marine or freshwater mollusks having a soft body with platelike gills enclosed within two shells hinged together
造句
The fauna in the Joli Fou consists of bivalves and arenaceous forams. 喬里富組內的化石主要是雙殼類和砂殼有孔蟲。
Jurassic marine bivalve is very rich, non-marine bivalves also developed rapidly, and their continental formation on the division and correlation played an important role. 侏羅紀的海相雙殼類很豐富，非海相雙殼類也迅速發展起來，它們在陸相地層的劃分與對比上起了重要作用。