Herbivore Dinosaurs Used Razor-sharp Claws to Dig, Grasp; Researchers Say

A new study suggests that herbivore dinosaurs used razor-like claws to dig or even grasp food.

The study, conducted by researchers at University of Bristol, shows that not all dinosaurs used large claws to hunt animals. The change in claw shape and function is related to the change in dietary habits and ultimately, evolution of the dinosaurs.  

Tyrannosaurus rex and Velociraptor, the popular dinosaurs in Jurassic Park movies, belonged to a group of dinosaurs called Theropods, which were some of the largest hunters to ever roam the earth. The claw design in these monstrous animals shows great variation, suggesting that they evolved to do varied tasks.

For the study, researchers focused on therizinosaurs, which were a group belonging to Therapods that lived 145 and 66 million years ago, according to a news release.

Therizinosaurs were seven meters tall and had 50 centimeter long claws. They even had elongated necks and feathers on their bodies. In other words, they looked every bit as mean killing machine as any carnivorous dinosaur could look. However, these weird Therizinosaurs were actually peaceful herbivores. Appearances can be deceptive.  

"The stereotypical image of theropod dinosaurs is that of large, predatory and carnivorous animals," said study author Stephan Lautenschlager, a vertebrate paleontologist at the University of Bristol in England, according to Livescience. "However, fossil findings in the last 15 to 20 years have shown that a number of different groups among theropods did not conform to this classical view. Many of these had apparently adapted to a different diet and become omnivores or herbivores - that is evident from the shape of the teeth and the morphology of the skull."

Therizinosaurs are bizarre. Researchers have had a tough time studying and placing them in the dinosaur family tree because these animals are a mixture of different characteristics. Research suggests that these dinosaurs are related to birds.

In the present study, researchers used computer models to simulate the possible function of the dinosaur claws. The team even compared the claws with the claws of modern animals.

The study results showed that over the course of evolution, claw design was modified several times. Some dinosaurs might have used claws to pierce, dig or grasp.

"It's fascinating to see that, with the shift from a carnivorous to a plant-based diet, we find a large variety of claw shapes adapted to different functions.  This suggests that dietary adaptations were an important driver during the evolution of theropod dinosaurs and their transition to modern birds," Lautenschlager said in a news release

The study is published in the journal Proceedings of the Royal Society B.

A slideshow from Discovery news illustrates the evolution of dinosaur claws.