All except one is true regarding Suboccipital triangle
Rectus capitis posterior minor doesn’t form boundary of suboccipital triangle, even though it is seen in this region.
Semispinalis capitis forms roof of suboccipital triangle
Rectus capitis posterior major and minor form boundaries of suboccipital triangle
Posterior atlantooccipital membrane forms floor of the triangle
It contains 3rd part of vertebral artery