Rhombuniopsis linan – Rare Extinct Unionidae from Yunnan Plateau

Rhombuniopsis linan, an extinct species from Yunnan Province, China, represents an exceptionally rare genus with all its species now extinct. This species was highly restricted to a single lake on the Yunnan Plateau. Complete dead shells are rarely encountered, and specimens retaining any periostracum are exceedingly few. This mollusk offers valuable insights into freshwater mollusk extinction and biogeography, making it highly sought after by collectors and researchers alike.