Paravietnura gen. n., a new intriguing genus of Neanurini from the Caucasus (Collembola, Neanuridae, Neanurinae)

Paravietnura gen. n. is described and established for two new species of Neanurini from the Caucasus. The new genus is characterized by an unusual combination of features: the fusion of all lateral tubercles on the head into a single mass, the strong reduction of chaetae on the head, the fusion of cephalic tubercles Af and Oc into a transverse band, the absence of labial chaetae f, the presence of microchaetae on furca rudimentary, and the penultimate abdominal tergum with two tubercles separated along the midline. Paravietnura gen. n. strongly resembles Vietnura Deharveng & Bedos, 2000, a monotypic genus up to date known only from Vietnam. The main characteristics of Paravietnura notabilis sp. n. include an ogival labrum, the absence of chaetae A on the head, relatively thick and widely sheathed long macrochaetae, and minute microchaetae without chaetopores on furca rudimentary. Paravietnura insolita sp. n. differs from the previous species in chaetotaxic details, the size of furcal microchaetae, and the shape of the labrum. Short comments on the generic diversity of the tribe in the Western Palaearctic are also provided.