| abstract | Adelphacarus reticulatus Lotfollahi sp. nov., the second known species of the oribatid mite genus Adelphacarus (Adelphacaridae), is proposed based on specimens collected from 40- to 75-cm depth in sandy clay loam soil of a natural grassland in the Marand region, East Azerbaijan province of Iran. It is distinct from the type species, A. sellnicki Grandjean, in having the sensillus broadened and curved in the distal half, a posterior notogastral shield with distinct irregular reticulation, the presence of an aggenital plate, differences in various setal lengths, and a richer leg setation. The distribution of A. sellnicki is reviewed, showing that the family is widespread, but not previously known from Asia. Various family-group classifications of Adelphacarus are also reviewed, and the validity of the name Adelphacaridae is supported. Other palaeosomatans represented in a general study of grassland and agricultural soils of the Marand region include Ctenacarus araneola (Grandjean), Gilarovella demetrii Lange, and Beklemishevia sp. (all Ctenacaridae), and two distinct morphospecies of Aphelacarus (Aphelacaridae). |