‘The Scary One’ – Extremely Powerful New Meat-Eating Predator Discovered

The decision at the end Cretaceous, Llukalkan aliocranianus could be as long as an elephant, had extremely powerful bites, very sharp teeth and huge claws in the feet.

Research published today (March 30, 2021) in the magazine Journal of Vertebrate Paleontology describes a newly discovered species of dinosaur – called the ‘scary one’, or Llukalkan aliocranianus.

Around 80 million years ago, when tyrannosaurs ruled the northern hemisphere, this lookalike was one of 10 currently known species of abelisaurids that flourished in the southern continents.

A formidable killer, Llukalkan was “probably among the best predators” in all of Patagonia, now in Argentina, during the Late Cretaceous because of its formidable size (up to five meters long), extremely powerful bite, very sharp teeth, d ‘huge claws in his feet and his keen sense of smell.

He had a strange short skull with rough bones, so in life his head had bulges and prominences like some current reptiles such as the monster Gila or some iguanas. His hearing was also different from that of other abelisaurids. The makeup of its skull suggests it was better than most other abelisaurids and similar to modern crocodiles.

Its full name comes from the native Mapuche for “ the one who scares ” – Llukalkan, and Latin for “different skull” – aliocranianus.

It lived in the same small area and time span as another species of furileusaurian abelisaurid (stiff-backed lizard) – Viavenator exxoni – just a few million years before the end of the Dinosaur Age.

Fossil remains of Llukalkan and Viavenator were found just 700m apart in the Bajo de la Carpa Formation, near the same famous fossil site in La Invernada, Argentina.

“This is a particularly important find because it suggests that the diversity and abundance of abelisaurids was remarkable, not only across Patagonia, but also in more local areas during the dinosaur twilight period,” explains L lead author, Dr Federico Gianechini, paleontologist at the National University of San Luis, Argentina.

The Abelisauridae were a striking family of theropod dinosaurs averaging five to nine meters in length that roamed mainly in Patagonia and other parts of the ancient southern subcontinent of Gondwana – today recognized as Africa, the ‘India, Antarctica, Australia and South America. To date, nearly 10 species of this formidable predator have been discovered across Patagonia. While the Abelisaurids resembled the T-Rex in general appearance with tiny, stocky arms, they had unusually short and deep skulls that often had ridges, bumps, and horns, and were unique.

Moving upright on their hind limbs with huge claws that they may have used to stab their prey, Llukalkan had extremely powerful bites and very sharp teeth to take down their prey while moving quickly thanks to their powerful hind legs.

The fossilized remains of Llukalkan include a superbly preserved, uncrushed brain case. This new species is similar in many ways to Viavenator, except that it is smaller, the holes in the skull through which the veins pass are larger and more widely separated from the supraoccipital ridge (one of the bones that forms the puzzle), among other differences. But the most distinctive feature of the new dinosaur is a small, air-filled posterior sinus in the middle ear area that has not been seen in any other abelisaurid found so far.

It means that Llukalkan probably heard differently from other abelisaurids – quite possibly better and similar to that of a modern crocodile, says co-author Dr. Ariel Mendez, of the Patagonian Institute of Geology and Paleontology, Argentina.

“This discovery involves a hearing adaptation different from other abelisaurids, and probably a more acute sense of hearing,” says Dr. Mendez.

Whatever his lifestyle, the fossil evidence of LlukalkanAdaptations suggest that abelisaurids were flourishing just before dinosaurs became extinct.

“These dinosaurs were still trying new avenues of evolution and rapidly diversifying just before they disappeared completely,” adds Mendez.

Despite their significant discovery, there is still much to discover. “This finding also suggests that there are probably more abelisaurids out there that we just haven’t found yet, so we’ll be looking for other new species and a better understanding of the relationship between furilesaurs,” says Gianechini.

Reference: March 30, 2021, Journal of Vertebrate Paleontology.
DOI: 10.1080 / 02724634.2020.1877151