What do we have in common with sharks, bluebirds, lizards, and toads? We are all vertebrates, or animals with backbones. Vertebrates use their backbones for movement and support. Vertebrates share other traits as well: an internal skeleton, muscles, a protective skin, blood that circulates through vessels, and an advanced nervous system, including a head with a brain.

Phylum and subphylum: Chordata, Vertebrata
Characteristics: a backbone, an advanced nervous system, skin, an internal skeleton, muscles
Habitats: found in all ecosystems around the world, from the polar regions to the tropics

Image credits: main image, cat skeleton, horse skeleton, courtesy of AMNH Department of Library Services, chicken skeleton, courtesy of AMNH, Roderick Mickens.