The clausilium is a calcareous anatomical structure which is found in one group of air-breathing land snails: terrestrial pulmonate gastropod mollusks in the family Clausiliidae, the door snails. The clausilium is one part of the clausilial apparatus.
The clausilium is a calcareous anatomical structure which is found in one group of air-breathing land snails: terrestrial pulmonate gastropod mollusks in the family Clausiliidae, the door snails. The clausilium is one part of the clausilial apparatus.
The presence of a clausilium is the reason for the common name "door snails", because all the snails in this family have a roughly spoon-shaped "door" or clausilium, which can slide down to close the aperture of the shell. However, this structure is emphatically not the same thing as an operculum, which is virtually non-existent in pulmonate snails, only occurring in the Amphiboloidea.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).