Dinosaur That Looked Like Penguin-Goose Mix With Too Many Teeth Discovered

A dinosaur that resembled a penguin-goose mix with too many teeth has been discovered in the depths of the Gobi Desert.

The near-complete skeleton was unearthed in 2008 from the Baruungoyot Formation, within the Gobi Desert in southern Mongolia, by a team led by Yuong-Nam Lee, paleontologist and professor at Seoul National University.

The fossil—which included a skull, spinal column, one forelimb, and two hindlimbs—belonged to a dinosaur that lived in the Late Cretaceous period dating back between 66 and 145 million years ago.

Lee told Newsweek: "The specimen was so delicate but beautifully preserved. It had a skull with many tiny teeth, and a very long neck was distinct. The shape of the rib cage, which is oriented posteriorly, indicates that this animal had a streamlined body, as penguins do."

Only ten percent of small specimens are found in such good condition, Lee said.
"Usually, small fossils are likely missed by researchers in the field and easily destroyed."

The species has been named the Natovenator polydontus, which translates to "swimming hunter with many teeth".

An artist's interpretation of the dinosaur shows it with a goose-like body and a mouth full of small teeth, floating on top of the water.

Insights into the discovery were published on December 1 in a Communications Biology study titled: A non-avian dinosaur with a streamlined body exhibits potential adaptations for swimming.

A semi-aquatic reptile

The Natovenator would have looked very similar to modern diving birds alive today, such as auks and penguins, the study said.

But this animal was a reptilian, rather than a bird. It was also a theropod—a carnivorous dinosaur that walked on two legs. Other famous dinosaurs such as the T. Rex belonged to this group.

But the Natovenator is the first theropod discovered to have had a streamlined body, meaning that while it could walk on land, it also would have moved effortlessly through the water.

The predator's body told paleontologists a lot about the way the dinosaur lived and hunted.

Based on its form, and the similarity between the modern diving birds we know today, paleontologists believe this dinosaur would have been a semi-aquatic predator, the study said.

"Finding semi-aquatic dinosaurs means that the ecological diversity was very high in dinosaurs, and it could change our prejudice about the lifestyle of dinosaurs," Lee said.

Until now, only avian dinosaurs were known for adapting to aquatic environments. The discovery of this new species "makes it clear" that some non-avian dinosaurs adapted to the water, the study said.

The dinosaur also had ribs that pointed towards its tail and a long neck similar to modern geese.

Both these characteristics would have allowed the dinosaur to swiftly plunge into the water, craning its neck to catch its prey.

The Baruungoyot Formation—where the fossil was discovered—is composed mainly of river channel sediments.

The area used to be home to fish, crocodilians and turtles. as well as dinosaurs. The most famous fossil to ever be discovered there was the Velociraptor. The dinosaur, which has been portrayed in many popular movies such as Jurassic Park, was a small turkey-sized dinosaur that would have lived at around the same time as the Natovenator.

Based on this, scientists can determine that the dinosaur would have lived in a freshwater environment, rather than near the sea, Lee said.

The penguin-like creature had an unusually high number of teeth in relation to its jaw, the study said.

This strongly indicates that it would have been a fish-eating dinosaur. Fish-eating animals usually have small, pointed teeth used to grip and hold the fish before swallowing.

It is also possible it fed on insects.

Overall, more research is needed to determine the species' diet. To confirm this, paleontologists would have to analyze some fossilized remains of its stomach contents.

Clues into evolution

The nearly-complete skeleton of the Natovenator can provide paleontologists with further clues into to the evolution of theropods.

For example, the Natovenator was very similar to the Halszkaraptor—-another goose-like dinosaur from modern Mongolia that lived during the same period.

Until now, paleontologists have not always been able to agree on the characteristics of the Halszkaraptor, Lee said.

"There was a debate about the authenticity of [a] Halszkaraptor holotype because it was a poached specimen," Lee said.

"And also, there were arguments against the semi-aquatic lifestyle of Halszkaraptor. We hope this article settles a controversy on Halszkaraptor," Lee said.

The fossils of other relatives of the Halszkaraptor were also too poorly preserved to provide clues in the ecology of this type of dinosaur. Before this new species was discovered many of its semi-aquatic characteristics—such as its long neck and streamlined body—were thought to be restricted to the Halszkaraptor.

The striking similarities between these two dinosaurs show that there was an "ecological niche" during this time, the study said,

"Because streamlining of the body provides hydrodynamic advantages during swimming, this particular dorsal rib morphology strongly indicates that Natovenator was a capable swimmer, providing the first compelling evidence of a streamlined body in a non-avian theropod dinosaur," the study said.

"It thus exemplifies the presence of diverse body forms among non-avian theropods. In addition, Natovenator helps us understand the body plans of halszkaraptorines because it shares many specialized features with Halszkaraptor."

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References

Yuong-Nam Lee at al, A non-avian dinosaur with a streamlined body exhibits potential adaptations for swimming, Communications Biology Published Online First: 1 December 2022, 10.1038/s42003-022-04119-9