Vertebrates

A vertebrate is an animal that has a backbone, also called a spine. Fish, birds, mammals, reptiles, and amphibians are all vertebrates. Even though vertebrates make up only 3 percent of all animals, they include the largest animals on Earth.

The Five Groups

Vertebrates are divided into five main groups. Fish live in water and breathe with gills. Amphibians live part of their life in water and part on land. Reptiles have scaly skin. Birds have feathers. Mammals have hair or fur and feed milk to their babies.

The Backbone

The backbone is made up of small bones called vertebrae. It protects the spinal cord, which carries messages between the brain and the body. The backbone also gives animals support so they can stand, swim, or fly. Humans have 33 vertebrae in their spine.

Fun Facts

• A giraffe has the same number of neck bones as a human, just seven, but each one is much longer.
• Snakes are vertebrates that can have over 400 vertebrae in their spine.
• The blue whale is the largest vertebrate ever, even bigger than the biggest dinosaurs.

Did You Know?

The first vertebrates appeared in the ocean about 500 million years ago. They were small, jawless fish that looked very different from fish today!