Ectotympanic

The ectotympanic, or tympanicum, is a bony structure found in all mammals, located on the tympanic part of the temporal bone, which holds the tympanic membrane (eardrum) in place. In catarrhine primates (including humans), it takes a tube-shape.^[1][2] Its position and attachment to the skull vary between primates, and can be either inside or outside the auditory bulla.^[3][4]

It is homologous with the angular bone of non-mammalian tetrapods. When the latter is present, it contacts the entotympanic.^[5]

References

1. Fricano, Ellen Elise Irwin (2018). "The Primate Ectotympanic Tube: Correlates of Structure, Function, and Development". {{cite journal}}: Cite journal requires |journal= (help)
2. Ankel-Simons, F. (2007). Primate Anatomy (3rd ed.). Academic Press. pp. 435–436. ISBN 0-12-372576-3.
3. Archibald, J.D. (1977). "Ectotympanic bone and internal carotid circulation of eutherians in reference to anthropoid origins". Journal of Human Evolution. 6 (7): 609–622. doi:10.1016/S0047-2484(77)80134-6.
4. Sellers, W.I. "Strepsirhine/Haplorhine Split" (PDF). Retrieved 18 August 2010.^{[permanent dead link]}
5. Maier, Wolfgang (August 2013). "The entotympanic in late fetal artiodactyla (Mammalia)". Journal of Morphology. 274 (8): 926–939. doi:10.1002/jmor.20149. ISSN 0362-2525.

External links

• webref: Anthropology Archived 2012-02-12 at the Wayback Machine
• Hershkovitz P (1974). "The Ectotympanic Bone and Origin of Higher Primates" (PDF). Folia Primatologica. 22 (4): 237–42. doi:10.1159/000155628. PMID 4218574.
• Jones FW, Lambert VF (October 1939). "The occurrence of the lemurine form of the ectotympanic in a primitive marsupial". J. Anat. 74 (Pt 1): 72–5. PMC 1252559. PMID 17104802.