Rhombuniopsis songmeng – Extinct Unionidae Species from Yunnan Plateau (Rare and Endemic)

Rhombuniopsis songmeng, an extinct species native to Yunnan Province, China, belongs to a unique genus within the Unionidae family. Endemic to a single lake on the Yunnan Plateau, this species is now completely extinct. Specimens, especially those retaining their periostracum, are exceedingly rare and highly sought after by researchers and collectors. This shell offers significant value for scientific study on freshwater mollusk extinction and evolutionary history.