Planispiral
Planispiral is a condition in which a tubicolous shell is coiled in a single horizontal plane and the diameter increases away from the axis of coiling. This term is usually used for describing gastropod shells. Many cephalopods and tubeworms can also have a planispiral shell (Allaby and Allaby, 1999).
References
- Allaby, A. & Allaby, M. (1999). "Planispiral". A Dictionary of Earth Sciences. Retrieved 2014-01-13.
External links
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Cephalopod anatomy
Types |
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Features |
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funnel
External anatomy |
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Internal anatomy |
limbs
Brachial crown | |
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Buccal region |
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Occipital region |
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Other parts |
- Chromatophores
- Photophores
- Nervous system
Developmental stages: Spawn → Paralarva (Doratopsis stage) → Juvenile → Subadult → Adult • Egg fossils • Protoconch (embryonic shell)