The “One Who Causes Fear” – Extremely Powerful New Meat-Eating Predator Discovered

Llukalkan aliocranianus

Jorge Blanco’s artist impression of Llukalkan aliocranianus. Credit: Jorge Blanco and Journal of Vertebrate Paleontology

Ruling in the Late Cretaceous, Llukalkan aliocranianus could be as long as an elephant, had extremely powerful bites, very sharp teeth, and huge claws in their feet.

Research published today (March 30, 2021) in the peer-reviewed Journal of Vertebrate Paleontology describes a newly discovered species of dinosaur — named the ‘one who causes fear’, or Llukalkan aliocranianus.

Around 80 million years ago as tyrannosaurs ruled the Northern Hemisphere, this lookalike was one of 10 currently known species of abelisaurids flourishing in the southern continents.

A fearsome killer, Llukalkan was “likely among the top predators” throughout Patagonia, now in Argentina, during the Late Cretaceous due to its formidable size (up to five meters long), extremely powerful bite, very sharp teeth, huge claws in their feet and their keen sense of smell.

It had a strange short skull with rough bones, so in life its head had bulges and prominences like some current reptiles such as the Gila monster or some iguanas. Its hearing was also different to other abelisaurids. The make-up of its skull suggests this was better than most of the other abelisaurids and similar to that of modern-day crocodiles.

Its full name comes from the native Mapuche for ‘one who causes fear’ — Llukalkan, and the Latin for ‘different skull’ — aliocranianus.

It lived in the same small area and period of time as another species of furileusaurian (stiff-backed lizard) abelisaurid — Viavenator exxoni — just a few million years before the end of the age of dinosaurs.

Llukalkan aliocranianus Discovery Site

Site of discovery of Llukalkan aliocranianus. Credit: Journal of Vertebrate Paleontology

Fossil remains of Llukalkan and Viavenator were found just 700m apart in the Bajo de la Carpa Formation, near the same famous fossil site at La Invernada, in Argentina.

“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,” says lead author Dr. Federico Gianechini, a paleontologist at the National University of San Luis, Argentina.

Abelisauridae were a striking family of theropod dinosaurs averaging five to nine meters long that prowled mainly in Patagonia and other areas of the ancient southern subcontinent Gondwana — recognized today as Africa, India, Antarctica, Australia, and South America. To date, almost 10 species of this fearsome predator have been unearthed across Patagonia. While abelisaurids resembled T-Rex in general appearance with tiny stubby arms, they had unusually short, deep skulls which often bore crests, bumps, and horns, and were unique.

Moving upright on their hind limbs with huge claws that they may have used to stab their prey, Llukalkan had extremely powerful bites and very sharp teeth with which to tear down their prey while moving fast thanks to their powerful hind legs.

Skull of Llukalkan aliocranianus

Skull of Llukalkan aliocranianus. Credit: Journal of Vertebrate Paleontology

The fossilized remains of Llukalkan include a superbly preserved and uncrushed braincase. This new species is similar in many respects to Viavenator, except that it is smaller, the holes in the skull through which the veins pass are larger and more widely separated from the supraoccipital crest (one of the bones that form the braincase), among other differences. But the new dinosaur’s most distinctive feature is a small posterior air-filled sinus in the middle ear zone that has not been seen in any other abelisaurid found so far.

It means that Llukalkan likely heard differently to other abelisaurids — most probably better and similar to that of a modern-day crocodile explains co-author Dr. Ariel Mendez from the Patagonian Institute of Geology and Palaeontology, Argentina.

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

However it may have lived, the fossil evidence of Llukalkan‘s adaptations suggests that abelisaurids were flourishing right before the dinosaurs went extinct.

“These dinosaurs were still trying out new evolutionary pathways and rapidly diversifying right before they died out completely,” adds Mendez.

Despite their significant finding, there is still a lot to discover. “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,” says Gianechini.

Reference: “A New Furileusaurian Abelisaurid from La Invernada (Upper Cretaceous, Santonian, Bajo De La Carpa Formation), Northern Patagonia, Argentina” by Federico A. Gianechini, Ariel H. Méndez, Leonardo S. Filippi, Ariana Paulina-Carabajal, Rubén D. Juárez-Valieri and Alberto C. Garrido, 30 March 2021, Journal of Vertebrate Paleontology.
DOI: 10.1080/02724634.2020.1877151

6 Comments on "The “One Who Causes Fear” – Extremely Powerful New Meat-Eating Predator Discovered"

  1. “… [physical characterustics] AND A KEEN SENSE OF SMELL.” Period. Maybe you can tell me what brand of aftershave they wore?

  2. No dinosaur have good hearing like the gator .thecodont the dinosaur allso a thecodont have simular brain architecture thecodont hearing works like this the skull have to be move to akinetic skull. Dinosaur skull is no where near akinetic like modern crocodilian first bony processes make the skull akinetic must be elongated protosuchus gator type mesoeucrocodylia are only thecodont with this feature that why they have better hearing they are best in thecodont protosuchus hearing is not good as gator type mesoeucrocodylia the bony processes is not fuse to braincase only 2 bone fuse to braincase gator and mammal have 6 these are high tech animal protosuchus elongated bony process is the reason they thought it was ancestor modern crocodilian dinosaur only have 2 bone fuse to braincase like other primitive reptile does not matter that tyrannosaur have more hole in braincase than the gator it lack elongate bony process so it’s hearing not good as the gator same with birds they can have less hole in braincase than the gator and still hear better than them because they have bigger brain they can hear different sound gator only can hear 1 sound gator juvnile sound can be hear by all species of modern crocodilian they can not tell the different mammal and birds can. Modern crocodilian are primitive that way.that why they know maniraptoran oviraptor is a bird not a dinosaur and the spinosauridae dinosaur is the ancestor of modern crocodilian dinosaurs was allways primitive and was no where as advance as modern crocodilian .lot of hole in braincase does not mean they have good hearing that just one part there is up dated scientific report out there clearly i read it

    • If you’re that smart could you learn to type a sentence that is readable? KTHXBI

      • Clyde Spencer | March 31, 2021 at 7:53 am | Reply

        “… abelisaurids were flourishing right before the dinosaurs WENT extinct.”

        Speaking of grammar, “extinct” is a state of being, not an activity. Therefore, one should say “became extinct,” or “experienced extinction.” It is alright to say that they “went to their graves,” or they “went hunting.” It is NOT alright to say they “went extinct!”

        Without any apparent standards in journalism, this corruption of grammar seems to be becoming more common. Next thing you know, people will be saying “went common.”

  3. Later i read irritator stapes is it in tomb like advance spinosauridae the gator .a aquatic feature all signs look good allosaurus stapes is different from irritator .stapes is a hearing feature

  4. Mark Driskill | April 5, 2021 at 2:09 pm | Reply

    I have been wondering if T-rex was only a scavenger with good smell and hunted dead dinosaurs to eat and not the living?

Leave a comment

Email address is optional. If provided, your email will not be published or shared.