Atypical thoracic vertebrae

T1 and T9 - T12 are considered atypical thoracic vertebrae.

• T1 bears some resemblance to low cervical vertebrae
• T9 has no inferior demifacet
• T10 often, but not always, shares features with T11 and T12. 

For a basic anatomic description of the structure a generic vertebra, see vertebrae.