The Stegouros elengassen, an enigmatic dinosaur whose tail left scientists intrigued, was introduced this Wednesday (1) by Chilean paleontologists, three years after its nearly intact remains were discovered in Patagonia, in southern Chile.
In February 2018, a group of 19 scientists were excavating at Cerro Guido, a prolific site with dinosaur remains in a rugged area of ​​Chilean Patagonia, where they found rocks with the bones of what looked like an ornithopod dinosaur.
At the bottom of the earth, surprisingly appeared the remains of a tail that confused them.
“It was the main surprise (…), this structure is absolutely unbalanced, because the tail was covered with these seven pairs of dermal bones, five of which merged in the middle of the tail, covering these bones, producing a weapon absolutely different from anything else. that anyone knew about any dinosaur,” said Alexander Vargas, one of the paleontologists, during a presentation of the discovery at the University of Chile, which was also attended by government officials.
Experts were also surprised to find 80% of the dinosaur’s skeleton almost intact.
After analysis, they estimated that the animal lived in that area between 71 million to 74.9 million years ago. It was about two meters long, weighed almost 150 kilos and was a herbivore.
The discovery was also published in the renowned scientific journal Nature.
strange tail
The very strange tail has seven pairs of laterally projecting dermal bones, which give it an appearance similar to a “Macuahuitl”—a war weapon used by the ancient Aztecs who inhabited Central America.
It was this characteristic that gave rise to the name that scientists gave to the dinosaur: “Stegouros elengassen”.
Stegouros translates as “covered tail”, while “elengassen” is the name of a mythical monster in the tradition of the ancient peoples of Patagonia or the Tehuelches of the South American continent.
Experts say the remains are from an unknown lineage of an “armored” dinosaur never seen in the southern hemisphere, with characteristics associated with other species already identified in the north of the continent, such as the pointed paired tails of Stegosaurus or the rounded tail of Ankylosaurus that they lived in both hemispheres.
“We don’t know the reasons why a structure like this (the tail) evolved. We know that within groups of armored dinosaurs there seems to be a tendency to independently develop different defense mechanisms based on dermal bones,” said another of the paleontologists, Sergio Soto.
The Stegouros fossils were found in the Las Chinas valley, at Cerro Guido, near the border with Argentina (about 3,000 km south of Santiago). With almost 15 kilometers in length, there are different rock formations that contain fossils and have been studied by scientists for several years.
For paleontologists, this area is “a kind of book that allows us to understand the succession of flora and fauna that inhabited this place”, which also helped to discover the proximity that existed millions of years ago between what is now America and the Antarctica.
Giant dinosaur fossil is found in Maranhão
Recently, the excavation for the construction of a railway in Davinópolis (metropolitan region of Empress), in Maranhão, revealed a fossil of a giant dinosaur that is still unknown to the scientific community.
Among the materials found are a femur measuring more than 1.5 meters in length, other long bones, such as a possible tibia, feet and hands, several ribs and vertebrae.
The fossil is the first known dinosaur for the region and possibly an important record for the evolutionary history of the group of sauropods, who lived in what is now Brazil about 130 million years ago, in the period known as the Early Cretaceous.
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