Sydney, Nov 21 (Prensa Latina) A team of scientists led by Lachlan Hart, a paleontologist and PhD candidate in the School of Biological, Earth and Environmental Sciences at UNSW Sydney, has assessed several methods of estimating the weight of the last of the temnospondyls -amphibians that look more like – became extinct during the Cretaceous period, about 120 million years ago, after thriving on Earth for over 200 million years, reached up to seven meters long and weighed about 260 kgs.