Ear and hearing in Sphenodon punctatus.
Observations on Sphenodon punctatus have revealed new features of the anatomy of the ear,and measurements in a living specimen by means of cochlear potentials show the form and level of this ear's performance in sound reception. For an animal lacking an external ear opening and a functional tympanic membrane, the sensitivity of from 100-900 Hz is surprisingly good in low tones with peak response around 200-400 Hz. The inner ear is well developed, with a tectorial membrane connected to a tectorial plate that extends throughout the cochlea. The best region of sensitivity agrees well with the main frequency components of the animal's vocalizations.
D000200:Action Potentials; D000818:Animals; D005075:Biological Evolution; D001844:Bone Conduction; D003051:Cochlea / Q000502:physiology*; D004423:Ear / Q000033:anatomy & histology*; D006309:Hearing / Q000502:physiology*; D012104:Reptiles / Q000033:anatomy & histology* / Q000502:physiology