The Entoliidae, also referred to as the entoliids, are a

taxonomic 280px, Generalized scheme of taxonomy Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme of classes (a taxonomy) and the allocation ...

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

of saltwater clams, marine

bivalve Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed b ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

s in the order

Pectinida Pectinida is a taxonomic order of large and medium-sized saltwater clams, marine bivalve molluscs, commonly known as scallops and their allies. It is believed that they began evolutionarily in the late Middle Ordovician epoch; many species, o ...

. They are related to and are considered the ancestors of modern

scallop Scallop () is a common name that encompasses various species of marine bivalve molluscs in the taxonomic family Pectinidae, the scallops. However, the common name "scallop" is also sometimes applied to species in other closely related famili ...

s. In the geological record the family contains at least seven species in five different genera, though only one is extant and it is very rare and cryptic, inhabiting the

Caribbean The Caribbean ( , ; ; ; ) is a region in the middle of the Americas centered around the Caribbean Sea in the Atlantic Ocean, North Atlantic Ocean, mostly overlapping with the West Indies. Bordered by North America to the north, Central America ...

and central west

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

in small, disjointed populations. A significant morphological feature lacking in the entoliids but present in modern scallops is the ctenolium, a comb-like structure under the anterior auricle through which scallops are able to produce a

byssal thread A byssus () is a bundle of filaments secreted by many species of bivalve mollusc that function to attach the mollusc to a solid surface. Species from several families of clams have a byssus, including pen shells ( Pinnidae), true mussels (Mytili ...

for attachment to a substrate. The entoliids did not/ do not secrete a byssal thread.

Genera and species

Genera and species within the family Entoliidae include: * '' Entolium'' Meek 1865 ** '' Entolium fossatum'' Marwick 1953 ** '' Entolium utokokense'' Imlay 1961 * '' Pectinella'' ** '' Pectinella sigsbeei'' ( Dall, 1886) ** '' Pectinella aequoris'' Dijkstra, 1991 * '' Pernopecten'' Winchell 1865 * '' Somapecten'' * '' Syncyclonema'' Meek 1864 ** '' Syncyclonema travisanus'' Stephenson 1941

References

{{Taxonbar, from=Q2294881 Bivalve families