Fossils & Ancient Environments Explorer

Discover what Earth looked like millions of years ago by exploring real fossils. Match fossils to ancient habitats and learn how scientists read clues from rocks.

Reference Guide

What Are Fossils?

Fossils are the preserved remains or traces of plants and animals that lived long ago. They form when organisms get buried in mud, sand, or ash and slowly turn to stone over millions of years.

Scientists who study fossils are called paleontologists. They use fossils like puzzle pieces to figure out what ancient life and environments were like.

Rock Layers Tell a Story

Rocks form in layers called strata. The bottom layers are older and the top layers are newer. Each layer is like a page in Earth's history book.

Different fossils in different layers tell us how the environment changed over time. Seashells in a mountaintop rock mean that spot was once under the ocean!

Fossils as Environment Clues

Each fossil tells us about the environment where the organism lived. Seashells and trilobites mean ancient oceans. Fern leaves mean warm, wet forests. Petrified wood points to swampy wetlands.

When scientists find several fossils together, they can paint a picture of what that place looked like long ago.

How Environments Change

Earth's surface has changed dramatically over billions of years. Continents move, sea levels rise and fall, and climates shift from tropical to icy and back again.

By comparing fossils from different rock layers, scientists can track these changes. A desert today might have been an ocean 300 million years ago!