part of part of Homo sapiens thoracic vertebra 6 zone of bone organ transverse costal facet of sixth thoracic vertebra 2026-03-19T00:00:00Z A zone of bone organ located on the anterior surface of the transverse process of the sixth thoracic vertebra, articulating with the tubercle of the sixth rib at the costotransverse joint. It is a smooth, oval synovial articular area that guides rib rotation during breathing and contributes to thoracic cage stability. David Osumi-Sutherland