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Joined 2026-09-21 Message
Incoming links: Paired fin
Fin Created 2026-10-20 Updated 2026-11-05
A fin is a projecting locomotor or stabilizing structure in an aquatic vertebrate. Median fins lie near the midline, while paired fins occur laterally. Shape, position and internal support affect thrust, steering and stability, so not every fin has the same mechanical role.
J. Andrew Gillis Created 2026-10-20 Updated 2026-11-05
A developmental biologist who tested shared developmental mechanisms of branchial arches and paired fins, comparing the effects of developmental signals rather than relying only on adult resemblance.[ref]
A shared role for sonic hedgehog signalling in patterning chondrichthyan gill arch appendages and tetrapod limbs by J. Andrew Gillis and Brian K. Hall. Authorship and experimental findings
Lateral fin-fold hypothesis 2026-10-20
The proposal that discrete paired fins evolved through differentiation and regional restriction of an earlier continuous ventrolateral appendage field.
Shark Created 2026-10-20 Updated 2026-11-05
A shark is a cartilaginous fish within Chondrichthyes. Its paired fins, jaws and sensory systems support diverse ways of life. The group includes both active predators and filter-feeding forms, so one feeding stereotype does not define it.