A terrifying dinosaur with a menacing armoured tail roamed Chile 75 million years ago, a new study reveals.
Researchers have analysed fossils found at Río de las Chinas Valley in the Magallanes Region of Chile, South America.
They report the discovery of a freaky-looking new species, called Stegouros elengassen, which measured around 6.5 feet (two metres) in length.
S. Elengassen had a unique tail weapon, which was larger than those found in dinosaurs. The team claims that it has serrated edges with a leaf-like arrangement.
Most likely, the herbivore was protecting its tail from small predatory megaraptor dinosaurs and smaller theropod dinosaurs known as noasaurids.
The Stegouros Elengassen evolved a long tail weapon that was unlike any other dinosaurs. It had serrated edges and a leaf-like arrangement. (Artist’s impression).
Río de las Chinas Valley, Estancia Cerro Guido, Magallanes Region, Chile
The discovery has been presented in a new paper, authored by researchers at Universidad de Chile, Santiago, and published in Nature.
‘Armoured dinosaurs are well known for their evolution of specialized tail weapons – paired tail spikes in stegosaurs and heavy tail clubs in advanced ankylosaurs,’ they said.
“Here are the details of an almost complete and semi-articulated skull of a small, armoured dinosaur that lived in Southern Chile’s late Cretaceous Period. This region is closely related biogeographically to West Antarctica.
S. elengassen lived in a delta consisting of intertwining rivers forming islands between them like the modern Nile, as well as plants such as ferns and forests of Nothofagus trees, study author Alexander Vargas told MailOnline.
S. elengassen is as an ‘ankylosaur’ – a herbivorous group of dinosaurs known for their armoured tank-like bodies and club-shaped tail tips, which lived 70 million to 66 million years ago.
Researchers say that Ankylosaurs found in Laurasia (the northern landmass which was once part of the Pangaea supracontinent) are well-studied.
The unique tail weapon from the armoured dinosaur Stegouros Elengassen has been digitally reconstructed. A pair of dermal bone bones encased the tail. Digitally, a small portion has been removed to expose the tail vertebrae.
Pangea was formed around 250,000,000 years ago from fragments of the supercontinent. This created the Northern landmass Laurasia and Gondwana.
Chilean paleontologist and lead study author Sergio Soto-Acuña, is pictured here with the fossil remains
However, those from southern Gondwana – Pangaea’s southern landmass, believed to be likely to include the earliest kinds of ankylosaur – are rare and poorly understood.
According to team, S. elengassen was alive in Gondwana around 71.7- 74.9 Million years ago.
Fossil analysis revealed that it had a large tail gun made up of seven sets of bony, flattened deposits fused together to form a frond.
Its unique feature distinguishes it from other armoured dinosaurs with paired clubs and spikes.
Stegouros Elengassen is a 3D render of an armoured dinosaur species. It has been overlayed onto modern-day environments
Stegouros Elengassen, the armoured dinosaur (depicted above), is well-known for creating specialised tail weapons.
S.elengassen is a skull-like ankylosaurus with features that are similar to those found in other ankylosaurs. This includes a large, curving head proportionately to its rest.
According to the authors, however, it is thought that most of the bones are primitive with some stegosaur characteristics.
Famous features of Stegosaurs include double rows, large triangular bony plates on their backs, and possibly a tail used to regulate the temperature.
According to phylogenetic analysis, the researchers discovered that S. elengassen is related to Kunbarrasaurus in Australia and Antarctopelta near Antarctica.
Kunbarrasaurus’ armoured rear is a hallmark of the species, which looks a lot like a modern-day Armadillo. Antarctopelta was distinguished by having spikes at its head.
S.elengassen & Antarctopelta, which are in what is now South America and Antarctica, likely diverged significantly from Kunbarrasaurus. (from Australia).
Currently there’s only one known species of Antarctopelta – Antarctopelta oliveroi – which lived in Antarctica during the Late Cretaceous Period.
S. elengassen as well as Antarctopelta most likely diverged form Kunbarrasaurus.
These authors suggest that there may have been different branches to the ankylosaur tree in Laurasia, Gondwana, and elsewhere in late Jurassic time (163 million to 140 million years)
They also reiterated how little we know about the history of armoured dinosaurs in Gondwana.