An excavation in Argentina has unearthed an undiscovered species of dinosaur, and the tyrannosaur-like predator has been given a name that fits so far: Llukalkan aliocranianus, or ‘someone who causes fear’.
Able to grow as long as an elephant, with sharp teeth and a powerful bite, L. aliocranianus would undoubtedly have been a terrifying sight for any other creature that happened to it during the Late Cretaceous, which led to the extinction of the dinosaurs 66 million years ago.
The new species is an abelisaurid, although one that has probably heard better (similar to a modern crocodile) than the other nine species in the family found so far. The dinosaur also has large claws in its feet and a sharp sense of smell, say researchers.
Artist’s impression of Llukalkan aliocranianus. (Jorge Blanco and Journal of Vertebrate Paleontology)
“This is a particularly important discovery because it suggests that the diversity and abundance of abelisaurids was remarkable, not only across Patagonia, but also in more local areas during the twilight period of the dinosaurs,” said paleontologist Federico Gianechini, of the National University of San. Luis in Argentina.
Patagonia and other areas of the ancient supercontinent Gondwana – now divided into Africa, India, Antarctica, Australia and South America – were where the abelisaurides roamed.
While their short forearms gave them a similar appearance to the T. rex, they had extraordinarily short and deep skulls, often bearing crests, bumps, and horns. This particular dino would have had bumps on its head, similar to the Gila monster lizard.
The researchers determined this 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 out new evolutionary paths and rapidly diversifying before they became completely extinct,” said paleontologist Ariel Mendez, of the Patagonian Institute of Geology and Paleontology in Argentina.
Skull of Llukalkan aliocranianus. (Journal of Vertebrate Paleontology)
Part of the petrified remnants of the ‘one that causes fear’ contains a brain cough that shows a characteristic unique among abelisaurides: a small posterior air-filled sinus in the middle ear zone, which helped with the crooked hearing.
This hearing may have improved the dinosaur’s abilities as a predator, and the research team says that both L. aliocranianus and V. exxoni would have been one of the most dangerous carnivores of the time.
Map and images showing where the monster 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 period for the abelisaurides and furileusaurs (‘stiff back lizards’) that make up this part of the family.
“This discovery 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.
The research was published in the Journal of Vertebrate Paleontology.