Teinolophos

• Flat Rocks, Victoria ( Australia)

Teinolophos trusleri is an extinct mammal. She lived in the Cretaceous period in Australia and one of the earliest known ancestor of the platypus.

From Teinolophos so far only parts of the mandible were found with individual molars. In the construction of the teeth similarities to Steropodon indicate a closely related, somewhat younger genus. However Teinolophos was significantly smaller than Steropodon or today's platypus and only reached a body length of about 10 centimeters.

A deep notch at the posterior part of the jaw, the discussion about the origin of the Ursäuger rekindled. In the opinion of Rich and others ( 2005) show the notch that the development of the ossicles and the secondary TMJ was not completed at the Teinolophus. This development is an important criterion for the definition of mammals. Rich and others conclude that this transformation took place twice in the course of mammalian evolution, and thus the Ursäuger significantly distant related to the other mammals were as previously thought. From other scientists, these theories are not recognized.