New and known species of the genus Thorne & Swanger, 1936 (Dorylaimida, Nordiidae) from Iran.

This contribution provides morphological and molecular data for one new and one known species of the genus Pungentus. The first species, P. azarbaijanensis n. sp., was recovered from the rhizospheric soil of grasses, collected in West Azarbaijan province, Iran, and was characterized by 2082-2365 μm long females having an angular lip region separated from the rest of the body by a constriction, 33-35 μm long odontostyle, vulva at 43.5-51.0%, 27.0-29.5 μm long rounded-conoid tail, and males unknown. It was compared morphologically with five species: P. angulosus, P. crassus, P. marietani, P. parapungens and P. pungens, which have didelphic-amphidelphic female reproductive system, body longer than 1.5 mm, and odontostyle longer than 20 μm. The second species, P. engadinensis, was recovered in three different regions of Iran (Mazandaran, Semnan and East Azarbaijan provinces). It was compared morphologically with some other populations reported all over the world. Besides morphological studies, molecular phylogenetic studies using partial sequences of 28S rDNA D2-D3 fragments were performed, and the phylogenetic relations of the two Iranian populations with other species and genera were discussed.