Early Occurrence of a Pennsylvanian-Age Medullosalean Frond Similar to Alethopteris Pseudograndinioides in the Intra-Montane Basin of Bohemia

Abstract

A single frond fragment found in the lower Bolsovian Substage of Central and Western Bohemia (the Czech Republic) closely resembles Alethopteris pseudograndinioides Zodrow et Cleal, a species not normally seen until rather younger, late Asturian floras. This discovery provides further evidence that some of the species that suddenly proliferated in mid-Asturian times in response to climate and/or landscape changes, originated in the upland vegetation of the Variscan Mountains.