Argentine paleontologists Daniel Hernandez (R) and Alberto Garrido (L) work to clear dirt and rock...

Argentine paleontologists Daniel Hernandez (R) and Alberto Garrido (L) work to clear dirt and rock away from the tibia leg bone of an estimated 40-foot long Giganotosaurus, the largest meat-eating dinosaur known, at the site where a team (back) of Argentine, Canadian, and Danish paleontologists are working on a rare find of at least four animals that were fossilized in a pile. This important find of bones in the Patagonian desert shows the huge flesh eaters, that lived some 90 million years ago, were more fearsome than ever supposed - they probably hunted in packs. (Picture taken March 24)