Zygosphene-zygantrum articulation
The zygosphene-zygantrum articulation is an accessory joint between vertebrae found in several lepidosauromorph reptiles. This pivot joint consists of a forward-facing, wedge-shaped process called the zygosphene, that fits in a depression on the rearside of the next vertebrae, called the zygantrum.[1] The zygosphene sits between the prezygapophysis in the neural arch, whereas the zygantrum sits between the postzygapophysis.[2]
This joint is found in snakes, lacertids, teiids, Gymnophthalmids as well as in some iguanids and cordylids.[3] It is also found in several fossil groups such as plesiosaurians, nothosaurians and pachypleurosaurians.[4] It is absent in today's Monitor lizard (Varanus), but occurs in fossil Varanids.[5]
The zygosphen-zygantrum joint function to stabilize the vertebral column. While it permits horizontal and vertical movements of the vertebral column, it prevents rotations of the single vertebrae against each other.[5]
References
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 5.0 5.1 Lua error in package.lua at line 80: module 'strict' not found.
