Proargyrolagus

Simpson reported, "Argyrolagids are marsupials but show no clear affinity with any others known. They probably arose from didelphids independently of other known families and are distinct at the superfamily level, at least."

Sanchez-Villagra and Kay reported, "The Argyrolagidae are one of the most enigmatic extinct groups of South American mammals. " Some workers have questioned the marsupial affinities of this genus. This may be due to the absence of Interatherium from prior studies.

In the large reptile tree Porargyrolagus nests between Interatherium and the macropodids (= kangaroos).

Sanchez-Villagra MR 1997. The phylogenetic relationships of argyrolagid marsupials. Zoological Journal of Linnean Society 131(4):481–496.

Sanchez-Villagra MR and Kay RF 1997. A skull of Proargyrolagus, the oldest argyrolagid (Late Oligocene Salla Beds, Bolivia), with brief comments concerning its paleobiology. Journal of Vertebrate Paleontology 17(4):717-724.

Simpson GG 1970. The Argyrolagidae, extinct South American marsupials. Bulletin of the Museum of Comparative Zoology 139, 1–86.

Wolff RG 1984. A new early Oligocene argyrolagid (Mammalia: Marsupialia) from Salla, Bolivia. Journal of Vertebrate Paleontology 4:108-113.\

wiki/Argyrolagus

Mammalia - Monotremata

Ornithorhynchus and kin

Marsupialia