Claim: Steropodontidae was a family of mammals, order Monotremata and class Mammalia of the kingdom Animalia.
Evidence: Kingdom: Animalia Order: Monotremata Class: Mammalia Monotremes (/ˈmɒnətriːmz/, from Greek μονός, monos ('single') and τρῆμα, trema ('hole'), referring to the cloaca) are one of the three main groups of living mammals, along with placentals (Eutheria) and marsupials (Metatheria). The Steropodontidae was a possible family of monotremes that are known from fossils from the Cretaceous of Australia. There are two genera placed in this family: Steropodon and Teinolophos, which have been tentatively placed in the family due to the similarity of the lower molars in these two genera. However, the latter may be more basal.