World’s First Swimming Dinosaur Discovered in Mongolia

Dinosaurs in all shapes and sizes filled Earth's habitats for more than 150 million years. There were long-necked giants, living tanks, razor-toothed carnivores and brightly colored birds in the past. Dinosaurs were not willing to take the plunge despite their success. Even as other forms of reptile made the transition from land to water, no non-avian dinosaur was ever found that could swim or dive. Paleontologists have been looking for a dinosaur for a long time.

The new species was not a saurian giant, as was previously reported. About 71 million years ago, a small swimmer lived in prehistoric Mongolia. Despite being a cousin of sharp-toothed predators, the new dinosaur had a very different look. The Natovenator polydontus is a dinosaur named after one of its teeth.

The place where the new dinosaur was found is known for its preservation of multiple dinosaur species. Before the strange nature of this new species became apparent, it was necessary to carefully prepare the dinosaur's bones. After the bones were exposed, Lee said, "we realized that this was something special, because it was beautifully preserved with a nice skull and an extremely long neck." The experts were able to see that the fossil was similar to another species, Halszkaraptor, which was first thought to be a swimming dinosaurs. Lee and co-authors carefully examined the bones of Natovenator because of the hypothesis. The researchers decided that Natovenator was a swimmer. It looked like a cormorant.

Paleontologists are too late to watch Natovenator in life and observe what a stroke looks like. Paleontologists will have to dig in more to find out how the dinosaur's body works. The Argentine Natural Science Museum's paleontologist, who was not involved in the new study, thinks that some of the details of Natovenator are indicative of the animal being aquatic.

The jaws and teeth of Natovenator could be used to grab prey from the water. The ribs of Natovenator are similar to those of penguins and auks, according to Lee and co- authors. Natovenator might have been able to swim more efficiently in lakes and streams if the arrangement had been in place. It hasn't been seen in any other dinosaur species.

There is proof that some dinosaurs swam. Dinosaurs have left deep scratches in the mud at various places around the world. Most of the time these tracks were made by theropod dinosaurs as they crossed rivers or waded out into the shallows to find food. Spinosaurus is thought to be more aquatic than most other dinosaurs. The debate continues about whether Spinosaurus was a skilled swimmer or even hunted prey while submerged, but the dense bones of the dinosaur suggest that the enormous predator was at least wading around in the shallows in search of a lungfish or coelacanth to eat. Natovenator is different from the others in that it appears to have specific ways of moving through the water.

There may have been an entire family of non-avian dinosaurs that swam. How the dinosaurs actually swam has not been fully explored. Lee and colleagues think that Natovenator swam with its forelimbs in a primitive version of what penguins do. Birds use the same movements underwater.

Natovenator and related species are likely to be tested in future studies. The idea that Natovenator was able to swim is likely to be challenged by studies of the dinosaur's teeth. Paleontologists are not able to see a preview of what penguins and auks would evolve into at this time.

Natovenator won't be the last dinosaur to raise such possibilities in the water. The lack of swimming dinosaurs is due to the incomplete nature of the fossil record and the nature of discovery. There are over a thousand dinosaur species that have been named. Even familiar species may have unexpected life histories, as paleontologists discover more. According to Agnolin, studies of already-known dinosaurs will lead to the discovery of swimming adaptions in other species.