The plant-eating dinosaur known as Nigersaurus taqueti has a featherweight skull armed with hundreds of needle-shaped teeth, the National Geographic Society said Thursday in a release.

Sereno, a professor at the University of Chicago and the National Geographic Explorer-in-Residence, said Nigersaurus operated more like a Mesozoic cow than a reptilian giraffe, grazing on greenery that consisted largely of ferns and horsetails.

An exhibit on Nigersaurus, including the original fossils and a reconstructed skeleton and skull, opened Thursday in Washington in the National Geographic Museum at Explorers Hall.

The 110 million-year-old dinosaur was found by Sereno and his team in 1999.

Details of the dinosaur and its lifestyle are published in the online journal of the Public Library of Science as well as in the December issue of National Geographic's "Extreme Dinosaurs" magazine.