robert karl stonjek

Birdlike Dinosaur Older Than Thought

A rooster-size dinosaur named Buitreraptor gonzalezorum provides solid
evidence that a group of theropods known as dromaeosaurs originated at least
20 million years earlier than previously thought. Not only does the find
indicate that the group got its start on the supercontinent Pangaea before
it split in two, but it suggests that birdlike flight may have evolved twice
on two separate supercontinents.

"Buitreraptor is one of those special fossils that tells a bigger story
about the earth's history and the timing of evolutionary events," says Peter
Makovicky, curator of dinosaurs at the Field Museum in Chicago and lead
author of a paper in the October 13 issue of Nature describing the species.
Makovicky dated the new species--whose name comes from the Spanish word
buitrera, for "vulture roost" and gonzalezorum, after the brothers Fabián
and Jorge González, Argentinian archaeologists who discovered it--to 90
million years old. Related swift, bipedal, birdlike dinosaurs, including
Utahraptor and Velociraptor, date to around this time, but their skeletal
remains have all been found in the American West or China. These far-flung
regions were once joined together as the supercontinent Laurasia 150 million
years ago.

Full Text at Scientific American
http://www.sciam.com/article.cfm?cha...0583414B7F0000

Posted by
Robert Karl Stonjek