Kollikodon
Kollikodon ritchiei is an extinct mammal. It is among the earliest known representatives of the monotremes and lived in the Cretaceous period in Australia.
Features
The fossil record of Kollikodon limited so far to a opalised part of a lower jaw, which was equipped with a premolar and two molars. Today's Ursäuger are toothless, but fossil relatives of the platypus as Steropodon and Obdurodon instructed more teeth, allowing conclusions about the relationship. The teeth reminded her cross-shaped structure at "Hot cross buns ", common in Anglo- Australian space buns so that the jocular name " Hotcrossbunodon " was coined for the genus. According to speculations, the teeth were used for biting of crustaceans. which would suggest a semi- aquatic lifestyle.
Otherwise, little is known about the animals. Due to the size comparison with the mandible today Ursäuger has extrapolated the body length of Kollikodon to 1 meter, which would be very large for Mesozoic mammals; verify such calculations can probably only by further skeletal remains.
System
Kollikodon is classified in its own family, Kollikodontidae and is considered representative of the basal Ursäuger. Whether the species was more closely related to the platypus, as is sometimes claimed, can be no other finds probably not answer.