Latin name Ausktribosphenos nyktos, meaning "Australian Cretaceous tribosphenic mammal that lived during the night". This creature was a small, insectivorous mammal that lived during the cretaceous perios approximately 115 million years ago. A fossilized jaw from one of these creatures was discovered by Nicola Barton in 1997, at Flat Rocks, southeast of Melbourne, Australia. It is believed to have been nocturnal, and is the oldest known Australian mammal. It was neither a marsupial nor a monotreme, it may have been either a placental mammal or a new type. It was named by Tom Rich and Pat Vickers-Rich.