Chordoma can occur over all the following sites, except -
Chordoma occurs only in vertebrae and clivus 
Chordoma

Chordoma is a rare malignant tumour originating from the remnants of the primitive notochord.
As the vertebrae develop, notochord disappears and in adults, the normal remnant of notochord is nucleus pulpous of the intervertebral disc. In chordoma, this embryonic notochordal foci remains inside the vertebral body and forms tumours.
It occurs in adult males after 50 years.
It commonly occurs in the sacrococcygeal or in the sphere-occipital regions. The sacrum is the most common site: - Sacrum 50% clivus (35%), cervical thoracic/lumbar (15%).
Most of them occur in vertebral bodies.
Rib
Clivus
Sacrum
Vertebral body