Endoscopic endonasal inferior transclival approach, step-by-step dissection. The longus capitis muscle has been removed, and the rectus capitis anterior muscle and its insertion into the inferior clival line can now be identified. The pharyngeal tubercle is a midline bony prominence medial to the inferior clival line that serves as attachment to the anterior atlanto-occipital membrane. (Image courtesy of JC Fernandez-Miranda)