The earliest evidence of cordaitalean cuticles from coal in the Pennsylvanian of Europe (Langsettian, Upper Silesian Basin, Czech Republic)

Abstract

A dispersed cuticular assemblage with Cordaites Unger represents the oldest record of cordaitalean remains in peat deposits. Cordaitalean cuticles are easily distinguished by their elongated tetragonal or oblong cells and typical stomatal complexes. This assemblage comes from the coal seam 26 of the Karviná Formation, Lower Suchá Member, a few meters above the Namurian/Westphalian boundary in the Upper Silesian Basin. Cordaitaleans represent 23% of the cuticular assemblage, and consist of two species of abaxial cuticles (Cordaabaxicutis cf. jaworznoensis Šimůnek and Florjan and C. jacobii Šimůnek sp. nov.) and four species of adaxial cuticles (Cordaadaxicutis jaroslavii Šimůnek sp. nov., C. orlovensis Šimůnek sp. nov., C. doubravensis Šimůnek sp. nov. and C. detmarovicensis Šimůnek sp. nov.)Cordaabaxicutis cf. jaworznoensis has stomata arranged in stomatiferous bands in irregular rows. The Polish Cordaabaxicutis jaworznoensis has regular stomatal rows. It is highly probable that Cordaabaxicutis cf. jaworznoensis is conspecific with Cordaites karvinensis Šimůnek and C. sustae Šimůnek. All these species have small papillae on the abaxial cuticle, which is typical for peat-swamp species. Cordaabaxicutis jacobii has stomata arranged in stomatal rows, however, another sample of this species tends to have them in multiple rows. The structure of the stomatal complex is similar to Cordaabaxicutis laziskae Šimůnek and Florjan, but the subsidiary cells are much smaller.Cordaadaxicutis jaroslavii has stomata arranged in sparse rows, whereas the other Cordaadaxicutis new species have very low stomatal densities and stomatal complexes irregularly dispersed on the epidermis. Cordaadaxicutis jaroslavii has slightly cutinised lateral subsidiary cells of stomata, C. orlovensis has prominent guard cells and similar lateral subsidiary and ordinary cells. Central parts of periclinal cell walls of C. doubravensis are thinner.The most common species in the dispersed cuticular assemblage are Cordaabaxicutis cf. jaworznoensis and Cordaadaxicutis jaroslavii. This cordaitalean assemblage represents at least four biological species. The rest of the dispersed cuticular assemblage is represented by lyginopterid and medullosan pteridosperms, cuticles of seed integuments and rachides.