Fig. 6. Gryphaeid oysters from the subgenus Boreiodeltoideum. A, E in Late Jurassic-Early Cretaceous oysters from Siberia: A systematic review

Fig. 6. Gryphaeid oysters from the subgenus Boreiodeltoideum. A, E. Deltoideum (Boreiodeltoideum) borealis sp. nov. A. TsSGM 2068/31, paratype, Lower Kimmeridgian, Lopsiya River, Northern Urals; exterior (A1) and interior (A2) of left valve. E. TsSGM 150/3887, holotype, Lower Kimmeridgian, Khatanga depression, north of Eastern Siberia; interior of RV (E1) and exterior of LV (E2). B–D, F. Deltoideum (Boreiodeltoideum) praeanabarensis Zakharov, 1966), Lower Volgian, Dyabaka-Tari River, north of Eastern Siberia. B. TsSGM 2068/10, view on left (B1) and right (B2) valves. C. TsSGM 2068/57, interior of right valve. D. TsSGM 2068/8, exterior (D1) and interior (D2) of left valve. F. TsSGM 150/2031, interior of left valve.