Tag Archive: tunnels

Huge Ancient Tunnels In South America Might Have Been Dug Out by Giant Sloths

  Deep inside Brazil, there are tunnels large enough for a person to walk through. They are neatly symmetrical—too neat to have been caused by any known geologic process. And they are lined with claw marks. Learn More: http://www.popularmechanics.com/science/environment/a25880/huge-tunnels-south-america-dug-by-extinct-giants-sloths/?src=socialflowTW&src=socialflowTW My…
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