Steropodon

Steropodon galmanii was a prehistoric species of monotreme, or a egg-laying mammal, that lived during the Mesozoic, in the Lower Cretaceous period. It is the second-earliest known relative of the platypus: the earlist is called Teinolophos.

 References 
Archer M. et al 1985. First Mesozoic mammal from Australia – an early Cretaceous monotreme. Nature 318: 363-366.

Category:Monotremes