Permineralized Marattiales from the Stephanian and Autunian of central France: a reinvestigation of Grandeuryella renaultii (Stur) Weiss emend

Abstract

A reinvestigation of specimens initially described by Renault (1883) as fertile Pecopteris oreopteridia and distinguished as Grand'Eurya renaulti Stur (1883) and Grandeuryella renaulti Weiss (1885), is presented. The species diagnosis is amplified to features of pinnule size and morphology, venation, and morphology of synangia, individual sporangia and spores. A lectotype is chosen from silicified specimens from Grand-Croix, France (Stephanian). The description of the genus Grandeuryella Weiss is emended for bilaterally symmetrical synangia borne on heavily vascularized receptacles along the lateral veins of highly recurved pecopterid pinnules; sporangia exannulate, united before dehiscence, free to receptacle afterwards, producing monolete spores. The taxonomic position of the species and of the genus is discussed and it is concluded that the validity of mode of attachment and fusion of sporangia as generic characters must be evaluated taxon by taxon. Grandeuryella is regarded as distinct from Eoangiopteris and Millaya, and possibly the equivalent of the compression genus Danaeites. Grandeuryella is compared to sections of extant Angiopteris. Those features that differ from Angiopteris are shared with other Paleozoic Marattiales and presumably represent synplesiomorphies.