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 of Doom was recruited on the vocal role to replace Kvoraph after his decision to quit the band in September 2009. In summer 2009, Anvil of Doom resumed touring, taking part in several festivals around Andalusia included in the so-called Re(TOUR)synthesis. In 2011, AOD released an EP entitled "Turn Your Back", along with a videoclip of the title track. This release was supported by an extensive Spanish tour, which saw the band playing next to international legends like Malevolent Creation and Pestilence. In summer 2012, Anvil of Doom starts pre-production for their long-expected second full-length, in order to begin recording by fall.