Unlike the human mouth, a snake's mouth is just right for taking in a big meal all at once.
First, the mouth is big because the jawbones are connected to the back of the skull, not the sides. When the mouth drops open, the long jaws make a big opening.
Second, the jaws can swing down far because they are not attached tightly to the skull. The jaw is linked to the end of a short bone, and the other end of the short bone is connected to the skull. The ligaments that hold these bones together are stretchy.
Finally, the two sides of the jawbone are not fused together at the chin. Instead, they are lined by another stretchy ligament that lets the two sides move apart.
So a snake's mouth can open wide partly because the jawbones can spread apart like sticks tied together with rubber bands.
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