Pseudoctenis DISCOVERED FROM THE LOWER JURASSIC HONGQI FORMATION IN JILIN PROVINCE

The Lower Jurassic Hongqi Formation, distributed mainly in Wanbao Basin of the southeastern Daxinganling Mountains in Taonan, Jilin Province, is predominately composed of coal-bearing clastic sedimentary rocks, overlying the tuffs of the Middle Permian Dashizai Formation with unconformity, and in turn overlain disconformably by the basal conglomerates of the Middle Jurassic Wanbao Formation, representing lacustrine and swamp facies developed on a local intermontane fault basin. In 1982, Yang Xuelin and Sun Liwen first reported fossil flora with occasional occurrence of Cycadophytes from Hongqi Formation. Recently, several fossil leaves of Pseudoctenis eathiensis, associated with Phoenicopsis and Anomozamites, etc. were discovered from Hongqi Formation. Although Neocalamites, Cladophlebis, Pseudoctenis, Anomozamites, Czekanowskia, Podozamites and Pityophyllum are comparable with the Early Jurassic fossil plants from the northeastern border of Qaidam Basin in Qinghai, Cycadophytes including Pseudoctenis and Anomozamites are actually not abundant, indicating that the characteristics of Continental Floristic Province under the control of warm temperate to "paratropical" climate are quite different from those of Maritime Floristic Province under the control of tropical climate, which is characterized by abundant Cycadophytes.