Otic notch

title: "Otic notch" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["skull", "vertebrate-anatomy", "human-head-and-neck"] topic_path: "science/biology" source: "https://en.wikipedia.org/wiki/Otic_notch" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::figure[src="https://upload.wikimedia.org/wikipedia/commons/2/25/Sclerocephalus_hauseri_head.jpg" caption="Skull of ''[[Sclerocephalus]]'', showing the otic notches"] ::
Otic notches are invaginations in the posterior margin of the skull roof, one behind each orbit. Otic notches are one of the features lost in the evolution of amniotes from their tetrapod ancestors.
The notches have been interpreted as part of an auditory structure and are often reconstructed as holding a tympanum similar to those seen in modern anurans. Analysis of the columella (the stapes in amphibians and reptiles) of labyrinthodonts however indicates that it did not function in transmitting low-energy vibrations, thus rendering these animals effectively deaf to airborne sound. The otic notch instead functioned as a spiracle, at least in the early forms.
References
References
- Lombard, R. E. & Bolt, J. R. (1979): Evolution of the tetrapod ear: an analysis and reinterpretation. ''Biological Journal of the Linnean Society'' No 11: pp 19–76 [http://onlinelibrary.wiley.com/doi/10.1111/j.1095-8312.1979.tb00027.x/abstract Abstract]
- Laurin, M. (1996): [http://tolweb.org/accessory/Hearing_in_Stegocephalians?acc_id=470 Hearing in Stegocephalians], from the [[Tree of Life Web Project]]
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