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Cretaceous–Paleogene extinction event

Adapted from Wikipedia · Explorer experience

An artist's view of a massive asteroid crashing into Earth's oceans millions of years ago, which scientists believe led to major changes in life on our planet.

The Big Change Long Ago

A very long time ago, about 66 million years ago, something big happened on Earth. This change is called the Cretaceous–Paleogene extinction event. It made many plants and animals disappear, including all the big dinosaurs that were not birds.

What Happened?

Scientists think a huge asteroid, like a giant rock from space, hit Earth. This made a big hole called Chicxulub in the Gulf of Mexico. The dust and smoke from this hit made the world very dark and cold. This hurt many plants and animals.

Life After the Change

Even though many animals disappeared, some survived. Small mammals and birds were able to live through this time. After the dark time ended, these survivors began to grow and change. New kinds of animals, like horses, whales, bats, and primates, started to appear. Birds, which were the only dinosaurs left, also evolved into many different kinds we see today.

Why We Know About This

People learned about this big change by looking at old rocks and fossils. Fossils are like nature’s photographs, showing what lived long ago. Scientists found special clues in the rocks, like tiny glass beads and a lot of a space element called iridium. These clues helped them understand that a big asteroid hit Earth and changed life forever.

The Cretaceous–Paleogene extinction event helped shape the world we live in today. It made space for new animals and plants to grow and change.

Images

A view of the Badlands near Drumheller, Alberta, showing layers of rock that reveal Earth's history from the time of the dinosaurs.
A rock sample showing the boundary between two major geological time periods, displayed at a natural history museum.
Layers of clay from the time of the dinosaurs, showing Earth's history in the Netherlands.
Fossil of Discoscaphites iris, an ancient sea creature from the time of the dinosaurs.
Fossilized rudist bivalves from the Cretaceous period found in the Omani Mountains.
A fossilized skeleton of a Tyrannosaurus rex on display at a museum, showcasing the ancient dinosaur's bones and scientific importance.
A scenic view of the Hell Creek Formation near Ft. Peck Reservoir in Montana, showing layers of rock from the Cretaceous–Paleogene period.
Father and son scientists exploring a geological site in Italy, studying rock layers from a major event in Earth's history.
Map showing the world during the Late Cretaceous period, about 90 million years ago.
A view of the Cretaceous-Paleogene boundary layer at Trinidad Lake State Park in Colorado, showing important geological history.
A colorful map showing the geography and countries of North America.
A radar image showing the outline of an ancient impact crater on the Yucatan Peninsula, where a massive asteroid struck Earth long ago.
Illustration showing how an asteroid impact can affect Earth, helping us learn about past events in our planet's history.

Related articles

Earth
Cretaceous
Paleogene
Asteroid
Gulf of Mexico

This article is a child-friendly adaptation of the Wikipedia article on Cretaceous–Paleogene extinction event, available under CC BY-SA 4.0.

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