Sprecher
Beschreibung
The enigmatic fossil-genus Lesleya Lesquereux classified either to early cycads or to pteridosperms is considered as an “upland”, “extrabasinal”, dry-tolerant plant. New excavation in the Vaulnaveys-le-Bas (French Alps) revealed about 60 specimens of the Westphalinan D (late Moscovian) age. Unfortunately, scleritization state of preservation cause that incomplete specimens are without epidermal structures preserved. Otherwise, some lanceolate leaves have obtuse apices and simple, slightly S-shaped venation preserved. The complete leaves might be up to 250 mm long. Similar leaf dimensions and venation occur in nineteen specimens from boreholes in different basins in the Bohemian Massif including the Lubná near Rakovník locality (the Bolsovian, early Moscovian), from where the most specimens also with acute bases and cuticles have been studied. The leaves are amphistomatic with haplocheilic, anomocytic stomata. So, the data are sufficient for erection of a new species Lesleya belledonnensis sp. nov. The specimens from French Alps show to allochthonous origin. In Lubná near Rakovník, two specimens have been found in tuff above coal seam among autochthonous plants, whereas most specimens are fragmentary and come from laminated tuffite above the tuff. This assemblage contains many allochthonous, draw-tolerant species like: Dicranophyllum, Discinites, Rhacopteris, Palaeopteridium and some endemic medullosan pteridosperms. Lesleya in French Alps is accompanied by a dominance in the taphocenosis of dry-tolerant plants as Cordaites in their giant forms and Dicranophyllum. The research was subsidised by a project GACR 25-16958S.