Final answer:
The two thoracic vertebrae that fit together have three joints: a single anterior joint called costal facet, and paired posterior joints called costal facets.
Step-by-step explanation:
Thoracic vertebrae have two facets called costal facets on the lateral sides of the body for articulation with the head of a rib. Additionally, there is an additional facet on the transverse process for articulation with the tubercle of a rib.
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