Diplomaragna ryvkini Shear 1990: 15, figs.
Diplomaragna ryvkini — Mikhaljova 1993: 25.
Diplomaragna longibrachiata — Mikhaljova 1993: 25.
Ancestreuma ryvkini — Mikhaljova 2000: 156; 2002b: 204; 2004: 104, figs, map; 2016: 12; 2017: 130, figs, map; Mikhaljova & Golovatch 2001: 109; Vorobiova et al. 2002: 62.
Material examined. 1 male, 2 juv. (FSCB), Russia, Siberia, Valley Tunkinskaya (Republic of Buryatia + Irkutskaya Oblast), 2500 m, along the road under cardboard, 21.VIII.2019, leg. L.A. Prozorova.
Distribution. Russia: Siberia (Republic of Buryatia, Irkutskaya Oblast, Republic of Tyva, Republic of Sakha [Yakutia], central and southern parts of Krasnoyarsky Krai); North Mongolia.
Remarks. This species was originally described in Diplomaragna (Shear 1990), but later transferred to the genus Ancestreuma (Mikhaljova 2000).