Several of these classes are specific types of fish, for example: jawless fish, like lampreys and hagfish, and cartilaginous fish, like sharks and rays.
Because their skeletons were cartilaginous, what remains of megalodons are mostly scattered clues, like some isolated vertebrae and lots of their enamel-protected teeth.
Once contracted, they compress the arms of the cartilaginous skeleton at the base of the salamander's tongue, which then launches out with the rest of its tongue tissues.
There's a magnificently well preserved dinosaur from Italy, which includes the cartilaginous tracheal rings, still preserved in the throat, and muscle fibers at the base of the tail.
As you might guess, your cartilaginous joints unite bones using cartilage, and are similar to their fibrous brethren in that they don't move very much, and they lack a joint cavity.
OK, if you say so, Professor. And since you're in a scientific mood, how about answering today's quiz question. Which type of joint can you crack? Is it … a) fibrous? b) cartilaginous? Or c) synovial?