WExogyra is an extinct genus of fossil marine oysters in the family Gryphaeidae, the foam oysters or honeycomb oysters. These bivalves grew cemented by the more cupped left valve. The right valve is flatter, and the beak is curved to one side. Exogyra lived on solid substrates in warm seas during the Jurassic and Cretaceous periods.
WInoceramus is an extinct genus of fossil marine pteriomorphian bivalves that superficially resembled the related winged pearly oysters of the extant genus Pteria. They lived from the Early Jurassic to latest Cretaceous.
WIsastrea is an extinct genus of corals that lived during the Jurassic and Cretaceous periods. Its fossils have been found in Europe, Africa, North America, Asia and South America.
WPholadomya is a genus of saltwater clams, marine bivalve molluscs in the family Pholadomyidae.
WStylina is a genus of extinct stony corals.
WTerebratula is a modern genus of brachiopods with a fossil record dating back to the Late Devonian. These brachiopods are stationary epifaunal suspension feeders and have a worldwide distribution.
WTrigonia is an extinct genus of saltwater clams, fossil marine bivalve mollusk in the family Trigoniidae. The fossil range of the genus spans the Paleozoic, Mesozoic and Paleocene of the Cenozoic, from 298 to 56 Ma.