Whether described as a vertebrate or reptile, Earth's animals can be classified and divided in many ways. Readers are introduced to scientific classification in an easy-to-understand way, complete with fun fact boxes about cool animals such as kangaroos and crocodiles. Full-color photographs of these animals will draw readers in and help them learn about the similarities and differences between animals groups. With sidebars complementing the main science content, readers won't be able to get enough of the animal kingdom.