Ever since French naturalist Georges-Louis Leclerc, Comte de Buffon, first described the sloth in 1749, the planet’s slowest moving mammal has had its work cut out for it. “These sloths are the lowest ...

Sloths, the world's slowest mammals, have evolved over 64 million years into a species that thrives throughout Central America and northern South America, but climate change and human sprawl could be ...

But when it comes to their biology, the Central and South American critters are anything but boring. "Thirty percent of their body weight is just digesting, fermenting leaves," says Cliffe. "So ...