ELI5: Explain Like I'm 5

Pleistocene megafauna

Pleistocene megafauna are the large animals that were around during the Pleistocene Period which lasted from around 2.6 million to 11,700 years ago. These animals were usually huge compared to animals today, like mammoths and giant sloths. We don't see these animals anymore because they all went extinct during this time period, most likely due to changes in the environment and hunting by humans.