A review of in situ spores in Silurian land plants

Abstract Spores are described from the sporangia of six rhyniophytoid taxa from early Pridoli (late Silurian) strata at Perton Lane, Hereford and Worcester, England. Those from species of Cooksonia are crassitate: C. pertoni subsp. pertoni contains Ambitisporites sp.; C. pertoni subsp. synorispora, Synorisporites verruca/us; and C. cambrensis has a crassitate spore with microgranulate sculpture on both proximal and distal surfaces, which has not yet been recorded in dispersed spore assemblages and will probably require a new genus. Retusoid spores of diverse aspect have been isolated from Salopella sp. and two new taxa. The Salopella spores are exceptionally large and provisionally assigned to Retusotriletes sp., the genus also used for spores of Caia langii which has elongate spinous sporangia. Spores of Pertonella dactylethra (characterized by sporangia of Cooksonia shape, but with spines) have a distinctive sculpture following the curvaturae perfectae, and are close to Retusotriletes coronadus from the Silurian of Spain.