(Águeda Vilhena Vialou, Denis Vialou via AP) In the past 30 years ... as well as similar-aged tracks of giant mammals. But ...

In the past 30 years ... as well as similar-aged tracks of giant mammals. But some archaeologists say it’s hard to imagine that humans would repeatedly traverse a site and leave no stone ...

In the past 30 years, new research methods—including ... Credit: Águeda Vilhena Vialou, Denis Vialou via AP This illustration depicts giant sloths, humans and mastodons living alongside one ...

In the past 30 years ... as well as similar-aged tracks of giant mammals. But some archaeologists say it’s hard to imagine that humans would repeatedly traverse a site and leave no stone ...

"In the past 30 years ... where bones of giant ground sloths show signs of being manipulated by humans. Sloths like these once lived from Alaska to Argentina, and some species had bony structures ...

(Águeda Vilhena Vialou, Denis Vialou via AP) In the past 30 years ... similar-aged tracks of giant mammals. But some archaeologists say it’s hard to imagine that humans would repeatedly ...

In the past 30 years ... as well as similar-aged tracks of giant mammals. But some archaeologists say it is hard to imagine that humans would repeatedly traverse a site and leave no stone tools.