Bones Show Dinosaurs Lived After Cataclysmic Meteor Strike

URL: http://www.abqjournal.com/news/state/424459nm01-13-06.htm

Friday, January 13, 2006
Bones May Show That Dinosaurs Lived After Cataclysmic Meteor Strike
By John Fleck
Albuquerque Journal Staff Writer

"Paleocene dinosaur" is, by definition, something of an oxymoron.

"Paleocene" is geologists' word for the epoch in Earth history that began 65 million years ago?- after the dinosaurs went extinct.

But there it is, on a shelf in the collections room at the New Mexico Museum of Natural History and Science?- the gigantic leg bone of a dinosaur. In rock that some scientists think is Paleocene. It is, museum paleontologist Spencer Lucas acknowledges, a bit of a puzzle.

Paleontology is a science of gaps. Most animals, when they die, do not become fossilized. Lots of rocks are never preserved. And of those that are preserved, most are buried beyond reach. But at any moment in history, some rocks are being eroded away, and scientists like Lucas try to be there to find the bones that emerge.

That is the case with what scientists call the Ojo Alamo Sandstone, emerging in bits and pieces in the San Juan Basin, slowly yielding its fossil treasures. Fossilized pollen dates some of the rock as Paleocene in age, the epoch that came after a mountain-sized meteor hit Earth and wiped out the dinosaurs. But Lucas and others, including retired U.S. Geological Survey scientist James Fassett, have been finding dinosaur bones in it for years.

In a talk Wednesday night in Albuquerque at the monthly meeting of New Mexicans for Science and Reason, Lucas said he thinks the most likely explanation is that some of the dinosaurs they're finding died long before, and their fossils later washed into rocks being formed in the Paleocene as a new river was remaking the local landscape.

Some of the rocks are simply older, from before the meteor hit.

But he acknowledges people like Fassett, who argue that some dinosaurs lingered long after the asteroid impact, might be right.

"It's quite plausible," Lucas said. "It's an awfully big planet."

"We'd do well to keep an open mind on this question," he said.