Scientists have found in Argentina giant dinosaur first
Jul 12 2018
It also showed that there were different ways giant dinosaurs evolved. The newly discovered fossils make revelations about the evolving of the giant ones many million years ago than thought of.
The earlier understanding of dinosaur existence was said to be 180 million years ago, which this discovery dismisses.
Dr Apaldetti, of the National University of San Juan, said they weighed in at an estimated seven to 10 tonnes.
They were discovered in a dinosaur "nest" unearthed at a World Heritage site known for its fossils in Argentina's north western San Juan province.
Sauropods were the first successful group of herbivorous dinosaurs, dominating most terrestrial ecosystems for more than 140 million years, from the Late Triassic to Late Cretaceous.
Giant dinosaurs lived on Earth nearly 30 million years earlier than previously thought, according to a team of paleontologists in Argentina, who unearthed fossils of the earliest-known giant dinosaur.
An improved respiratory system and modifications to the vertebral musculature and hind limbs were key factors to the giant growth spurt, theorize the researchers.
Unlike later sauropods, Ingentia's legs were not pillar-like and its neck was shorter.
What is really unexpected is that the lessemsaurids achieved their huge bodies independently of the very big sauropods like Brontosaurus and Diplodocus, which did indeed evolve later during the Jurassic.
"The evolution from small bipedal to giant quadrupedal sauropodomorphs involved numerous anatomical changes", the researchers wrote in their study. Called the Ingenia prima, this dinosaur was thrice the dimensions of the bulkiest of Triassic dinosaurs. This way of growing was widespread amongst the dinosaurs of that era, but excluding Ingentia prima, no other species reached more than three meters in length while weighting around 1.8 tones. It was at least twice as large as the other plant-eaters that shared the warm, savannah environment it inhabited.
They included shoulder blades, cervical vertebrae and bones from the forelimbs, feet and skull of the four dinosaurs.
Like dinosaurs that lived later, it had bird-like air sacs, which may have been needed to keep large animals cool and supply large amounts of oxygen.
While later giant dinosaurs grew in an accelerated yet continuous manner, an examination of its bones showed that Ingentia grew seasonally rather than continuously, but at an even higher rate.