For millions of years, enormous, plant-eating glyptodonts lumbered across the Americas. Some species were as large as cars: up to 10 feet long. They were covered with thick armor, made from bone that grew from within their skin.

Glyptodont shells, or carapaces, were incredible heavy. Some weighed more than 1,100 pounds—up to 20 percent of the animal's total body weight. Look closely at this skeleton, and you will see adaptations that helped glyptodonts haul around such a heavy load.