The form of ossification that takes place is the endomembrane or endochondral type. In joints classified as SYNARTROSIS, there isn't an intermediate formation of ligament or cartilage, meaning the bone grows not from cartilage ossification but from undifferentiated cells that will calcify into bone cells, forming the primary structural units called OSTEONAS. The skull bones, particularly in the temporal region (Temporary Suture), exhibit this type of joint, which experiences rapid growth over a lifetime through mechanisms distinct from those affecting movable joints.