Obdurodon insignis

Obdurodon insignis is an extinct species of ornithorhynchid monotreme discovered in the Tirari Desert in central Australia. The animal resembled the related modern platypus Ornithorhynchus but, unlike the platypus, had a bill that possessed molars as an adult.

Taxonomy  
The holotype specimen, SAM P18087, a tooth, was uncovered in 1971 from the Lake Ngapakaldi to Lake Palankarinna Fossil Area in South Australia. The second specimen discovered there, AMNH 97228, is an upper right molar. In total, 4 specimens are known, dating from the Oligocene to the Pliocene.

The tooth was placed into the newly erected genus Obduron when described in 1975 by American palaeontologists Michael O. Woodburne and Richard H. Tedford. The genus named was derived from Latin to describe the obdurate, that is persistent, molar which is lost in the modern platypus. The species name insignis referred to the importance of the new taxon's "distinguishing mark" in the fossil record.

Description 
O. insignis is thought to have had a similar build to the modern platypus. However, like O. dicksoni but unlike the modern platypus, it had more permanent dentition.

The holotype is the front molar of the upper right jaw, corresponding to the M2 molar, with the unusual character of six roots. Fragments of jawbone have also been assigned to the species, along with a single piece of post-cranial material, a pelvis. Obdurodon insignis had one more canine tooth (NC1) than its ancestor Steropodon galmani.

References 

Category:Obdurodon
Category:Prehistoric monotremes
Category:Oligocene mammals of Australia
Category:Miocene mammals of Australia
Category:Pliocene mammals of Australia
Category:Pliocene extinctions
Category:Fossil taxa described in 1975