Article: A new fern from the Lower Permian of China and its bearing on the evolution of the marattialeans
A fertile marattialean fern from the Lower Shihhotse Formation, Lower Permian of Taiyuan, north China is ascribed to a new genus, Taiyuanitheca, as T. tetralinea sp. nov. The fronds are Pecopteris-like with two rows of synangia arranged on each side of the midvein on the adaxial surface of the pinnules. The synangia are sessile and ring-like with elliptical sporangia that are fused together along their full length. The new fern is compared with fossil and extant marattialeans and new evolutionary pathways are proposed for this group of plants.