Little tree sloths like this one inch through life in slow motion, hanging upside-down while munching leaves. But just look at their ancient ancestors!To many of us, the most familiar animals are the ones that evolved in North America, Europe and Africa, places whose evolutionary histories are closely linked. South American mammals started from different roots, so they evolved in different directions.
Little tree sloths like this one inch through life in slow motion, hanging upside-down while munching leaves. But just look at their ancient ancestors!
Giant, down-to-earth ground sloths reared up on hind legs, ripped down branches with huge claws and stripped leaves with long, grasping tongues!
These two hoofed mammals are like nothing alive today
Homalodotherium (ho-ma-LOW-da-THEER-ee-um; 10K au audio) and Astrapotherium (a-STRAP-o-THEER-ee-um; 10K au audio) evolved in South America while it was an isolated island. They became extinct long before humans evolved, so we know them only by studying their fossils.