What Are the Largest Prehistoric Animals?

What Are the Largest Prehistoric Animals?
The dinosaurs might have gone extinct some 66 million years ago, but that did not mark the end of large, sometimes scary, animals on Earth. Even as recently as 10,000 years ago, there were massive creatures that roamed the land and sea. One of the most notorious of these now extinct creatures is megalodon, a massive shark that has inspired many blockbuster films over the years. But megalodon just scratches the surface. What are some of the largest prehistoric animals to have ever lived? Let’s find out!

What Was the Largest Prehistoric Sea Creature?

Estimating the total size of very large prehistoric animals has always been tough, since most of what we know about these animals come from only partial remains. Still, we do have a few ideas about what the largest sea creatures were.

As mentioned earlier, one of the most famous prehistoric animals is a giant shark species known as megalodon. This now-extinct creature is thought to have resembled a great white shark, except for its size was likely 3 times that of the average great white. Considered the world’s largest carnivorous fish, megalodon could grow up to 70 feet long, and had an astonishing (or terrifying) 276 teeth. It is actually these teeth that have provided scientists with the main evidence of megalodon’s existence. They have been found on the ocean floor and average 7 inches a piece, much larger than the 3 inch teeth of modern great whites. We don’t know a whole lot about their diet, but scientists speculate they dined on large prey, like whales, seals, and sea turtles.

Megalodons had a cosmopolitan distribution, meaning they could be found across most of the world. They lived approximately 23 to 2.6 million years ago. Climate shifts and a changing ecosystem likely caused their extinction. Interestingly, it appears that their extinction had an impact on other animals. For example, the size of whales increased significantly after the shark disappeared.

Much of megalodon’s body was cartilage and wasn’t fossilized. As such, there is still a lot we don’t know about these incredible sea beasts.

What Are the Largest Prehistoric Land Animals?

Moving onto land, an ancestor of the rhino known as Indricotherium (also called Paraceratherium) is considered by many to be the largest land mammal to have ever existed. These 40 foot long giants sort of looked like an elephant with the neck of a giraffe. Their long, slender legs and neck helped them graze from trees. Indricotherium lived in the steppes of Eurasia about 30 to 16.6 million years ago. It weighed an estimated 30 tons (a modern elephant weighs roughly 6 tons). As central Asian forests eventually gave way to grasslands, indricotherium gradually began to die out.

Josephoartigasia was the world’s largest rodent, much bigger than the capybaras of today that it resembled. They were estimated to have weighed over a ton, and fed on fruits and plants throughout South America. A josephoartigasia skull found in Uruguay measured 1.7 feet long.


Indricotherium and josephoartigasia were not alone, however. The reality is that large mammals were not all that uncommon in prehistoric times. For example, the glyptodon was a distant relative of the armadillo, and featured a huge shell just like their modern cousins. Glyptodon was about 10 feet long, the size of a small car, and weighed almost a ton. They lived anywhere from 2 million to 10,000 years ago, and might’ve been hunted into extinction by early humans who used their massive shells for shelter.

Or how about the steppe mammoth? This large, elephant-like animal had tusks measuring up to 17 feet. The steppe mammoth could grow to be 20 feet long, and could weigh over 10 tons. Despite this formidable size, this gentle giant fed mainly on plants and insects, living throughout Eurasia some 5 million to 10,000 years ago. Like glyptodon, steppe mammoths likely died out due to human hunting.

What’s the Largest Animal That Ever Lived?

Did you know that the largest animal that ever lived can still be found in oceans today? Blue whales can reach up to 100 feet long, longer than two yellow school buses. Their tongue alone can weight as much as an elephant, and on average their bodies weigh upwards of 200 tons. Somewhat ironically, despite being the world’s largest animal, their diet consists mainly of krill; tiny crustaceans that grow to be about 2 inches in length. These massive creatures have likely been around for the last 54 million years or so. And they’ll presumably be around for millions of years to come.

Did you like this post? Click here to find more science-themed posts from the Sporcle Blog. Or test your scientific knowledge with some fun science quizzes on Sporcle!