The longissimus atlantis is parallel to, but ventral to longissimus capitis. It attaches to ala atlantis.
Origin: transverse processes of the first thoracic and last cervical vertebrae
Insertion: wing of the atlas
Action: Extends the neck; in unilateral action to raise the neck obliquely and turn it to one side.
Nerve: Dorsal branches of the thoracic and cervical nerves.