This taxon is the type species of the genus. Fjellberg (1986) redescribed the species and designated a lectotype and paralectotypes from the original sample from Novaja Semlja, collected in 1875 and kept in Naturhistoriska Riksmuseet, Stockholm.
Among the species with a mucronal seta, A. bidenticulata may be recognised by few (fewer than 13) anterior setae on the ventral tube, a short, curved mucro, and pigmentation of the body usually not uniform (some segments darker than rest). Reproductive specimens lack modified setae.
The species is common in damp Arctic tundra of the Holarctic region (Babenko & Fjellberg 2006) and is also frequent along streams and lakes in the Scandinavian mountains, in the highlands of Great Britain, and in continental Europe south to the Mediterranean area. In Asia the distribution of A. bidenticulata follows the Arctic coast, while the southern limit is unknown (Potapov 2001). In North American it is reliably recorded from Alaska and arctic Canada, but more southern populations probably represent other species.