Some true and alleged permotriassic conifers of Siberia and Russian platform and their alliance

Abstract

Twigs Retinosporites ? sibirica and fructifications Tomiostrobus radiatus – Araucarites tomiensis from the Lower Triassic of the Kuznetz basin were tentatively regarded as belonging to the same plants. A. tomiensis and T. radiatus yield microspores (of Aratrisporites type) and megaspores and belong to lepidophytes (Pleuromeiaceae). R. ? sibirica on gross morphological and epidermal features is ascribed to Quadrocladus. Pollen produced by these plants were of the Lueckisporites type. Quadrocladus borealis and corresponding female fructifications Sashinia borealis coming from the Uppermost Permian of the Russian platform are described. Sashinia-plants combine very primitive female fructifications and advanced male fructifications. Taxonomical and phylogenetical corollaries of these findings are discussed. The Lower Triassic flora of Siberia seems to have come from the Subangara area of the Permian.