The Harley-Davidson insignia shaped bone has a lot going on. It sits front row center in the skull. The orchestra pit - the "sella" or hypophyseal fossa cradles the pituitary gland.  Just forward that cradle of endocrine importance are the two optic canals.

Most of this bone begins as cartilage. The skull bones are of two main sorts: those that begin as cartilage and those that are formed between membranes. The cranial plate like vault bones are those from membrane. Most of the smaller base of skull bones are formed in cartilage.

In conditions which affect cartilage to bone progression, the two sorts of bones will be affected differently giving rise to the characteristic head and facial features of the respective conditions. An example of cartilage to bone lag is seen in the more common form of dwarfism.