The extinction of the Pleistocene megafauna may be people’s fault after all, according to a recent study.
A team of archaeologists recently examined animal bones at sites dating to the waning years of the last Ice Age. Their results suggest that extinct megafauna like giant sloths, giant armadillos, and elephant-like creatures were on the menu for Pleistocene hunters in South America. And that means human hunters may have played a nontrivial role in killing off the continent’s last great Ice Age megafauna.
Giant ground sloth: It’s what’s for dinner
Archaeologist Luciano Prates of Mexico's National University of La Plata and his colleagues counted the animal bones left behind by ancient people at 20 archaeological sites in modern-day Argentina, Chile, and Uruguay. They compared the number of bones from extinct megafauna (technically, “megafauna” describes any animal over 44 kilograms) to the number of bones from smaller prey. They also tallied the remains of still-living species of megafauna like vicuñas. The archaeologists hoped to learn whether giant sloths, giant armadillos, and now-extinct species of horses were staples in the diets of Ice Age South Americans.
They chose sites that dated back more than 11,600 years, before the last of the now-extinct Ice Age megafauna vanished from the continent. The team only counted bones with clear signs that people had butchered the animal for food, like cut and percussion marks.
At 15 of the 20 sites, most of the butchered bones came from now-extinct megafauna; at 13 of those sites, extinct Pleistocene megafauna accounted for more than 80 percent of the total animal bones. That suggests that ancient hunters had a clear preference for now-extinct prey like giant sloths, giant armadillos, extinct horses, and even relatives of modern elephants—at least when they could get them.
In what’s now central Chile, the top menu item was Notiomastodon platensis, an extinct relative of modern elephants (they were about the size of a modern Asian elephant but had no tusks). Meanwhile, in Patagonia (the southern swath of South America, spanning parts of Argentina and Chile) and the Pampas grasslands of Uruguay and Argentina, people seemed to prefer two species of giant sloths.