Animal Classification

Scientists organize animals into groups based on how they are alike. This system is called classification. It helps us understand how animals are related to each other. There are millions of animal species on Earth.

How Classification Works

Animals are sorted into big groups and then into smaller groups. The biggest group is called a kingdom. All animals belong to the animal kingdom. Then they are split into smaller groups like classes, orders, and families.

Main Animal Groups

The two biggest groups are vertebrates and invertebrates. Vertebrates have backbones and include fish, birds, and mammals. Invertebrates have no backbone and include insects, spiders, and jellyfish. Most animals on Earth are invertebrates.

Fun Facts

• There are about 8.7 million different animal species on Earth.
• Insects make up about 80 percent of all known animal species.
• A Swedish scientist named Carl Linnaeus created the modern classification system in the 1700s.

Did You Know?

Every species has a two-part scientific name in Latin. Humans are called Homo sapiens, which means 'wise person.'