A sutural bone is one of the types of bones most of which are classified by shape (but in the case of sutural bones only, by their location in the human body).
Sutural bones are very small bones located specifically within the sutural joints between the cranial bones of the skull. They are classified by their location - hence the name of this type of bone - rather than by their shape. The number of sutural bones varies considerably because different people have different numbers of sutural bones.
This type of bone is not always included in lists of "types of bones" because it is not one of the 5 main types of bones.
All sutural bones are un-named bones.
See also books about orthopaedics.