Caudal vertebrae are the vertebrae in the tail - the tail bones. 
The vertebrae that form the skeleton of the tail. ... (05 Mar 2000) ... 
Type: Term Definitions: 1. the vertebrae that form the skeleton of the tail.
The vertebrae of the tail. In birds, the anterior caudal vertebrae fuse with the sacral and lumbar vertebrae and some of the thoracic vertebrae to form the synsacrum; the next four to nine vertebrae articulate freely; and the posterior ones fuse to form the pygostyle (tail bone).