A research associate of Novosibirsk State University and Institute of oil and gas geology and geophysics of Trofimuk of the Siberian Branch of the Russian Academy of Science Igor Kosenko has proved that in the territory of present Yakutia there were tropical seas 145 million years ago.
Kosenko has found remains of ancient oysters on the coast of the northern Yakut rivers which became the main evidence proving the "warm" past of our Siberia.
Found oysters used to inhabit the territory of modern Yakutia in the late Jurassic-early Cretaceous periods. Their strong calcite shells are sturdy against processes and the phenomena which occur after their formation.
It has become clear that at the time of dinosaurs the temperature in water areas of modern northern Siberia was comparable to the water temperature in the Black Sea — +18... 20 degrees Celsius.