Dermal bone

Dermal bone forms directly within connective tissue, without first developing from a cartilage model. It makes much of the skull and parts of the shoulder girdle in vertebrates.

Osteoblast: A bone-forming cell that secretes and mineralizes the extracellular bone matrix. Osteoblasts produce the matrix that becomes dermal bone.
Bone: A mineralized connective tissue that provides structural support, protection, and a reservoir for minerals. Dermal bone is one developmental type of bone tissue.
Calvaria: The dome-shaped upper portion of the skull, formed chiefly by flat bones. Its frontal and parietal bones are prominent dermal bones.
Vertebrate dermal skeleton: The set of skeletal elements that develop within the skin of vertebrates. Dermal bone is the principal material of this skeletal system.
Endochondral bone: Bone that develops by replacing a cartilage model. It is the main developmental counterpart to dermal bone.
Osteocyte: A mature bone cell embedded in the mineralized matrix that helps maintain bone tissue. Some osteoblasts become osteocytes as newly formed dermal bone matures.
Compact bone: Dense bone tissue organized into tightly packed structural units called osteons. Dermal bones can contain compact tissue in their outer layers.
Frontal bone: A skull bone forming the forehead and the upper portions of the eye sockets. It develops by intramembranous ossification as a dermal bone.
Ostracoderm: An extinct group of jawless fishes, many of which had extensive bony armor. Their armor provides an early fossil record of dermal skeletal elements.
Chondrocranium: The embryonic cartilaginous framework that contributes to the braincase and parts of the skull base. Many bones associated with it form by replacing cartilage, unlike dermal bones.

Linked from 17 pages