Obdurodon tharalkooschild

Obdurodon tharalkooschild is an extinct species of monotreme in the genus Obdurodon.  It is known from a single tooth found at the Miocene-aged Two Tree Site fossil beds in Riversleigh in Queensland, Australia.

Taxonomy 
The type material, a single tooth, was discovered in 2012 by a team from the University of New South Wales including Mike Archer, Suzanne Hand, and Rebecca Pian. The description, published in the same year, was the fourth species of the family Ornithorhynchidae to be described, the second from the Riversleigh site, and estimated to have been the largest.

The specific name was chosen in honour of an indigenous Australian creation story for the platypus, where a duck named Tharalkoo gives birth to a chimeric creature after being ravished by a rakali.

Description 
The living animal is assumed to be very similar in form to a modern platypus, but larger, exceeding Monotrematum in size and length. 
The species was estimated to have been present in the middle and upper Miocene (5–15 million years ago). The wear patterns on the tooth are suggestive of crushing, perhaps by consuming hard-shelled animals such as turtles, rather than using a shearing action.
Obdurodon tharalkooschild is thought to have inhabited fresh water and hunted for a variety of animal prey in the forests that dominated the Riversleigh site at the time of deposition. The species diet is assumed to have included crustacea like those consumed by the modern platypus, although larger species were available due to its greater size. The potential prey of the Riversleigh fauna also included frog, turtle, fish and the lungfish, species that are present in the deposition at the Two Tree Site of the Riversleigh formations. The ornithorhynchid species were unknown in the later fossil record at the time of discovery, and it defied the assumptions of a single lineage of a platypus-like animal that progressively lost its teeth and became smaller in size.

Cultural references 
The name given to the species was discussed in a 1990 paper by Mike Archer, an Australian mammalogist, detailing a creation story with an Ugly Duckling motif in the context of palaeontology. A philosophical examination of historical sciences such as palaeontology, published in 2018, uses the tooth of this platypus as an example of the results obtainable by multiple methods of research into traces of evidence; the author refers to the species by the vernacular "platyzilla".

References 

Category:Obdurodon
Category:Prehistoric monotremes
Category:Miocene mammals of Australia
Category:Riversleigh fauna
Category:Fossil taxa described in 2013