There are 5 lumbar vertebrae in the lumbar region. There are 5 sacral vertebrae, which are fused as one bone and known as the sacrum, in the sacral region. There are 3 to 5 coccygeal vertebrae, which ...

In particular, they make a much stronger connection between the hips and their backbone, and they do that by converting some of their vertebrae into a special modified structure called the sacrum that ...

L5-S1 is the exact spot where the lumbar spine ends and the sacral spine begins. The lumbosacral joint connects these bones.

Purussaurus mirandai is the only crocodylian that has been found to have the extra vertebra in its sacrum, the scientists said.