An atoll is a ring-shaped coral reef that surrounds a lagoon in the middle. These unique islands are found in warm, tropical oceans and are often associated with beautiful beaches and crystal-clear waters.


Atolls form over millions of years as coral grows around the edges of a volcanic island. As the volcano slowly sinks into the ocean, the coral continues to grow upward, eventually creating a circular reef with a lagoon in the center where the volcano used to be.

While atolls might seem far removed from dinosaurs, they actually help scientists understand how the Earth has changed over time. The process of atoll formation shows how sea levels and landscapes can change over millions of years, which is important for understanding the environments where dinosaurs lived.


Picture a donut floating in the ocean. The donut’s ring is made of coral and small islands, and the hole in the middle is filled with calm, blue water. That’s what an atoll looks like from above!

Fun Fact

Did you know that the largest atoll in the world is Kiritimati, also known as Christmas Island? It’s located in the Pacific Ocean and has a land area of about 150 square miles (388 square kilometers)!

People Also Ask

  • How are atolls related to dinosaurs?
  • Can people live on atolls?
  • How long does it take for an atoll to form?

How are atolls related to dinosaurs? While dinosaurs didn’t live on atolls, studying atolls helps scientists understand how the Earth’s geography has changed over time. This information helps them reconstruct what the world looked like when dinosaurs were alive. Some dinosaur fossils have even been found in rocks that were once part of ancient coral reefs!

Can people live on atolls? Yes, people can and do live on atolls. Many atolls in the Pacific Ocean are inhabited, with communities that have lived there for thousands of years. However, because atolls are low-lying, they face challenges from rising sea levels due to climate change.

How long does it take for an atoll to form? Atolls form very slowly, typically taking hundreds of thousands to millions of years to develop. The process starts with a volcanic eruption under the ocean and continues as coral grows and the volcano gradually sinks.