The ginkgophytes from the German Kupferschiefer (Permian), with considerations on the taxonomic history and use of Baiera and Sphenobaiera

Abstract

Ginkgophyte foliage fossils (impressions and compressions lacking cuticle) from several of the historical Kupferschiefer localities in Germany have been re-studied using macromorphometry. Baiera digitata is by far the most common ginkgophyte in the Kupferschiefer, while other taxa are relatively rare.Anew taxon, for which the name Baiera mansfeldensis is proposed, differs from B. digitata in having a much thinner, curved petiole and a curved lamina, as well as a narrow basal angle. Esterella gracilis, a taxon previously known exclusively from France, is reported for the first time from Germany. The foliage genera Baiera and Sphenobaiera have a complicated taxonomic history, and the problematic contiguity that exists between the two taxa has lead to considerable confusion. It appears that the radiation of the ginkgophytes started well before the end-Permian mass-extinction, and that Permian ginkgophytes were more diverse than previously believed.