It had feathers, an iron grip and a flexible tail for balance in chases: fossil hunters discovered a new relative of the “Hollywood star” Velociraptor in New Mexico. The agile predator shows how sophisticated the representatives of the dromaeosaurids were at the end of the dinosaur era, the paleontologists say.
Blockbusters such as “Jurassic Park” have made them famous: in addition to giants like Tyrannosaurus rex and Co, the so-called raptors in the films create tension. This term is used in popular culture for all representatives of the group of dromaeosaurids. These were comparatively small, two-legged robbers with sharp claws on the forelimbs and hind limbs. Unlike the animals depicted in the films, all of the raptors were probably feathered.
In the long age of the dinosaurs, the dromaeosaurs formed a very successful group: They produced numerous species from the Central Jurassic to the Upper Cretaceous and were widespread in the world, as can be seen from fossil finds. It is believed that they were also related to the early birds. The newly discovered representative now illuminates the development history of the dromaeosaurids shortly before the asteroid impact about 66 million years ago ended the dinosaur era with a bang.
An actor from the last act
The fossil was discovered in the San Juan Basin in New Mexico and consists of 20 bone fragments. According to the dating, it dates from 67 million years ago. “It was a stroke of luck that we discovered the remains that protruded from a small hill due to weathering,” says Steven Jasinski from the University of Pennsylvania in Philadelphia. He and his colleagues have now put together the fossil pieces of the puzzle and examined the shape of the animal and its characteristics.
As they report, it was a previously unknown representative of the dromaeosaurids, who was about one meter high and two meters long. The scientists gave it the name Dineobellator notohesperus. The animal therefore had the typical narrow snout, long clawed arms, a crescent-shaped claw on the foot and a long tail. The researchers even found clues to the “personal fate” of the specimen examined. The dinosaur had apparently survived a broken rib, as evidenced by a healed fracture. But in the end, an injury to the front extremities was his doom, according to evidence.
A top of the line dinosaur evolution
As the researchers continue to report, the fossil once again shows that all of the dromaeosaurids were probably pinnate: they discovered small bumps on the remains of the animal’s forearm bone. As you explain, there were feathers in these structures. What distinguishes Dineobellator within his family, however, are the features of his forelimbs and tail, the paleontologists report. Characteristics of the animal’s clawed arm or hand structures therefore suggest that the dineobellator could move them more flexibly than other species. This ability could have been useful to hold prey particularly effectively. Dineobellator probably snatched up smaller animals like birds and lizards. However, he may have overwhelmed other dinosaurs with his arms and clawed feet, the scientists say.
As they report further, the tail also had unusual properties. While most raptors probably carried him straight to the body, Dineobellator was apparently able to bend his extension very sharply: the tail base was unusually flexible, according to the analyzes. As the researchers explain, this probably served to stabilize the prey hunt that fled in zigzags. “You have to look at the movements of a cat’s tail when hunting,” says Jasinski. “While the tail itself stays straight, it whips around constantly as the animal changes direction. A stiff tail that is very agile at its base allows for increased agility and changes in direction, and may assist dineobellators in tracking prey, especially in more open habitats, ”says the paleontologist.
It can be seen that dineobellator was a top model at the end of the evolutionary history of the dromaeosaurids. “The discovery presents an interesting representative of a group of iconic carnivorous dinosaurs who lived shortly before the extinction event that killed all non-bird dinosaurs,” concludes Jasinski. He and his colleagues are now hoping for further discoveries of dineobellator or other dinosaurs that provide more insight into the late Cretaceous wildlife in the south of today’s USA.
Source: University of Pennsylvania, professional article: Scientific Reports, doi: 10.1038 / s41598-020-61480-7