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Динозавры притворялись дикобразамиBrowsing the richest collection of Harvard University, American paleontologists have discovered the remains of an interesting dinosaur from South Africa, which ran on our planet 200 million years ago. This creature (it was somewhat larger cat) had a thin and stiff feathers, which could toporets and give reptiles similarity with a hedgehog.

Somehow it so happened that a medium-sized dinosaurs creators of popular science books and films do not pay special attention is more concerned with giant forms. And that is perfectly in vain - because "kids" were far more diverse and more original giants, basically similar to each other as two drops of water. It is in the small little dinosaurs can be traced and alternative development group, which never materialized, and funny evolutionary parallel, and non-standard behavioral and environmental strategy.

However, until recently, the heterodontosaurs (Heterodontosauridae, on the Russian language the name is translated as "pangolins with different teeth"), living on our planet from 200 to 112 million years ago, was known mostly to specialists. However, it was caused by the fact that before the beginning of the XXI century, the remains of the representatives of this family were found not often. In addition, there were large gaps in the fossil record of early plated ornithischians ? dinosaurs, there was not enough finds other members of the detachment, which made it difficult for precise identification of fossils (for which you want to compare the remains).

However, after 2001, all has changed: just over ten years there were found a lot of bones and prints of heterodontosaurus, not only in South Africa, where their first and only found, but in North America and China. The result was much to learn about these interesting animals, which are one of the most primitive dinosaurs. In particular, it was established that for all the representatives of the family was typical present "tooth variety" - besides the usual conical teeth that these dinosaurs had four great fangs, as well as several flattened cutters. And this despite the fact that garantizara, like most early dinosaurs, kept the Horny beak!

Strictly speaking, recently discovered in Museum collections at Harvard University Pegomastax africanus, who lived in the South of the Black continent, as all his relatives, was very toothy. Paleontologist Paul Sereno of the University of Chicago, who is a specialist in this group, notes that this kid whose length was about 60 centimeters and a weight of 3-4 kg, was a typical representative of heterodontosaurus. The shape of the skull and short beak of this dinosaur make it more like a parrot, but full similarity "hinder" four big Fang, located right at the base of the beak, and many cutters.

Sereno tried to find out the purpose of these tusks, which, according to him, betray reptiles similarity "with a small vampire". For this he had to study the shape and pattern of macrocarpon and cracks on the surface of the tooth enamel. The researcher was looking for in the first place particles of silicon - they were kept in cells dominated then horsetails, ferns and ancient gymnosperms. And if they can be found on the teeth inhabitant of a distant epoch, we can safely say that he was a vegetarian. And if not - then say with confidence that the reptile was predatory or loved carrion.

Held under the scanning electron microscope analysis showed that, first, particles of silicon there, and, secondly, - the scars fangs dinosaur were very similar to the teeth of a water Olenka (the so-called small artiodactyls mammal from tropical Africa). Apparently, Pegomastax africanus used his long front teeth to cut the leaves and stems of plants and digging out the roots - that is, to earn his food as well as now it is done olen'ka. From this we can conclude that the small reptile had a rather peaceful nature.

Interestingly, there is a very unusual parallel with the evolution of therapsid (Therapsida) - just another branch of reptiles, from which later occurred mammals. These creatures, which appeared in Permian period, that is 90 million years earlier than Pegomastax africanus (who lived 200 million years ago) and his relatives, had a similar differentiation of teeth. They were also four large Fang and several cutters, which helped not only predatory, but herbivores representatives of this group to find food. It turns out that two completely unrelated groups of reptiles, separated by the same big time interval, "enjoyed" one and the same device.

The similarity Pegomastax africanus with therapsids is caused also by the fact that the latter already had relatively rare hair (their skin is not carried scales), and heterodontosaurs was covered by a long and narrow feathers, reminiscent of porcupine quills (but it still had feathers). Moreover, they also do not form a continuous cover, so it is unlikely that the kid used them as insulation that was true for small dinosaurs deprived of inertial teplokrovnosti (that is, read the article "Scientists have managed to paint dinosaur"). But for what it was then need this "urchin sobaka"?

Mr., Sorano draws attention to the fact that a: "In the excited state this "bristles" visually increase P. аfricanus. However, judging by the long lower limbs, the primary defense mechanism of the animal was fleeing". That is, to all appearances, this cover is just scaring potential enemy raising their feathers, dinosaur seemed to be two to three times more than it was in reality. And many predators similar size was reluctant to attack so great (and actually very tricky) production.

But the most interesting that the reaction of raising the wool when frightened (the same: "hair stood on end") is characteristic for therapsid and their descendants, that is, mammals! That is before us another convergent (not due to kinship) the similarity of the two groups of animals. It seems that such a protection strategy was typical of many small animals era of the dinosaurs, which could not afford "let" a more effective means of protection (in the form of huge teeth, claws and tails).

It is also interesting to imagine and then, from whom Pegomastax africanus defended this way. Hardly from large dinosaurs - they probably just didn't pay attention to such a trifle. Therefore, "urchin sobaka" helped the lizard to scare their children and... primitive mammals, which by that time already existed and were about the same size as the baby-heterodontosaurs. That is, this lizard used against the descendants of therapsid-a weapon that first time, "developed" of their ancestors.

Interestingly, seems like "decoration" was not only this dinosaur - in the spring of this year, Chinese paleontologists have found in the North of China lizard, which they called Tianyulong confucius (literally: "dragon Confucia from a place Tianyu"). Now, this serpent, which was not much larger P. africanus, also had a similar pen cover. Perhaps this "coat" was typical of all heterodontosaurus, just before the prints of feathers was difficult to identify (and they were not always).

So this interesting group "dinosaurs-urchins" lasted until the middle of chalk, with an especially large representatives was not among them (a maximum of two metres in length, that of the dinosaurs, you know, it is not the size). However, about 110 million years ago they disappeared without a trace. Apparently, this was associated with the emergence of advanced mammals, which replaced the cold-blooded heterodontosaurus from all their habitat (the similarity in size suggests that they existed in the same ecological niches). And from this scourge ancient reptiles could not save even their wonderful "urchin sobaka", as well as the habit of lifting "hair standing"...
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