The Largest Dinosaur Ever Found

There's ongoing debate about which dinosaur might be the largest animal to have ever roamed the Earth. One candidate is a 98 million year old skeleton of a long-necked titanosaur discovered in northwest Patagonia in 2012. There are several hypotheses about why these creatures grew so massive. For example, we do still have megafauna that reach towering sizes like elephants, rhinoceros, and hippopotamus.