Translartion. Region: Russians Fedetion –

Source: Novosibirsk State University – Novosibirsk State University –

At the popular science marathon “Darwin Week” junior researcher of the A. A. Trofimuk Institute of Oil and Gas Geology and Geophysics of the Siberian Branch of the Russian Academy of Sciences, engineer of the scientific and educational center “Evolution of the Earth” Faculty of Geology and Geography of Novosibirsk State University, paleontologist Vsevolod Efremenko told which dinosaurs lived in Chukotka and Sakhalin, where to look for their remains and how representatives of the paleofauna adapted to life beyond the Arctic Circle. At present, it is reliably known that 12 species of dinosaurs lived in Siberia. Scientists have discovered about 30 places in Russia where their remains have been preserved to this day, but this does not mean that dinosaurs lived only in those places. It is possible that they lived everywhere, but, unfortunately, bones and teeth, and even more rarely – imprints of feathers and fur, are preserved only in certain conditions.

— Scientists very rarely find complete dinosaur skeletons. Even finding bone joints is a great success for paleontologists. In 95% of cases, they find teeth, vertebrae, bones or their fragments, parts of skulls and jaw fragments. A significant part of the finds are shells, remains of insects and other invertebrates, imprints of fish and fossil plants — in terms of biomass, they all significantly exceeded dinosaurs. In addition, for their remains to be preserved for tens of millions of years, special conditions are required, which are possible when many factors come together, which is a rather rare phenomenon. Nevertheless, all this makes our work more interesting, — said Vsevolod Efremenko.

The remains of dinosaurs should be looked for in sedimentary rocks, which are the compressed remains of ancient lakes, rivers and swamps. They are usually formed in an aquatic environment, contain fossils and are destroyed fairly quickly on the earth’s surface. The remains of prehistoric animals are not preserved in volcanic and metamorphic rocks. Success in the search for dinosaurs can be expected if it is possible to determine the places where the shores of seas, rivers or lakes, as well as swamps, used to be, and to determine the excavation sites by their contours.

At the beginning of the Cretaceous period, 145 million years ago, the position of the continents on our planet was already close to the modern one, only the oceans occupied a significantly larger area, and there were no polar ice caps in the polar region. In Siberia and Asia there was a mountainous terrain, and dinosaurs could have lived in the intermountain plains along the banks of rivers and lakes. Closer to the extinction – 66 million years ago – the continents occupied an even closer position to the modern one, and sedimentary basins are almost no longer observed in Siberia. Accordingly, there are almost no sedimentary rocks in which paleontologists can count on finds from that period. Therefore, the remains of dinosaurs of that period could not have been preserved. But in the Far East, the situation was different, so paleontologists discover very interesting finds there.

— The climate in the Cretaceous period was quite comfortable for dinosaurs — moderate in the Arctic, warm northern in Siberia, and close to subtropical in the Transbaikal Territory. This is evidenced by the climatic reconstruction made on the basis of paleoflora. Dinosaurs could easily settle throughout the territory of Eurasia, Siberia, including Chukotka and Sakhalin. Even in Antarctica, fossil birds are found that once felt quite comfortable in those places, — explained Vsevolod Efremenko.

The most ancient dinosaurs discovered in Russia lived in the Jurassic period (201-145 million years ago). In Siberia, two of their locations are known – in the Krasnoyarsk and Transbaikal regions.

The most famous dinosaur of Transbaikalia was found in the vicinity of the village of Kulinda. Scientists have named it Kulindadromeus transbaikaliensis. It lived in these places about 168 million years ago. It was a small non-avian dinosaur of modest size (about the size of an average dog) covered in feathers and scales. It combined bird and reptilian features and was most likely warm-blooded.

In the Krasnoyarsk Territory, in the vicinity of the village of Sharypovo, the remains of two dinosaurs of the Jurassic period were discovered: several bones of the predatory tyrannosaurid kilesk (a distant relative of the tyrannosaurus) and many bones of several stegosaurs, from which a whole skeleton was later assembled. Surprisingly, the bones of this herbivorous dinosaur were found among numerous shells of prehistoric turtles in a coal quarry.

— Paleontology is a very creative science. We can guess from individual bones what genus and species of dinosaur they belong to, and then reconstruct the entire skeleton. This was the case with the kileskos, which hunted stegosaurs. The remains of these ancient animals are found next to each other. But in order not to damage the priceless finds, the paleontologist must work very carefully in the excavation. Since all the bones are scattered, it is necessary to clearly record the position of each of them, so that when assembling the dinosaur skeleton, you do not end up with a chimera, — the paleontologist explained.

In the Cretaceous period (145-66 million years ago), the diversity of dinosaurs was enormous. At least a dozen sites of their remains have been discovered in Siberia. One of the largest is in the vicinity of the village of Shestakovo in the Kemerovo region. It was here that paleontologists found a large number of bones and even entire skeletons of Psittacosaurus sibirica, a small dinosaur that lived here 125-100 million years ago. The remains of the sauropod Sibirotitan were also found at this location — large cervical vertebrae. These 20-ton giants shared this territory with Psittacosaurus, as well as the recently discovered Ceratosaurus kiyakursor. It was a very mobile, long-legged, small dinosaur. Scientists have found parts of its skeleton — the humerus, cervical vertebrae, a fragment of the girdle of the forelimb, as well as the bones of the hind limb in anatomical articulation. Unfortunately, neither the skull nor its parts were found, and scientists cannot yet say with complete certainty whether this dinosaur was a predator or a herbivore.

The northernmost dinosaur site is Teete in the Republic of Sakha (Yakutia). During the Cretaceous period, the climate here was warm and mild. Here, paleontologists have discovered stegosaurid teeth and vertebrae, as well as sauropod teeth.

— Over three field seasons, expedition members collected a rich collection of teeth and vertebrae of small therapsids and salamanders. Remains of turtles, fish, lizards and extinct reptiles were also found. Surprisingly, this territory is a refugium — a region where species of ancient animals that have already become extinct in other places have survived for a long time, — said Vsevolod Efremenko.

The scientist also spoke about other paleontological finds indicating that dinosaurs lived in Chukotka, Sakhalin and the Far East. Herbivorous duck-billed hadrosaurs lived in Chukotka, as well as ceratopsians – it was previously believed that they inhabited only North America. Eggshells were also found, which means that dinosaurs did not end up in the polar latitudes as a result of migration. They constantly lived and reproduced in these places.

Many significant finds were made in Blagoveshchensk in the Far East. One of the most striking is the duck-billed dinosaur Olorotitan. The uniqueness of the find was that at the time of its discovery it was the most complete articulated dinosaur skeleton discovered in Russia. Its body length was approximately 8 meters, height – 3.5 meters, and weight could reach 3 tons.

The richest finds were made in the Transbaikal Territory. They belong to the Jehol biota – these are fossil remains of feathered dinosaurs, birds, mammals and plants, which are found in large quantities in the Lower Cretaceous deposits of North-Eastern China. So far, these unique locations of ancient fauna have not been fully studied and, according to Vsevolod Efremenko, there is enough work for many generations of paleontologists.

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