Untangling the phylogeny of Neanura MacGillivray, 1893 (Collembola, Neanuridae, Neanurinae): new species and evidence for monophyly in a taxonomically unstable family

The genus Neanura MacGillivray, 1893 is a morphologically diverse member of Neanurinae, previously considered problematic in terms of its definition and phylogenetic stability. Based on material from the Caucasus and Crimea, we describe five new species: N. anophtalmica sp. nov., N. caucasica sp. nov., N. ghirkanica sp. nov., N. potapovi sp. nov. and N. taurica sp. nov. To test their phylogenetic placement, we analysed a morphological dataset of 36 neanurine species using both maximum parsimony and Bayesian inference. All analyses recovered Neanura as a well-supported monophyletic genus, in contrast to many other genera of Neanurinae. Within Neanura, three intrageneric subclades were consistently identified: (N. anophtalmica + N. pallida), (N. caucasica + N. deharvengi) and (N. potapovi + N. ghirkanica + N. persica + N. taurica). These groups are supported by suites of morphological characters including eye number, pigmentation, cephalic chaetotaxy and tuberculation, and reflect contrasting evolutionary trends towards either reduction or elaboration. The type species N. muscorum was always placed within the genus, although its exact position varied between analyses. Our findings reject the hypothesis that the new species represent a separate genus; instead, they broaden the morphological and geographical scope of Neanura. Biogeographically, the Caucasus–Pontic–Hyrcanian region emerges as an important centre of diversification, bridging the European and Iranian faunas. This study provides the first robust phylogenetic framework for Neanura and offers new insights into the diversification of Neanurinae.