A new species of Ashicaulis (Osmundaceae) from the Mesozoic of China: A close relative of living Osmunda claystoniana L.

► Morphospecies Ashicaulis claystoniites sp. nov. is the first Mesozoic taxon close to living Osmunda claytoniana L. ► Morphological and anatomical features of living Osmunda claytoniana L. have changed little since the Mesozoic. ► The ancestor of Osmunda claytoniana L. might originate in Gondwana and then expand into Laurasia.