Long before today’s tree-dwelling sloths, a 4-ton giant roamed South America — and it may have stood and fought like a bear.

Forbes contributors publish independent expert analyses and insights. I write about biodiversity and the hidden quirks of the natural world. When we think about the scope of our world’s diversity, ...

The blue whale holds the title as the largest animal ever known to have lived on Earth. This video explores how big blue whales can grow, how they survive in the ocean, and what makes them such ...

Everyone knows that animals come in all shapes and sizes, and millions of years ago, some of those animals were absolutely enormous. Today, if you look across the land of North America, the biggest ...

Due to its vast size — stretching from Canada and Greenland in the north, to Mexico in the south — North America contains a vast range of habitats. From land to sea, there are forests, mountains, ...

Most of the large animals that have walked the surface of Earth are no longer here. Why? Dan Mann thinks it’s because our recent climate has been too stable, at least when compared to the wacky ups ...

Some extinct mammals from Australia's Mammoth Cave included (from left) a giant long-nosed echidna, a short-faced kangaroo, a wombat-like marsupial and a Tasmanian thylacine. - Peter Schouten Recent ...