Opisthotic
The opisthotic, sometimes spelled opisthootic, is a bone of the skull that participates in the otic capsule; along with the prootic and epiotic, it encloses the inner ear.[1]
Function
[edit]The opisthotic forms the posterior part of the otic capsule. Together with the other periotic bones, it encloses the bony labyrinth, which allows for the senses of hearing and balance.[1]
Evolution
[edit]As with other bones of the otic capsule, the opisthotic forms a part of the chondrocranium.[1] Though the otic capsule is believed to have been present in the ancestor of living vertebrates, the opisthotic only becomes ossified in osteichthyes, with the appearance of endochondral bone.[2][3]
In teleost fishes, the opisthotic articulates with the epiotic and the sphenotic to form the otic capsule.[1]
In amphibians and sauropsids, the opisthotic and prootic articulate to form the otic capsule;[1] in most diapsids, it is fused to the exoccipital to form the otoccipital.[4] In mammals, it fuses with the prootic and the epiotic to form the petrosal; as the petrosal in humans is fused with the squamosal and tympanic to form the temporal bone, the opisthotic forms part of the petrous part of the temporal bone.[5]
References
[edit]- 1 2 3 4 5 Kardong, Kenneth (2015). Vertebrates: Comparative Anatomy, Function (7th ed.). McGraw-Hill.
- ↑ Higuchi, Shinnosuke; Sugahara, Fumiaki; Pascual-Anaya, Juan; Takagi, Wataru; Oisi, Yasuhiro; Kuratani, Shigeru (January 2019). "Inner ear development in cyclostomes and evolution of the vertebrate semicircular canals". Nature. 565 (7739): 347–350. doi:10.1038/s41586-018-0782-y. hdl:10630/33079. ISSN 1476-4687. PMID 30518864.
- ↑ Clack, Jennifer A. (2016), "Vertebrate Diversity in a Sensory System: The Fossil Record of Otic Evolution", in Clack, Jennifer A.; Fay, Richard R; Popper, Arthur N. (eds.), Evolution of the Vertebrate Ear : Evidence from the Fossil Record, Springer Handbook of Auditory Research, vol. 59, Cham: Springer International Publishing, pp. 1–16, doi:10.1007/978-3-319-46661-3_1, ISBN 978-3-319-46661-3
- ↑ Martínez, Rubén D. F.; Lamanna, Matthew C.; Novas, Fernando E.; Ridgely, Ryan C.; Casal, Gabriel A.; Martínez, Javier E.; Vita, Javier R.; Witmer, Lawrence M. (2016-04-26). "A Basal Lithostrotian Titanosaur (Dinosauria: Sauropoda) with a Complete Skull: Implications for the Evolution and Paleobiology of Titanosauria". PLOS ONE. 11 (4) e0151661. Bibcode:2016PLoSO..1151661M. doi:10.1371/journal.pone.0151661. ISSN 1932-6203. PMC 4846048. PMID 27115989.
- ↑ Thomas, Lyell J. (1926). "Ossification centers in the petrosal bone of the mouse". The Anatomical Record. 33 (2): 59–68. doi:10.1002/ar.1090330202. ISSN 1097-0185.