Home – Home – Jornals – Geography and Natural Resources 2023 number 5S

An analysis is made of the paleogeographical distribution of Coniopteris ferns in Europe, Central Asia and Siberia over the course of seven ages (from the Gettangian to the Bathonian) of the Early and Middle Jurassic. It has been established that in the Gettangian the Coniopteris had a wide distribution from Europe to Southern Siberia. This may be indicative of its late Triassic origin. It is shown that in the Early Jurassic, the centers of evolution of the genus were located in the Siberian paleofloristic region: in the Hettangian and Sinemurian in the Ural subprovince, and in the Pliensbachian and Toarcian in the Cis-Yenisei subprovince. Particular attention is paid to the distribution of Coniopteris during the Early Toarcian climatic optimum. It has been established that due to climate warming, the center of evolution of the genus had shifted toward the north, i. e. to Western Siberia, and migrants from Europe and Central Asia (Coniopteris burejensis, C. maakiana, and C. murrayana) appeared in the Cis-Yenisei and Angara-Vilyui subprovinces. The main migration route could pass through the Turgai trough which connected Siberia and Central Asia. It was revealed that the C. kirgisika, C. latifolia, C. nerifolia, C. porcina, C. pulcherrima, C. spectabilis and C. zindanensis species first appear in the Pliensbachian in the Cis-Yenisei subprovince and penetrated into Central Asia no earlier than the Aalenian. Thus these ferns cannot be considered as indicators of the Early Toarcian warming in the territory of the Siberian region, and their appearance in the Aalenian in Central Asia should be regarded as evidence of a cooling. It has been established that the most dynamic processes of migration and extinction of Coniopteris species manifested themselves in the north of the Siberian paleofloristic region (Angara-Vilyui subprovince) where climate change had the most dramatic effect.