During the fourth week of the development, the sclerotome cells migrate ventromedially to surround the notochord and form the vertebral bodies. The body of each vertebra develops from the caudal part of one sclerotome and cranial portion of the next sclerotome. The mesenchymal cells between the vertebral bodies contribute to the formation of the intervertebral disc. While the notochord regresses entirely in the region of the vertebral bodies, it persists in the region of the intervertebral discs, thus forming the nucleus pulposus. Laterally, the circular fibers form the annulus fibrosus.

Sclerotomal cells which cover the neural tube form the vertebral arches, while the cells passing ventrolaterally develop into the costal processes and ribs. During the sixth week, chondrification centres appear in the mesenchymal vertebrae.
Ossification starts during the 8th week and continues throughout the development. The two primary ossification centres fuse to form a single centrum. Ossification centers develop in each half of the vertebral arch.

1. Vertebral foramen
2. Notochord
3. Costal process
4. Mesenchymal vertebral body
5. Vertebral arch

1. Vertebral foramen
2. Notochord
3. Costal process
4. Vertebral body
5. Vertebral arch
6. Chondrification centers

1. Vertebral foramen
2. Notochord
3. Vertebral body
4. Vertebral arch
5. Ossification centers