CNN
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A new study has found evidence that at least one type of dinosaur may have been skilled swimmers, diving through water like a duck to stalk prey.
the study, Posted in Biology of communications On December 1, he described a newly discovered species, Natovenator polydontus. The theropod, or hollow-bodied dinosaur with three fingers and claws at each end, lived in Mongolia during the Late Cretaceous period, 145 to 66 million years ago.
Scientists from Seoul National University, the University of Alberta and the Mongolian Academy of Sciences collaborated on the research.
The researchers noted that the nattovenator had contoured ribs, like those of diving birds.
“The shape of its body suggests that Natovenator was a swimming predator, and that the streamlined body evolved independently in separate lineages of theropod dinosaurs,” the authors wrote.
The natovinator specimen resembles Halszkaraptor, another dinosaur discovered in Mongolia, and scientists believe it was likely semi-aquatic. But the Natovenator specimen is more complete than Halszkaraptor, making it easier for scientists to see its streamlined shape.
The researchers explain that Natovenator and Halszkaraptor used their arms to propel themselves through the water.
David Hone, a paleontologist and professor at Queen Mary University of London, told CNN it’s difficult to pinpoint exactly where Natuvinator sits on the spectrum, from all-terrestrial to completely aquatic. But he said the sample’s arms “look like they’re pretty good at moving water.” Hon participated in a peer-reviewed study on the biology of communication.
Additionally, Natovenator had dense bones, essential for animals diving below the surface of water.
As the authors write, he had a “relatively streamlined body.”
Hoon said the next step would be to model the shape of the dinosaur’s body to help scientists understand exactly how it moved. “Does she paddle with her feet, some sort of dog swatter?” How fast can she go? »
Further research should also focus on the environment in which Natuvinator lived. The specimen was discovered in the Gobi Desert in Mongolia, but there is evidence that lakes and other bodies of water existed in the desert in the past.
“There is a real question, well, you have a dinosaur swimming in the desert, what is it swimming in? ” he said. “Finding the fossil record of these lakes is going to be difficult, but sooner or later we might find one. And when we do, we might find a lot more of these things. »
Nizar Ibrahim, a senior lecturer in paleontology at the University of Portsmouth whose research includes findings indicating Spinosaurus was likely semi-aquatic, told CNN he was not yet fully convinced by the study’s findings. He argued that a more rigorous quantitative analysis would have made the results more convincing.
“I wanted to see, for example, a really robust description of bone density, an animal’s bone histology, in a larger data set,” he said. “Even the anatomy of the ribs, if they kind of put that into a bigger picture – the huge data set that would have been helpful. »
He said “the anatomical evidence is less clear” for a swimming nattovinator than for Spinosaurus.
And like Hone, he’s also curious to know exactly what waters the Natovenator might have swum in. “The environment this animal was found in, in Mongolia, is a bit the opposite of what you would expect for a water-loving animal,” he said.
But he hopes the study will help open the door to more extensive information about dinosaur behavior. Dinosaurs were once considered purely terrestrial, but growing evidence suggests that at least some species spent as much time in water as they did on land.
“I’m sure there will be many, many surprises,” Ibrahim said. “And we’ll find that not only have dinosaurs been around for a very long time, but they’re also, you know, very diverse and very good at conquering a new environment. »