EXCEPTIONAL PRESERVATION IN LOWER DEVONIAN COALIFIED FOSSILS FROM THEWELSH BORDERLAND - A NEW GENUS BASED ON RENIFORM SPORANGIA LACKING THICKENED BORDERS

Reniform sporangia, comprising two equal valves and containing retusoi d spores, recovered from Lower Old Red Sandstone strata of Devonian ag e (micrornatus-newportensis Spore Biozone: lower Gedinnian+/-lower Loc hkovian) on North Brown Glee Hill in the Welsh Borderland are placed i n Resilitheca salopensis pen. et sp. nov. Conventional compression fos sils from Targrove, Ludlow of fertile axes showing isotomous branching with limited overtopping are considered conspecific because the termi nal reniform sporangia contain the same spores. Spore ultrastructure i s described using scanning and transmission electron microscopy. Secti ons show faint traces of lamellae. Particles associated with spores an d sporangium wall are compared with the globules of pteridophytes and Ubisch bodies of angiosperms, and related to the development of the sp orangium. The new plants are compared with Cooksonia caledonica Edward s known only from impressions, and with Renalia Gensel showing far mor e pronounced pseudomonopodial branching.