Cuticular characteristics of Neuralethopteris jongmansii LAVEINE (medullosalean foliage, Westphalian, Intrasudetic Basin, Poland)

Foliar cuticles are described for the first time from the medullosalean pteridosperm Neuralethopteris jongmansii LAVEINE. This species is not as common, either in abundance or distribution, as Neuralethopteris schlehanii (STUR) CREMER, the abaxial cuticle of which has paracytic (in morphological sense) and anomocytic stomata. In contrast, the stomata of Neuralethopteris jongmansii occur on both abaxial and adaxial cuticles and are anomocytic, monocyclic with prominent proximal papillae and sometimes paracytic. The epidermal cells of N. jongmansii are papillate and partly differ from N. schlehanii cuticles. However, there is a striking similarity between the foliar cuticles of N. jongmansii and Neurodontopteris auriculata (BRONGNIART) POTONIÉ. Although N. auriculata is a much younger fossil-species with pinnules that are more robust and of a different shape than N. jongmansii, their epidermal structures are practically the same – polygonal papillate cells, anomocytic, monocyclic stomata with prominent proximal papillae. Even their stomatal densities are equivalent. Despite this, there is a marked difference in the frond architecture of both genera. Neuralethopteris has „alethopterid“ bifurcate-pinnate frond architecture, Neurodontopteris has quite a different bifurcate-semi-pinnate frond architecture. Based on comparison of the cuticles, Neuralethopteris jongmansii and Neurodontopteris auriculata appear very similar and it may reflect common palaeoenvironmental demands. was collected is not known, the fact that other occurrences of N. jongmansii in Europe are in Langsettian (Lower Pennsylvanian) strata (CLEAL et SHUTE, 1995) suggests that it probably came from the lower part of the Žacléř Formation (Table 1). The cuticles were prepared by a standard maceration method using Schulze’s Reagent, as described by KERP (1990), KRINGS & KERP (1997) and KERP & KRINGS (1999). 3. GEOLOGICAL SETTING The Intrasudetic Basin extends from the north-eastern Czech Republic into south-western Poland, where the Wałbrzych locality is located (Fig. 1). Mississippian strata of the Intrasudetic Basin are largely coarse-grained siliciclastics that reach 5 km in thickness. Sedimentation changed at the end of the Mississippian, after which the coal-bearing Wałbrzych Formation was deposited. It reaches up to 250 m thickness, and is of Serpukhovian and earliest Bashkirian (lower Namurian) age. The overlying coal-barren Biały Kamień Formation is up to 380 m thick and largely comprises sandstones and conglomerates. In the Polish part of the Intrasudetic Basin, the lower part of the overlying Žacléř Formation (upper Bashkirian, Langsettian and Duckmantian) is coalbearing. The study samples probably come from this stratigraphic level, a conclusion supported by the fact that coals of the Žacléř Formation were mined in the vicinity of Wałbrzych. The uppermost Bashkirian (Duckmantian) part of the formation only contains a few workable coal seams in the Polish part of the basin. The Moscovian and Kasimovian (upper Westphalian and lower Stephanian) Glinik Formation, which reaches 850 m in thickness, is practically devoid of workable coal seams. The uppermost formation in the Polish part of the basin is the Ludwikowice FormaArticle history: Manuscript received May 30, 2016 Revised manuscript accepted November 23, 2016 Available online February 20, 2017