Animal Classification

How Do Scientists Classify Animals?

Scientists classify animals using physical traits, behaviors, and genetics in a process called taxonomy.

Scientists look at traits like backbones, body coverings, reproduction methods, and diet.

Example: Lion Classification:

All vertebrates have a backbone.

Mammals: Warm-blooded, fur or hair, live births (usually), milk for young (e.g., whales, humans).

Birds: Feathers, lay eggs, hollow bones for flight (e.g., eagles).

Reptiles: Scales, cold-blooded, lay eggs (e.g., snakes, lizards).

Amphibians: Begin in water with gills, develop lungs, moist skin (e.g., frogs, salamanders).

Fish: Live in water, gills, fins, scales (e.g., sharks, goldfish).

Invertebrates do not have a backbone.

Insects: 6 legs, three body parts, often wings (e.g., ants, butterflies).

Arachnids: 8 legs, 2 body parts, no wings or antennae (e.g., spiders).

Crustaceans: Mostly aquatic, hard exoskeleton, gills, jointed limbs (e.g., crabs, shrimps).

Mollusks: Soft-bodied, many have shells, muscular foot (e.g., snails).

Worms: Long, soft bodies, no limbs (e.g., earthworms, flatworms).

Echinoderms: Spiny skin, live in oceans, radial symmetry (e.g., starfish).

Cnidarians: Soft-bodied, tentacles with stinging cells, mostly aquatic (e.g., jellyfish, coral).

Sponges: Simple, porous bodies, filter feeders (e.g., sea sponge).

Here are some interesting facts about animal classification:

Humans share 98–99% of their DNA with chimpanzees!
Sponges are animals, even though they don’t move.
Whales and bats are mammals, even though they live in water or fly.
Genetic testing revealed that giant pandas are true bears, not raccoon relatives as once thought.

Let’s quickly recap what we learned about animal classification: