Class:
* Mammalia: Mammals (dogs, cats, humans, whales, bats, etc.)
* Aves: Birds (chickens, eagles, penguins, etc.)
* Reptilia: Reptiles (lizards, snakes, turtles, crocodiles, etc.)
* Amphibia: Amphibians (frogs, salamanders, caecilians)
* Agnatha: Jawless Fish (lampreys, hagfish)
* Chondrichthyes: Cartilaginous Fish (sharks, rays, skates)
* Osteichthyes: Bony Fish (tuna, salmon, goldfish, etc.)
Key Characteristics of Vertebrates:
* Vertebral Column: A backbone made of bones called vertebrae.
* Skull: A bony or cartilaginous structure that protects the brain.
* Endoskeleton: An internal skeleton made of bone or cartilage.
* Bilateral Symmetry: Their bodies can be divided into two symmetrical halves.
* Closed Circulatory System: A system of blood vessels that carries blood throughout the body.
* Well-Developed Nervous System: A brain and spinal cord that coordinate bodily functions.