Llukalkan aliocranianus: New Species of Carnivorous Dinosaur Unearthed in Argentina

Thursday, April 1, 2021

Life reconstruction of Llukalkan aliocranianus. Image credit: Jorge Blanco.

A new genus and species of furileusaurian (stiff-backed lizard) abelisaurid dinosaur being named Llukalkan aliocranianus has been discovered by a team of paleontologists from Argentina.

Llukalkan aliocranianus roamed our planet during the Late Cretaceous period, about 80 million years ago.

The dinosaur was a member of Abelisauridae, a family of big predators known from the ancient supercontinent Gondwana.

It grew to about 5 m (16.4 feet) in length, and had extremely powerful bite, very sharp teeth, huge claws, and keen sense of smell.

It also had a strange short skull with rough bones, so in life its head had bulges and prominences like some living reptiles.

“But the most distinctive feature of Llukalkan aliocranianus is a small posterior air-filled sinus in the middle ear zone that has not been seen in any other abelisaurid found so far,” said Dr. Ariel Mendez, a paleontologist at the Patagonian Institute of Geology and Palaeontology.

“It means that this dinosaur likely heard differently to other abelisaurids — most probably better and similar to that of a modern day crocodile.”

“This finding implies a different hearing adaptation from other abelisaurids, and likely a keener sense of hearing.”

Reconstruction of the complete skull and mandible of Llukalkan aliocranianus, from the Late Cretaceous of Neuquén Province, Argentina, in left lateral view. The preserved bones are located in their supposed natural positions, whereas non-preserved parts and bones are in gray. The prearticular bone has a medial location, laterally covered by the angular and surangular. The maxilla, jugal and quadrate correspond to the right side, although they were mirrored to accommodate with the image. Scale bar – 5 cm. Image credit: Gianechini et al., doi: 10.1080/02724634.2020.1877151.

The fossilized cranial remains of Llukalkan aliocranianus were recovered from the Bajo de la Carpa Formation at La Invernada fossil area in northwestern Patagonia, Argentina.

According to the team, the ancient predator lived in the same small area and period of time as Viavenator exxoni, another species of furileusaurian abelisaurid from the Bajo de la Carpa Formation.

“This is a particularly important discovery because it suggests that the diversity and abundance of abelisaurids were remarkable, not only across Patagonia, but also in more local areas during the dinosaurs’ twilight period,” said Dr. Federico Gianechini, a paleontologist at the National University of San Luis.

Llukalkan aliocranianus was similar in many respects to Viavenator exxoni, except that it was smaller, the holes in the skull through which the veins pass were larger and more widely separated from the supraoccipital crest, among other differences.

“This discovery also suggests that there are likely more abelisaurid out there that we just haven’t found yet, so we will be looking for other new species and a better understanding of the relationship among furilesaurs,” Dr. Gianechini said.

The discovery of Llukalkan aliocranianus is reported in a paper published in the Journal of Vertebrate Paleontology.


Federico A. Gianechini et al. A New Furileusaurian Abelisaurid from La Invernada (Upper Cretaceous, Santonian, Bajo De La Carpa Formation), Northern Patagonia, Argentina. Journal of Vertebrate Paleontology, published online March 30, 2021; doi: 10.1080/02724634.2020.1877151

Source: www.sci-news.com/