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 Peak have formed after Mount Cerberus. According to the Global Volcanism Program of the Smithsonian Institution, its formation occurred during the late Pleistocene epoch. It has not erupted in recent times; it is thought that its last activity was probably thousands of years ago. Anvil Peak has experienced deep erosion, more so than the other cones on the islands, which is partially due to its height. Anvil Peak Anvil Peak is a cone volcano located in Aleutian Islands, Alaska, United States. The volcano was originally named in 1951, on a map by the United States Geological Survey. Its name was taken