Identification of the specimen revealed the existence of a hitherto unknown lineage of armored dinosaurs, whose tail had a particular shape.
A team of researchers from the University of Chile found a new species of armored dinosaur after finding a complete 74 million-year-old fossil in the southern Magallanes Region, the most important discovery in Chilean paleontology along with Chilesaurus diegosuarezi.
The discovery, of high global impact and disclosed this Wednesday, occurred in an inhospitable area near Torres del Paine National Park when in February 2018 a group of paleontologists extracted with great difficulty a block of rock with fossil remains exposed on the steep hill of the Valley of the River of the Chinas.
The identification of the specimen, led by scientists Sergio Soto and Alexander Vargas, revealed the existence of a hitherto unknown lineage of armored dinosaurs which, in this case, included a tail that amazed the researchers by not resembling that of any specimen cataloged to date.
The end of its tail had a particular shape similar to the macuahuitl, a feared club used by the ancient Aztecs, a rarity that allowed it to be clearly identified as a new type of armored dinosaur.
As the work teams removed the rock, they found a practically complete skeleton with an articulated posterior area, half of which had seven pairs of laterally projected dermal bones that gave it an appearance similar to a macuahuitl, the war club used by the Aztecs.
Six myths about dinosaurs that still confuse many people
With a dimension around 2 meters, the new species was named “Stegouros lengassen”: denomination that, according to the Chilean researchers, is translated as “roofed tail” from Stegouros, while the term “elengassen” refers to an armored monster from the tradition of the Tehuelche people, originating from the southern part of the country.
The “rosetta stone”
The paleontologist Sergio Soto, main author of the study, points out that the research allowed to determine that the specimen was a transitional ankylosaur, that is, “an evolutionary link between ankylosaurs (armored species of dinosaurs) and other older lineages of armored dinosaurs. ”.
“Stegouros has only some of the traits normally found in ankylosaurs, particularly in the skull, but many others are absent. It also has some stegosaurus-like traits, inherited from a common ancestor with them, but lost in other ankylosaurs. evolution, “added the researcher.
Based on these data, the team from the University of Chile maintains that the discovery is a “Rosetta Stone” of this group of prehistoric animals, a finding that allows us to explain and give meaning to the evolution of these battleships whose remains have been found in few quantities in the Southern Hemisphere.
For his part, paleontologist Alexander Vargas emphasized that stegosaurs are among the most recognizable species, both for their powerful dorsal plates and for their paired barbed tail weapon.
Australotitan, the 70-ton giant dinosaur discovered in Australia
“Advanced ankylosaurs, on the other hand, are famous for their broad backs armored by rows of osteoderms, and for having a huge rounded mace at the end of their tail. Clearly, the tail weapon on our dinosaur was none of the above.” , described the Chilean scientist.
Another conclusion of this work is that armored dinosaurs are the only landline vertebrate lineage that has independently evolved three radically different types of specialized tail weapons: the paired spikes of stegosaurs, the mace of advanced ankylosaurs, and the Stegouros macuahuitl just found.
Unknown in South America
Until now, ankylosaurs had been found in isolated remains in South America, so the discovery of Stegouros elengassen, also in such a good state of conservation, exceeded all expectations.
The researchers’ conclusions also allowed this new species to be related to two previous discoveries of armored dinosaurs with which it shares some characteristics: Antarctopelta from Antarctica and Kunbarrasaurus from Australia.
The new finding of Chilean paleontology allows, in this way, to add information to study the ankylosaurs of the Southern Hemisphere and compare them with their northern relatives: they are smaller, with lighter armor and slimmer limbs.
The work proposes to recognize the new species as Parankylosauria (“next to the Ankylosauria”) and distinguish them from their similar ones in the northern part of the planet.
Patagonian Cretaceous World
Chile and all of South America, in addition to Africa, Oceania, India and Antarctica, was located on the western margin of the megacontinent called Gondwana during the age of the dinosaurs.
This discovery, according to the head of the Paleontology Area of the National Museum of Natural History of Chile and part of the study, David Rubilar, provides information not only for the prehistoric fauna of the South American country but also represents “valuable evidence” of the connection of the southern continents millions of years ago. (I)
Paul is a talented author and journalist with a passion for entertainment and general news. He currently works as a writer at the 247 News Agency, where he has established herself as a respected voice in the industry.
