Were Velociraptors Truly Formidable Killers?

The Jurassic Park films introduced the world to what appeared to be one of the most vicious killers of all time. Standing at approximately 2 meters tall by 4 meters long, Velociraptor was portrayed as a cunning, intelligent pack hunter with the ability to slice up human flesh as if it was butter. These films depict Velociraptor as an incredibly capable dinosaur; from being able to open doors, to outrunning motorcycles to forming bonds with humans, the Velociraptor seems to be a Swiss army knife of sorts. Since Jurassic park has been released however, there have been many new developments in the field of paleontology pertaining to the group of dinosaurs known as the Dromaeosaurs. In this article, I will discuss whether Velociraptor and their close relatives were truly the cold-blooded killers the Jurassic Park movies make them appear to be.

The Velociraptors in Jurassic Park are large; they are comparable to the size of a bear, and appear to be closely related to reptiles. Their real life counterparts are very different from the Jurassic Park version; the real life Velociraptors are about the size of a large turkey and weighed roughly 55 pounds. Did the films truly enlarge the Raptors to make them appear more frightening? The answer is surprisingly no; there are multiple raptor species that are larger than what is seen in Jurassic Park, and all of them share similar physical attributes. Species such as Utahraptor, Achillobator, and Dakotaraptor all exceeded 5 meters in length, and are widespread in both geography and time; they range from approximately 124 million years ago to the very end of the age of dinosaurs 65 million years ago, living in Asia and both of the Americas. While Velociraptor may have been puny in size, its close relatives were quite large. Considering the fact that some raptors grew to massive sizes, the only true physical inaccuracy was the lack of feathers on the raptors. While the Velociraptors in Jurassic Park appear reptilian, in reality they would have looked like turkeys as well. Fossils of various raptor species, most notably Microraptor and Sinornithosaurus demonstrate the presence of feathers in raptors. However, the exclusion of feathers in Jurassic Park is understandable; the first feathered raptors were found in 1996, while the first movie debuted in 1993.

Raptors lived in all of the continents of the world except for Australia, and outlasted many other, small predators of the Cretaceous. Did their hunting methods help ensure their success? The way raptors hunted depended largely on the species and the environment in which they lived. Most paleontologists theorize that raptors hunted in packs, much like what modern wolves do; hunting in groups would make it much easier for them to take down prey. The evidence in support of this theory exists, including a bone bed of Utahraptors containing individuals of various ages in early 2015 (see James Kirkland, Utah State University). The bones of an iguanodon, a common prey item for the Utahraptors was also discovered alongside the predators, indicating a clear predator/prey relationship. While some raptors may have worked in groups to hunt prey, it is also possible that they lived in solitude, capable of hunting animals larger than themselves. Modern eagles have been known to take down animals as large as reindeer; in prehistory, giant Carcharodontosaurids were able to take down sauropods, some of which were the largest animals to walk the earth. Raptors are believed to have possessed superior intelligence to almost all of the prey they encountered based upon brain-to-body ratio; their intelligence alone could outmatch the prey they encountered. Additionally, raptors were armed with a magnificent tool to hunt their prey: the killing claws on their feet.

The defining trait of the Dromaeosaurs was the killing claw on each foot. For a long time, these claws were believed to be able to slice through the skin of its victims, effectively disemboweling them. Upon closer inspection, however, the “killing claws” would not have been able to slice through flesh; the lack of serrations on the sides of the claws would have made it very difficult to be able to pierce and tear flesh off a living animal. So how did they use it? While paleontologists have had many theories, including the ability to climb trees and even perch on branches, one theory has gained a lot of traction more recently; that instead of using the claw to tear flesh, they were used to pin down prey, while the raptor bit off chunks of flesh. While the animals struggled, the raptors would use their arms, coated in feathers, to maintain balance by flapping them. The prey would eventually die from blood loss, as the claws of the raptors would sink deeper and deeper, puncturing major blood vessels as the prey struggled. This strategy is used by modern birds such as hawks and eagles; since raptors are extremely close relatives to birds of prey, we can assume that they used methods that were similar. For example, the anklebones of Deinonychus, a raptor from North America, indicate that raptors used this strategy, as they show that its feet were adapted well for grasping, but surprisingly poor for running. The raptors also used their “killing claws” to climb trees, especially in the case of smaller raptors such as Microraptor. Raptors also had very large eyes for a dinosaur; these eyes may have been able to see in the dark, which could come in handy when ambushing large prey.

Based on these facts, I believe that raptors used the strategies of modern-day, predatorial bird, but implemented the strategy like a leopard. Like leopards, raptors used their claws to climb into a tree, and simply wait until its prey wandered underneath. Once the prey was in position, the raptor leapt down and sunk its claws into the flesh of its prey, while at the same time biting down. This strategy could be used to deadly effectiveness, in a fast, efficient manner. This technique could also be adapted by different types raptors; Sinornithosaurus, who could fly, would have been able to fly and land on its prey and pin them to the ground. However, species such as Deinonychus could have climbed to a higher location, landed on the back of a larger animal, such as Tenontosaurus, and then let it bleed out.

While the raptors in Jurassic Park look and act differently than they would have in actuality, one fact remains the same; raptors were amongst the most deadly killers to walk the earth. While their killing claw was not used to slash their prey, it was still one of the most gruesome weapons in the history of the earth.

Header image courtesy of Mark Witton, found here