The sauropod dinosaurs - the biggest animals ever to walk the Earth - were enormous plant-eating beasts with long necks and tails. The biggest are aptly named titanosaurs, and could reach 30 metres long and weigh 80 tonnes.
However, some titanosaurs may have been even bigger than that, says Rodolfo Garcia at the National University of Rio Negro in Argentina, 'New Scientist' reported.
Garcia has found a 7.5-centimetre-long titanosaur tooth at Salitral de Santa Rosa in Rio Negro
