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.<ref>{{cite journal | last = Fricano | first = Ellen Elise Irwin | title = The Primate Ectotympanic Tube: Correlates of Structure, Function, and Development | year = 2018 | url = https://jscholarship.library.jhu.edu/handle/1774.2/61419 | journal = Johns Hopkins University}}</ref><ref>{{cite book | last = Ankel-Simons | first = F. | title= Primate Anatomy | edition = 3rd | publisher = Academic Press | year = 2007 | pages = 435–436 | isbn = 0-12-372576-3 }}</ref> Its position and attachment to the skull vary between primates, and can be either inside or outside the auditory bulla.<ref>{{cite journal | last = Archibald | first = J.D. | title = Ectotympanic bone and internal carotid circulation of eutherians in reference to anthropoid origins | journal = Journal of Human Evolution | volume = 6 | issue = 7 | year = 1977 | pages = 609–622 | doi = 10.1016/S0047-2484(77)80134-6}}</ref><ref>{{cite web | url = http://homepage.mac.com/wis/Personal/lectures/primate-adaptation/04StrepsirhineHaplorhineID.pdf | title = Strepsirhine/Haplorhine Split | last = Sellers | first = W.I. | accessdate = 18 August 2010 }}{{Dead link|date=August 2019 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

It is homologous with the angular bone of non-mammalian tetrapods. When the latter is present, it contacts the entotympanic.<ref>{{Cite journal |last=Maier |first=Wolfgang |date=August 2013 |title=The entotympanic in late fetal artiodactyla (Mammalia) |url=https://onlinelibrary.wiley.com/doi/10.1002/jmor.20149 |journal=Journal of Morphology |language=en |volume=274 |issue=8 |pages=926–939 |doi=10.1002/jmor.20149 |issn=0362-2525|url-access=subscription }}</ref>

==References== {{reflist}}

==External links== * [http://www.webref.org/anthropology/e/ectotympanic.htm webref: Anthropology] {{Webarchive|url=https://web.archive.org/web/20120212191458/http://www.webref.org/anthropology/e/ectotympanic.htm |date=2012-02-12 }} *{{cite journal |author=Hershkovitz P |title=The Ectotympanic Bone and Origin of Higher Primates |journal=Folia Primatologica |volume=22 |issue= 4|pages=237–42 |year=1974 |doi=10.1159/000155628 |url=http://content.karger.com/ProdukteDB/produkte.asp?Aktion=ShowPDF&ArtikelNr=155628&Ausgabe=238881&ProduktNr=223842&filename=155628.pdf |pmid=4218574}} *{{cite journal |author=Jones FW, Lambert VF |title=The occurrence of the lemurine form of the ectotympanic in a primitive marsupial |journal=J. Anat. |volume=74 |issue=Pt 1 |pages=72–5 |date=October 1939 |pmid=17104802 |pmc=1252559 }}

Category:Skull bones Category:Mammal anatomy