That's right. The small bones that enable mammals to hear better than fish, birds, or any other animals were located in the jawbones of the animals that came before us. How did they end up in our ears?
Mammals evolved from reptile-like animals that had more than one bone in their lower jaw (dentary bone, quadrate bone, articular bone and angular bone)...
...Very slowly, over tens of millions of years, two of these bones moved to the middle...
...In the ear, the bones became part of sensitive sound-ampligying system found only in mammals. The modern mammal middle ear is comprised of the malleus (hammer), incus (anvil), stapes (stirrup), tympanum (ear drum) and tympanic bone.
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