The systematic placement is tentative because family and genus group definitions of freshwater Rissooidea are ... [details]

Protoconch low-trochiform; no ornamentation discernable; diameter of initial whorl c. 350 mm. Shell conical, with ... [details]

A species of Bacbotricula having a single keel positioned in lower third of whorl. Keel originating on second whorl. [details]

Bacbotricula having two spiral keels, one central and one at base of whorl. Both keels originate on the third shell ... [details]

The genus name is a combination of the Vietnamese denomination of northern Vietnam, "Bắc Bộ", and the type ... [details]

From the Vietnamese word for "delta","Đồng bằng". [details]

From the Vietnamese expression for "brickworks", "nhà máy gạch". [details]

Lacustrine layers of the Na Duong Formation [Latest Eocene to Early Oligocene (?)] [details]

Lacustrine layers of the Na Duong Formation [Latest Eocene to Early Oligocene (?)]. [details]

Lacustrine layers of the Na Duong Formation [Latest Eocene to Early Oligocene (?)]. [details]

Cao Bang brickyard section, eastern Cao Bang Basin (N 22°40.72, E 106°15.23) [details]

Cao Bang brickyard section, eastern Cao Bang Basin, Vietnam (N 22°40.72, E 106°15.23). [details]

Holotype: GPIT/GA/5019; paratype 1: GPIT/GA/5020; paratype 2: GPIT/GA/5021; paratype 3: GPIT/GA/5022; paratype 4: GPIT/GA/5023 ... [details]

Holotype: GPIT/GA/5014; paratype 1: GPIT/BI/5575; paratype 2: GPIT/GA/5015; paratype 3: GPIT/GA/5016; paratype 4: GPIT/GA/5017; ... [details]