zygosphene

anatomy

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July 16, 2026

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The term "zygosphene" refers to a median process on the neural arch of vertebrae found in most snakes and some lizards. It is a wedge-shaped structure, with "zyg-" relating to a yoke or pair, and "sphene" meaning wedge in Greek. The related term "zygosphenal" describes something pertaining to or constituting a zygosphene.12

It is important to distinguish this from the "zygomatic bone," also known as the cheekbone, which is a diamond-shaped bone in the face that forms part of the orbit and the zygomatic arch. The zygomatic bone develops without a cartilaginous precursor and is ossified at birth.34

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snake
Vertebrae
…almost exclusively in snakes, the zygosphene being a projecting shelf on the upper part of the vertebra and the zygantrum being a pocket into which the zygosphene fits and within which it can swivel. These five points permit lateral and vertical rotation while preventing almost entirely any twisting of the…
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…almost exclusively in snakes, the zygosphene being a projecting shelf on the upper part of the vertebra and the zygantrum being a pocket into which the zygosphene fits and within which it can swivel. These five points permit lateral and vertical rotation while preventing almost entirely any twisting of the…
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