Sunday, March 6, 2011

Dinosaur refuge in New Mexico?

Bone discovery suggests dinosaurs survived 700,000 years past meteorite strike

Postmedia News: A fossilized sauropod bone, dated by a team of Canadian and U.S. scientists to 64.8 million years ago, appears likely to force a serious rethinking of the demise of dinosaurs, which were supposed to have been wiped out in a catastrophic meteorite strike no later than 65.5 million years ago -- 700,000 years before the death of the giant, vegetarian beast that left its femur behind in present-day New Mexico.

A study of the bone in the journal Geology, co-authored by University of Alberta paleontologist Larry Heaman and two U.S. colleagues... also represents a landmark achievement in the use of a uranium-lead dating technique -- developed at the University of Alberta -- that allowed the team to pinpoint the age of the bone directly from a fragment of the specimen, not just indirectly from the layer of rock in which it was found.

The bone was unearthed near the New Mexico-Colorado border by U.S. paleontologist James Fassett... In the past, Fassett has controversially proposed that the region may have been a refuge for some dinosaurs that survived the colossal meteorite strike widely believed to have ended the dinosaur age between 65.5 and 66 million years ago. The new findings appear to support Fassett's theory...

'For some time, there's been other evidence that suggests dinosaurs survived,' he said, at least in some small pockets... But it hasn't been 'ironclad evidence,' he noted. 'What was missing was some way to directly date the bone itself. Up to now, it's just never been possible, so this is the first real success.'
Image source here.