Adalatherium hui (Krause et al. 2020; Late Cretaceous) was originally considered a relative of multituberculates, but here nests with basal quadrupedal kangaroos, like Potorous and Hypsiprymnodon.

Paedotherium typicum (Burmeister 1888, Cerdeño E and Bond M 1998; Miocene-Pleistocene) was originally considered a rabbit-like typothere notoungulate, but here nests between Dasyuroides and Phalanger among the marsupials. The Cretaceous taxa, Vintana and Groeberia are more closey related, hinting at the probable Jurassic origin of Paedotherium.

The maxillary notch was just noticeable here, in the photo, hot in the drawing. The top of the squamosal appears to be lost here, in comparison to Interatherium (above). The four molars and two premolars are flattened. The incisors are procumbent. The lacrimal has an odd anterior process. As in Interatherium, the anterior jugals are squanred off. Like Vintana, the orbit is in the posterior half of the skull. Unlike Interatherium, the legs of Paedotherium are much longer relative to the dorsal vertebrae. The ?tabulars (known as mastoid bullae) are expanded to form spheres.

Yalkaparidon coheni (Archer, Hand and Godthelp 1988; Oligocene; QM-F13008) is a traditional enigma marsupial here nesting basal to two other enigma marsupials, Vintana and Groberia (below). Workers call it 'Thingodonta' and consider it an diprodontian. Here it is a diprodontian-mimic. These taxa are close to Paedotherium and another traditional enigma, Adalatherium.

Vintana sertichi (Krause et al. 2014; Late Cretaceous, UA 9972; 12.4 cm skull length; is a Madagascar mammal originally considered a member of the Allotheria and Gondwanatheria, two clades that do not appear in the large reptile tree. The LRT nests Vintana with basal quadrupedal kangaroos, like Potorous and Hypsiprymnodon.

Krause et al reported, “The new taxon is the largest known mammaliaform from the Mesozoic of Gondwana. Its craniofacial anatomy reveals that it was herbivorous, large-eyed and agile, with well-developed high-frequency hearing and a keen sense of smell. The cranium exhibits a mosaic of primitive and derived features, the disparity of which is extreme and probably reflective of a long evolutionary history in geographic isolation."

Groeberia minoprioi (Patterson 1952,  MMP 738)
Groeberia pattersoni (Simpson 1970; Eocene and Oligocene) Simpson & Wyss 1999, considered it close to diprotodontians (wombats). The LRT supports that nesting as Groeberia nests with Vintana, another former enigma, both within the marsupials.

Archer M, Hand S and Godthelp H 1988. A new order of Tertiary zalambdodont marsupials. Science 239(4847):1528-1531.

Burmeister CV 1888. Relaciónde un viaje a la Gobernaciónde Chubut. Anales del Museo Nacional de Buenos Aires 3:175–252,

Cerdeño E and Bond M 1998. Taxonomic Revision and Phylogeny of Paedotherium and Tremacyllus (Pachyrukhinae, Hegetotheriidae, Notoungulata) from the Late Miocene to the Pleistocene of Argentina. Journal of Vertebrate Paleontology 18(4): 799-811.

Chimento NR, Agnolin  FL and Novas FE 2015. The bizarre ‘metatherians’ Groeberia and Patagonia, late surviving members of gondwanatherian mammals. Historical Biology: An International Journal of Paleobiology. 27 (5): 603–623. 
doi:10.1080/08912963.2014.903945

Krause DW, Hoffmann S, Wible JR, Kirk EC, and several other authors 2014. First cranial remains of a gondwanatherian mammal reveal remarkable mosaicism. Nature. online. doi:10.1038/nature13922. ISSN 1476-4687.

Krause DW et al. 2014. Vintana sertichi (Mammalia, Gondwanatheria) from the Late Cretaceous of Madagascar. Journal of Vertebrate Paleontology Memoir 14. 222pp.

McKenna MC 1980. Early history and biogeography of South America's extinct land mammals.

Patterson B 1952. Un nuevo y extraordinario marsupial deseadiano. Rev Mus Mun Cienc NatMar del Plata. 1:39–44.

Simpson GG 1970. Addition to the knowledge of Groeberia (Mammalia, Marsupialia) from the mid-Cenozoic of Argentina. Breviora 362:1-17

wiki/Vintana
wiki/Paedotherium
wiki/Groeberia
wiki/Adalatherium
wiki/Yalkaparidon