Protypotherium

Protypotherium was a typical representative of the Interatheriidae, a group of typotherian notoungulates with rodent-like appearances, usually with slender forms. The genus has a wide stratigraphic and geographic distribution, around 29 million years. Fossils assigned to Protypotherium have been found in numerous localities in Argentina, Bolivia, Chile, and Uruguay.{{Cite journal |last1=Barrio |first1=Claudio |last2=Carlini |first2=Alfredo A. |last3=Goin |first3=Francisco J. |date=1989 |title=Litogénesis y antigüedad de la Formación Chichinales de Paso Córdoba (Río Negro, Argentina) |url=https://www.researchgate.net/publication/284902990 |journal=Actas, IV Congreso Argentino de Paleontología y Bioestratigrafía, Mendoza |volume=4 |pages=149–156}}{{Cite journal |last1=Kramarz |first1=Alejandro |last2=Garrido |first2=Alberto |last3=Forasiepi |first3=Analía |last4=Bond |first4=Mariano |last5=Tambussi |first5=Claudia |date=2005 |title=Stratigraphy and vertebrates (Aves and Mammalia) from the Cerro Bandera Formation, Early Miocene of Neuquén Province, Argentina. |url=http://www.andeangeology.cl/index.php/revista1/article/view/V32n2-a06/html |journal=Revista Geológica de Chile |volume=32 |issue=2 |doi=10.4067/S0716-02082005000200006 |doi-access=free |access-date=2022-11-17 |archive-date=2022-10-01 |archive-url=https://web.archive.org/web/20221001182253/http://www.andeangeology.cl/index.php/revista1/article/view/V32n2-a06/html |url-status=live }}50x50px Material was copied from this source, which is available under a Creative Commons Attribution 3.0 International License{{Cite book |last1=A. G. Kramarz |url=https://www.researchgate.net/publication/233955394 |title=The Paleontology of Gran Barranca. Evolution and Environmental Change Through the Middle Cenozoic of Patagonia |last2=M. G. Vucetich |last3=A. A. Carlini |last4=M. R. Ciancio |last5=M. A. Abello |last6=C. M. Deschamps |last7=J. N. Gelfo |publisher=Cambridge University Press |year=2010 |isbn=978-0-521-87241-6 |editor-last=Richard H. Madden |pages=143–151 |chapter=A new mammal fauna at the top of the Gran Barranca sequence and its biochronological significance. |editor-last2=Alfredo A. Carlini |editor-last3=Maria Guiomar Vucetich |editor-last4=Richard F. Kay}}{{Cite journal |last1=Scarano |first1=Alejo C. |last2=Vera |first2=Bárbara |last3=Reguero |first3=Marcelo |date=2021-09-01 |title=Evolutionary Trends of Protypotherium (Interatheriidae, Notoungulata) Lineage throughout the Miocene of South America |url=https://doi.org/10.1007/s10914-020-09534-5 |journal=Journal of Mammalian Evolution |language=en |volume=28 |issue=3 |pages=885–895 |doi=10.1007/s10914-020-09534-5 |s2cid=230986107 |issn=1573-7055 |access-date=2022-11-17 |archive-date=2023-02-06 |archive-url=https://web.archive.org/web/20230206215106/https://link.springer.com/article/10.1007/s10914-020-09534-5 |url-status=live }} The oldest occurrence of Protypotherium dates back to the Late Oligocene (Deseadan) Fray Bentos Formation of Uruguay.{{Cite journal |last1=Mones |first1=A. |last2=Ubilla |first2=M. |date=1978 |title=La Edad Deseadense (Oligoceno inferior) de la Formación Fray Bentos y su contenido paleontológico, con especial referencia a la presencia de Proborhyaena cf. gigantea Ameghino (Marsupialia: Borhyaenidae) en el Uruguay. Nota preliminar. |url=https://www.researchgate.net/publication/36891196 |journal=Comunicaciones Paleontológicas del Museo de Historia Natural de Montevideo |volume=7 |issue=1 |pages=151–158}}

