. "Kollikodon ritchiei is a fossil monotreme species. It is known only from an opalised dentary fragment, with one premolar and two molars in situ. The fossil was found at Lightning Ridge, New South Wales, Australia, as was Steropodon.Kollikodon lived in the lower Cretaceous period, during the middle Albian age (100\u2013104 million years ago). Like Steropodon, Kollikodon was a relatively large mammal for the Mesozoic."@en . . . . . "Kollikodon ritchiei"@en . .