Velociraptor may not have used claws for slashing after all, says study

Despite their memorable depiction in the Jurassic Park movie franchise, velociraptor dinosaurs likely did not use their sharp claws for slashing prey but instead to pin and grasp them, according to a new study.

The research, published earlier this month in the Journal of the Arizona-Nevada Academy of Science, observed the modern-day red-legged seriema, a South American predatory bird which has a sharp, curved claw similar to the “raptor” group of dinosaurs, including the velociraptor, deinonychus, and the utahraptor.

This bird, which stalks and preys on small mammals, reptiles, amphibians and insects, is unique as it possesses prominent “recurved sickle claws” on its second pedal digits that are held off the ground, similar to the claws of the extinct deinonychosaurs, said the team of scientists, including those from Brigham Young University in the US.

Instead of using their claws as slashing weapons, scientists hypothesise that deinonychosaurs rather used their claws to pin and grasp.

Scientists say their observations of claw use in the red-legged seriemas are consistent with what they have called the Raptor Prey Restraint (RPR) hypothesis.

Due to the high degree of similarity between the claws of seriemas and the claws of deinonychosaurs, as well as their shared ancestry and similar predatory lifestyles, they say it is likely that seriemas are among the “best proxies” for the raptor dinosaurs’ claw use.

“This claw is not built for slashing, to paraphrase a boots-walking song, It was doing something else,” study co-author Brian Curtice told Live Science.

Scientists argue that the curved claws of these dinosaurs did not even have serrations or a “cutting surface” to help slash through the flesh of its prey as shown in Jurrasic Park, where these dinosaurs even took on larger animals using their claws to slash.

In the study, they also analysed the feeding behavior of red-legged seriemas at the Wildlife World Zoo, Aquarium, and Safari Park in Phoenix.

The birds, about 90 cm (3ft) tall and weighing nearly 2kg (4lb), pounced on a rubber snake in the study, whacking it against a rock to attempt to kill it.

It used its sharp claw to pin the snake to the ground while it tore at it with its beak.

They also displayed the same pinning-and-grasping skills on dead mice in their natural feeding behaviour.

While the birds aren’t “perfect” analogues to the raptor dinosaurs, and there could still be anatomical differences between the two that may change how the claws function, researchers say it is still likely that the dinosaurs also used their claws in similar ways.

“Thus, the way in which seriemas use their claws has the potential to shine additional light on how deinonychosaurs used theirs,” researchers said in the study.