Scientists Find Youngest Dinosaur Bone

(EndPlay Staff Reports) - Scientists have discovered one of the youngest known dinosaur bones, a finding that gives fuel to the theory that a meteor killed the dinosaurs.

Yale University recently announced that researchers found the fossilized horn of a ceratopsian in 2010 in the Hell Creek formation in southeastern Montana. The horn is likely from a Triceratops, common to the area.

It is the youngest dinosaur bone believed to be found at the site where the dinosaur died rather than redeposited from older sediments.

The research team found the fossil about five inches below what's known as the K-T boundary, a geological layer that marks a transition between the geologic Cretaceous period during which land-dwelling dinosaurs died and the Tertiary period when mammals started becoming the dominant animals.

This possibly disproves what's known as the "three-meter gap," what Yale said is a sticking point in the theory that a meteor that struck Earth about 65 million years ago killed all land-dwelling dinosaurs. There had seemed to be a lack of fossils within the 10 feet of rock below the K-T boundary, making some think dinosaurs had already died out.

This gap, according to Discover magazine, is thought to correspond with a period of about 100,000 years.

"This demonstrates that dinosaurs did not go extinct prior to the impact and that at least some dinosaurs were doing very well right up until we had the impact," Yale paleontologist Tyler Lyson told the UK Guardian .

Discover magazine said there had been other finds in recent years close to the K-T boundary but none as significant as this.

Lyson told LiveScience this one find isn't enough necessarily to argue against the theory that dinosaurs were already "gradually declining in numbers." She said more field work will need to be done to see if there's other dinosaurs within this gap.

"I'm confident that with more field work, we will find more dinosaurs within this interval," she said.