| Mesungulatidae Temporal range: Late Cretaceous, | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | † Dryolestida (?) |
| Clade: | † Meridiolestida |
| Clade: | † Mesungulatoidea |
| Family: | † Mesungulatidae Bonaparte, 1986 |
| Genera | |
Mesungulatidae is an extinct clade of meridiolestidan dryolestoid mammals from the Late Cretaceous of South America and possibly other Gondwannan landmasses. [1] They are particularly notable for their ecological speciation and large size. [2]
Most mesungulatids are generally large animals, making them inherently distinctive from other groups. Specific synapomorphies include a strong precingulum and postcingulum on the upper molars - which are extended lingually but do not meet around the paracone - three cusps on the lower stylar shelf, an absent metacone and rectangular lower molars. [3] They are thought to have had a somewhat transverse mastication, like docodonts and modern ungulates. [4] Compared to other dryolestoids their molar eruption patterns are delayed. [1]
Mesungulatids are generally large sized herbivores or omnivores, being among the several Mesozoic mammals deviating from the classical insectivore stereotype. They are among the dominant mammals in Late Cretaceous South American assemblages, and among the most derived species present. [5] [2]
Gondwanatheria is an extinct group of mammaliaforms that lived in parts of Gondwana, including Madagascar, India, South America, Africa and Antarctica during the Upper Cretaceous through the Paleogene. Until recently, they were known only from isolated teeth, a few lower jaws, two partial skulls and one complete cranium. They are generally considered to be closely related to the multituberculates and likely the euharamiyidians, well known from the Northern Hemisphere, with which they form the clade Allotheria.
Ferugliotherium is a genus of fossil mammals in the family Ferugliotheriidae from the Campanian and/or Maastrichtian period of Argentina. It contains a single species, Ferugliotherium windhauseni, which was first described in 1986. Although originally interpreted on the basis of a single brachydont (low-crowned) molar as a member of Multituberculata, an extinct group of small, rodent-like mammals, it was recognized as related to the hypsodont (high-crowned) Sudamericidae following the discovery of additional material in the early 1990s. After a jaw of the sudamericid Sudamerica was described in 1999, these animals were no longer considered to be multituberculates and a few fossils that were previously considered to be Ferugliotherium were assigned to unspecified multituberculates instead. Since 2005, a relationship between gondwanatheres and multituberculates has again received support. A closely related animal, Trapalcotherium, was described in 2009 on the basis of a single tooth.
Ferugliotheriidae is one of three known families in the order Gondwanatheria, an enigmatic group of extinct mammals. Gondwanatheres have been classified as a group of uncertain affinities or as members of Multituberculata, a major extinct mammalian order. The best-known representative of Ferugliotheriidae is the genus Ferugliotherium from the Late Cretaceous epoch in Argentina. A second genus, Trapalcotherium, is known from a single tooth, a first lower molariform, from a different Late Cretaceous Argentinean locality. Another genus known from a single tooth, Argentodites, was first described as an unrelated multituberculate, but later identified as possibly related to Ferugliotherium. Finally, a single tooth from the Paleogene of Peru, LACM 149371, perhaps a last upper molariform, and a recent specimen from Mexico, may represent related animals.
Eutriconodonta is an order of early mammals. Eutriconodonts existed in Asia, Africa, Europe, North and South America during the Jurassic and the Cretaceous periods. The order was named by Kermack et al. in 1973 as a replacement name for the paraphyletic Triconodonta.
Dryolestida is an extinct order of mammals; most of the members are mostly known from the Jurassic and Cretaceous. They are considered members of the clade Cladotheria, close to the ancestry of therian mammals. It is also believed that they developed a fully mammalian jaw and also had the three middle ear bones. Most members of the group, as with most Mesozoic mammals, are only known from fragmentary tooth and jaw remains.
Peligrotherium is an extinct meridiolestidan, and the sole member of the family Peligrotheriidae, from the Paleocene of Patagonia, originally interpreted as a stem-ungulate. Its remains have been found in the Salamanca Formation. It was a dog-sized mammal, among the largest of all dryolestoids, and closely related to mesungulatids, another lineage of large sized herbivorous dryolestoids. A recent phylogenetic study finds it to be the sister taxon to Reigitherium.
Cladotheria is a clade of mammals. It contains modern therian mammals and several extinct groups, such as the dryolestoids, amphitheriids and peramurids. The clade was named in 1975 by Malcolm McKenna. In 2002, it was defined as a node-based taxon containing "the common ancestor of dryolestids and living therians, plus all its descendants". A different, stem-based definition was given in 2013, in which Cladotheria contains all taxa that are closer to Mus musculus than to the "symmetrodont" Spalacotherium tricuspidens.
