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 Creek (Alaska) placer gold mine in Nekula Gulch by a headwater tributary to Anvil Creek. The Caribou Bill mine (NM238) is also nearby. There is an Anvil Creek fault. Anvil Creek (Alaska) Anvil Creek is a stream in Alaska. Part of it is in the Nome mining district near Nome, Alaska and became a center of gold rush attention after three Swedes found gold along it. The resulting influx of prospectors brought thousands of people to Nome in the spring of 1899. The large placer mine gold find was one of the first in Alaska and the Anvil Creek Gold Discovery Site