Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but not all oysters, are in the superfamily Ostreoidea.
Crassostrea is a genus of true oysters containing some of the most important oysters used for food.
The Ostreidae, the true oysters, include most species of molluscs commonly consumed as oysters. Pearl oysters are not true oysters, and belong to the order Pteriida.
The order Ostreida includes the true oysters. One superfamily (Ostreoidea) and two extant families are recognised within it. The two families are Ostreidae, the true oysters, and Gryphaeidae, the foam oysters.
Pinctada is a genus of saltwater oysters, marine bivalve mollusks in the family Pteriidae. These pearl oysters have a strong inner shell layer composed of nacre, also known as "mother of pearl".
Spondylus is a genus of bivalve molluscs, the only genus in the family Spondylidae. They are known in English as spiny oysters or thorny oysters.
Goniatites is a genus of extinct cephalopods belonging to the family Goniatitidae, included in the superfamily Goniatitaceae. Hibernicoceras and Hypergoniatites are among related genera.
Ostrea edulis, commonly known as the European flat oyster, is a species of oyster native to Europe. In Great Britain and Ireland, regional names include Colchester native oyster, mud oyster, or edible oyster. In France, Ostrea edulis are known as huîtres plates except for those that come from the Belon River estuary in Brittany, France, which are known as Belons.
The Pteriomorphia comprise a subclass of saltwater clams, marine bivalve molluscs. It contains several major orders, including the Arcida, Ostreida, Pectinida, Limida, Mytilida, and Pteriida. It also contains some extinct and probably basal families, such as the Evyanidae, Colpomyidae, Bakevelliidae, Cassianellidae, and Lithiotidae.
Rock oysters are true oysters of the genus Saccostrea, belonging to the subfamily Saccostreinae of the family Ostreidae.
Orthogarantiana is an extinct genus from a well-known class of fossil cephalopods, the ammonites. It lived during the Middle Jurassic.
Pycnodonte is a genus of extinct oysters, fossil marine bivalve mollusks in the family Gryphaeidae, the foam oysters or honeycomb oysters. Shells of species in this genus are found around the world in fossil shell beds from the Valanginian to the Early Pleistocene. They are a commonly found fossil in Cretaceous shellbeds of the Navesink Formation in New Jersey.
Oxynoticeratidae is a family of true ammonites included in the superfamily Psiloceratoidea.
Tarasiiformes is an extinct order of prehistoric ray-finned fish.
Calycoceras is an extinct genus of cephalopods belonging to the subclass Ammonoidea and family Acanthoceratidae that lived during the Cenomanian stage of the Late Cretaceous, 100-94 Mya. Their shells had ornate ribs.
Lopha is a genus of marine bivalve molluscs in the family Ostreidae.
Agerostrea is an extinct genus of fossil oysters, marine bivalve molluscs in the family Ostreidae, the true oysters. It is present in the Maastrichtian, the upper stage of the Late Cretaceous epoch, from 72.1 to 66 million years ago.
Utahconus is an extinct genus of conodonts.
Rastellum is an genus of extinct molluscs, which lived from the Middle Jurassic to the Late Cretaceous.
