Revision of the genusTrogulus Latreille: the morphologically divergentTrogulus torosusspecies-group of the Balkan Peninsula (Opiliones: Dyspnoi: Trogulidae)

Abstract

Within the species-rich European harvestman genus Trogulus Latreille, 1802, the Balkan Trogulus torosus species-group as defined by Schönhofer and Martens is revised. The group is remarkable because it includes the world's largest Opiliones species, Trogulus torosus Simon, 1885, and Trogulus ozimeci sp. nov. is the first member of the family showing obvious adaption to subterranean life. According to nuclear 28S and mitochondrial cytochrome b gene data, the T. torosus species-group and the Trogulus hirtus species-group form a monophyletic unit. Only the former is treated here as a paraphyletic group. Despite this paraphyly, the T. torosus species-group members share a number of morphological, morphometric, geographical, and ecological traits and are treated here as a unit for revisional work. Morphometric data are shown to be not only useful for species discrimination but also for species-group delineation. Within the T. torosus species-group six species are recognized: Trogulus banaticus Avram, 1971, Trogulus setosissimus Roewer, 1940, and T. torosus are re-described; Trogulus megaligrava sp. nov., T. ozimeci sp. nov., and Trogulus tenuitarsus sp. nov. are described as new. Unusually within Trogulus, strong affiliations with subterranean habitats exist and are discussed.