Cartilage comprises the skeleton of Greenland sharks.
It has the longest known lifespan of all vertebrate species -LRB- 392  120 years -RRB- , and is among the largest extant species of shark .	shark	shark	vertebrate	vertebrate
Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton , five to seven gill slits on the sides of the head , and pectoral fins that are not fused to the head .	elasmobranch	elasmobranch	fish	fish	cartilaginous skeleton	Chondrichthyes#Skeleton
