Evolution of the cochlea signals that displace the eardrum by a mere picometre. Because of its prominence and preserved state in the fossil record, until recently, the ear had been used to determine phylogeny. The ear itself contains different portions, including the outer ear, the middle ear, and the inner ear and all of these show evolutionary changes that are often unique to each lineage [14]. It was the independent evolution of a tympanic middle ear in the Triassic era that produced strong selection pressures towards improved hearing organs in the separate lineages of land vertebrates. The cochlea is the tri-chambered auditory detection portion
Evolution of the cochlea (lower frequency) papillae, but it is uncertain whether either is homologous to the hearing organs of lepidosaurs, archosaurs and mammals and we have no idea when they arose. Fish have no dedicated auditory epithelium, but use various vestibular sensory organs that respond to sound. In most teleost fishes it is the saccular macula that responds to sound. In some, such as goldfishes, there is also a special bony connection to the gas bladder that increases sensitivity allowing hearing up to about 4 kHz. The size of cochlea has been measured throughout its evolution based on the fossil record. In one