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 Unit which was based at RAF Lossiemouth in March 1983: his duties centred around the instruction of trainee pilots on the SEPECAT Jaguar and, on 7 March 1983, Stirrup was carrying out a student progress check from the rear seat of his aircraft when they suffered a serious bird strike. Stirrup was unable to ascertain whether his student was conscious and forward vision through the canopy was obscured: one of his engines caught fire, and although ejecting from the aircraft would have been justified, not knowing whether the student was conscious or not, Stirrup managed to land at RAF Leuchars.