Editing Tuatara (section)

==== Hearing ====
Together with [[turtle]]s, the tuatara has the most primitive hearing organs among the amniotes. There is no tympanum ([[eardrum]]) and no earhole,<ref name="lutzp27" /> and the [[middle ear]] cavity is filled with loose tissue, mostly [[adipose tissue|adipose (fatty) tissue]]. The [[stapes]] comes into contact with the [[Quadrate bone|quadrate]] (which is immovable), as well as the [[hyoid bone|hyoid]] and [[squamosal]]. The [[hair cell]]s are unspecialised, innervated by both [[Afferent nerve|afferent]] and [[efferent nerve]] fibres, and respond only to low frequencies. Though the hearing organs are poorly developed and primitive with no visible external ears, they can still show a frequency response from 100 to 800&nbsp;[[Hertz|Hz]], with peak sensitivity of 40&nbsp;[[Decibel|dB]] at 200&nbsp;Hz.<ref>{{cite web |author=Kaplan, Melissa |date=6 September 2003 |title=Reptile Hearing |website=Melissa Kaplan's herp care collection |url=http://www.anapsid.org/reptilehearing.html |access-date=24 July 2006}}</ref>