Atlanto-axial joint Atlanto-axial joint The atlantoaxial joint is a joint in the upper part of the neck between the first and second cervical vertebrae; the atlas and axis. It is a pivot joint. The atlantoaxial joint is of a complicated nature. It consists of no fewer than four distinct joints. There is a pivot articulation between the odontoid process of the axis and the ring formed by the anterior arch and the transverse ligament of the atlas. There are three atlantoaxial joints: one median and two lateral: The ligaments connecting these bones are: The atlantoaxial joint in common terminology is actually a
Neoteny in humans skull, thinness of the skull bones, lack of brow ridges, lack of sagittal crests, form of the teeth, relative size of the brain and form of the brain as ways in which the juvenile skulls of these human ancestors resemble the skulls of adult modern humans. Montagu said that the retention of these juvenile characteristics of the skull into adulthood by australopithecine or pithecanthropine could have been a way that a modern type of human could have evolved earlier than what actually happened in human evolution. The psychiatrist Stanley Greenspan and Stuart G. Shanker proposed a theory in "The First