Final answer:
An immovable bone example is a suture in the skull, which is a type of synarthrodial joint called a synarthrosis, offering protection for vital organs like the brain.
Step-by-step explanation:
An example of an immovable bone or synarthrodial joint is the suture found in the skull. A synarthrosis is an immobile or nearly immobile joint that provides strong union between bones, which is crucial in areas where protection of internal organs is necessary. The suture joints of the skull protect the brain, whereas the manubriosternal joint safeguards the heart by uniting the manubrium and body of the sternum. So, the suture in the skull, which is a type of synarthrodial joint called a synarthrosis, offering protection for vital organs like the brain acts as a goof example of an immovable bone.