Revision of Palearctic species of the genus Dimorphaphorura (Collembola: Onychiuridae: Onychiurinae: Oligaphorurini) with description of new species

In this paper, the Palearctic genus Dimorphaphorura Bagnall, 1949 (Collembola: Onychiuridae), is revised. The diagnosis of the genus is defined within the tribe Oligaphorurini based on the development of the furcal area, shape of furcal rudiment, and furcal chaetotaxy. Six new species are described: D. olenae sp n. from Ukraine, D. inya sp n., D. pseudoinya sp n., D. sibirica sp n., D. caucasica sp n., and D. sophyae sp n. from Russia. The type species of the genus, D. differens Bagnall, 1949 is redescribed, and the lectotype and paralectotypes are designated. All previously known species are redescribed or with additional characters complemented: D. alnus (Fjellberg, 1987) comb n., D. chatyrdagi (Kaprus', Weiner & Pomorski, 2002) comb n., D. daii (Pomorski, Skarżyński & Kaprus', 1998) comb n., Dimorphaphorura eremia (Kaprus',Weiner & Pomorski, 2002) comb n., D. hackeri (Christian, 1986) comb n., D. irinae (Thibaud & Taraschuk, 1997) comb n., D. melittae (Christian, 1993) comb n., D. pseudoraxensis (Nosek & Christian, 1983) comb n., D. raxensis (Gisin, 1961) comb n., D. steposa (Kaprus', Weiner & Pomorski, 2002). An identification key to all Dimorphaphorura species is provided.