Final answer:
The Pleistocene Extinction was a mass extinction event at the end of the Pleistocene epoch, primarily affecting large animals. It is believed to have been caused by over-hunting by humans and environmental changes due to the last glaciation period.
Step-by-step explanation:
The Pleistocene epoch was characterized by a mass extinction event at its end, known as the Pleistocene Extinction. This extinction primarily affected large, or megafauna, animals. In North America, species such as the woolly mammoth, mastodon, giant beavers, giant ground sloths, saber-toothed cats, and the North American camel became extinct around 10,000-12,000 years ago. The cause of this extinction is believed to be a combination of over-hunting by humans and environmental changes due to the last glaciation period.