New dinosaur fossil pushes the evolution of gigantism among sauropods 30 million years – Science News



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Think of a dinosaur that feeds on plants, and chances are you imagine something like a brachiosaur.

Key Points:

  • Dinosaur fossils, including a new species, were unearthed in Argentina
  • Fossilized remains suggest that the gigantism of dinosaurs emerged at the end of the Triassic, there are 205 million dinosaurs
  • The iconic geologists belonged to a group of dinosaurs called sauropods – massive creatures with thick legs looking like columns and a long neck and a long tail

    the discovery of a new species Dinosaurs suggest that the gigantism of sauropods has evolved about 30 million years earlier than expected.

    The newly discovered bones, belonging to a plant eater nicknamed Ingentia prima, also suggest two different ways, these giant dinosaurs evolved

    The discovery of fossils was unveiled today. in Nature Ecology and Evolution by an Argentine crew led by the paleontologist of the National University of San Juan. Cecilia Apaldetti

    "We are rethinking the evolution of giant size in dinosaurs," says Dr. Apaldetti.

    Most paleontologists believe that sauropod dinosaurs first appeared in the Jurassic, starting with Vulcanodon 11 meters. There are about 180 million years

    The discovery of Ingentia prima – a dinosaur that existed about 205 million years ago and which measured about 8-10 meters from long – questioned this idea

    . the new dinosaur walked on two legs or four, and was a sauropod at all, is subject to debate.

    Big dino haul

    The history of Ingentia prima begins with a breeder in northern Argentina "He has [told the local museum]," I saw bones inside rocks but they do not seem to come from cows, "says Dr. Apaldetti.

    When she and her colleagues went to see them, they found a rich mine of fossils dating from the Triassic and Jurassic, that is from 190 to 21 years ago

    Today, the region is dry and bushy, but at a time when fossilized specimens lived and breathed animals, it is part of the supercontinent Pangea.

    Being close to the equator, the climate was warm with periodic rains, says Dr. Apaldetti: "Something similar to a current savannah.a large amount of shrubs to satisfy the large herbivores of this time. "

    Among the fossilized remains, in 2015, they found a new species of dinosaur – Ingentia prima – alongside other previously known relatives called Lessemsaurus sauropoides .

    Weighing between 7 and 10 tons, the two dinosaurs sported a long neck and a long tail, as well as air sacs in their bodies, as did the sauropods

    The air sacs are supposed to help keep the massive beasts cool.

    But unlike their more recent four-legged counterparts Ingentia prima appeared to stand on bent feet

    Their bones also showed signs of seasonal growth, also different from what paleontologists think that sauropods grew later. 19659008] Dinosaurs such as Brachiosaurus, says Dr. Apaldetti, have probably grown at a fairly fast but steady pace.

    The bones of Ingentia prima show that they grew even faster, but slowed down to others. "With this discovery, we can see that the first steps towards gigantism occurred 30 million years before the giants virtually dominated the entire planet," said Dr. Apaldetti

    . not necessarily involved the same anatomy The technical changes that all the other giants such as titanosaurs required. "

    Four legs or two?

    But Steve Salisbury, paleontologist at the University of Queensland who was not involved in the study, is not convinced that ]] Ingentia prima was a sauropod

    Rather than walking on all fours, he suspects that they probably walked on both.

    "Dinosaurs similar to Ingentia prima are generally called "basal sauropodomorphs, that is to say that they are on the side of the dinosaur family tree that includes sauropods, but they are not there yet. "

    " Most basal sauropodomorphs are thought to have walked on their hind legs. Eating cousins, theropods, but had a long neck and ate plants, like their descendants, the sauropods. "

    The new fossil was missing some vital bones, such as Ingentia prima from the hip, thigh bone and most of the lower leg.

    Without them, Dr. S Alisbury says , it is difficult to evaluate the posture of the animal.

    And on the basis of the few bones reported in the article, "the hand of Ingentia prima does not seem not ideal for planting. "

    " They do not have much skeleton and, overall, the pieces therein are not so different from other basal sauropodomorphs. "

    So Ingentia could have gotten on all fours, but probably spent most of his time on two legs – much like another basal sauropodomorph who lived 210 million years ago Plateosaurus engelhardti which is known to be much more complete Although Ingentia prima resembe to a great sauropodomorphic base, unfortunately, they are not enough in this article to make it look too different from something like Plateosaurus engelhardti, and it's about right. agree that it was bipedal, "he knows d)

    " If that's the case, the move to four-legged locomotion must have taken place later. "

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