Oligocarpia kepingensis sp nov from the Lower Permian of the northern Tarim Basin, Xinjiang and its in situ spores

A Palaeozoic gleicheniaceous fern Oligocarpia kepingensis sp, nov. Is described from the Lower Permian of the northern Tarim Basin, Xinjiang, China. The material comprises fertile organs including sori, sporangia, spores and associated sterile leaf of the Sphenopteris type. The sori are circular and 0.6-0.8 mm in diameter, and each sorus consists of 4-6 oval sporangia without an indusium. A transverse annulus completely encircles the sporangium. Each sporangium produces probably 256 trilete spores resembling the dispersed genus Leiotriletes, Comparisons are made between O. kepingensis and other species of Oligocarpia In the soral organization and spores. it is reasonable to include Oligocarpia in Gleicheniaceae based on its similarities of fertile character to the extant gleicheniaceous members.