Argentinosaurus is one of the strongest contenders for largest animal ever to walk on land. From nose to tail-tip it stretched about 100 feet - basically the full length of a basketball court - and it would have weighed something like 100 tons. Picture 14 African elephants stacked on a single set of legs.
It lived in what’s now Argentina around 95 million years ago, in the warm, wet forests of the Cretaceous. Its body had a long whip-like neck for grazing over treetops, four pillar-thick legs, and an equally long tail that helped keep it balanced.
Scientists figured out its size from just a handful of giant bones - including a single vertebra over five feet tall. To support its weight, those bones had hollow chambers (like the bones of modern birds) which kept them strong but surprisingly light.
