Systematics of the Gondwanan pseudoscorpion family Hyidae (Pseudoscorpiones:Neobisioidea): new data and a revised phylogenetic hypothesis

Abstract

The neobisioid pseudoscorpion family Hyidae has a distribution spanning the margins of the Indian Ocean and its phylogenetic position has been suggested to lie midway between a clade containing the Bochidae and Ideoroncidae, and a clade containing the remaining neobisioid families, Gymnobisiidae, Neobisiidae, Parahyidae and Syarinidae. Their central position within the Neobisioidea, and their biogeographic patterns, have prompted the present study, which is designed to test the monophyly of the family, deduce the phylogeny of all known hyids and to describe several newly discovered species. The phylogenetic analysis of the 14 species of the pseudoscorpion family Hyidae along with 20 other species of Neobisioidea demonstrates the monophyly of the family and its distinctness from all other neobisioid families. Two genera, Hya Chamberlin and Indohya Beier, are recognised, even though the phylogenetic analysis did not consistently recover the monophyly of Indohya. The effect of outgroup selection was tested on the Hyidae and revealed markedly different tree topologies. Hyella Harvey, with the type species H. humphreysi Harvey, is newly synonymised with Indohya owing to similarities between the previously described species and some new troglobitic species. The Indohyinae Harvey is synonymised with Hyidae. Two new epigean species and three new troglobitic species of Indohya are described: I. damocles, sp. nov., I. gollum, sp. nov., I. haroldi, sp. nov. and I. napierensis, sp. nov. from northern Western Australia, and I. jacquelinae, sp. nov. from Madagascar. All species of Indohya are short-range endemics, having very small distributional ranges. New data are presented for Indohya humphreysi (Harvey), including the first description of the male. The first protonymphs of the family Hyidae are described, including those of Hya minuta (Tullgren) and Indohya gollum, sp. nov.