Calcium: Chemical element and alkali metal common in Earth’s crustal minerals and sea salts. It is also found in bone minerals and teeth, and plays a role in moving certain substances into and out of cells.
Cartilage: (adjective: cartilaginous) A type of strong connective tissue commonly found in joints, noses, and ears. In certain primitive fishes, such as sharks and rays, cartilage forms the internal structure of the body, or skeleton.
Extinct: An adjective describing a species that has no living members.
Power: External influences that can change the motion of objects, move objects closer together, or cause motions or stresses in stationary objects.
Megalodon: A type of extinct shark, Otodus megalodon (Previously Carcharocles megalodon), lived between the early Miocene (an era that began about 23 million years ago) and the end of the Pliocene (about 2.6 million years ago). Most scientists believe this was the largest fish ever. Its name is of Greek origin and means huge tooth. The average adult of this species may have been over 10 meters (33 feet) long and weighed over 30 tons (66,000 pounds).
Shark: A type of predatory fish that has survived in some form for hundreds of millions of years. The structure of the body is determined by cartilage, not bones. Like skates and rays, sharks belong to a group known as elasmobranchs. They tend to grow and mature slowly and have few children. Some lay eggs, while others give birth to live young.
Spine: (Sing. Vertebrae) Bones that make up the neck, spine, and tail of vertebrates. The bones in the neck are called the cervical vertebrae. The bones in the tail are called caudal vertebrae in animals that have caudal vertebrae.
Whale: A common but rather imprecise term for a type of large marine mammal. This group includes dolphins and dolphins.
Source: www.snexplores.org
