It was christened Stegouros elengassen. The specimen is about two meters in size. And it dates from the late Cretaceous period. That is, about 71.7 to 74.9 million years ago. It was discovered in Magallanes, in the extreme south of Chile. But the extraordinary thing about the discovery is that it is a new species. The new dinosaur found in Chile has unique characteristics.
Distinctive tail
This provides information about the early evolution of these armored dinosaurs. This particular one evolved a large tail gun. It is different from those seen in other dinosaurs.
The group of ankylosaurs is diverse and well studied. However, the southern ones are rare and poorly known.
It is believed that in the south, in Gondwana, the first ankylosaurs arose. An article in the journal Nature defends this theory. It is entitled Bizarre tail weaponry in a transitional ankylosaur from subantarctic Chile. Biologist Alexander Vargas and his colleagues describe the well-preserved and complete skeleton.
“It has distinctive features like those of other ankylosaurs,” Vargas explains. “An example might be its skull,” he specifies. “The rest of its skeleton is largely primitive. With some stegosaurian features.”
Relationship with other dinosaurs
Stegouros also possessed at the end of its tail a weapon of great size. Seven pairs of flattened and fused bony deposits made it fearsome. Phylogenetic analyses were also carried out. Something equivalent to the construction of the family tree of the ankylosaurus. Thus it was related to the Kunbarrasaurus found in Australia. And also the Antarctopeltas of Antarctica.
What conclusion does this leave? Apparently, there are different branches of the ankylosaur family tree. They were in Laurasia and Gondwana in the late Jurassic period.
New dinosaur found in Chile raises, they say, new questions. There is still much to learn about the evolution of armored dinosaurs. And particularly in Gondwana, in the south.
