Dinosaurs were the most fascinating creatures that once ruled the world for more than 150 million years. The peculiar fossils serve as a window into the past, revealing the diverse dinosaur species that inhabited the planet’s ecosystems, ranging from forests to deserts. However, it is unclear whether dinosaurs spent time in or near water. As it turns out, they did!
A one-of-a-kind fossil sheds new light on the world of swimming dinosaurs. Meet Natovenator polydontus — the name translates as “swim hunter with many teeth,” and is given to this newly discovered species. The discovery makes it a first known case of a streamlined, non-avian dinosaur that walked on two legs. This unique fossil find adds to the evidence of dinosaur diversity that once existed.
Analysis of the fossil
Natovenator was found buried in Upper Cretaceous rocks dating from 100 million to 66 million years ago at the Hermiin Tsav fossil formation in the Gobi Desert of southern Mongolia. This location is famous for preserving a wide range of dinosaur fossils as well as other types of ancient life.
Reportedly, the well-preserved bones of this species were discovered during the Korean-Mongolian International Dinosaur Expedition in 2008. Ever since then, the fossils were kept in a storage facility — awaiting to be studied by paleontologists.
Later, researchers from Seoul National University, the University of Alberta and the Mongolian Academy of Sciences investigated the bones. Surprisingly, it turned out to be a fantastic find.
The tiny predator’s fossilized bones were delicate, but beautifully preserved. A nearly complete skull with many teeth, as well as the majority of the neck, spinal column, tail and limbs, were among the remains discovered.
The team first assumed the remains belonged to a lizard or a mammal. They were able to decode the creature’s bodily features by closely inspecting the specimen. As a result, a new dinosaur species was discovered.
It belonged to the therapod family, which means “beast feet.” It was a group of carnivorous dinosaurs that walked on two legs.
However, one intriguing aspect of this discovery is how a semi-aquatic species was discovered in a desert. According to studies, the Gobi region was very different during this period than it is now. The habitat supported dense conifer forests with lake streams, where several marine creatures lived.
At the time, the new species coexisted with other magnificent beasts such as Alectrosaurus, a large carnivorous dinosaur, and Nemegtosaurus, a massive herbivore that ate tall trees.
According to CT scans, the dinosaur had a streamlined body with a goose-like neck.
“Its body shape suggests that Natovenator was a potentially capable swimming predator,” stated the research paper of this new study. It further explained, “streamlining a body is a major adaptation for aquatic animals to move efficiently in the water. Whereas diving birds are well known to have streamlined bodies, such body shapes have not been documented in non-avian dinosaurs.”
Authors also speculate that the new species was a semiaquatic diving predator. The artist’s recreation highlights the species’ skill to float on the water’s surface as well as dive below and swim to catch a fish.
This study suggests that dinosaurs were more adaptable to different ecosystems than paleontologists expected. The team suspects that this one-foot-long dinosaur resembled modern diving birds because of its rib orientation, which pointed towards its tail.
The closely packed tiny teeth, on the other hand, made the otherwise friendly-looking creature appear dangerous. The species’ long jaws and numerous tiny teeth suggest that it evolved to catch wriggling prey in the water. Moreover, the dinosaur’s long neck would have aided the species in hunting for prey in water bodies, like lakes. It was primarily dependent on a fish or insect-based diet, though the teeth also indicate a more varied diet.
The link to other dinosaur species
The experts also traced Natovenator’s evolutionary relationships with other theropod dinosaurs. The new species appears to be most similar to Halszkaraptorines, a type of non-avian theropod dinosaur that lived in prehistoric Mongolia. Initially, it was thought to be a swimming dinosaur, however, experts were unable to decode its exact body shape. Natovenator is also thought to be a cousin of sharp-toothed predators, like Velociraptors.
Among the group of swimming dinosaurs, there is a hot debate around Spinosaurus. In 2014, scientists found the fossil of a Spinosaurus fossil from the Moroccan desert. The fossil showcased features like a sail-like structure on its back, short legs, and sharp teeth that evolved to catch fish. Moreover, the dense and heavy bones suggested it to be an excellent swimmer.
Nevertheless, this new discovery adds to our understanding of the Cretaceous period’s aquatic lifestyle. And on a lighter note, this newly discovered species has a strong chance of appearing in the next Jurassic World film. The details of this new creature have been published in the journal Communications Biology.
Images via Yusik Choi, Communications Biology and Pexels