Предлагаем восстановить, заказать, купить диплом Вуза в любом городе России. Только настоящий бланк ГОЗНАК с гарантией.
Viewings: 4879Recently a group of American palaeontologists have discovered the most ancient dinosaur in the world, which is jokingly called "the grandfather of all dinosaur". This reptile lived on the territory of modern Tanzania 245-242 million years ago. In the end, all age groups "lengthenedy 10 million years, and it became clear that the dinosaurs originated in Africa.
About where and when the first dinosaurs, say not so easy. In principle, exactly paleontologists can say only one thing - the dinosaurs as it appeared in the Triassic. Apparently, their ancestors were so interesting pangolins, as Ornithodira. They already cheerfully ran on land on two hind legs, and this property was key to the evolution of dinosaurs, because all "terrible lizards" the source were bipedality - chetveronogo some of them are secondary. More like their descendants of reptiles arnitidine Marasuchus and Lagerpeton who lived in South America in the middle Triassic.
These lizards, claiming ancestors, and of paleontologists led to the idea that primitive dinosaurs need to look there. Indeed, until recently, all the most ancient remains of dinosaurs were found on this continent, which is exactly on the plains prehistoric Argentina 230 million years ago sported two tiny (about 1 meter long and 40-50 cm in height) of the dinosaur species Eoraptor and Eodromaeus. That is already present dinosaurs, scientists do not doubt - data reptiles had every set of features inherent "terrible lizards".
It turns out, dinosaurs origin - "Hispanics", and they appeared somewhere 230 million years ago? Until recently the majority of paleontologists felt this version is the most correct, though there were those who insisted on the South African origin of these reptiles. The fact that two years ago sterling Nesbitt from the University of Washington (USA) and his colleagues have found in Tanzania 14 skeletons reptiles that lived there 242-245 million years ago, which was first considered a dinosaur. However, it later emerged that Asilisaurus (so called lizard) all the same was not - he was the representative of the previously mentioned groups Ornithodira , which was the ancestor for "terrible lizards".
However, paleontologists immediately thought that if Africa were initdir, that, probably, and dinosaurs was available too. However, to prove it was not easy - the most ancient representative of the African "terrible lizards" Lesothosaurus diagnosticus, size is not much greater than his South American counterparts, ran around the Black continent much later - somewhere 200-198 million years ago. Doubts continued up until the beginning of December of the current year all the same Dr. Nesbitt and his colleagues did not find much more ancient and primitive resident of the African continent, which already had all the signs of a real dinosaur.
Interestingly, they found that "grandfather dinosaur" quite a long time ago - in the early 30-ies of the last century British paleontologist Francis Parrington found in Tanzanian Manda formation (by the way, there later and found the remains of Asilisaurus) bone of the forelimb and several vertebrae belonging unknown reptile. The age of this creature was 242-245 million years. The remains were thoroughly studied and described his colleague Alan CARICOM, who called the lizard Nyasasaurus parrington, but decided that was not a dinosaur, and a representative of the same infodir. Later were found and other remains of the creature, but none of paleontologists engaged in their study, also did not suspect that this is a "accessories" dinosaur.
And recently, a group of Sterling Nesbitt conducted the most comprehensive analysis of the bones of this reptile. The scientists compared the material Dariga with bones Nyasasaurus of the South African Museum in Cape town, as well as other dinosaurs and their relatives. In the end, they found something that didn't pay attention to their predecessors, namely the creature possessed almost all the signs inherent in these dinosaurs. So, it was able to establish that Nyasasaurus had a wide bone ridge at the edge of the shoulder, which had joined the chest muscles of the animal and the ridge is more than 30 percent of the length of the bone. Such by virtually all of the dinosaurs, but arnitidine like "decoration" did not possess. It is also notable that in his rump there are three vertebrae, while arnitidine had only two.
In addition, microscopic examination of the bones of the front limbs, made under the guidance of Sary Warning from the University of California, Berkeley, showed that the animal was growing very quickly - it is also the hallmark of the dinosaurs. "Bone Nyasasaurus 100 percent matches what is typical for other members of the superorder of the dinosaurs. We came across a good example of the so-called "transitional fossils" - fabric structure suggests that this lizard grown as fast as other primitive dinosaurs, but somewhat slower than later members of the group" - says Ms. Warning.
And this is a very characteristic feature is known that arnitidine and other relatives "terrible lizards" after hatching from the egg grew very slowly (by the way, this is why most are immature individuals of these groups), but their descendants, barely after breaking the shell, started to grow not on days, and on hours. Perhaps this property was one of those that provided the dinosaurs dominant position among other reptiles hundreds of millions of years - the one, who quickly become an adult, earlier is necessary ecological niche than "brake" competitors. Interestingly, then it is likely led to the victory of birds and mammals - these beings also differ very fast growth.
"Regardless of whether Nacozari really dinosaurs or just their immediate families, our discovery is revolutionary for paleontology with all the ensuing consequences. First, it was proved that dinosaurs appeared much earlier, than was considered before. In addition, now have a reason to question the traditional hypothesis that dinosaurs survived "evolutionary boom" at the end of the Triassic - it does not fit the character of the evolution of other animals at the time," says study leader Dr. Nesbitt.
How looked newly "grandfather of all dinosaur"? It is assumed that it was large enough to Triassic reptiles being: its length was three meters, the height is slightly more than a meter and a weight of 30 to 60 kilograms. Like all dinosaur-like dinosaurs, he moved on two hind legs and the front legs of reptiles have been shortened. Because the teeth and jaw fragments were not found, it is difficult to say, what did I eat Nyasasaurus, however, we can assume that he was a predator or a scavenger - plant-eating dinosaurs appeared much later, in the Jurassic period. No mass findings suggests that this reptile was led by a single, possibly family, but not a gregarious way of life.
So, it seems, the homeland of the dinosaurs still should be considered as South Africa. However, in those times this continent like South America, was part of a giant new supercontinent of Pangaea, therefore, it is still impossible Nyasasaurus could appear on the South American lands, and then migrate to Africa (and also, for example, come back from Australia, or Antarctica). So surely can say only, that the first "terrible lizards" appeared 245 million years ago in the far South of the then terrestrial land.
You are reading news Дедушка динозавров был родом с юга if You liked the article Дедушка динозавров был родом с юга, prokomentiruet her.