The First Lumbar and Last Three Thoracic Vertebrae of a Beaver
Note how the head and tubercle are not as distinct as they are in the anterior ribs. Both fit into the space between adjacent vertebrae. Also note that the vertebra on the left is not a thoracic vertebra. It lacks demifacets and has a flattened transverse process. It is the first of the lumbar vertebrae.
Click here to see other lumbar vertebrae.