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 ...

Mojave fringe-toed lizards have numerous traits tailored to their sand-dwelling lifestyle. Foremost are the lizards' scaly hind toes, which resemble snowshoes and keep them from sinking as they sprint ...