Juliidae
Juliidae, common name the bivalved gastropods, is a family of minute sea snails, marine gastropod mollusks or micromollusks in the superfamily Oxynooidea, an opisthobranch group.
| Juliidae Temporal range: | |
|---|---|
| Julia exquisita | |
| A drawing of the shell (the exterior of the right valve) of a taxon named "Julia borbonica" | |
| Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Subclass: | Heterobranchia |
| Infraclass: | Euthyneura |
| Superorder: | Sacoglossa |
| Superfamily: | Oxynooidea |
| Family: | Juliidae E. A. Smith, 1885 |
| Synonyms | |
|
Prasinidae Stoliczka, 1871 (Prasinidae is a senior, but unused, synonym of Juliidae) | |
These are sacoglossan (sap-sucking) sea snails, and many of them are green in color.
These snails are extremely unusual in that their shells consist of two separate hinged pieces or valves. The valves are joined by a ligament, and look nothing like a normal snail shell; instead the valves look almost exactly like the two hinged valves of a clam, a bivalve mollusk, which is a related but very different class of mollusks.
Up until the mid-20th century, the Juliidae were known only from fossil shells, and not surprisingly, these fossils were interpreted as being the shells of bivalves. Julia, which is the type genus of the family, was named in 1862 by Augustus Addison Gould, who described it as a bivalve genus. Juliidae are known from the Eocene period to the Recent, but they probably first appeared during the Paleocene.