Age of Dinosaurs Ended Abruptly

Paleontologists have recently determined that the end of the Age of Dinosaurs came about abruptly, in one fell swoop, rather than progressively, as other researchers suggested in the past.

These conclusions are based on a thorough analysis of a single dinosaur horn. The issue as to whether the extinction of these giant lizards took place gradually or violently is still a matter of heated debate in the international scientific community.

However, experts do agree that a massive asteroid struck the planet about 65 million years ago, acting as the main culprit for the widespread extinction event that killed of the dinosaurs. The event is known as the Cretaceous-Tertiary (K-T) boundary.

In some studies, researchers listed a scenario in which the extinction event was in fact already under way before the asteroid struck. Massive volcanic eruptions may have been one of the factors driving this phenomenon, LiveScience reports.

But the team that conducted the new study is not convinced this was the case. In this investigation, they show that one of the main arguments used by those who believe a gradual extinction happened is in fact unfounded. As is often the case, the argument relates to the fossil record.

Thus far, experts were unable to find any dinosaur fossils in a 10-foot (3-meter) layer of rock immediately underneath the K-T layer. This is interpreted by some as indicating a time where no fossils were laid because only few dinosaurs were left alive.

This research found the aforementioned dinosaur horn exactly in this supposedly-barren layer, some 45 centimeters (18 inches) below the K-T layer. Early analyses of the remain indicate that the bone most likely belonged to a Triceratops.

It was discovered in a rock formation called the Hell Creek Formation of southeastern Montana, where several other Triceratops specimens have been found in the past. “We need to do more field work to find more dinosaurs within the 3-meter gap,” Tyler Lyson explains.

Having just “one dinosaur in the gap doesn't necessarily falsify the idea that dinosaurs were gradually declining in numbers. However, this find indicates that at least some dinosaurs were doing fine right up to the K-T boundary,” he adds.

“I'm confident that with more field work, we will find more dinosaurs within this interval,” explains the researcher, who holds an appointment as a vertebrate paleontologist with the Yale University.

Details of the new research appear in a paper published in the July 13 issue of the esteemed scientific journal Biology Letters.