Prehistoric metatherians

Sparassodonta (from Greek ['], to tear, rend; and , gen. [', ''''], tooth) is an extinct order of carnivorous metatherian mammals native to South America, related to modern marsupials. They were once considered to be true marsupials, but are now thought to be a separate side branch that split before the last common ancestor of all modern marsupials.

Didelphodon (from [[Didelphis|[is]]] "opossum" and "tooth") is a genus of extinct metatherian mammal from the Late Cretaceous of North America.

Alphadon is an extinct genus of small, primitive mammal that was a member of the metatherians, a group of mammals that includes modern-day marsupials. Its fossils were first discovered and named by George Gaylord Simpson in 1929.

Deltatheridium (meaning triangle beast or delta beast) is an extinct species of metatherian. It lived in what is now Mongolia during the Upper Cretaceous, circa 80 million years ago. A study in 2022 strongly suggested that Deltatheridium was a marsupial, making it the earliest known member of this group.

Eodelphis, from eo- (dawn) and [[Didelphis|[]delphis]] (a genus of Opossum), thus meaning "dawn opossum", is a genus of stagodontid metatherians from the Late Cretaceous of North America, with distinctive crushing dentition. Named species include E. browni and the more advanced E. cutleri. Both come from the Late Campanian (Judithian "Land Mammal Age") of Dinosaur Provincial Park, Alberta. Specimens are also known from the Judith River Formation of Montana. E. cutleri is related to the Maastrichtian genus Didelphodon as indicated by its enlarged premolars and more robust jaw. Eodelphis was pro

Pucadelphys is an extinct genus of non-marsupial metatherian. The genus contains a single species, P. andinus. Fossils of Pucadelphys have been found in the Santa Lucía Formation in Tiupampa in Bolivia.

Deltatheroida is an extinct group of basal metatherians that were distantly related to modern marsupials. The majority of known members of the group lived in the Cretaceous; one species, Gurbanodelta kara, is known from the late Paleocene (Gashatan) of China. Their fossils are restricted to Central Asia and North America. This order can be defined as all metatherians closer to Deltatheridium than to Marsupialia.

Herpetotherium is an extinct genus of metatherian mammal, belonging to the possibly paraphyletic family Herpetotheriidae. Native to North America from the Eocene to Early Miocene, fossils have been found in California, Oregon, Texas, Florida, Montana, Wyoming, Colorado, North and South Dakota, Nebraska, and Saskatchewan. The oldest species, H. knighti, is dated to around 50.3 mya, and the most recent, an unnamed species, may be as recent as 15.97 mya. A morphological analysis of marsupials and basal metatherians conducted in 2007 found Herpetotherium to be the sister group to extant marsupials

Herpetotheriidae is an extinct family of metatherians, closely related to marsupials. Species of this family are generally reconstructed as terrestrial, and are considered morphologically similar to modern opossums. They are suggested to have been insectivores. Fossils of herpetotheriids come from North America, Asia, Europe, Africa, and perhaps South America. The oldest representative is Maastrichtidelphys from the latest Cretaceous (Maastrichtian) of the Netherlands and the youngest member is Amphiperatherium from the Middle Miocene of Europe. The group has been suggested to be paraphyletic,

Andinodelphys is an extinct genus of non-marsupial stem metatherian.

Deltatheridiidae is an extinct family of basal carnivorous metatherians that lived during the Cretaceous and Paleogene. They were closely related to marsupials. Their fossils are restricted to Central Asia (Mongolia and Uzbekistan) and North America (United States - Oklahoma, Texas, Utah, Wyoming). They mostly disappeared in the KT event, but a ghost lineage, currently represented by Gurbanodelta, survived until the late Paleocene by decreasing in size and becoming insectivorous.

Asiatherium is an extinct genus of mammal, probably belonging to Metatheria. It lived during the Late Cretaceous, and its fossilized remains were discovered in Mongolia.

Peratherium is a genus of metatherian mammals in the family Herpetotheriidae that lived in Europe and Africa from the Early Eocene to the Early Miocene. Species include the following: Peratherium africanum Peratherium antiquum Peratherium bretouense Peratherium cayluxi Peratherium constans Peratherium cuvieri Peratherium elegans Peratherium lavergnense Peratherium matronense Peratherium monspeliense Peratherium perrierense Peratherium sudrei

Peradectes is an extinct genus of small metatherian mammals known from the latest Cretaceous to Eocene of North and South America and Europe. The first discovered fossil of P. elegans, was one of 15 Peradectes specimens described in 1921 from the Mason pocket fossil beds in Colorado. The monophyly of the genus has been questioned.

Albertatherium (meaning "beast of Alberta") is an extinct genus of alphadontid metatherians that lived during the Late Cretaceous of North America. The genus contains two species, Albertatherium primus (the type species), and Albertatherium secundus. Fossils have been found in the Eagle Formation of Montana and the Milk River Formation of Alberta.

Nanocuris is an extinct genus of Deltatheridiidae from the Cretaceous of Canada (Saskatchewan) and United States (Wyoming - Lance Formation and Hell Creek Formation). Initially, it was classified in a proper family, Nanocuridae, in the clade Eutheria, but a reanalysis of a new specimen revealed a delthatheroid affinity of the genus.

Pappotherium is an extinct genus of mammals from the Albian (early Cretaceous) of Texas, US, known from a fossilized maxilla fragment bearing two tribosphenic molars, discovered within the Glen Rose Formation near Decatur, Wise County, Texas.

Turgidodon is an extinct genus of alphadontid marsupial from the Late Cretaceous of western North America.

Peradectidae is a family of small metatherian mammals, spanning from the Paleocene (or possibly Latest Cretaceous) to the Miocene. Fossils are known from the Northern Hemisphere, including Europe, Asia and North America. The monophyly of the group has been questioned, with some authors suggesting that Peradectes should be the only genus placed in the family. The morphology of peradectids has been considered to be similar to opossums, with at least some exhibiting morphology suggesting a tree dwelling arboreal/scansorial lifestyle. Their diet is suggested to have included insects and fruit.

Mimoperadectes is an extinct genus of metatherian mammal from the Eocene of North America. thumb|left|Restoration

Unnuakomys is an extinct genus of metatherian mammal from the Maastrichtian age of the Late Cretaceous. It was discovered in the Prince Creek Formation of Alaska, and is the northernmost metatherian known. The type (and only) species is U. hutchisoni.

thumb | right | alt=Pediomys upper and lower molars. | Pediomys upper and lower molars. Pediomys is an extinct genus of pediomyid marsupial from the Late Cretaceous of North America.

Alphadontidae was a family of mammals belonging to the clade Metatheria, the group of mammals that includes modern-day marsupials.

Lotheridium is an extinct genus of deltatheroidan mammals that lived in what is now Asia during the Late Cretaceous, about 72–66 million years ago. The genus contains a single species, Lotheridium mengi, named in 2015 after paleontologist Jin Meng. It is known from a single fossil specimen—a skull with associated lower jaws—found in the Qiupa Formation of Henan Province, China and housed in the collections of the Zhejiang Museum of Natural History. The skull measures in length, suggesting Lotheridium was large compared to most other deltatheroidans. Though the preserved skull is almost complet

Amphiperatherium is an extinct genus of metatherian mammal, closely related to marsupials. It ranged from the Early Eocene to the Middle Miocene in Europe. It is the most recent metatherian known from the continent.