Scientists have identified two ancient reptiles that swam in ice-cold waters off Australia 115 million years ago and are among the first of their kinds to be found after the Jurassic era, researchers said on Saturday. The discoveries, Umoonasaurus and Opallionectes, belonged to a group of animals called Plesiosaurs, long-necked marine reptiles that lived during the time of the dinosaurs. Researchers, led by palaeontologist Benjamin Kear and a team from the University of Adelaide and the South Australian Museum, identified the new species after piecing together fossils from 30 individuals collected from an opal mine over the past 30 years.