Evolution of the cochlea about 7 mm long. Like in lepidosaurs and archosaurs, it contains a lagena, a vestibular sensory epithelium, at its tip. Only in therian mammals (marsupials and placentals) is the cochlea truly coiled 1.5 to 3.5 times. Whereas in monotremes there are many rows of both inner and outer hair cells in the organ of Corti, in therian (marsupial and placental) mammals the number of inner hair-cell rows is one, and there are generally only three rows of outer hair cells. Amphibians have unique inner ear structures. There are two sensory papillae involved in hearing, the basilar (higher frequency) and amphibian
Jock Stirrup in Oman Stirrup flew BAC Strikemasters during the Dhofar War in the close air support and interdiction roles, giving him valuable battle experience of the use of air power in counter-insurgency operations. After he returned to Great Britain in 1975, Stirrup was posted to No. 41 Squadron where he flew the SEPECAT Jaguar in the fighter reconnaissance role. Stirrup went on to serve in an exchange tour in the United States where he flew the all-weather tactical reconnaissance RF-4C Phantom. Promoted to squadron leader on 1 January 1980, Stirrup was serving as a flight commander on No. 226 Operational Conversion