Analysis printed at this time within the peer-reviewed Journal of Vertebrate Paleontology describes a newly found species of dinosaur — named the ‘one who causes worry’, or Llukalkan aliocranianus.
Round 80 million years in the past as tyrannosaurs dominated the Northern Hemisphere, this lookalike was certainly one of 10 presently identified species of abelisaurids flourishing within the southern continents.
A fearsome killer, Llukalkan was “seemingly among the many prime 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, large claws of their ft and their eager sense of odor.
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 totally different to different abelisaurids. The make-up of its cranium suggests this was higher than many of the different abelisaurids and much like that of modern-day crocodiles.
Its full title comes from the native Mapuche for ‘one who causes worry’ — Llukalkan, and the Latin for ‘totally different cranium’ — aliocranianus.
It lived in the identical small space and time period as one other species of furileusaurian (stiff-backed lizard) abelisaurid — Viavenator exxoni — just some million years earlier than the tip of the age of dinosaurs.
Fossil stays of Llukalkan and Viavenator had been discovered simply 700m aside within the Bajo de la Carpa Formation, close to the identical well-known fossil website at La Invernada, in Argentina.
“This can be a notably essential discovery as a result of it means that the range and abundance of abelisaurids had been exceptional, not solely throughout Patagonia, but additionally in additional native areas through the dinosaurs’ twilight interval,” says lead writer Dr Federico Gianechini, a paleontologist on the Nationwide College of San Luis, Argentina.
Abelisauridae had been a putting 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 this time as Africa, India, Antarctica, Australia, and South America. So far, nearly 10 species of this fearsome predator have been unearthed throughout Patagonia. Whereas abelisaurids resembled T-Rex normally look with tiny stubby arms, that they had unusually quick, deep skulls which frequently bore crests, bumps, and horns, and had been distinctive.
Transferring upright on their hind limbs with large claws that they could have used to stab their prey, Llukalkan had extraordinarily highly effective bites and really sharp tooth with which to tear down their prey whereas shifting quick because of their highly effective hind legs.
The fossilised stays of Llukalkan embody a wonderfully preserved and uncrushed braincase. This new species is analogous in lots of respects to Viavenator, besides that it’s smaller, the holes within the cranium by which the veins cross are bigger and extra extensively separated from the supraoccipital crest (one of many bones that kinds the braincase), amongst different variations. However 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 to this point.
It implies that Llukalkan seemingly heard in another way 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 discovering implies a distinct listening to adaptation from different abelisaurids, and certain a keener sense of listening to,” says Dr Mendez.
Nonetheless it might have lived, the fossil proof of Llukalkan‘s diversifications means that abelisaurids had been flourishing proper earlier than the dinosaurs went extinct.
“These dinosaurs had been nonetheless making an attempt out new evolutionary pathways and quickly diversifying proper earlier than they died out utterly,” provides Mendez.
Regardless of their important discovering there may be nonetheless rather a lot to find. “This discovery additionally means that there are seemingly extra abelisaurid on the market that we simply have not discovered but, so we can be searching for different new species and a greater understanding of the connection amongst furilesaurs,” says Gianechini.