The chondrocranium (or cartilaginous neurocranium) is the primitive cartilaginous skeletal structure of the fetal skull that grows to envelop the rapidly growing embryonic brain.
While the majority of the chondrocranium is succeeded by the bony skull, some components do persist into adulthood.
[1] In cartilaginous fishes (e.g. sharks and rays) and agnathans (e.g. lampreys and hagfish), the chondrocranium persists throughout life.
[3] Embryologically, the chondrocranium represents the basal cranial structure, and lays the base for the formation of the endocranium.
The more rostral portion of the chondrocranium that lie anterior to the notochord constitutes the prechordal chondrocranium, and is derived primarily from neural crest-derived mesenchyme.