (National Geographic News is owned by the National Geographic Society.)

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