Notoryctidae or marsupial moles, is a order of mammals of the order Notoryctemorphia. They are rare and poorly understood burrowing mammals of the deserts of Western Australia, with an ancestry going back 20 million years or so. Once classified as a monotreme, they are now thought to be a marsupial, though a recent non-peer-reviewed preprint suggests they may instead be a member of the Dryolestida, an otherwise extinct group of mammals.