SPOROPHYTES, MEGASPORES, AND MASSULAE OF AZOLLA-STANLEYI FROM THE PALEOCENE JOFFRE-BRIDGE LOCALITY, ALBERTA

Several hundred vegetative and fertile specimens of Azolla Lam. have b een recovered from the Paleocene Paskapoo Formation at the Joffre Brid ge locality (Middle Tiffanian (Ti-3) age) near Red Deer, Alberta. The spore complexes closely resemble those of the Paleocene A. stanleyi Ja in and Hall, and the vegetative material is referred to that species. The specimens are unusually complete in that the remains of the fragil e sporophyte are preserved, commonly with reproductive structures in p lace. Plants reaching up to 2.25 cm in length consist of alternately b ranched rhizomes bearing alternate, imbricate, sessile leaves. Leaves are ovate with entire margins, papillate surfaces, and a single midvei n. Reproductive structures have been examined using light, scanning, a nd transmission electron microscopy. This new material is compared wit h the other Paleocene species for which sporophytes are known and disc ussed in terms of evolutionary trends for the genus. The specimens sug gest that most of the vegetative characteristics of modern Azolla spec ies were established by the middle Paleocene.