Giant Raptor Fossil Discovered in South Dakota

By Jon Tennant | November 2, 2015 1:32 pm

An artist’s rendering of Dakotaraptor steini. (Credit: Emily Willoughby)

Scientists have discovered the remains of one of the largest raptors known to man in the fossil graveyards of North America.

A research team led by Robert DePalma, curator of vertebrate paleontology at the Palm Beach Museum of Natural History, discovered the partial skeleton in the Late Cretaceous (66 million years old) Hell Creek Formation of Harding County, South Dakota. They’ve named the raptor Dakotaraptor steini, and it is the second recently named raptor from Hell Creek. Known from a partial skeleton, it represents one of the largest known dromaeosaurids, the scientific name for what are popularly known as ‘raptors’, and close relatives of the first birds.

Sizing Up the Field

Popularized by “Jurassic Park” movies, ‘raptors’ are known for being fast, nimble, small dinosaurs with stiff tails and feet equipped with wicked sickle claws.

Dakotaraptor is estimated to have been around 16 feet in length, so it’s still nowhere near the size of other gigantic predators around the same time, like Tyrannosaurus rex. But compared to Velociraptor, which was roughly the size of a turkey, Dakotaraptor is among the biggest (and most dangerous) raptors known. The only competitor would have been its close but much older cousin, Utahraptor, which the largest skeletons reveal could have grown up to 22 feet in length and weighed up to 1,100 pounds.



Skeletal reconstruction of Dakotaraptor based on available material for Utahraptor, Dromaeosaurus, Deinonychus, and Achillobator, demonstrating overall proportions and the large size of the creature. (Credit: Robert DePalma)

The sickle claw on the middle toe of Dakotaraptor was used as a lethal weapon and measured 9.5 inches along the outer curve. Scientists are still not sure whether these claws were used for disembowelling prey, or clinging on to them like a crampon, but either way, having a claw that large stuck in you would be pretty painful. DePalma and colleagues published their work in the Kansas University Paleontological Contributions.

Pack Hunter?

Whether or not Dakotaraptor would have hunted in packs, as popularly reconstructed, is still open for debate, as well. Some dromaeosaurids have been found with track evidence of moving together, and even feeding together, while some large tyrannosaurids like Yutyrannus definitely would have hunted in packs.

“I think there is at least moderate evidence that some dromaeosaurids were pack hunters, but it’s not a slam dunk that all of them were, or that they normally hunted this way,” says Steve Brusatte, a dinosaur researcher at the University of Edinburgh, and not associated with the study.

The jury is still out on whether Dakotaraptor was a lone hunter, or roamed with a raptor pack.

Feathered Beast

While some dromaeosaurs like the notorious Velociraptor are known to have had at least feathers covering their arms, resembling superficial wings, the presence of feathers in larger dromaeosaurids remains controversial. Dakotaraptor possesses a row of ‘quill knobs’, or papilli, on the surface of its ulna, one of the lower arm bones. In modern birds, these reinforced knobs show where the feather quills would have attached, and is clear evidence that while Dakotaraptor would have been unable to fly due to its size, it would have had feathers on its arms. While other large dinosaurs, like Yutyrannus, show evidence of a bristle-like ‘protofeather’ coat along their body, Dakotaraptor is the largest dinosaur found with true wings.

Brusatte thinks there are two main reasons why Dakotaraptor had feathers if it couldn’t fly: “Either it evolved from an ancestor that could fly but had lost the ability to fly, like an ostrich, or dinosaurs evolved big quill-pen feathers for another reason, such as display or egg brooding.”

Under the second case, this means that only later on in the evolution of feathers did they become suitable for flight.

Still More Questions

The discovery of Dakotaraptor raises some questions about where it would have fitted in the food chain in the Hell Creek ecosystem. Previously, different growth stages of T. rex were thought to have occupied every carnivorous niche, and out-competed any other possible large predators. Dakotaraptor might have avoided direct competition with T. rex by adopting a different style of hunting: while young T. rex had long legs built for pursuing prey over longer distances, Dakotaraptor seems to have been more lightly built, the perfect killing machine for ambushing and grappling with its prey.

Dakotaraptor very well may have been filling a similar niche as a pre-teen T. rex. That’s a chilling thought on Halloween…” says Brusatte.

CATEGORIZED UNDER: Living World, top posts
MORE ABOUT: dinosaurs, paleontology
  • Bob Juniper

    I’ll bet that’s today”s chicken that you get at KFC.

    • nik

      If it is, its got to be better than MacDonalds chicken nuggets. Do you know what goes into them?
      Better that you dont.

      • 1064nm

        *hint*- ‘aint chicken.

        • nik

          A little bit is, a lot isn’t.
          I have a policy, I never buy anything in batter or breadcrumbs.
          If I cant see what it is, I wont buy it, fresh or cooked.

      • Bob Juniper

        I eat all organic and very little meet . I don’t even look at Mcdonalds when I drive by, meat from China. Look that up and see whats on grocers shelves too.

        • Kevin Mc

          1) it’s meat not meet

          2) McDonalds gets NO meat from China, have no idea where you got that notion, but whoever told you that is pilling your chain.

          • Bob Juniper

            I know,typo. If you look at my second use of the word it is spelled correctly. How do you know for sure? I recently read that the fish is from China.

          • Kevin Mc

            Still wrong, the fish are mostly from Iceland, which a lot of people don’t like since they still engage in whaling, but again not China. Just as a rule, one thing China rarely exports is food, they are a major importer of food to keep their massive population fed.

          • Bob Juniper

            What makes you an expert ? I hope you are right.

          • nik

            They do import food, in huge quantities, [except US beef] but they also process it and export it as finished products.

          • nik

            There is an edit facility if you want to correct it.

          • Bob Juniper

            Thanks but I’m not that concerned about what people think.

          • nik

            Burgers are often made from waste meat from every country in the world, so could just as easily contain meat from China. The scraps are often scraped off the floor of abattoirs, or anywhere else that meat is prepared, shipped in the same type of Wheelybins that garbage is disposed in.

            A ‘foot and mouth’ outbreak in the UK some years ago was found to have been caused by leftovers, fed to pigs, that came from a UK Chinese restaurant, but originated from China.

            A young woman athlete in the USA bought burgers from a well known supermarket. They were contaminated with a bacteria, that destroyed her nervous system, and she is now in a wheelchair, for life. The supermarket settled out of court.
            The supermarket had been unable to get its US supplier to certify that its burgers were free from contamination, but bought them anyway.

            Many years ago, at my kids insistence, I took them to a local MacDonald’s in London, twice. Both times I suffered a bad stomach upset, there was NO third time!

            I avoid fast food outlets like the plague, literally.

          • Kevin Mc

            An awful lot of people eat at fast food places all the time with no problem. As I state below, very very little food is exported from China for a very good reason, they have a massive population to feed. If they were ever going to export beef, it would probably be to Japan, much closed and higher prices.

          • nik

            If money is involved, there are no limits

          • Kevin Mc

            Right, which is why any exported beef would go to Japan not the US.

          • nik

            Thats not logical!

          • nik

            Dont you mean, ‘pulling your chain’?

          • Kevin Mc

            Please Google “pulling your chain”.

  • Don’t Even Try It!

    Ah! Just in time for Thanksgiving! BBQ or Deep Fried Dakotaraptor, umm umm good!


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