Home – Home – Jornals – Russian Geology and Geophysics 2018 number Неопубликованное

Identification of patterns of geographic differentiation of individual groups of marine invertebrate fauna in the geological past is important for understanding their evolutionary history, solving issues and problems of biostratigraphic subdivision and correlation of deposits. Paleobiogeographic data are also necessary to identify the stages of development of biota and the geological history of marine paleobasins and to verify paleogeodynamic reconstructions. In this work, taking into account the latest data on paleontology and biostratigraphy of the Boreal Triassic, the taxonomic composition and distribution of Upper Anisian ammonoids in various regions of the Boreal region are revised. A correlation of Upper Anisian deposits of Northeast Asia, British Columbia, Arctic Canada, Svalbard, Franz Josef Land and Khabarovsk Territory was carried out at the zonal level and a basis was obtained for a comparative analysis of coeval ammonoid faunas. As a result of a qualitative and quantitative comparative analysis of ammonoid complexes for various chrons of the Late Anisian, it was established that in the Late Anisian, British Columbia was constantly part of the Canadian province of the Boreal region, and Northeast Asia was part of the Siberian province. At the end of the Late Anisian (most of the late part of the Frechites nevadanus or Frechites chischa chrons), provincial differences were smoothed out and for the first time all Boreal regions were included in the Siberian province, with the exception of the territory of British Columbia. Analysis of the geographical distribution of some groups of ammonoids in the Late Anisian and changes in the areas of taxa over time made it possible to identify probable migration routes of Longobarditidae (genus Longobardites) and to introduce significant changes in the ideas about the centers of origin and migration of some Beyrichitidae.