part of part of Homo sapiens rib 12 surface groove costal groove of twelfth rib 2026-03-19T00:00:00Z A surface groove on the inferior border of the body of the twelfth rib that accommodates the subcostal nerve and accompanying vessels. The groove is poorly defined or absent in the twelfth rib, which is the shortest rib and lacks the typical inferior curvature that shelters neurovascular structures in typical ribs. David Osumi-Sutherland