Larger Than Life: Earth's Biggest Animals

Lesson Plan - Get It!

Audio:

From the deepest sea to the tallest mountain, the earth has been home to some massive animals.

• Can you think of any animals that are nearly as large as the blue whale?

Although the largest animal to ever exist, the blue whale, is alive today; many of the earth's giants went extinct long ago. To understand how some animals grew to such large sizes, let's jump into a time machine and go back. Buckle up!

Welcome to the Cretaceous period! Dinosaurs have already existed for some time; however, this period is home to one very special dinosaur. Take a look at the photo below.

• Can you spot and click on the largest dinosaur to ever be discovered?

There are many factors that allowed dinosaurs to grow so big. Check them out in this video!

Eventually, the dinosaurs' time on the earth came to an end. Let's hop back into our time machine and go to the Pleistocene era!

Look around and describe what you see. Those aren't elephants; those are woolly mammoths! Their thick fur kept them warm during this colder period. Scroll through the photos to discover more amazing Pleistocene animals.

These Pleistocene megafauna, or giant animals, reigned supreme after the dinosaurs. No one knows for sure why these animals were able to grow so large. However, some scientists speculate that being large was an advantage because they could better compete for resources and fend off predators. It's even thought that larger mammal bodies were advantageous in cooler environments because they held heat better.

The fall of the Pleistocene megafauna is as much of a mystery as their rise.

• Besides changes in climate, what do you think could have caused the Pleistocene megafauna to disappear?

Many scientists believe humans hunted these giant animals to extinction!

• We've seen the fall of the dinosaurs and the demise of the Pleistocene megafauna, but what about the blue whale?
• What makes the blue whale so special that it holds the spot of the largest animal to ever live?

With a pen and paper, check out the video below and write down two reasons.

Now that you've learned a thing or two about the earth's largest animals, climb back into the time machine and head to the Got It? section to review what you learned.