New armored dinosaur found in Chile had bizarre weaponized tail

An artist's impression of a new species of armoured dinosaur named Stegouros elengassen. Paleoartist credit: Mauricio Álvarez

(CNN)A new species of armored dinosaur discovered in Chile had a weaponized tail not seen before in any other dinosaur.

Roughly 2 meters (6.5 feet) in size, the small armored dinosaur called an ankylosaur dates from the late Cretaceous period, around 71.7 million to 74.9 million years ago. Its largely complete fossilized skeleton was found in Magallanes province in Patagonia, Chile's southernmost region.
Chilean paleontologist Sergio Soto was the lead author of the study.
The dinosaur, named Stegouros elengassen, had evolved a large tail weapon unlike those seen in other armored dinosaurs such as the paired spikes of Stegosaurus and the club-like tail of Ankylosaurus.
    While its skull had features in common with other ankylosaurs, its tail weaponry was "bizarre," according to the study, which was published in the journal Nature on Wednesday. The dinosaur's tail had seven pairs of flattened, bony deposits fused together in a frond-like structure.
      "The tail is extremely strange, as it is short for a dinosaur and the posterior half is encased in dermal bones (bones that grow in the skin) forming a unique (tail) weapon," said Sergio Soto Acuña, main author of the study and a doctoral student at the Universidad de Chile, via email.
        He said it resembled the tail of a rattlesnake or spiny-tailed lizard. But unlike these creatures, the dinosaur possessed true bones under the scales. The most similar feature would be the tail of a giant armadillo, but they are also extinct, he added.
        Stegouros, which means "roofed tail" in Greek and "elenggassen" is from Aonikenk, the language of the original inhabitants of Patagonia, and refers to a mythological armored beast. The fossil was found in 2018.
          The study noted that very few ankylosaurs had been found from southern Gondwana -- the lower part of the ancient supercontinent Pangea.
            "Unlike the ankylosaurs of the northern hemisphere, our new dinosaur possesses light armor, slender legs, and a smaller size," he said.
            The fossilized plants discovered in the same region indicate that the climate was warmer when this dinosaur inhabited the place -- very different from the current cold climate prevailing in Patagonia.