Biogeography of Mesozoic leptosporangiate ferns related to extant ferns

Skog. J. E. (Biology Department, George Mason University, Fairfax, VA 22030 . U.S.A.). Biogeography of Mesozoic leptosporangiate ferns related to extan t ferns. Brittonia 53: 236-269. 2001.-The paleobiogeography of the extant l eptosporangiate fern families present in the Mesozoic is reviewed based mai nly on data from megafossils that possess enough characters to be assigned to a family. Times of first appearances are discussed for each family, foll owed by their distribution throughout the Mesozoic. Paleolatitudes and clim atic conditions indicate that first appearances of many fern families occur about or above 30 degrees and in conditions of higher moisture. Much of fe rn distribution in the past was likely due to long-distance dispersal.