PHILADELPHIA University of Pennsylvania researchers have unearthed a new genus of gargantuan dinosaur in a corner of Egypt that paleontologists had all but ignored since World War II, when earlier finds stored in German museums were blasted from existence by Allied warplanes. In the June 1 issue of Science, the Penn team reports on its discovery of Paralititan stromeri, one of the most massive animals ever to walk the earth, and presents evidence that the quadruped walked in ancient mangrove swamps in what is now the Sahara Desert.