Gobiconodontidae is a family of extinct mammals that ranged from the mid-Jurassic to the early Late Cretaceous, though most common during the Early Cretaceous. The Gobiconodontids form a diverse lineage of carnivorous non-therian mammals, and include some of the best preserved Mesozoic mammal specimens.
Several mammals are known from the Mesozoic of Madagascar. The Bathonian Ambondro, known from a piece of jaw with three teeth, is the earliest known mammal with molars showing the modern, tribosphenic pattern that is characteristic of marsupial and placental mammals. Interpretations of its affinities have differed; one proposal places it in a group known as Australosphenida with other Mesozoic tribosphenic mammals from the southern continents (Gondwana) as well as the monotremes, while others favor closer affinities with northern (Laurasian) tribosphenic mammals or specifically with placentals. At least five species are known from the Maastrichtian, including a yet undescribed species known from a nearly complete skeleton that may represent a completely new group of mammals. The gondwanathere Lavanify, known from two teeth, is most closely related to other gondwanatheres found in India and Argentina. Two other teeth may represent another gondwanathere or a different kind of mammal. One molar fragment is one of the few known remains of a multituberculate mammal from Gondwana and another has been interpreted as either a marsupial or a placental.
Reigitherium was a mammal that lived during the Late Cretaceous, in the. Its fossils have been found in the Los Alamitos and the La Colonia Formations of Argentina.
Coloniatherium is a meridiolestid mammal from the Late Cretaceous of Argentina. The single species, Coloniatherium cilinskii, was a large member of the family Mesungulatidae.
Donodon is an extinct genus of mammal from the Ksar Metlili Formation of Talssint, Morocco, which has been dated to the Late Jurassic to Early Cretaceous epochs. The type species D. prescriptoris was described in 1991 by the palaeontologist Denise Sigogneau-Russell. A second species, D. minor, was named in 2022. Donodon was a member of Cladotheria, a group that includes therian mammals and some of their closest relatives. It differed from dryolestids in having upper molars that were not compressed mesiodistally. Some studies have suggested that it was closely related to various South American cladotherians in the clade Meridiolestida, with specific similarities to Mesungulatum, a herbivorous mesungulatid, being noted. On the other hand, a 2022 phylogenetic analysis found it to be only distantly related to meridiolestidans, and instead closer to crown group therians.
Necrolestes is an extinct genus of mammals, which lived during the Early Miocene in what is now Argentine Patagonia. It is the most recent known genus of Meridiolestida, an extinct group of mammals more closely related to therians than to monotremes that dominated South America during the Late Cretaceous. It contains two species, N. patagonensis and N. mirabilis, The type species N. patagonensis was named by Florentino Ameghino in 1891 based on remains found by his brother, Carlos Ameghino in Patagonia. Fossils of Necrolestes have been found in the Sarmiento and Santa Cruz Formations.
Gobiconodonta is an order of extinct mammals known from the Early Jurassic to early Late Cretaceous. They are generally held to be part of Eutriconodonta.
Jugulator is an extinct genus of mammals from the Cretaceous of North America. It contains one species, Jugulator amplissimus. A eutriconodont, it is known from the Cedar Mountain Formation, and is both a large sized and possibly ecologically specialised taxon, showcasing the diversity of mammals in the Mesozoic.
Leonardus is an extinct mammal genus from the Late Cretaceous of South America. It is a meridiolestidan dryolestoid, closely related to the also Late Cretaceous Cronopio and the Miocene Necrolestes.
Meridiolestida is an extinct clade of mammals known from the Cretaceous and Cenozoic of South America and possibly Antarctica. They represented the dominant group of mammals in South America during the Late Cretaceous. Meridiolestidans were morphologically diverse, containing both small insectivores such as the "sabretooth-squirrel" Cronopio, as well as the clade Mesungulatoidea/Mesungulatomorpha, which ranged in size from the shrew-sized Reigitherium to the dog-sized Peligrotherium. Mesungulatoideans had highly modified dentition with bunodont teeth, and were likely herbivores/omnivores.
Groebertherium is a genus of dryolestoid mammal from the Late Cretaceous Los Alamitos and Allen Formations of Argentina. It is not closely related to other contemporary dryolestoids, all of which are part of the clade Meridiolestida.
The Dorotea Formation is a geological formation in the Río de Las Chinas Valley of the Magallanes Basin in Patagonian Chile whose strata date back to the Campanian to Maastrichtian of the Late Cretaceous.
Orretherium is a genus of mesungulatid mammal that lived in South America (Chile) during the Late Cretaceous period in what is now the Dorotea Formation.
