7 Giant Animals That Are Now Extinct Part 1

3. Josephoartigasia

The Horse-Sized Rodent

This prehistoric rodent was the largest rodent ever discovered.

Key facts:

• Size comparable to a modern horse
• Massive front teeth
• Likely herbivorous
• Lived about 4 million years ago

Earlier estimates of extreme bite force are debated, but scientists agree it had a strong jaw for chewing plants. Climate change likely ended its species.