Picture a prehistoric cormorant, an aquatic bird that dives deep and doesn’t surface until it has a bill full of fish. This is probably what Natovenator polydontus was like. This new dinosaur species closely resembles a deep-diving duck and further highlights the diversity of the species that likely existed during the age of dinosaurs.
In a new study published in the December 2022 issue of the journal Communications Biology, researchers have uncovered that N. polydontus was a non-avian, semi-aquatic species the size of a duck that likely lived in what is today the Gobi Desert in southern Mongolia. It had a long neck that would have made this semi-marine species well-positioned to hunt within the lake that it likely called home 77 million years ago. It would have looked similar to a diving bird with its toothed beak and front fins that were ideal for paddling. But interestingly, its snout was flat like a bill rather than a beak.
“Its streamlined body was perfectly adapted to swimming and hunting underwater,” says Sungjin Lee, study author, and researcher at Seoul National University.
What the World Would Have Looked Like 77 Million Years Ago
Researchers aren’t entirely sure when N. polydontus lived, but they think it was around the Late Cretaceous period alongside other dinosaurs like the Alectrosaurus — a large carnivore that resembled Tyrannosaurus — and the Nemegtosaurus — a huge herbivore that feasted high in the trees.
Still, the question becomes, how did a duck end up in the desert? Researchers contend that the world would have looked different than it does today in the Gobi Desert. It would have been a freshwater habitat where many aquatic species lived and was also seasonally arid. We know this because we find aquatic arthropods in the sediment that also housed N. polydontus, which shows that water was at least part of the habitat.
Lee says that the species had a lot of teeth, perfect for catching and holding onto its slippery prey. “It likely fed mainly on fish though we don’t know this for sure,” says Lee.
He says that it’s not clear how the species went extinct because, thus far, they’ve only found a few similar specimens. But he doesn’t think it was still alive when a massive asteroid barreled into the Earth 66 million years ago.
Why This New Discovery is So Important
The discovery is important because it shows us a new type of species and proves that non-avian dinosaurs could be semi-aquatic. “For a long time, we’ve thought that non-avian dinosaurs were all terrestrial, and this finding proves otherwise,” says Lee. We know that it was semi-aquatic because of its streamlined body, a shape that made it hydrodynamic.
Thomas R. Holtz Jr., a vertebrate paleontologist at the University of Maryland, agrees that the research is significant because it adds to our knowledge about this newly discovered group of small raptor dinosaurs called Halszkaraptorians. This new specimen is also more complete and, unlike other findings, had an intact ribcage.
“For the first time, we see the sort of proportions that would resemble that of a duck or a cormorant,” says Holtz. “It had a torpedo, sausage-shaped body that we see in the diving birds of today.”
Sometimes paleontologists will see a specimen from a commercial collector and recognize it as something new. But this isn’t the gold standard of discovery because when money is exchanged, there’s always the chance for deception.
“There was always a little skepticism that the first specimen was a forgery that had been altered from the original bones to look like something else,” says Holtz.
But perhaps even more importantly, it was discovered by the scientist who described it in the study instead of being purchased from a commercial fossil dealer.
N. polydontus had the characteristics of the other Halszkaraptorians while also adding to our knowledge. These were the first raptors that were more akin to a duck than a leopard in their mode of life, says Holtz. “It further shows the diversity that existed within this ancient group of animals.”