On the bottom of your skull, there is a distinctive hole. The technical name for the opening is the foramen magnum – the “great hole” that the spinal cord and other critical soft tissues run through. This bone aperture has taken on great importance in the ongoing investigation into when the human lineage split from those of other apes. If the foramen magnum indicates the position of the spine in relation to the head, and therefore whether the creature was bipedal or moved about some other way, then the position of the opening might indicate when our ancestors developed the upright, bipedal posture so often taken to be the hallmark of humanity.

Not everyone has agreed on the importance of foramen