Final answer:
The sagittal suture is not an example of a fibrous joint, unlike the other given options which are indeed examples of fibrous joints.
Step-by-step explanation:
A fibrous joint is a type of joint where adjacent bones are directly connected to each other by fibrous connective tissue.
Out of the given options, the sagittal suture is not an example of a fibrous joint. The sagittal suture is a type of fibrous joint found between most bones of the skull.
The other options, such as radioulnar, dentoalveolar, and intervertebral, are all examples of fibrous joints. For example, the radioulnar joint is connected by a syndesmosis, a type of fibrous joint, and the intervertebral joint is connected by an intervertebral disc, which is another type of fibrous joint.