Yes, they definitely do. See the relatedlink listed below or more information:
No, dolphins have a bone-based skeletal system.
Bottle nosed dolphins are mammals and they do have a back bone.
The Ulna Bone
The name of mid hand bone is metacarpal. These are five in number in each hand.
You just take a bone put it in your hand and crush it!
The metacarpal bones in the hand are among the easiest to break due to their location and exposure to direct trauma. These long bones are vulnerable to fractures from impact or excessive force, such as punching or falling onto an outstretched hand. Immediate medical attention is recommended if you suspect a broken bone in your hand.
The lunate bone is a carpal located in the hand.
Dolphins
The ulna doesn't ve any contact with any bone from the hand
Bottlenose dolphins have appendages similar to many mammals. They have adapted to swimming even though the bone structure is the same.
metacarpals
One symptom of a left bone crack in your hand is severe pain. Also, the inability to move your hand is another symptom.