Both the oribatid mite families Oppiidae and Suctobelbidae are highly diverse globally, but these groups are insufficiently studied in Mongolia. This work deals with four species of oribatid mites from Khar Yamaat Nature Reserve, Mongolia. Ramusella (Insculptoppia) mongoliensis sp. nov. and Suctobelbella (Ussuribata) yamaatiensis sp. nov., and Suctobelbella (Flagrosuctobelba) ulykpani sp. nov. are proposed based on adults. Supplementary description of a hitherto known species, Suctobelbella tatarica (Krivolutsky, 1968) is provided, which reported for the first time from Mongolia. All species are inhabitants of the litter and soil of the mosaic groves in the dry grassland composed of Eurasian aspen, dwarf bog birch, and bristly roses growing on the north-facing slope of the mountains. Following the descriptions and comparisons, aspects of the taxonomy, distribution and habitat ecology of studied species are discussed.
Badamdorj Bayartogtokh (Wed,) studied this question.