Megafauna Extinction Facts

At the end of the last glacial period, which is often called the Ice Age, a mass extinction of large animals (megafauna) such as woolly mammoths, giant sloths, and short-faced bears occurred. These extinctions occurred over thousands of years and at different times in various parts of the world. For example in North America these extinctions occurred approximately 14,500 years ago whereas in Australia they occurred thousands of years earlier. On this page we list interesting facts about these megafauna extinctions. The information below addresses the questions, what caused the megafauna extinctions, why did these extinctions involve mostly large mammals, and where did the megafauna extinctions occur. These facts are written for both kids and adults.

Megafauna Extinction Background Information

Megafauna is define as an animal species with a weight greater than 100 pounds (45 kilograms); however many of the mammals that went extinct during the last glacial period were much bigger than this.
The megafauna extinctions occurred at the end of the last glacial period. A glacial period is a period when the world experiences colder temperatures and glacier advances from the earth's poles. The last glacial period began approximately 125,000 years ago and ended about 14,500 years ago.
Glaciers are very slow moving sheets of ice and snow.
The use of the term "ice age" to refer to the earth's last glacial period is misleading because there are actually numerous glacial periods, where ice sheets advance from the poles and then recede, within an ice age.

Interesting Megafauna Extinction Facts

This mass extinction involved some incredible animals that were incredibly huge; including the large predator cat Smilodon, mammoths, mastodons, cave bears, woolly rhinoceros, cave lions, giant sloths, straight-tusked elephant, short-faced bears, Bison antiquus, and the short-faced kangaroo.
The Megafauna Extinction is also referred to as the Holocene extinction or the Quaternary extinction event.
The megafauna extinctions did not occur everywhere on the earth and occurred at different times in different regions, some thousands of years apart.
Experts disagree on what caused the megafauna extinctions; popular theories include human hunting, world climate change, and disease. Many believe it occurred due to a combination of these causes. There is a less accepted theory that the extinctions happened due to a comet either hitting or exploding close to the earth.
The reason why there is so much controversy among experts on the cause of this mass extinction is simply the lack of enough empirical evidence to support any theory combined with valid points for the three main theories; human hunting, world climate change, and disease.
Many experts believe this mass extinction was caused by the hunting of humans who gradually moved out from Africa, where humans originated, to populate the rest of the world. They point out that regional extinctions seem to match the arrival of the first humans to these regions. This theory is also supported by the fact archaeological sites have been unearthed of mammoths with spear points embedded in their bones.

Those experts who believe climate change was the main factor point out how the world experienced rapid climate changes at the end of the last glacial period. Several experts specifically point to the Younger Dryas interval, referred to as the "Big Freeze", which was a sudden return to freezing weather conditions as the last glacial period was coming to an end. Some experts believe as the weather got warmer animals that were adapted for survival in the cold weather died-off due to the stress of the heat on them.
Experts who believe disease was the main factor causing the extinction of these huge mammals point out that some diseases, like rabies, can spread quickly among different types of animals. It has also been suggested that possibly humans, who were populating the various regions of the world, brought with them diseases that wiped out these huge mammals.