''Proterotherium'' (meaning "first beast") is an extinct genus of litoptern mammal of the family Proterotheriidae that lived during the Late

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" ...

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, t ...

and

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the eas ...

. Fossils of this genus have been found in the

Ituzaingó Formation The Ituzaingó Formation ( es, Formación Ituzaingó), in older literature also described as Entre Ríos or Entrerriana Formation, is an extensive geological formation of Late Miocene (Tortonian, or Huayquerian in the SALMA classification) age in ...

of Argentina, and the Galera Formation of Chile.

Classification

The genus ''Proterotherium'' was first described by Florentino Ameghino in 1883, on the basis of fossil remains found in Upper Miocene deposits in Patagonia. The type species is ''Proterotherium cervioides''. Numerous other species have been ascribed to this genus, many of which come from lower-middle Miocene deposits, such as ''P. americanum'', ''P. australe'', ''P. brachygnathum'', ''P. cavum'', ''P. cingulatum'', ''P. curtidens'', ''P. dichotomum'' , ''P. divortium'', ''P. gradatum'', ''P. intermedium'', ''P. karaikense'', ''P. mixtum'', ''P. nitens'', ''P. perpolitum'', ''P. politum'', ''P. main'', and ''P. pyramidatum''. However, many of these species are now considered to be synonymous with the type species, and others belong to other genera, such as ''

Tetramerorhinus ''Tetramerorhinus'' is an extinct genus of proterotheriid litoptern that lived during the Early and Middle Miocene in what is now Argentina and Peru. Description This animal resembled a small horse, with slender, elongated legs. The body was a ...

'', a genus long confused with ''Proterotherium''. ''Proterotherium'' is the type genus of Proterotheriidae, a group of litopterns characterized by a morphology very similar to that of equids, especially in regards to the legs. ''Proterotherium'' is a typical example of the Miocene proterotheres, very specialized in the morphology of the legs and also in the dentition. A very similar animal was ''Anisolophus''.

Cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...

based in the

phylogenetic analysis In biology Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that pro ...

published by McGrath ''et al.'', 2020, showing the position of ''Proterotherium'':

References

{{Taxonbar, from=Q9063287 Proterotheriids Miocene mammals of South America Huayquerian Neogene Argentina Fossils of Argentina Neogene Chile Fossils of Chile Taxa named by Florentino Ameghino Fossil taxa described in 1883 Ituzaingó Formation Prehistoric placental genera