New evidence suggests an evolutionary link between dinosaurs and birds

Apr 19, 2013 14:29 GMT  ·  By

The fact that dinosaurs used to lay eggs can by no means be labeled as breaking news. However, the claim that some of these long-lost animals used to sit on their eggs in a manner fairly similar to that of today's birds is bound to make some heads turn. This is because this particular piece of news adds support to previously formulated theories that there is an evolutionary link between dinosaurs and birds.

In this year's spring issue of the scientific journal Paleobiology, a team of researchers documents the findings of a research into the nesting behavior of a dinosaur species known as Troodon.

The species used to roam the Earth roughly 75 million years ago, during the late Cretaceous.

They were meat-eating dinosaurs, which measured an average of 8 feet (2.4 meters) in length, the researchers explain.

After carefully analyzing fossilized remains of dinosaur eggs belonging to this species, the researchers reached the conclusion that, although the Troodon did lay its eggs on the ground, only a portion of the egg got to be submerged in either sand or mud.

Thus, the eggs would have been laid in vertical position, their lower part being buried in the ground and their upper part being sat on by the dinosaurs.

“Based on our calculations, the eggshells of Troodon were very similar to those of brooding birds, which tells us that this dinosaur did not completely bury its eggs in nesting materials like crocodiles do,” study co-author Darla Zelenitsky reportedly said.

“Both the eggs and the surrounding sediments indicate only partial burial; thus an adult would have directly contacted the exposed parts of the eggs during incubation,” lead author David Varricchio further added.

As the researchers explain, the findings of this investigation make a case of how birdlike behavior first evolved in theropods (i.e. a caste of dinosaurs that are known to be related to present-day birds).

“For now, this particular study helps substantiate that some bird-like nesting behaviors evolved in meat-eating dinosaurs prior to the origin of birds. It also adds to the growing body of evidence that shows a close evolutionary relationship between birds and dinosaurs,” Darla Zelenitsky argued.