In this photograph taken by Tom Nevins, a Common Gartersnake is swallowing prey — a Gray Treefrog — that is much larger than the snake’s mouth. It can do this because of the structure of its jaws. The quadrate bone, which attaches the upper and lower mandibles, is not rigidly attached. Rather, it pivots, allowing vertical and horizontal rotation of the jaw. In addition, the two pieces of the lower jaw (left and right) are connected in the front of the jaw by an elastic ligament, allowing each side of the lower jaw to move independently. Due to these adaptations, a snake can consume large prey by basically walking over it with its jaws.