Sharks are a group of 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. Modern sharks are classified within the clade Selachimorpha (or Selachii) and are the sister group to the rays. Under this broader definition, the earliest known sharks date back to more than 420 million years ago.
Since then, sharks have diversified into over 505 species. They range in size from the small dwarf lantern shark (Etmopterus perryi), a deep sea species of only 17 centimetres (6.7 in) in length, to the whale shark (Rhincodon typus), and the largest fish in the world, which reaches approximately 12 metres (39 ft) in length.
Build your knowledge and learn more about these fascinating rulers of the sea, while you enjoy the intellectual challenge of the cleVer Cube, the finest quality rotational puzzle.