The vertebr have the faces of their centra more or less bi-concave.
The vertebrae are generally without epiphyses to their centra.
In the Ichthyosauria the neural arches were united to the centra by cartilage only.
This sheath forms the basis of the centra of the future vertebr.
Injuries to the centra were very frequent, but differed extraordinarily in their importance.
There are no inter centra, and the neural arches are firmly united to the centra.
Both neural and haemal arches are ossified continuously with the centra.
This is the remaining substance of the notochord, which finds room between the cup-shaped sides of the centra.
The centra increase in length posteriorly, the last lumbar having the greatest length of any vertebra in the column.
Similar but much smaller foramina occur on the sides of the centra of the eighth and ninth caudals.