The malleus or hammer's a hammer-shaped small bone or ossicle of the middle ear which connects with the incus and's attached to the inner surface of the eardrum. The word's Latin for hammer. It transmits the sound vibrations from the eardrum to the incus. The malleus's unique to mammals, and evolved from a lower jaw bone in basal amniotes called the articular, which still forms part of the jaw joint in reptiles. Embryologically it's derived from the first pharyngeal arch along with the rest of… (More on Malleus)