Talanema longicauda sp. n. (Dorylaimida: Qudsianematidae) from Iran, with new insights into the evolutionary relationships of the genus

A new species of the genus Talanema , recovered from moss samples collected in northwestern Iran, is described, including SEM observations and molecular (28S-rDNA) analysis. Talanema longicauda sp. n. is characterised by its 1.46-1.89 mm long body, lip region offset by constriction and 16-18  μ m wide with perioral liplets, odontostyle 21-24  μ m long, guiding ring double, neck 340-395  μ m long, pharyngeal expansion occupying 44-50% of the total neck length, uterus long and tripartite, transverse vulva ( ), tail similar in both sexes, conical with a dorsal concavity especially appreciable in females (46-63  μ m, , ), spicules 60-68  μ m long, and 11-15 shortly spaced ventromedian supplements ending at level of the anterior end of spicules, with hiatus. Molecular study confirms the monophyly of Talanema and suggests the existence of two major subclades within the genus with biogeographical projection.