Stirtodon
Stirtodon is an extinct genus of monotreme mammal from the Late Cretaceous Griman [Creek Formation] of Australia. The genus contains a single species, S. elizabethae, known from a large isolated premolar. Stirtodon may be the largest toothed monotreme discovered. Several other monotremes are known from the Griman Creek Formation, including Dharragarra, Kollikodon, Opalios, Parvopalus, and Steropodon.