What type of joint is a cranium or vertebrae?
As mentioned in livestrong.com . . .
"There are three major types of joints in the body . . . fibrous, cartilagenous, and synovial."
Fibrous are generally immovable; cartilaginous are slightly immovable; synovial are completely movable (hinged, rotational, and gliding).
The cranium (or skull) is the only fibrous suture joint in the body. One would think that the skull would be solid and immovable, but that is not entirely true. The bones of the cranium are held together by thin cartilaginous tissues that allow the bones to be compressed and slide over each other during the journey through the birth canal. That is why a newborn baby will often have a misshapen head for a few days after birth.
The vertebrae are a type of cartilaginous joint called a symphysis joint. This means each individual vertebra is held to another by a cartilaginous ring (or disc) that allows the spinal column to twist and flex in all directions while still protecting the spinal cord.