Two new dinosaur fossils discovered in China

New Delhi : The study dinosaur fossils and their evolution received a new dimension when paleontologists say that they have discovered two new dinosaur fossils in China. An international team of scientists found the bones of the dinosaurs namely Bannykus and Xiyunykus, indicating the adaptations related to eating insects that live in colonies. The findings have shed light on the evolution of insect eating dinosaurs.

The dinosaurs are both alvarezsaurs, an enigmatic group of theropod (meat-eating) dinosaurs which have commonness with birds. One among the scientists from Wits University in South Africa, Jonah Choiniere said, "“Alvarezsaurs are weird animals with their strong, clawed hands and weak jaws, they appear to be the dinosaurian analogue to today’s aardvarks and anteaters,”. 

On the other hand, researchers, including those from the Institute for Vertebrate Palaeontology and Palaeoanthropology in China said alvarezsaurs did not originally eat insects.

A group of gigantic animal had more meat-eating teeth and hands for catching small prey.

Only later-evolving members reduced their teeth and evolved a hand with a huge, single claw capable, perhaps, of tearing open rotting logs and anthills.

“The new fossils have long arms, and so show that alvarezsaurs evolved short arms only later in their evolutionary history, in species with small body sizes,” said Roger Benson, a professor at Oxford University in the UK.

“This is quite different to what happens in the classic example of tyrannosaurs, which have short arms and giant size,” Benson said.

The fossils were discovered during collaborative international fieldwork in China.  Xiyunykus was discovered in 2005 in Xinjiang, northwestern China. Bannykus was discovered a few years later, in 2009, in Inner Mongolia, north-central China.

Both the variety of dinosaurs is important to understand the transitional steps involved in the process of alvarezsaurs adapting to new diets.