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 Explore the American scientists team A team of American scientists concluded that dinosaurs descended from giant carnivorous species such as tyrannosaurs, which were born as small as kittens and grow into giant creatures, were changing their environment by eliminating smaller species. The study, the results of which was recently published in the journal Science, helps solve an ancient mystery about a period in which dinosaurs dominated for about 150 million years : Why were there so many more large species than small ones, while the opposite is true for terrestrial animals today. In the entirety of the Mesozoic era, from 252 million years ago to 66 million years ago, there were relatively no longer any large species of dinosaurs weighing more than a ton compared to those weighing less than 60 kilograms. According to some scientists, the larger species of dinosaurs that start their lives are also very small in size because they from in eggs before birth, may exploit the resources o...

 Photos of Mars 2021 The US Space Agency ( NASA) published new pictures of the arrival of its '' Perseverance'' spacecraft the day before to Mars , in which the mobile robot appeared suspended two meters above the surface of the Red Planet immediately before landing on it. The robot was slowly placed on the surface of Mars during the final stage of the operation , that is, in the last 20 meters, as it was suspended by 3 wires dangling from the landing craft equipped with 8 retarder missiles that slowed the landing. The picture was taken from the bottom of the landing craft, and it shows the top of the mobile robot, its six wheels, and below the surface of Mars. Another image of the landing process was shown immediately before this stage, taken by the MRO probe, which is located in the orbit of Mars. When enlarged, it can see the mobile robot protected by a capsule entering the atmosphere, and its speed was slowed by the bulge of a huge hypersonic umbrella. And observed ...