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

A Palaeozoic gleicheniaceous fernOligocarpia 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 theSphenopteris 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 genusLeiotriletes. Comparisons are made betweenO. kepingensis and other species ofOligocarpia in the soral organization and spores. It is reasonable to includeOligocarpia in Gleicheniaceae based on its similarities of fertile character to the extant gleicheniaceous members.