The Hercules pseudoscorpions from Madagascar: A systematic study of Feaellidae (Pseudoscorpiones: Feaelloidea) highlights regional endemism and diversity in one of the "hottest" biodiversity hotspots

Madagascar is amongst the "hottest" biodiversity hotspots with extreme levels of diversity and endemism. Throughout the last decades, there has been substantial progress in documenting the Malagasy invertebrate fauna but no study has ever focused on pseudoscorpions (Arachnida: Pseudoscorpiones) in the arachnid fauna. Here we review the Malagasy fauna of Hercules pseudoscorpions (family Feaellidae), which are common in soil habitats of arid biomes across Madagascar. Using morphology and molecular data, we recover three reciprocally monophyletic clades that correspond to three new genera in well-defined biogeographical regions and identify twelve new species: Antsiarananaella gen. nov. for Antsirananaella lorenzorum sp. nov., Antsiarananaella leniae sp. nov., Antsiarananaella faulstichi sp. nov. and Antsiarananaella marlae sp. nov.; Mahajanganella gen. nov. for Mahajanganella fridakahloae sp. nov., Mahajanganella heraclis sp. nov. and Mahajanganella schwarzeneggeri sp. nov.; Toliaranella gen. nov. for Toliaranella fisheri sp. nov., Toliaranella griswoldi sp. nov., Toliaranella mahnerti sp. nov., Toliaranella meridionalis sp. nov. and Toliaranella pumila sp. nov. Local endemism in this fauna is high and most species have small distributions, ranging from 20 km to 350 km linearly. Genetic distances between populations are also high, suggesting restricted dispersal or selection against dispersal in this fauna. Species' ranges seem to be delimited by geological barriers including volcanic fields (Ambre-Bobaomby in the north of Madagascar), mountain ranges (foothills of the Central Highland Plateau), and rivers (Manankolana, Mandrare, Manombo and Onilahy Rivers and their anabranches), but mainly by different biome habitats. Overall, Madagascar emerges as a global "hotspot" of feaellid radiation and these animals may be used in future studies to test biogeographical hypotheses across xeric biomes on this island.