The zygosphene-zygantrum articulation is an accessory joint between vertebrae found in several lepidosauromorph reptiles.
[2] This joint is found in snakes, lacertids, teiids, Gymnophthalmids as well as in some iguanids and cordylids.
[4] It is absent in today's Monitor lizard (Varanus), but occurs in fossil Varanids.
[5] The zygosphene-zygantrum joint's function is 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.