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The Stuff We Work With 5

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The lower jaw of mammals consists of only two bones, a right and left dentary. Lower jaws of other vertebrates consist of a number of bones that in mammals either have been lost evolutionarily or commandeered for other duties (for example, the tiny malleus, or hammer, of the middle ear is the equivalent of the articular bone of the lower reptilian jaw). The dentaries are joined by connective tissue (or fused, as in ourselves) at the mandibular symphysis.

Lateral and medial views of labeled wolf dentaries

Fig. 1: Lateral and medial views of canid dentary.

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