A newly discovered dinosaur species is called ‘the one that causes fear’ because of its sheer size and brutal feeding habits.
Llukalkan aliocranianus was one ‘formidable killer’ that roamed South America about 80 million years ago, towards the end of the dinosaur age.
Skull remains studied by paleontologists at the National University of San Luis in Argentina reveal one short, stunted skull and sharp teeth.
It reached a length of five meters, had enormous claws and a keen sense of smell to track its prey, which it is said to have caught move quickly thanks to powerful hind legs.
The species was ‘probably among the apex predators’ all over Patagonia, now in Argentina, during the late Cretaceous, which stretched from 100.5 million to 66 million years ago.
It was a lookalike of the famous tyrannosaurs, who ruled the Northern Hemisphere about 80 million years ago.
Artist impression of Llukalkan aliocranian by Jorge Blanco. A terrifying killer, it was ‘probably one of the apex predators’ in all of Patagonia, now in Argentina, during the late Cretaceous
Abelisauridae were a distinctive family of theropod dinosaurs averaging 16 to 9 meters in length that roamed mainly in Patagonia and other parts of the ancient southern supercontinent Gondwana.
Gondwana is recognized today as Africa, South America, Australia, Antarctica, the Indian Subcontinent and the Arabian Peninsula.
Although abelisaurids generally resembled T-Rex with small stubby arms, they had unusually short, deep skulls that often bore combs, bumps, and horns.
When Tyrannosaurus and its relatives roamed North America and Asia, the abelisaurids occupied a similar niche in Patagonia and other parts of South America.
Abelisaurids had huge jaws. Like T-Rex, they relied on crushing and killing prey.
But abelisaurids had even smaller arms than the tyrannosaurs.
L. aliocranianus represents not only a new species, but also a new genus.
Its full name comes from the native Mapuche for ‘one who causes fear’ – (Llukalkan) and the Latin for ‘other skull’ (aliocranianus).
It was one of 10 species of abelisaurids known to science that thrived on the southern continents.
Abelisaurids were the dominant predators in the Southern Hemisphere, around the same time that tyrannosaurids roamed North America and Asia.
They were part of the broader theropod clade of massive bipedal carnivores with sharp grabbing claws.
“This is a particularly important discovery because it suggests that the diversity and abundance of abelisaurids was remarkable not only in Patagonia, but also in more localized areas during the twilight of the dinosaurs,” said lead study author Dr. Federico Gianechini of the National University. from San Luis, Argentina.
“This discovery also suggests that there are probably more abelisaurids that we have not yet found.”
The fossilized remains of Llukalkan include an excellently preserved and non-crumbled braincase.
They were discovered in the Bajo de la Carpa Formation, in the Argentinian province of Neuquén.
The most distinctive feature of the species is a small posterior air-filled sinus in the middle zone that has so far not been seen in any other abelisaurid found to date.
The fossilized remains of Llukalkan include an excellently preserved and non-crumbled braincase (pictured) and sharp teeth
Site of Llukalkan aliocranianus, from the Bajo de la Carpa Formation (Santonian) in the La Invernada fossil region, in northwestern Patagonia
The composition of its skull suggests that its hearing was better than most other abelisaurids and comparable to that of modern crocodiles.
L. aliocranianus also had a strange, short skull with rough bones.
In life, its head had bulges and protrusions like some modern-day reptiles, such as the Gila monster.
Fossil evidence of Llukalkan’s adaptations suggests that abelisaurids thrived just before the dinosaurs became extinct.
“These dinosaurs were still trying new evolutionary pathways and are rapidly diversifying before becoming extinct,” said study co-author Dr. Ariel Mendez of the Patagonian Institute of Geology and Palaeontology, Argentina.
L. aliocranianus lived in the same small area and period as another species of abelisaurid – Viavenator exxoni – just a few million years before the end of the dinosaur age.
Researchers have compared the strange morphology of Llukalkan aliocranianus to the Gila monster (pictured) – a venomous lizard native to the Southwestern US.
Fossil remains of the two genera Llukalkan and Viavenator were found 700 meters apart in the Bajo de la Carpa formation, near the same famous fossil site in La Invernada.
This new species resembles Viavenator in many ways, except that it is smaller, and the holes in the skull through which the veins pass are larger and further separated from the supraoccipital crest – a bone that makes up the brain pan.
Today’s study published in the Journal of Vertebrate Paleontology
HOW THE DINOSAURS WENT AROUND 66 MILLION YEARS AGO
Dinosaurs ruled and dominated the Earth about 66 million years ago, before suddenly becoming extinct.
The Cretaceous Tertiary Extinction is the name given to this mass extinction.
For years, the changing climate was believed to destroy the food chain of the huge reptiles.
In the 1980s, paleontologists discovered a layer of iridium.
This is an element that is rare on Earth, but found in space in large quantities.
When this was dated, it coincided exactly with the time when the dinosaurs disappeared from the fossil record.
A decade later, scientists discovered the massive Chicxulub crater at the tip of Mexico’s Yucatán Peninsula, which dates back to the period in question.
Scientific consensus now says that these two factors are linked and that they were both likely caused by a massive asteroid crashing into Earth.
With the projected size and impact speed, the collision would have created a massive shock wave and likely triggered seismic activity.
The fallout would have created plumes of ash that likely covered the entire planet and made it impossible for dinosaurs to survive.
Other animals and plant species had a shorter time span between generations that allowed them to survive.
There are several other theories as to the cause of the famous animals’ demise.
One early theory was that small mammals ate dinosaur eggs and another proposes that poisonous angiosperms (flowering plants) killed them.