Diplomaragna ryvkini Shear, 1990: 15, 14: figs 6–8. Diplomaragna ryvkini — Mikhaljova 1993: 25.
Diplomaragna longibrachiata — Mikhaljova 1993: 25.
Ancestreuma ryvkini — Mikhaljova 2000: 156; 2002: 204; Mikhaljova & Golovatch 2001: 109.
Remarks. Originally described in Diplomaragna (Shear 1990), this species has since been transferred to the restored Ancestreuma (Mikhaljova 2000). The species is known from different regions of Siberia (Buryatia, Irkutsk Area, Republic of Tyva, Republic of Sakha (=Yakutia), Krasnoyarsk Province) as well as Mongolia (Khubsugul Lake, River Ongolich).
MAP 1. Distribution of Diplopoda species in Mongolia. Borderlines show borders between the aimaks. Filled diamond: Angarozonium amurense, filled square: Shearia longa sp. nov., open square: Asiatyla communicantis (Golovatch, 1977), filled triangle: Ancestreuma principale Golovatch, 1977, open triangle: Ancestreuma longibrachiatum (Shear, 1990), filled circle: Asiatyla ulykpani (Shear, 1990), open circle: Ancestreuma ryvkini (Shear, 1990), cross: Ancestreuma sardyk (Shear, 1990).