The three newly-identified species show combinations of features not previously seen before in other living or fossil monotremes, according to Professor Kris Helgen from the Australian Museum Research Institute and colleagues. Six monotremes living in the same place at the same time, 100 million years ago at Lightning Ridge, New South Wales, Australia; clockwise from lower left: Opalios splendens; Stirtodon elizabethae, the largest monotreme of the...
