Dermal bone

The dermal bone, the pattern and form of bones derived from intramembranous ossification, define essential components of the vertebrate skeleton including the skull, jaws, gills, fins and exoskeleton.

The function of dermal bone is conserved throughout vertebrates, varying in shape and numbers of bones in the skull and postcranial structures. In bony fish, dermal bone is found throughout the body in the fin rays and scales. However, these traits have been lost in higher vertebrates.