New data about three sphenophylls and their spores from the volcanic tuff of Wuda, Taiyuan Formation, earliest Permian, China

Abstract

A new species Sphenophyllum parvifolium sp. nov. is proposed for a whole plant based on organically connected leafy shoots and cones from the Wuda locality, Inner Mongolia, North China. The most characteristic feature is the sporangiophore with lanceolate expansions bearing sporangia. Cones were studied morphologically, including cuticles and in situ spores. Cones yielded monolete spores of the Laevigatosporites or Latosporites type. Other sphenophylls from this locality include Sphenophyllum cf. oblongifolium and Sphenophyllum cf. angustifolium, both with associated cones yielding in situ spores of the same type as Sphenophyllum parvifolium, and sterile specimens of Sphenophyllum kawasakii. Some foliated axes of this type bear cones, but without in situ spores. Hook-like structures at the ends of leaf lobes of these Sphenophyllum species could have enabled the plants to climb. All species are from a volcanic tuff bed, between coal seams Nos. 6. and 7 in the Wuda Coalfield. The age of the plant-bearing tuff in the Taiyuan Formation is 298.34 ± 0.09 Ma (Asselian, earliest Permian).