Unusual case of occipital vertebra in a medieval skeleton.

The craniovertebral junction (CVJ) is a transitional region of the spine that exhibits extensive structural variability. Developmental defects include a vast array of anatomical anomalies that result from remnants of the proatlas and are grouped under the term 'occipital vertebra'. The purpose of the present paper is to describe the case of a medieval skeleton, which was found to display a previously unreported manifestation of occipital vertebra. It consisted of two large basilar processes that articulated with the anterior arch of the atlas. In addition, the left process exhibited a supplementary contact zone with the dens of the axis. These structural defects were associated with an accessory canal situated posterior to the right hypoglossal canal.