A tooth-bearing Early Cretaceous dentary anchors a specimen-level test of Mesozoic monotreme affinity.
Represented range110–100 Ma
RegionsGriman Creek Formation, Lightning Ridge, New South Wales, Australia
CladesSteropodon galmani · Monotremata
Claim ledger
morphology · medium
AM F66763 is a right dentary fragment with three tribosphenic molars from the Griman Creek Formation; its monotreme affinity rests on published dental comparison and does not make Steropodon a direct ancestor or establish a universal monotreme first appearance.