It Seems it Took More Than an Asteroid Hit to Finish the Dinosaurs

"Some Dinosaurs Survived the Asteroid Impact"
LiveScience (April 28, 2009)

"The great splat of an asteroid that might have wiped out the dinosaurs apparently didn't get all of them. New fossil evidence suggests some dinosaurs survived for up to half a million years after the impact in remote parts of New Mexico and Colorado.

"The whole idea that a space rock destroyed the dinosaurs has become controversial in recent years. Many scientists now suspect other factors were involved, from increased volcanic activity to a changing climate. Either way, some 70 percent of life on Earth perished, and an asteroid impact almost surely played a role.

"Scientists recently analyzed dinosaur bones found in the Ojo Alamo Sandstone in the San Juan Basin. Based on detailed chemical investigations of the bones, and evidence for the age of the rocks in which they are found, the researchers think some dinosaurs outlived the crash that occurred 65 million years ago and stuck around for a while.

" 'This is a controversial conclusion, and many paleontologists will remain skeptical,' said David Polly, one of the editors of the journal Palaeontologia Electronica, in which the research was published today...."

I'm pretty sure we haven't heard the last word on what happened around 65 million years ago.

The scientists who found these oddly young bones checked out the possibility that the bones were old, had been exposed by erosion, and re-deposited in newer rocks.

That apparently didn't happen: The bones match the rocks they were found in - and a 'some assembly required' hadrosaur skeleton was found. 34 bones of it, anyway - and that many bones of an individual being found together would be unlikely if they were debris washed downstream by a river long ago.

This is a pretty good overview of another bit of evidence - one which suggests that the extinction event that finished the dinosaurs is more complex than we thought.