Aphilodontidae

Aphilodontidae is a monophyletic clade of soil centipedes in the family Geophilidae found in South America and South Africa. These centipedes are closely related to Geoperingueyia and characterized by shieldlike setae on the front of the head, lateral parts of the flattened cuticle above the mouthparts, and combined forcipular trochanteroprefemur and femur. The number of legs in this clade varies within species as well as among species and ranges from as few as 33 pairs of legs (in Mecophilus carioca) to as many as 93 pairs (in Aphilodon cangaceiro). The three species in the Brazilian genus Mecophilus have the fewest legs (33 or 35 pairs in the males of M. carioca; 35 pairs in both sexes of M. tupiniquim, females of M. carioca, and males of M. neotropicus) and smallest size (6.5 to 8 mm in length) in this clade. The two species with the fewest legs in the Neotropical genus Aphilodon also feature notably modest numbers with limited variation recorded: A. meganae (37 pairs in males, 39 in females) and A. indespectus (39 pairs in males, 41 in females). Aphilodon meganae is also notable for its small size (7 to 8 mm in length), the smallest in its genus. Species with more legs also exhibit greater variation in the number of leg pairs (e.g., A. cangaceiro, with odd numbers ranging from 87 to 91 in males, 89 to 93 in females). The largest species in this clade (A. micronyx and A. pereirai) can reach 70 mm in length.