Silicified fern-like plant from the upper Turonian of Vienne, western France
Résumé
A new locality with silicified permineralized plant megafossils is reported from the upper Turonian of Vienne, Aquitaine-Limousin-Poitou-Charentes, western France. Interestingly one particularly large specimen consists of a bipinnate compound frond or leaf with intercalary pinnules or subleaflets between pinnae. Pinnae or leaflets and pinnules or subleaflets are alternate distichously arranged. Pinnae show in their basal part an increase in lengths of pinnules or subleaflets. Pinnule or subleaflet margin is entire except for its distal part in which two large teeth are symmetrically positioned on each side of the acute apex. Pinnules or subleaflets are inserted by a broad base. Besides its fern-like gross morphology, this frond or leaf shows a strong midvein, at least two narrower pinnate secondary veins and faint reticulate much finer veins. Such a venation pattern may rather suggest it to be an angiosperm eudicotyledon. Thus, this also raises concern on a previous fern attribution of materials from the Turonian of south-eastern France.