Earliest Triassic (Induan) spores and pollen from the Junggar Basin, Xinjiang, northwestern China

Permian-Triassic boundary strata cropping out in the southern Junggar Basin contain a continuous and varied fossil record, making this fluvio-lacustri ne succession a potential candidate for a non-marine boundary stratotype. A bundant, diverse and well preserved miospores an recorded and illustrated f rom the upper part of the Guodikeng Formation and the basal part of the Jiu caiyuan Formation, comprising 92 species and 48 genera, as well as some acr itarchs. Seven new species (Anapiculatisporites decorus Ouyang et Norris, s p. nov., Baculatisporites uniformis Ouyang et Norris, sp. nov., Kraeuselisp orites varius Ouyang et Norris, sp. nov., Lapposisporites echinatus Ouyang et Norris, sp. nov., Klausipollenites angustus Shu et Norris, sp. nov., Ali sporites exilis Ouyang et Norris, sp. nov., Pilasporites perreticulatus Ouy ang et Norris, sp. nov.) and 8 new combinations are proposed. Pteridophytic spores and gymnospermous pollen are almost equally diverse, comprising 45 species in 20 genera, and 43 species in 25 genera, respectively. Pteridophy tes are numerically more important, notably Limatulasporites, Kraeuselispor ites, Lundbladispora, Anapiculatisporites and Verrucosisporites, but also p rominent are bisaccate pollen of Falcisporites, Klausipollenites and Alispo rites. Less abundant taeniate pollen are largely bisaccate. These palynoflo ras are grouped together as the Lundbladispora-Lunatisporites-Aratrisporite s Assemblage, argued to be Early Triassic (early Induan), and comprising bo th newly evolved Mesozoic taxa (herbaceous and shrubby lycopsids, coniferou s trees, pteridosperms) and relict Paleozoic taxa (sphenophyllids, cordaita leans and possibly Paleozoic lycopods). The lower boundary of the Triassic in the section is redrawn somewhat lower than by previous authors. The tran sitional nature of the Permian-Triassic palynofloras and of the paleophytop rovinces is discussed; neither indicates a sudden catastrophic event affect ing terrestrial floras at the P-T boundary on a global scale. The Early Tri assic vegetation appears to have grown under humid sub-tropical conditions in lowland flood plains and marshes dominated by hydrophilous and mesophilo us pteridophytes and pteridosperms, but with locally drier upland environme nts supporting xerophilous and mesophilous conifers and pteridosperms. The Induan vegetation is closely comparable to that of the Angara, especially t he Subangara Province, although it contains some elements of the Euramerica n Province in association with a few Gondwanan, Cathaysian and cosmopolitan taxa. (C) 1999 Elsevier Science B.V. All rights measured.