| Thirty-two new genera and 63 new species of small minnow mayflies (Insecta: Ephemeroptera: Baetidae) are described from the Afrotropical. (15 genera, 30 species), Neotropical (13 genera, 24 species), Australian (three genera, 19 species), and Nearctic (one genus) regions. New Afrotropical genera include Barnumus, Bugilliesia, Crassabwa, Dabulamanzia, Delouardus, Demoreptus, Edmulmeatus Glossidion, Herbrossus, Kivua, Maliqua, Nesydemius, Peuhlella, Susua, and Xyrodromeus. New Neotropical genera include Adebrotus, Andesiops, Aturbina, Cryptonympha, Deceptiviosa, Nanomis, Prebaetodes, Rivudiva, Spiritiops, Tomedontus, Varipes, Waltzoyphius, and Zelusia. New Australian genera include Edmundsiops, Offadens , and Papuanatula. The new Nearctic genus is Plauditus. New regional generic reports involve Cloeodes and Pseudocloeon from Australia; Apobaetis from the Neotropics; and Pseudocloeon from the Afrotropics, Nearctic, and Palearctic. The generic concepts of Afroptilum, Baetis (in part), and Pseudocloeon are revised, resulting in numerous synonyms, establishment of new genera, and reassignments of species. Percentages of endemism of the six major world biogeographic regions show that the Neotropical region has the most distinctive fauna, with 96% endemic genera; it is followed by the Afrotropics (84%), Australia (44%), Orient (38%), Nearctic (15%), and Palearctic (14%). Determination of Sorensen's coefficient of biotic affinities is used to discuss baetid faunistics in each biogeographic region, and partly corroborates previous models indicating major centers of evolution. Current problems and prospects in the taxonomy and systematics of Baetidae are discussed. |
