African Chelonethi : studies on the systematics, biogeography and natural history of African pseudoscorpions (Arachnida)

The systematics, biogeography and natural history of the pseudoscorpions of sub-Saharan Africa are studied from a phylogenetic perspective. Observations on the ecology and biology of species from Cameroon are presented. These concentrate on niche preferences, successions in disturbed habitats, cleaning behaviour and feeding. Reproductive biology and spermatozoan morphology are reviewed in relation to the systematics of the order. Putative hemispermatophores, found in the families Cheliferidae, Atemnidae and Withiidae, are described for the first time. The morphology of the female 'gonopods' (renamed gonosacs) is surveyed. Ontogeny is discussed in relation to Grandjean's stase concept and Nelson's formulation of the biogenetic law. The first known calyptostasic pseudoscorpion protonymph is described in a species of Pseudochthonius Balzan (Chthoniidae). The development of the chelal trichobothria is reinterpreted through the application of Grandjean's priority rule and a new system of ontogenetic notations proposed. A revised pseudoscorpion classification is presented, based on a cladistic analysis of the families. Two new suborders are recognized: the Avenenata, containing the superfamilies Chthonioidea and Feaelloidea; and the Venenata, comprising the superfamilies Neobisioidea, Garypoidea, Cheiridioidea and Cheliferoidea. The tribe Pseudotyrannochthoniini of the Chthoniidae is raised to the rank of a separate family. The tribe Hesperolpiini is transferred from the Olpiidae to the Garypidae and raised to subfamilial rank. The subfamily Garypininae is removed from the Olpiidae and given familial rank. The Holarctic genera Larca and Archeolarca are transferred from the Garypidae to the new subfamily Larcinae of the Geogarypidae. The phylogeny of the families is expressed in the cladogram: (((Pseudotyrannochthoniidae (Chthoniidae, Tridenchthoniidae)) (Feaellidae, Pseudogarypidae) ((Hyidae (Ideoroncidae, Bochicidae (Gymnobisiidae (Neobisiidae, Syarinidae)))) (Menthidae (Olpiidae, Garypidae) (Garypinidae, Geogarypidae)) (Sternophoridae (Pseudochiridiidae, Cheiridiidae) (Chernetidae (Atemnidae, Withiidae, Cheliferidae)))))))) [where parentheses indicate nested sets of relationships]. A phylogenetic revision of all species of the family Feaellidae is presented. The area cladogram for this group emphasises the isolated position of the South African biota and the close relationship between the East African, Indian and Madagascan faunas. This indicates that vicariance events pre-dating the breakup of Gondwanaland have been important in shaping contemporary biogeographical patterns of African pseudoscorpions.