Trituberculata
The name comes from the three tubercles (cusps) of the molar teeth (not to be confused with Triconodonta). The clade Trituberculata is not always regarded as valid. They probably do not form a monophyletic group. Instead, some may be "true" basal mammals (though not always closest related to each other). Others (such as the symmetrodonts) may fall just outside the therian crown group.