Evolution of the cochlea and the elongated cochlea allows for better sensitivity for higher frequencies. As in all lepidosaurs and archosaurs, the single-ossicle (columellar) middle ear transmits sound to the footplate of the columella, which sends a pressure wave through the inner ear. In snakes, the basilar papilla is roughly 1mm long and only responds to frequencies below about 1 kHz. In contrast, lizards tend to have two areas of hair cells, one responding below and the other above 1 kHz. The upper frequency limit in most lizards is roughly 5–8 kHz. The longest lizard papillae are about 2mm long and contain 2000 hair
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