Morphology and epidermal anatomy of Nilssonia (cycadalean foliage) from the Upper Triassic of Lunz (Lower Austria)

The Carnian flora from Lunz (Lower Austria) ranks among the richest and most diverse fossil floras from the Upper Triassic. It is one of the first modern Triassic floras with bennettitaleans. Although this flora is often referred to in the literature, modern taxonomic studies are mostly absent; only some of the reproductive structures have been studied in detail. Many of the plant remains yield excellently preserved cuticles. During a systematic study of the Pterophyllum leaves from Lunz, it appeared that several species previously accommodated in that taxon have to be transferred to other genera. This paper deals with four species that are transferred to Nilssonia (cycadalean foliage); the macromorphology and epidermal anatomy are described and discussed. The following new combination is introduced: Nilssonia riegeri nov. comb. Two new species are described (i.e. Nilssonia lunzensis and Nilssonia neuberi) based on material originally mentioned in a species list as Ctenis lunzensis Stur nom. nud. and Pterophyllum neuberi Stur nom. nud. The diagnosis for a fourth species, Nilssonia sturii Krasser, is emended. The Nilssonia species from Lunz range among the earliest representatives of the genus Nilssonia.