Spec's cimolestans are an ancient group of mammals that reaches back well into the Late Cretaceous. DNA analyses have recently confirmed the suspicions that they are very basal eutherians and Cimolesta forms a sister taxon to Placentalia, to which all surviving eutherians of Home Earth (and thus most of its mammals) belong, as well as most Spec eutherians from the Florida pseudorat to the sut.