SPOROPHYTES AND GAMETOPHYTES OF POLYTRICHACEAE FROM THE CAMPANIAN (LATE CRETACEOUS) OF GEORGIA, USA

A new genus and species (Eopolytrichum antiquum) of the moss family Po lytrichaceae are described for fossil sporophyte capsules and associat ed gametophytes from the early Campanian (Late Cretaceous) Buffalo Cre ek Member of the Gaillard Formation in central Georgia, U.S.A. The cap sules show diagnostic features of the Polytrichaceae but differ from t hose of all extant genera. The capsules are terete in cross section, s omewhat dorsiventrally flattened, and have a swollen, asymmetrical apo physis and mammillose exothecium. Stomatal complexes, each surrounded by a ring of subsidiary cells, are confined to the apophysis. The oper culum is tall and dome shaped, but the calyptra and beak of the opercu lum are not preserved. The remains of a peristomial membrane are prese nt around the rim of the capsule after the operculum has dehisced, but peristome teeth are absent, and the epiphragm is retained in the oper culum. Spores are alete, spherical, and echinulate. Associated sterile and fertile gametophytes have leaves with adaxial, presumed photosynt hetic, lamellae on the blade surface in addition to other anatomical s tructures comparable to extant Polytrichaceae. Inadequacies in the mos s fossil record have led to contrasting interpretations as to the age of the origin of mosses and the extent of evolutionary change in the g roup since the Paleozoic. These fossils, which represent the first une quivocal polytrichaceous sporophytes known from the fossil record, alo ng with other fossil mosses from this early Campanian locality, provid e the first definitive evidence of modern families of mosses in the Cr etaceous and demonstrate that mosses were already diverse by approxima tely 80 million years before present.