Classifying Animals

Did you know that there are over 1,000,000 different species, or types, of animals? With so many species, scientists have to find a way to sort them into groups. Two of the main groups are vertebrates and invertebrates.

Vertebrates are animals that have a backbone. Humans are in this group. Also in this group are whales, monkeys, birds, and frogs. Just about any pet you have in your home is a vertebrate. Dogs, cats, goldfish, hamsters, and snakes are vertebrates.

Invertebrates have no backbone. Many of them live in the ocean. Clams, jellyfish, squids, and octopuses are invertebrates. Those that live on land are spiders, worms, and insects.

Scientists are finding new species of animals every day. Every one of them can be put into one of these two groups.