†superfamily Megalonychoidea (edentate)
Parent taxon: Phyllophaga according to C. Muizon et al. 2004
See also Carroll 1988, Simpson 1948 and Simpson 1967
Sister taxa: Pseudoglyptodon, Orophodontidae, Elipsodon, Ortotheridae
Subtaxa: Nothrotheriidae Proplatyarthrus
Ecology: ground dwelling herbivore
Distribution: found only at Puesto Almendra, Gran Barranca, Chubut (Oligocene of Argentina)