Proterotheriidae is an extinct family of litoptern ungulates known from the Oligocene-Late Pleistocene of South America. Members of the group were small-medium sized cursorial herbivores with brachydont teeth, with their toes showing progressive reduction, with later members of the group bearing weight on a single large toe similar to living horses.
Neolicaphrium is an extinct genus of ungulate mammal belonging to the extinct order Litopterna. This animal lived from the Late Pliocene (Chapadmalalan) to the Late Pleistocene (Lujanian) in southern South America, being the last survivor of the family Proterotheriidae.
Proterotherium is an extinct genus of litoptern mammal of the family Proterotheriidae that lived during the Late Miocene of Argentina and Chile. Fossils of this genus have been found in the Ituzaingó Formation of Argentina, and the Galera Formation of Chile.
Megadolodus is an extinct genus of proterotheriid litopterns.
Olisanophus is a genus of extinct litoptern from the late middle Miocene of southern Bolivia. It was named in 2020 by Andrew McGrath and colleagues, for two distinct species from the same deposits of an unnamed formation of the Honda Group. The type species is O. riorosarioensis, known from elements of the partial upper and lower left and right dentitions and possibly a partial mandible, and the referred species is O. akilachuta, known for 6 teeth. Some intermediate material from the same deposits was referred to Olisanophus sp., not showing diagnostic features of either species. Both species were recovered together in a phylogenetic analysis, where they were sister taxa to a group of Diplasiotherium and Mesolicaphrium.
Mesolicaphrium is a genus of extinct litoptern from the late middle Miocene of southern Colombia. It was named in 2020 by Andrew McGrath and colleagues, for the species previously classified as Prolicaphrium sanalfonensis from the La Victoria and Villavieja Formations of the Honda Group, Colombia. The type species is M. sanalfonense, known from the jaw symphysis and two right mandibular rami, and teeth. Mesolicaphrium is derived from the similarity to the names Prolicaphrium and Neolicaphrium, and being in between both taxa in age. The taxon was recovered in a phylogenetic analysis as the sister taxon of Diplasiotherium, closely related to Olisanophus.
Neodolodus is a genus of extinct litoptern from the late middle Miocene of southern Colombia. It was named in 1986 by Hoffstetter and Soria, for the species Neodolodus colombianus from the Castilletes Formation and the La Victoria and Villavieja Formations of the Honda Group. The type species N. colombianus is known from a right mandibular ramus, teeth, and part of the fore- and hindlimbs. Neodolodus has been classified as a species of Prothoatherium or Lambdaconus, but was recognized as a distinct genus by McGrath and colleagues in 2020. The taxon was recovered in a phylogenetic analysis as the sister taxon of Protheosodon, between other proterotheriid genera like Picturotherium and Anisolophus.
Uruguayodon is an extinct genus of proterotheriid from the middle Pleistocene of Uruguay. It is known from the type and only species U. alius, named by Corona and colleagues in 2019 for dentaries and a partial postcrania from the Raigón Formation. Uruguayodon represents one of the latest occurrences of Proterotheriidae, with only Neolicaphrium representing other remains from the Pleistocene to possibly Holocene.
Brachytherium is an extinct genus of proterotheriid mammal from the Late Miocene to Late Pliocene of Argentina. It is represented by the type and only species B. cuspidatum, a taxon named in 1883 by Ameghino for a partial mandible with teeth. Though it was considered a dubious taxon at times, Brachytherium was revised as valid by Schmidt in 2015, who also synonymized the species Proterotherium gradatum and Lophogonodon paranensis, expanding the material known, all of which is from the Ituzaingó Formation. Some material previously referred to Brachytherium has been given the new name Neobrachytherium.
Neobrachytherium is an extinct genus of proterotheriid mammal from the Late Miocene of Argentina and Uruguay. It is represented by multiple species, including the type N. intermedium, originally named in 1891 by Moreno and Mercerat as a species of Licaphrium, N. morenoi, originally named in 1914 by Rovereto as a species of Brachytherium, and N. ameghinoi and N. ullumense, named in 2001 by Soria, who reclassified all the species in the new genus Neobrachytherium. The various species are known from cranial and dental material from the Corral Quemado, Loma de las Tapias and Ituzaingó Formations. Neobrachytherium may be closely related to Thoatherium, Diadiaphorus and Thoatheriopsis.
Protheosodon is an extinct genus of proterotheriid litoptern. It lived from the Late Oligocene to the Early Miocene in what is now Argentina and Colombia.
Prolicaphrium is an extinct genus of proterotheriid litoptern that lived during the Early Miocene, in what is now Argentina. Fossils have been found in the Sarmiento Formation of Argentina.
Tetramerorhinus is an extinct genus of proterotheriid litoptern that lived during the Early and Middle Miocene in what is now Argentina and Peru.
Thoatheriopsis is an extinct genus of proterotheriid from the Miocene of Mendoza Province, Argentina. The taxon is known only from the specimen MLP 81-XI-28-1, which includes an upper tooth row, and was named as the new binomial Thoatheriopsis mendocensis by Miguel Soria posthumously in 2001. The only provenance information known about the specimen is that it comes from the Anfiteatro de Cacheuta, and it is probably from the Mariño Formation, of which it could be from either the Areniscas Entrecruzadas or the Estratos de Mariño Member, which are both present at the known location of discovery. This means that the age for Thoatheriopsis cannot be determined beyond either being from the Santacrucian or Laventan South American Land Mammal Ages in the Early or Middle Miocene. Thoatheriopsis was found to be a close relative of Diadiaphorus and Neobrachytherium.
Anisolophus is an extinct genus of proterotheriid from the Early to Middle Miocene of Argentina. The genus was named by Burmeister in 1885 to accommodate the species Anchitherium australe, which they had named earlier in 1879. Soria then referred the species Licaphrium floweri and Anisolophus minisculus to the genus, making Licaphrium, named in 1887 by Florentino Ameghino, a junior synonym of the genus. Both A. australis and A. floweri are known from the Santacrucian age Santa Cruz Formation, while A. minisculus is known from the Collón Curá Formation.
Lambdaconus is a genus of proterotheriid from the Late Oligocene to Early Miocene of Argentina. The type species is L. suinus, named in 1897 by Ameghino, with referred species including L. lacerum, named as Proterotherium lacerum in 1902 by Ameghino, and L. inaqeuifacies.
Villarroelia is an extinct genus of proterotheriid from the Middle Miocene of Colombia.
Magdalenabradys is an extinct genus of mylodontid ground sloths that lived during the Middle Miocene and Early Pliocene of what is now Colombia and Venezuela. Fossils have been found in the Villavieja Formation of the Honda Group in Colombia, and the Codore and Urumaco Formations of Venezuela.
Guilielmofloweria is an extinct genus of proterotheriid litoptern that lived from the Middle to Late Eocene of what is now Argentina. Fossils have been found in the Sarmiento Formation of Argentina.
The Camacho Formation is a Huayquerian geologic formation in Uruguay.
