Carboniferous cuticles from the Lubná coal seam (Kladno Formation, Kladno-Rakovník Basin, Czech Republic)

Abstract

More than 500 cuticle fragments have been selected from the Lubna coal seam section (Radnice Member, Kladno Formation, Pennsylvanian, Bolsovian, Czech Republic). The dispersed cuticles were classified into 25 informal categories (not including cordaitaleans). Among the dispersed cuticles, lycopsids dominate, namely sporangium walls of sub-arborescent Omphalophloios and cuticles from leaf cushions of arborescent lycopsids (Lepidodendron, Lepidophloios). Different kinds of stomata-less cuticles with polygonal and tetragonal cell imprints are difficult to assign to particular groups of ferns and pteridosperms. Some dispersed cuticles belong to the orders Lyginopteridales and Callistophytales. However, ferns and medullosans were not proven in the cuticular spectra, even though they probably grew in the original assemblage. Cordaitaleans were represented by dispersed leaf cuticles and also cuticles from fructification. They have been found only in three samples and classified using the artificial system of dispersed cordaitalean cuticles as two new species of Cordaabaxicutis Simunek et Florjan. and a new species of Cordaadaxicutis Simunek et Florjan. Sphenopsids are represented only by very rare Sphenophyllum cuticles in two samples. Many cuticles with polygonal cell imprints belong to pteridosperm and cordaitalean seeds. The presence of unidentified multicellular bodies is enigmatic. The dominance of lycopsids indicates a wet tropical forest, but the presence of Omphalophloios suggests perhaps seasonal alternation of wet and less humid periods. Cordaitaleans also grew in drier, more clastic, better-drained parts of the swamp. The cuticular assemblage from samples just below the roof-shales is the most diversified and probably contains also elements from the surroundings of the peat bog.