An excavation in Argentina has unearthed a previously undiscovered dinosaur species, and the tyrannosaurus-like predator has been given a name that matches what we know about it so far: Llukalkan aliocranianus, or “the one who causes fear”.
Able to grow like an elephant, with sharp teeth and a strong bite, L. aliocranianus it would no doubt have been a frightening sight for any other creature that came upon it during the late Cretaceous, leading to the extinction of the dinosaurs 66 million years ago.
The new species is an abelisaurid, although it probably had better hearing (similar to a modern crocodile) than the other nine species in the family found so far. The dinosaur also had huge claws on its feet and a keen sense of smell, the researchers say.
The artist’s impression of Llukalkan aliocranianus. (Jorge Blanco and Journal of Vertebrate Paleontology)
“This is a particularly important finding, as it suggests that the diversity and abundance of abelisaurids were remarkable, not only in Patagonia, but also in several local areas during the twilight period of the dinosaurs,” says paleontologist Federico Gianechini of the National University of San . Luis in Argentina.
Patagonia and other areas of the Gondwana supercontinent – now divided into Africa, India, Antarctica, Australia and South America – were where the abelisaurids roamed.
While their short forearms gave them a similar look T. rex, had unusually short and deep skulls, often bearing crests, swellings and horns. This particular dino would have had swellings on its head, similar to the monster lizard Gila.
The researchers determined that L. aliocranianus shared the same part of the world at the same time as another abelisaurid, Viavenator exxoni, although the new species would have been smaller.
“These dinosaurs were still trying new evolutionary paths and rapidly diversifying even before they disappeared completely,” says paleontologist Ariel Mendez of the Patagonian Institute of Geology and Paleontology in Argentina.
The skull of Llukalkan aliocranianus. (Journal of Vertebrate Paleontology)
Some of the fossilized remains of the “scarer” include a brain, which has a unique feature among abelisaurids: a small posterior sinus filled with air in the middle ear area, which helped that hearing like a fang.
This hearing could have improved the dinosaur’s abilities as a predator, and the research team says both L. aliocranianus and V. exxoni he would have been among the most dangerous meat eaters of the time.
Map and images showing where the specimen was found in Argentina. (Gianechini et al., Journal of Vertebrate Paleontology, 2021)
There is probably more to be found in the region, about 80 million years ago – a period that seems to have been a prosperous one for the abelisaurids and furileusauri (“stiff-backed lizards”) that made up this part of the family.
“This finding also suggests that there are several abelisaurids that we have not yet found, so we will look for other new species and a better understanding of the relationship between furilesaurs,” says Gianechini.
The research was published in Journal of Vertebrate Paleontology.