An enigmatic dinosaur – sporting a swan neck, amphibian fins and Velociraptor – missed claws – could walk like a duck on land and probably swim like a penguin during its apogee on Earth, scientists they have found after examining their fossilized remains.
In fact, the remains, which were on the black market for years, painted such an absurd image of a dinosaur that paleontologists thought it was a sophisticated fake at first. [See images of the swan-necked, amphibious dinosaur]
Their discovery reveals that the bird-like dinosaur was probably semi-aquatic and felt at home in the water, the researchers said. This is surprising because the newly discovered species is a theropod: a group of bipedal dinosaurs, mainly carnivores, which includes Tyrannosaurus rex and it is believed that most theropods did not spend much time in the water, researchers said. (The main exception is Spinosaurus .) T. rex could probably swim, they show fossilized footprints underwater.)
Probably the newly identified species swam with their arms similar to fins, and his long neck probably helped him with the search for food and the ambush, the researchers said.
The newly discovered dinosaur comes from Ukhaa Tolgod, a cemetery of dinosaurs in southern Mongolia. The researchers named him Halszkaraptor escuilliei or "Halszka" for short, honoring Halszka Osmólska (1930-2008), a Polish paleontologist specializing in Mongolian dinosaurs. The name of the species honors François Escuillié, who returned the specimen hunted to Mongolia, the researchers wrote in the study
"Illegal export of Mongolia, Halszka resided in private collections around the world before being acquired in 2015 and offered to paleontologists for studying and preparing for their return to Mongolia, "senior researcher Pascal Godefroit, a paleontologist at the Royal Belgian Institute of Natural Sciences in Brussels, said in a statement.
Once H. escuilliei was delivered safely to scientists, they began to analyze it. But the strange dinosaur did not fit into any of the predatory dinosaur groups known in Mongolia. On the contrary, it had a mixture of reptiles, birds and amphibians. It even had sickle-shaped "killer feet," like those of Velociraptor researchers noted.
"The first time I examined the specimen, I even wondered if it was a genuine fossil," said study senior researcher Andrea Cau, a paleontologist at the Giovanni Capellini Geological Museum in Bologna, Italy, in the statement.
To ensure that the specimen was real, and not a false configured black market, the researchers analyzed it with synchrotron multiresolution x-ray microtomography. This technique allowed the researchers to take multiple X-rays that were 100 billion times more powerful than X-rays used in hospitals. The scientists then assembled these X-rays to create a virtual 3D image of the dinosaur.
To the delight of the scientists, the results showed that the specimen appeared to be a genuine animal, and not a false specimen assembled from different fossils, said the co-study of the study. The researcher Dennis Voeten, researcher at the European Synchrotron Radiation Facility (ESRF).
The synchrotron also revealed that the dinosaur has several teeth in the mouth that can not be seen with the naked eye, according to study co-investigator Vincent Beyrand, a researcher at the ESRF said. "We also identified a neurovascular mesh within its snout that resembles that of modern crocodiles to a remarkable degree," Beyrand said in the statement. "These aspects suggest that Halszka was an aquatic predator."
The synchrotron also showed that Halszka walked on two legs while on land, probably with the same posture that modern ducks have. While in the water, the bird-like dinosaur probably used its arms as fins to swim, as do penguins today, the researchers said. [In Images: Digging Up a Swimming Dinosaur Called Spinosaurus]
Despite its strange characteristics, Halszka is not the only strange dinosaur in the Gobi desert. Several other strange Mongol theropods seem to be closely related to him, which led the researchers to create Halszkaraptorinae, a new group that is a subfamily of dromaeosaurs a group of dinosaurs commonly known as raptors.
However, some scientists are still skeptical about the validity of Halszka.
It could be a new kind of weird dinosaur, "but since the specimen was collected by poachers and sold on the black market, I'm not 100 percent sure it has not been tampered with," said Steve Brusatte, a paleontologist at the University of Edinburgh. "Some fakes these days are so sophisticated."
The conclusion that the dinosaur was semi-aquatic is not "overturned," Brusatte added. "The evidence is mainly circumstantial at this point," he told Live Science in an email. "For example, the long neck is seen in many other small theropods, and it is even seen in modern dinosaurs that are not aquatic, such as ostriches."
Despite this uncertainty, "I am very enthusiastic about this fossil, but I think it raises more questions than it answers, and we will probably debate about it for years," said Brusatte.
The study was published online yesterday (December 6) in the journal Nature.
Original article on Live Science.