The spider genus Stictonanus Millidge, 1991 in the Juan Fernandez archipelago (Araneae, Linyphiidae): systematics and biogeography
We studied the systema??cs of the Juan Fernandez linyphiid species originally classified in the genus Juanfernandezia Koçak & Kemal, 2008. In an earlier study, we had hypothesized that the two Juanfernandezia species, each endemic to a single island, form a clade that was sister to the southern South American genus Notholepthyphantes Millidge, 1985. We have carried out a mul??-locus phylogene??c analysis to infer the rela??onships of Juanfernandezia based on an extended taxon sampling. Our study shows that Juanfernandezia is sister to the South American genus Stictonanus Millidge, 1991, which un??l recently remained poorly known. The striking similarity of the soma??c and genitalic morphology of these two genera suggest that the clade is be??er classified as a single genus, with Stictonanus being the oldest available generic name for this lineage. Stictonanus , circumscribed now to include five species, is sister to a lineage composed of two small genera, Notholepthyphantes and Falklandoglenes Usher, 1986. Stictonanus fernandezi (Berland, 1924) comb. nov. and Stictonanus paolae Hormiga & Arnedo, sp. nov., both from the Juan Fernandez Islands, are described and illustrated. The type species of the genus, Stictonanus paucus Millidge, 1991, and the second con??nental species, S. exiguus Millidge, 1991, are here redescribed and illustrated (the male of S. exiguus is described here for the first ??me). We further infer a ??me calibrated tree to discuss the biogeographic history of Stictonanus