'Teeth To Beak' Mystery Resolved By Dinosaur Fossils Found In China

Scientists have recently discovered a group of 13 fossilized Limusaurus about 154 million years old, in a mud pit in Xinjiang, China. Closer look at the dinosaur fossils revealed that, out of the 13 Limusaurus, some had small sharp teeth while some did not have any. Scientists suggested that the Limusaurus had teeth in the hatchling stage, which were gradually lost with age.

The findings of the paleontological analysis of the Limusaurus fossils were published in the Current Biology journal. The findings indicate that the Limusaurus group trapped in the mud pit included babies as well as adults and they all followed a specific pattern of tooth loss, which was found to be age-dependent, according to Fox 61.

Wang Shuo, co-author in the published article and an expert evolutionary biologist, working at the Capital Normal University, Beijing, said, "At first we thought they were different dinosaurs - one with teeth and one without and we started to study them separately." But further analysis suggested that, "They were largely identical and we found solid evidence that teeth were lost. There were empty tooth sockets in their jaw bones."

Scientists are of the opinion that the anatomical changes of the creatures are due to a transition in their mode of nutrition, probably from being omnivores to plant-eating herbivores. Similar changes have also been observed in the duck-billed platypus and some other fishes and amphibians, but it has never been reported earlier in reptiles or dinosaur fossils, The Verge reported.

According to James Clark, professor of biology at George Washington University, and another co-author of the study, suggested that the loss of teeth may help in explaining the origin of birds from dinosaurs and how they developed a beak.

"It suggests a mechanism that arrests the development of teeth - an intermediate pathway for the origin of beaks," Prof. Clark said.

The present discovery is in continuation with other palaeontological discoveries, especially the fossilized Limusauruses found in several parts of China and other parts of the world.