Home – Home – Jornals – Russian Geology and Geophysics 2002 number 2

The fauna of Mesozoic epicontinental seas that existed on the territory of the present-day Arctic margin of Eurasia, North America, and islands in the Arctic Ocean is dominated by stenohaline mollusks (ammonoids, coleoids, bivalves, gastropods, brachiopods, foraminifers, ostracods, radiolarians, etc.). The marine biota consists of cosmopolitan taxa of the boreal Pacific and boreal Atlantic origin, Tethyan immigrants, and endemics, including hundreds of endemic species, tens of endemic genera, and six endemic families. Numerous lines of invertebrates in the Arctic basin evolved sustainably for tens of millions of years. The high taxonomic diversity of the specific marine biota and the ways of its panboreal migration could have been maintained by an oceanic basin that existed on the territory of the present-day Arctic throughout the Mesozoic, as a great volume of oceanic water was necessary to provide stable salinity and temperature in the surrounding epicontinental basins through 180 Ma.
Long and sustainable development of the specific Mesozoic marine biota was provided by the South Anyui ocean in Triassic and Jurassic time and by the Amerasian ocean in the Cretaceous. This evidence substantiates the hypothesis of the presence of oceans in the Arctic territory through the Mesozoic which was suggested proceeding from geodynamic reconstructions.