Middle ear to sounds of higher frequency, because these are better taken up by the inner ear (which also responds to higher frequencies than those of non-mammals). The malleus, or "hammer", evolved from the articular bone of the lower jaw, and the incus, or "anvil", from the quadrate. In other vertebrates, these bones form the primary jaw joint, but the expansion of the dentary bone in mammals led to the evolution of an entirely new jaw joint, freeing up the old joint to become part of the ear. For a period of time, both jaw joints existed together, one medially and one
Anvil open the shells of molluscs much as thrushes do, to sea otters that bring stones to the surface and drift on their backs, holding the stones on their chests as anvils on which they break open clams and similar hard-shelled prey. Gulls of various species, some crows, and large birds of prey smash open hard food items, such as bones and tortoises, by dropping them onto rocks. Anvil firing is the practice of firing an anvil into the air using gunpowder. It has been popular in California, the eastern United States and the southern United States, much like how fireworks