Bomfleur et al. state that “Osmundales has arguably the richest and most informative fossil record of any extant group of ferns” and provide a comprehensive literature list for sources and further reading. The order is well represented in the fossil record from the Permian onwards. Osmundalean or potentially osmundalean fern foliage including "Anomopteris" Brongn., "Todites" Seward, "Cladotheca" T.Halle, "Osmundopsis" T.M.Harris, "Cacumen" Cantrill & J.A.Webb, "Osmunda", "Damudopteris" D.D.Pant & P.K.Khare, "Dichotomopteris" Maithy, and "Cladophlebis" Brongn., 1849) is commonly found from the Permian onwards together with dispersed spores such as "Osmundacidites" Couper and "Todisporites" Couper. But their affinitity to the Osmundales, and Osmundaceae in particular, is difficult to judge. In the Triassic foliage becomes frequent which is similar to identical to the fronds of modern-day "Todea", "Osmundastrum" and "Claytosmunda". The better understood rhizome fossil record indicates that the group was most diverse in the Permian, and already much reduced in the Triassic regarding the number of substantially different forms (see Bomfleur et al. and literature cited therein).