New species of carnivorous dinosaur discovered in Argentina | Paleontology

New genus and species of abelisaurid furileusaurian (stiff-backed lizard) dinosaur named Llukalkan aliocranianus was discovered by a team of Argentine paleontologists.

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

Llukalkan aliocranianus traveled our planet at the end of the Cretaceous, about 80 million years ago.

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

It was approximately 5m (16.4ft) long and had an extremely powerful bite, very sharp teeth, huge claws, and a keen sense of smell.

He also had a short, weird skull with rough bones, so in life his head had bulges and prominences like some living reptiles.

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

“This means that this dinosaur probably heard differently from other abelisaurids – probably better and similar to that of a modern day crocodile.”

“This discovery involves a hearing adaptation different from other abelisaurids, and possibly a more acute sense of hearing.”

Complete reconstruction of the skull and mandible of Llukalkan aliocranianus, from the Late Cretaceous period from the province of Neuquén, Argentina, in left lateral view.  Preserved bones are located in their supposed natural positions, while parts and non-preserved bones are grayed out.  The prearticular bone has a medial location, covered laterally by the angular and the surangular.  The maxilla, jugal and square correspond to the right side, although they have been mirrored to fit the image.  Scale bar - 5 cm.  Image credit: Gianechini et al., Doi: 10.1080 / 02724634.200.1877151.

Complete reconstruction of the skull and mandible of Llukalkan aliocranianus, from the Upper Cretaceous of the province of Neuquén, Argentina, in left lateral view. Preserved bones are located in their supposed natural positions, while parts and non-preserved bones are grayed out. The prearticular bone has a medial location, covered laterally by the angular and the surangular. The maxilla, jugal and square correspond to the right side, although they have been mirrored to fit 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 in the La Invernada fossil area in northwest Patagonia, Argentina.

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

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

Llukalkan aliocranianus looked like in many ways Viavenator exxoniexcept that it was smaller, the holes in the skull through which the veins pass were larger and more widely separated from the supraoccipital ridge, among other differences.

“This finding also suggests that there are probably more abelisaurs than we have yet found, so we will be looking for other new species and a better understanding of the relationship between furilesaurs,” said Dr Gianechini. .

The discovery of Llukalkan aliocranianus is reported in a paper published this week 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

Comments are closed.