Definition: the air-filled cavity within the skull of vertebrates that lies between the outer ear and the inner ear. It is linked to the pharynx (and therefore to outside air) via the Eustachian tube and in mammals contains the three ear ossicles, which transmit auditory vibrations from the outer ear (via the tympanum) to the inner ear
Definition: Component found in mineralized skeletal tissue, (a specialized form of biogenic tissue in which the extracellular matrix is mineralized, and which functions in mechanical and structural support.)
Definition: External ear (pinna) length is a standard measurement in mammalogy, usually measured in a living mammal or a fresh mammal carcass. External ear length is measured from the base of the notch at the bottom of the ear to the apex (highest point) of the ear.