The new Argentine dino might give us clues to what the world was like before the asteroid wiped out their kind.

In this slow-growth model, even the smallest titanosaurs would have taken nearly a century to reach their full size, meaning they would have been relatively small for a good chunk of their lives.

A replica fossil of the titanosaur _Patagotitan_, one of the largest dinosaurs ever discovered. It would have weighed about 70 tons (63.5 metric tons.) Spencer Platt/Getty Images News via Getty Images ...

You’re probably familiar with classic sauropod dinosaurs – the four-legged herbivores famous for their long necks and tails. Animals such as Brachiosaurus, Apatosaurus and Diplodocus have been ...