'Warrior' Velociraptor Cousin May Have Been Among The Last Surviving Raptors

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An artist's illustration of the Dineobellator notohesperus, which lived on Earth shortly before the mass dinosaur extinction event (Credit: Sergey Krasovskiy)

When Robert Sullivan, a research associate at the New Mexico Museum of Natural History and Science in Albuquerque, found some dinosaur bones in 67-million year-old Cretaceous rocks in New Mexico's San Juan Basin, in 2008, he had little idea they belonged to a new raptor species. More significantly, the feathered dinosaur roamed southern North America just prior to the mass extinction event, when most raptors had already disappeared from the fossil record.

The Dineobellator notohesperus ("Navajo warrior from the Southwest") belonged to a group of dinosaurs known as dromaeosaurids — the same family as the Asian Velociraptor. However, unlike the massive raptors depicted in the Jurassic Park movie franchise, this one stood about 3.5 feet (about 1 meter) tall, 6 to 7 feet (about 2 meters) long, and weighed no more than 50 pounds (22.7 kilograms). The quill nobs — small bumps on the surface where feathers would be attached by ligaments — on its forearm bones led the researchers to conclude that the Dineobellator was covered in feathers.

Researchers believe the tiny Dineobellatos was a fierce predator (Credit: Steve Jasinski)

Its diminutive size probably made it hard for the raptor to battle larger predators single-handedly. However, Steven Jasinski, head of the Paleontology and Geology Section at the State Museum of Pennsylvania, who led the study, believes that similar to other raptors, these dinosaurs probably lived in packs. According to the researchers, the hypercarnivore's upper arm bones allowed muscles to be attached from a different angle, providing more strength, while its massive claws gave it excellent grip and grasping power.

"Combining the large claws with the stronger arms and grasping ability suggests Dineobellator could have used this combination to jump on and attack much larger dinosaurs than themselves, and this would have been especially useful if a pack went after dinosaurs several times their size," Jasinski said.

The Dineobellator curved vertebrae bone suggested it was extremely agile (Credit: Mary P. Williams)

The Dineobellator's combative lifestyle was apparent from the injury scars on the fossil's rib and a cut on its sickle-shaped claws. The researchers speculate that the former was probably the result of a battle with a larger predator, while the latter was a remanent of a skirmish with a fellow Dineobellator. "It is interesting to find out new things about a species of dinosaur, but it's especially surprising when you can understand a bit more about the life of a single individual," Jasinski said.

One of the dinosaur's most unique features was its tail bone. Raptors were known for having long, stiff tail bones that helped provide balance and allowed for higher speed. However, the Dineobellator's tail vertebrae appeared to be curved inwards, suggesting extreme agility as well. Jasinski believes this enabled the dinosaurs to not only run at rapid speeds in a straight line but also quickly change directions when needed.

Steve Jasinski and his team plan on continuing their search for Dineobellator fossils in New Mexico (Credit: Steve Jasinski)

The researcher says, "Think of a cheetah chasing a gazelle. The tail is held straight, but when the gazelle changes direction, the cheetah whips its tail around to counterbalance its change of direction. This increases the cheetah's agility by having the tail act as a counterbalance for the sudden changes in direction." These qualities probably meant that the Dineobellator excelled in pursuit, making it a formidable predator despite their small size.

However, David Evans, deputy head of the Department of Natural History at the Royal Ontario Museum in Canada, who was not involved in the study, believes the researchers' conclusions of the creature's strength and agility based on just 20 bones, is premature.

"Ultimately, the specimen is still very fragmentary and leaves a lot of questions, including the strength of the functional inferences in the study," Evans told Live Science in an email. "Although the bones suggest Dineobellator may have had a suite of special adaptations that could be related to predation, for instance, the scrappy nature of the fossils makes it difficult to evaluate the significance of the seemingly unique shapes of its bones." The researcher believes more complete fossils of the raptor need to be found to confirm the conclusions.

The Dineobellators roamed Earth just before the mass extinction event that killed all dinosaurs (Credit: museumsvictoria.com.au)

Fortunately, that is precisely what Jasinski and his team, who published the results of their study in the journal Scientific Reports on March 26, 2020, plan on doing next. "It was with a lot of searching and a bit of luck that this dinosaur was found weathering out of a small hillside," Jasinski says. "We do so much hiking, and it is easy to overlook something or simply walk on the wrong side of a hill and miss something. We hope that the more we search, the better chance we have of finding more of Dineobellator or the other dinosaurs it lived alongside."

Resources: penntoday, www.livescience.com, CNN.com

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124 Comments
  • poodledog22
    poodledog22Tuesday, May 26, 2020 at 5:08 pm
    Dineobellator is cool! Skrill78 seems to know a lot about dinosaurs.
    • l78
      l78Thursday, May 21, 2020 at 6:14 pm
      ...wow...😲
      • skrill78
        skrill78Friday, May 15, 2020 at 5:09 pm
        Everyone says that Jurassic park got the raptors wrong, but the novels were written around the time that the Deinonychus was called 'Velociraptor antirrhopus'. The raptors seem more alike to a Deinonychus than a velociraptor. Most people assume that it is a 'Velociraptor mongoliensis'.
        • moonlight35
          moonlight35Friday, May 15, 2020 at 2:35 am
          Me and my friend LOVE dinosaurs.!Like if you agree!!!
          • tiktok4life
            tiktok4lifeWednesday, May 13, 2020 at 10:55 am
            I love learning about what the world has around me and dogo keeps me updated with all the news
            • tiktok4life
              tiktok4lifeWednesday, May 13, 2020 at 10:46 am
              I love dinosaurs
              • meisdancer
                meisdancerThursday, May 7, 2020 at 3:57 pm
                wow that was cool!I like dinosaurs there cool!
                • riona
                  rionaThursday, May 7, 2020 at 11:17 am
                  and if those things were alive they would probely kill you apollo04
                  • riona
                    rionaThursday, May 7, 2020 at 11:12 am
                    my favorite period is the cretaceous triassic and jurrasic
                    • riona
                      rionaThursday, May 7, 2020 at 10:58 am
                      i love dinosaurs so much because they are amazing and they have lot's of mysterys
                      • riona
                        rionaThursday, May 7, 2020 at 10:59 am
                        really cool if we saw diosaurs today