-Soft bodied "foot" is modified to ring of tentacles around mouth.
-Shell is composed mostly of aragonite and is filed with gas to govern buoyancy.
-8 genera survive into Triassic and radiate from there.
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-Marine mollusc with straight, curved or coiled shell. -Soft bodied "foot" is modified to ring of tentacles around mouth. -Shell is composed mostly of aragonite and is filed with gas to govern buoyancy. |
| -Well represented in Late Permian, with 17 species in 11 genera. -8 genera survive into Triassic and radiate from there. |
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