LAUSR

Abstract A new and exceptionally hairy marattialean fern of an early Permian age having pecopterid sterile pinnules and strongly enrolled fertile pinnules, Scolecopteris minuta sp. nov., is described from the uppermost Taiyuan Formation of the Wuda coalfield in Inner Mongolia. The fertile fronds are at least tripinnate, with lanceolate to linear penultimate pinnae and oblong ultimate pinnae. Each pinnule bearing 6–9 ovate to fusiform pedicellate synangia, arranged abaxially in a single row to either side of the midvein. The deeply incised pinnule margins are strongly reflexed downwards and inwards, closely enveloping and sheathing the synangia. Each synangium is comprised of a ring of sporangia which were closely pressed together before dehiscence. The sterile fronds are of pecopterid form. Taken as a whole, the combination of characters of Scolecopteris minuta sp. nov. indicates attribution to the Latifolia group of Scolecopterids sensu Millay (1979) . In its exceptionally hairy frond rachises and the equally exceptionally dense growth of smaller hairs both on the adaxial and abaxial sides of the fertile pinnules, and even on the tips of the synangia of S. minuta. We propose that this dense hairiness functioned primarily as a deterrent to spore-eating insects and perhaps also to other predators.