Mylodon darwini (Owen 1840; Late Pleistocene; 3-4m in length) is a sloth with a premaxillary ascending process, a reversal to cynodonts because most placentals lack this nose bar. The premaxilla is toothless. The canines are absent. Pedal digit 1 is absent.

Paramylodon harlani (Brown 1903; 3m in length; Pliocene-Pleistocene, 5-.01mya) is an extinct ground sloth with dermal ossicles, small skin bones. Here Paramylodon was derived from Barylambda and was a sister to Glyptodon (below).

More robust than Barylambda, Paramylodon had fewer teeth, a larger pelvis and a deeper chest. The hands and feet were not well built for rapid movement. The manus claws were elongated. The pes was twisted so the weight was carried on the lateral side. The heel was as long as the toes.