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 firing Although its practice has lessened in recent years, enthusiasts still participate in anvil launching events and competitions. On September 5, 2011, The Science Channel premiered "Flying Anvils", a reality television series about anvil firing. Individuals may be crushed by a falling anvil. The black powder can also prematurely ignite when the top anvil is placed, which can cause black marks on any nearby individuals. As in any case where an explosive is confined on all sides by metal, shrapnel presents a hazard. If a damaged or structurally weak anvil is used, the anvil base may shatter upon ignition. The technique