ten-eyed scorpions "Centrurides", and the twelve-eyed scorpions "Androctonides". More recently, some twenty-two families containing over 2,500 species of scorpions have been described, with many additions and much reorganization of taxa in the 21st century. There are over 100 described taxa of fossil scorpions. This classification is based on Soleglad and Fet (2003), which replaced Stockwell's older, unpublished classification. Further taxonomic changes are from papers by Soleglad et al. (2005). The extant taxa to the rank of family (numbers of species in parentheses) are: Order Scorpiones Parvorder Pseudochactida Soleglad & Fet, 2003 Superfamily Pseudochactoidea Gromov, 1998 Family Pseudochactidae Gromov, 1998 (1 sp.) (Central Asian scorpions of semi-savanna habitats) Parvorder Buthida Soleglad & Fet, 2003 Superfamily Buthoidea C. L. Koch, 1837 Family Buthidae C. L. Koch, 1837 (1209 spp.) (thick-tailed scorpions, including the most dangerous species) Family Microcharmidae Lourenço, 1996, 2019 (17 spp.) (African scorpions of humid forest leaf litter) Parvorder Chaerilida Soleglad & Fet, 2003 Superfamily Chaeriloidea Pocock, 1893 Family Chaerilidae Pocock, 1893 (51 spp.) (South and Southeast Asian scorpions of non-arid places) Parvorder Iurida Soleglad & Fet, 2003 Superfamily Chactoidea Pocock, 1893 Family Akravidae Levy, 2007 (1 sp.) (cave-dwelling scorpions of Israel) Family Belisariidae Lourenço, 1998 (3 spp.) (cave-related scorpions of Southern Europe) Family Chactidae Pocock, 1893 (209 spp.) (New World scorpions, membership under revision) Family Euscorpiidae Laurie, 1896 (170 spp.) (harmless scorpions of the Americas, Eurasia, and North Africa) Family Superstitioniidae Stahnke, 1940 (1 sp.) (cave scorpions of Mexico and Southwestern United States) Family Troglotayosicidae Lourenço, 1998 (4 spp.) (cave-related scorpions of South America) Family Typhlochactidae Mitchell, 1971 (11 spp.) (cave-related scorpions of Eastern Mexico) Family Vaejovidae Thorell, 1876 (222 spp.) (New World scorpions) Superfamily Iuroidea Thorell, 1876 Family Caraboctonidae Kraepelin, 1905 (23 spp.) (hairy scorpions) Family Hadruridae Stahnke, 1974 (9 spp.) (large North American scorpions) Family Iuridae Thorell, 1876 (21 spp.) (scorpions with a large tooth on inner side of moveable claw) Superfamily Scorpionoidea Latreille, 1802 Family Bothriuridae Simon, 1880 (158 spp.) (Southern hemisphere tropical and temperate scorpions) Family Hemiscorpiidae Pocock, 1893 (16 spp.) (rock, creeping, or tree scorpions of the Middle East) Family Hormuridae Laurie, 1896 (92 spp.) (flattened, crevice-living scorpions of Southeast Asia and Australia) Family Rugodentidae Bastawade et al., 2005 (1 sp.) (burrowing scorpions of India) Family Scorpionidae Latreille, 1802 (183 spp.) (burrowing or pale-legged scorpions) Family Diplocentridae Karsch, 1880 (134 spp.) (closely related to and sometimes placed in Scorpionidae, but have spine on telson)