The Skeleton: Part 1, The Skull



The human skull develops from three separate sets of bone forming tissues. These embryonic tissue groups include the neurocranium group, the splanchnocranium group, and the dermatocranium group.

In development, both the neurocranium and splanchnocranium begin as regions of hyaline cartilage. Later in development, these cartilages are converted to bones of the skull through a process known as endochondral bone formation.


The dermatocranium portion of the skull begins as fibrous membranes that are later converted to bone in a process of membrane bone formation.






































Divisions of the skull

Neurocranial division

Dermatocranial division

Splanchnocranial division

Sphenoid as a composite bone

Temporal as a composite bone

Occipital as a composite bone

Lamprey head skeleton

Shark and Ratfish head skeleton

Head skeleton of bony fishes

Neurocranial ossification in bony fishes

Dermal bones and scales in bony fishes

Dermal bones and the fish/amphibian link

Anapsids, diapsids, synapsids and others

Diapsids variations

Reduced dermal bone

Secondary palate formation

Hyomandibular expression

Quadrate and articular expression

Occipital condyle number

Sample Questions