Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Components (hierarchy name)
4. components (objects parts)
5. [components by specific context]
6. biological components
7. animal components

Anotations

Scope note:

The calcareous, horny, or shelly plates secreted by some gastropod mollusks, which serve to close the shell when the animal is retracted. These are found in many marine and some terrestrial and freshwater species. Opercula are used in jewelry or as decoration on art and ceremonial objects.