Dinosaurs Used Terrifying Claws for More Than Just Hunting: Claw Function in Theropods

Some of the largest and most fearsome predators that roamed the Earth were theropod dinosaurs. This group of animals included species such as the Tyrannosaurus rex and the Velociraptor, which possessed massive claws. Now, archaeologists have found that these claws might not have just been used for hunting; they were probably used for other tasks.

Theropod dinosaurs have a broad range of claw morphologies. This means that different species probably used their claws for different purposes-and not just hunting. That's why scientists decided to investigate a bit further to see what these purposes might have been.

The researchers focused on therizinosaurs, an unusual group of theropods that lived between 145 and 66 million years ago. These large animals stood up to 7 meters tall and had claws that were about 50 centimeters in length on their forelimbs. They also possessed elongated necks and had a coat of primitive feathers along their bodies. Yet these dinosaurs weren't carnivorous; instead, they were peaceful herbivores.

"Theropod dinosaurs were all bipedal, which means their forelimbs were no longer involved in walking as in other dinosaurs," said Stephan Lautenschlager, one of the researchers, in a news release. "This allowed them to develop a whole new suite of claw shapes adapted to different functions."

The researchers created detailed computer models to see how the different claws on the forelimbs were used. These models simulated a variety of possible functions for different species and claw morphologies. The scientists also compared the dinosaurs' claws to the claws of today's mammals.

So what did they find? It turns out that during the course of evolution, several theropod groups, including therizinosaurs, changed from carnivores to herbivores. During this transition, claws changed to be used for digging, grasping and piercing.

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

The findings are published in the journal Proceedings of the Royal Society B.