New insights into the taxonomy and the evolutionary relationships of the rare nematode genus Ferris & Ferris, 1973 (Nematoda, Dorylaimida, Belondiridae), after the molecular characterization of an Iranian population of its type species.

A new Iranian population of is characterized, including morphometrics, microphotographs, and molecular (18S, 28S rDNA) studies. It is compared with previously known populations. The results derived from molecular analyses failed to find close evolutionary relationships with other traditional genera of Belondiridae and Swangeriinae, adding more uncertainties about the internal phylogeny of the family. The taxonomy of is revised, with a new diagnosis, list of species, key to their identification, and a compilation of their main morphometrics.