New research painted a more accurate picture of the megafauna that spread widely around the Americas before they went extinct. By Jeanne Timmons Ground sloths emerged in South America tens of ...

For a long time, scientists believed the first humans to arrive in the Americas soon killed off these giant ground sloths ...

The Hoffman's two-toed sloth is one of the world's slowest mammals—so sedentary that algae grows on its furry coat. The plant gives it a greenish tint that is useful camouflage in the trees of ...

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