Position of the costal facets of thoracic vertebrae
- The first through ninth thoracic vertebrae have one upper and one lower (two in total) semicircular costal facet posteriorly on the sides of the vertebrae (the upper costal facet of the first thoracic vertebra is circular).
- Tenth to twelfth thoracic vertebrae with one circular costal facet (upper costal facet of tenth thoracic vertebrae is semicircular).