An excavation in Argentina 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 aliocranian, or ‘someone who causes fear’.
Able to grow as long as an elephant, and with sharp teeth and a powerful bite, L. aliocranianus would undoubtedly have been a terrifying sight to any other creature that happened during the late Cretaceous, leading to the extinction of the dinosaurs 66 million years ago.
The new species is an abelisaurid, although it likely 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 in its feet and a keen sense of smell, researchers say.
Artist’s impression of Llukalkan aliocranian(Jorge Blanco and Journal of Vertebrate Paleontology)
“This is a particularly important discovery because it suggests that the diversity and abundance of abelisaurids were remarkable not only in Patagonia, but also in more localized areas during the twilight of the dinosaurs,” said paleontologist Federico Gianechini of the National University of San Luis. in Argentina.
Patagonia and other parts of the ancient supercontinent Gondwana – now split into Africa, India, Antarctica, Australia, and South America – were where the abelisaurids roamed.
While their short forearms gave them a similar look to the T. rex, they had unusually short and deep skulls, often with combs, bumps, and horns. This particular dinosaur is said to have had bulges on its head, similar to the Gila monster lizard.
The researchers have established this L. aliocranianus shared the same part of the world at the same time as another abelisaurid, Viavenator exxonialthough the new species would have been smaller.
“These dinosaurs were still trying new evolutionary pathways and are rapidly diversifying before becoming extinct,” said paleontologist Ariel Mendez of the Patagonian Institute of Geology and Paleontology in Argentina.
Skull of Llukalkan aliocranianus. (Journal of Vertebrate Paleontology)
Some of the fossilized remains of the “fear-causing one” includes a brainpan, which exhibits a feature unique among abelisaurids: a small posterior, air-filled sinus in the middle zone, which helped with that crocodile-like hearing.
That hearing may have improved the dinosaur’s predator abilities, and the research team say both L. aliocranianus and V. exxoni would have been one of the most dangerous carnivores of the time.
Map and images showing where the specimen was found in Argentina. (Gianechini et al., Journal of Vertebrate Paleontology, 2021)
It is likely that there is more to be found in the region as well, dating back about 80 million years ago – a period that appears to have been a prosperous period for the abelisaurids and furileusaurs (‘stiff-backed lizards’) that make up this part of the family.
“This discovery also suggests that there are probably more abelisaurids that we have not yet found, so we will look for other new species and better understand the relationship between furilesaurs,” said Gianechini.
The research is published in the Journal of Vertebrate Paleontology