Research revealed at the moment within the peer-reviewed Journal of Vertebrate Paleontology describes a newly found species of dinosaur — named the ‘one who causes concern’, or Llukalkan aliocranianus.
Around 80 million years in the past as tyrannosaurs dominated the Northern Hemisphere, this lookalike was one in every of 10 at the moment identified species of abelisaurids flourishing within the southern continents.
A fearsome killer, Llukalkan was “likely among the top predators” all through Patagonia, now in Argentina, through the Late Cretaceous as a result of its formidable dimension (as much as 5 meters lengthy), extraordinarily highly effective chew, very sharp tooth, enormous claws of their ft and their eager sense of scent.
It had a wierd quick cranium with tough bones, so in life its head had bulges and prominences like some present reptiles such because the Gila monster or some iguanas. Its listening to was additionally completely different to different abelisaurids. The make-up of its cranium suggests this was higher than a lot of the different abelisaurids and much like that of modern-day crocodiles.
Its full title comes from the native Mapuche for ‘one who causes concern’ — Llukalkan, and the Latin for ‘completely different cranium’ — aliocranianus.
It lived in the identical small space and time frame as one other species of furileusaurian (stiff-backed lizard) abelisaurid — Viavenator exxoni — only a few million years earlier than the top of the age of dinosaurs.
Fossil stays of Llukalkan and Viavenator have been discovered simply 700m aside within the Bajo de la Carpa Formation, close to the identical well-known fossil web 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 writer Dr Federico Gianechini, a paleontologist on the National University of San Luis, Argentina.
Abelisauridae have been a placing household of theropod dinosaurs averaging 5 to 9 meters lengthy that prowled primarily in Patagonia and different areas of the traditional southern subcontinent Gondwana — recognised at the moment as Africa, India, Antarctica, Australia, and South America. To date, virtually 10 species of this fearsome predator have been unearthed throughout Patagonia. While abelisaurids resembled T-Rex on the whole look with tiny stubby arms, they’d unusually quick, deep skulls which frequently bore crests, bumps, and horns, and have been distinctive.
Moving upright on their hind limbs with enormous claws that they might have used to stab their prey, Llukalkan had extraordinarily highly effective bites and really sharp tooth with which to tear down their prey whereas transferring quick because of their highly effective hind legs.
The fossilised stays of Llukalkan embrace a wonderfully preserved and uncrushed braincase. This new species is comparable in lots of respects to Viavenator, besides that it’s smaller, the holes within the cranium by way of which the veins move are bigger and extra extensively separated from the supraoccipital crest (one of many bones that types the braincase), amongst different variations. But the brand new dinosaur’s most distinctive characteristic is a small posterior air-filled sinus within the center ear zone that has not been seen in some other abelisaurid discovered thus far.
It implies that Llukalkan possible heard otherwise to different abelisaurids — most likely higher and much like 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 could have lived, the fossil proof of Llukalkan‘s diversifications means that abelisaurids have been flourishing proper earlier than the dinosaurs went extinct.
“These dinosaurs were still trying out new evolutionary pathways and rapidly diversifying right before they died out completely,” provides Mendez.
Despite their vital discovering there’s nonetheless quite a bit to find. “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.