Nuculanida is an
order
Order, ORDER or Orders may refer to:
* Categorization, the process in which ideas and objects are recognized, differentiated, and understood
* Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...
of very small saltwater clams,
marine
Marine is an adjective meaning of or pertaining to the sea or ocean.
Marine or marines may refer to:
Ocean
* Maritime (disambiguation)
* Marine art
* Marine biology
* Marine debris
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* Marine pollution
Military
* ...
bivalve
Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...
mollusc
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...
s in the
subclass Protobranchia
Protobranchia is a subclass of bivalve molluscs. It contains the extant orders Nuculanida, Nuculida, and Solemyida.
These are deep water clams of a small and primitive order with a taxodont hinge (composed of many similar, small teeth), gener ...
.
Description
These bivalves are distinguished by the presence of relatively primitive, "protobranchiate" gills. There are a row of short teeth along the hinge of the shell. The shells are often internally
nacre
Nacre ( , ), also known as mother of pearl, is an organicinorganic composite material produced by some molluscs as an inner shell layer; it is also the material of which pearls are composed. It is strong, resilient, and iridescent.
Nacre is f ...
ous.
Families
Families within the order Nuculanida include:
*
Bathyspinulidae
Bathyspinulidae is a family of bivalves belonging to the order Nuculanida
Nuculanida is an order of very small saltwater clams, marine bivalve molluscs in the subclass Protobranchia.
Description
These bivalves are distinguished by the pr ...
Coan & Scott, 1997
*
Lametilidae
*
Malletiidae
Malletiidae is a family of bivalves in the order Nuculanida.
Taxonomy
* '' Adrana''
** '' Adrana egregia'' (Guppy, 1882)
** '' Adrana electa'' ( A. Adams, 1846)
** '' Adrana elizabethae'' Ortea & Espinosa, 2001
** '' Adrana gloriosa'' ( A. ...
H. and A. Adams, 1858
*