Pertaining to the atlas and occiput, e.g. atlanto-occipital joint.
- a. fusion — a congenital defect observed in calves; causes tetraplegia at birth or by two months of age.
- a. malformation — includes hypoplasia of the odontoid process, atlanto-occipital fusion.
- a. malformation of Arab horses — includes occipitalization of the atlas and atlantalization of the axis. It causes incoordination with a characterisitic extension of the head at birth or soon afterwards.
- a. membrane — there are two, the dorsal and ventral, each of which connects the cranial edge of the atlas to the margin of the foramen magnum.
