This is a shallow, thin groove that runs anteromedially from the hiatus for the greater petrosal nerve just anterior to the arcuate eminence to the foramen lacerum at the apex of the petrous temporal bone. It carries the greater petrosal nerve toward the foramen lacerum where it will join with the deep petrosal nerve, a branch of the carotid sympathetic plexus, to form the Vidian nerve or nerve of the pterygoid canal.

A groove or its equivalent, a sulcus, denotes a shallow channel in the bone. Petrous means like a rock. It comes from the Latin petra meaning rock. Galen was the first to use this term to describe the thick, rock-like region of the temporal bone.

Sulcus nervi petrosi majoris