A contribution to the knowledge of the pteridosperm genera Pseudomariopteris Danze-Corsin nov emend, and Helenopteris nov gen.

The macromorphology and epidermal anatomy of three Late Carboniferous-Early Permian pteridosperm species, conventionally assigned to the form-genus Ps eudomariopteris Danze-Corsin, are described from the Stephanian of the Blan zy-Montceau Basin (Central France). The generic diagnosis of Pseudomariopte ris is emended, and P. busquetii is designated as the type species of the g enus. The combination P. cordato-ovata (Weiss) Gillespie et al. is validate d to replace the illegitimate name P. ribeyronii (Zeiller) Danze-Corsin. Th e species diagnoses of P. busquetii and P. cordato-ovata are emended. On th e basis of its epidermal anatomy, P. paleaui, another species orininally de scribed from Central France, is transferred to the newly established genus Helenopteris Krings et Kerp, and the new combination Helenopteuis paleaui i s introduced. Lectotypes of P. busquetii and H. paleaui are selected. In ad dition, specimens from other basins are (re-)examined and illustrated. Seed s attached to a P. busquetii specimen suggest a callistophytalean relations hip for Pseudomariopteris. Compression fossils and cuticles of Pseudomariop teris and Helenopteris are interpreted in terms of palaeoecology: Pseudomar iopteris busquetii and P. cordato-ovata had climbing/scrambling growth habi ts; specialized climber hooks can be demonstrated for both species, either in compression or in cuticular preservation. Although the growth habit of H . paleaui is not yet entirely clear, the size of its fronds suggests that t his taxon most probably was also a scrambler/climber. Finally, based on epi dermal features, a tentative reconstruction of stages of the pinnule ontoge ny of H. paleaui is provided. (C) 2000 Elsevier Science B.V. All rights res erved.