Evolution of the cochlea of the ear, consisting of the scala media, the scala tympani, and the scala vestibuli. Regarding mammals, placental and marsupial cochleae have similar cochlear responses to auditory stimulation as well as DC resting potentials. This leads to the investigation of the relationship between these therian mammals and researching their ancestral species to trace the origin of the cochlea. This spiral-shaped cochlea that is in both marsupial and placental mammals is traced back to approximately 120 million years ago. The development of the most basic basilar papilla (the auditory organ that later evolved into the Organ of Corti in mammals) happened
Jock Stirrup plans could be afforded over the coming years. The planning for the invasion of Iraq required new equipment and Stirrup became increasingly involved in planning for urgent operational requirements. A particular difficulty faced by Stirrup was the need to place equipment orders with industry before the Government was prepared to publicly commit to the action. Stirrup briefed ministers on this point but was prevented from placing the orders according to his desired timescale. In the end some critical items such as body armour, boots and desert clothing were not available to all the personnel who needed them when they deployed.