The Deinonychosaur “killer claw” was likely used to pin down prey rather than cut it

The Deinonychosaur “killer claw” was likely used to pin down prey rather than cut it

The Deinonychosaur “killer claw” was likely used to pin down prey rather than cut it

The “killer claw” of the red-legged seriema has been found to be used to pin down prey rather than to cut it. In addition to demonstrating the ferocity of this long-legged bird (made famous after one of them started a fight with a golf ball), it gives us a good idea of ​​how its ancient ancestors liked it Velociraptor they also used their legs.

With no living dinosaurs to study (John Hammond, we need you), scientists sometimes turn to the next best thing in an attempt to study their behaviors (and intelligence). As for the extant animals, the red-footed series (Cariama Cristat) is a very good match, even if it’s not a perfect match.

“Animal behavior is very complex, and I think we’re doing it a disservice by simplifying it and assuming that any modern animal is a perfect analogy for an extinct group,” Brigham Young University paleontologist Taylor Oswald told IFLScience. “The next best thing is to find extant animals that are related and ecologically similar enough for us to start drawing general conclusions about function and behavior.”

“Among modern animals, the sereria may be the best representatives of the deinonychosaurs we have because they are birds that are themselves close relatives of the deinonychosaurs, and because they are carnivorous, terrestrial, and have a preferentially raised sickle-shaped claw on their toes II. “

killer claw

Seriemas consistently used the II to pin down prey and items. Images courtesy of Fossil Crates

This raised claw on the number II has earned the nickname “killer claw” because it has long been thought to be an adaptation for hunting, although the exact use of it has been debated. Jurassic Park fans will be familiar with killer claw as it is the same a Velociraptor he taps impatiently as he hunts for children hiding in the kitchen.

Some, like that lovable rogue Dr. Alan Grant, thought it might be useful for slashing, but a more recent theory, the Raptor Prey Restraint (RPR) hypothesis, suggests it’s more likely to be used for pinning. Researchers in a new study decided to investigate this further by looking at how the red-legged sergea uses its killer claw when fighting rubber hoses, key locks and mice.

An observational study looked at captive behavior of the sereria at Wildlife World Zoo, Aquarium and Safari Park in Phoenix, Arizona, and Tracy Aviary And Botanical Gardens in Salt Lake City, Utah. They found that the birds used their legs in a consistent and specific manner, with the number II killing claw being used to pin objects and prey, while the beak tore off anything it was holding. In short, the RPR hypothesis seems likely to be correct, and likely extends to the convergently evolved killer claws of Deinonychosaurs as well.

velociraptor killing claw

The velociraptor might as well have used its killer claw in exactly the same way as the seriemas. Photo courtesy of Fossil Crates/Gustavo Monroy

“The sickle shape and raised position of the series’ killer claws are rather unique and suggest that more than just self-defense is going on,” explained Oswald. “In other words, many types of claws can be used as weapons and deal damage, not just sickle claws, so the sickle shape probably has a different function.”

“Our observations indicate that these claws are used for pinning, and this is consistent with what we see in other birds of prey (although the exact positioning of the foot is different) and consistent with the deinonychosaur hypothesis of Dr. Denver Fowler and colleagues. -authors in 2011.”

In their day, deinonychosaurs used their killer claws to pin down animals such as invertebrates, lizards, and small dinosaurs such as Protoceratopsand early mammals. When it comes to the red-legged series, the menu is not so different, with invertebrates such as grasshoppers and beetles, as well as small rodents, lizards, frogs and other birds. No dinosaurs and, of course, the occasional golf ball.

The study was published in the Journal of the Arizona-Nevada Academy of Science.

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