File:Protypotheriump.jpg

The genus Protypotherium was first described in 1882 by Florentino Ameghino, based on fossil remains found in the Ituzaingó Formation in Entre Ríos Province, Argentina, in soils dating from the Late Miocene. The type species is Protypotherium antiquum. Another well-known species is P. australe, also from the Santa Cruz Formation,{{Cite book |last=Sinclair |first=William John |url=https://archive.org/details/reportsofp61319091912prin/mode/2up|title=Mammalia of the Santa Cruz Beds, part 1: Typotheria of the Santa Cruz Beds.|chapter=Reports of the Princeton University Expeditions to Patagonia, 1896-1899.|date=1909 |publisher=The University |location=Princeton |doi=10.5962/bhl.title.12486|doi-access=free|volume=7|pages=1–110}} but several other species have been attributed to this genus, such as P. altum, P. attenuatum, P. claudum, P. colloncurensis, P. diastematum, P. distinctum, P. endiadys, P. minutum, P. praerutilum, and P. sinclairi,{{Cite journal |last1=Kramarz |first1=Alejandro G. |last2=Bond |first2=Mariano |last3=Arnal |first3=Michelle |date=2015 |title=Systematic Description of Three New Mammals (Notoungulata and Rodentia) from the Early Miocene Cerro Bandera Formation, Northern Patagonia, Argentina |url=http://naturalis.fcnym.unlp.edu.ar/repositorio/_documentos/sipcyt/bfa005267.pdf |journal=Ameghiniana |volume=52 |issue=6 |pages=585–597 |doi=10.5710/AMGH.27.06.2015.2906 |issn=0002-7014 |doi-access=free |access-date=2019-10-19 |archive-date=2020-09-07 |archive-url=https://web.archive.org/web/20200907165846/http://naturalis.fcnym.unlp.edu.ar/repositorio/_documentos/sipcyt/bfa005267.pdf |url-status=live }} all found in various localities in Argentina in Lower and Middle Miocene deposits. A species from Chile, P. concepcionensis was described in 2019.{{Cite journal |last1=Solórzano |first1=Andrés |last2=Encinas |first2=Alfonso |last3=Bobe |first3=René |last4=Maximiliano |first4=Reyes |last5=Carrasco |first5=Gabriel |date=2019-12-01 |title=The Early to late Middle Miocene mammalian assemblages from the Cura-Mallín Formation, at Lonquimay, southern Central Andes, Chile (~38°S): Biogeographical and paleoenvironmental implications |url=https://www.sciencedirect.com/science/article/pii/S0895981119302160 |journal=Journal of South American Earth Sciences |language=en |volume=96 |pages=102319 |doi=10.1016/j.jsames.2019.102319 |bibcode=2019JSAES..9602319S |s2cid=202174453 |issn=0895-9811 |access-date=2022-11-17 |archive-date=2019-10-17 |archive-url=https://web.archive.org/web/20191017214144/https://www.sciencedirect.com/science/article/pii/S0895981119302160 |url-status=live }}

File:Protypotherium.jpg

Protypotherium was a rather specialized member of the interatheriids, akin to the bizarre Miocochilius; these two forms, according to a 2017 study, formed a monophyletic derived clade within the family Interatheriidae. In the same study, it is indicated that the species P. australe would be the most basal known species of the genus and may be ancestral to the other species of Protypotherium and the genus Miocochilius. In spite of its name, Protypotherium was not an ancestor of "Typotherium", a genus that is now considered to be a synonym of Mesotherium, another notoungulate belonging to another family, the Mesotheriidae.

The following cladogram of the Interatheriinae is based on Vera et al. 2017, showing the position of Protypotherium.{{Cite journal |last1=Vera |first1=Bárbara Soledad |last2=Reguero |first2=Marcelo Alfredo |last3=Gonzalez |first3=Laureano Raul |date=December 2017 |title=The Interatheriinae notoungulates from the middle Miocene Collón Curá Formation in Argentina |journal=Acta Palaeontologica Polonica |volume=62 |doi=10.4202/app.00373.2017 |doi-access=free |hdl=11336/56874|hdl-access=free }}50x50px Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License

{{clade

|label1=Interatheriinae

|1={{clade

|1=Eopachyrucos pliciferus

|2={{clade

|1=Santiagorothia chiliensis

|2={{clade

|1=Federicoanaya sallaensis

|2={{clade

|1=Brucemacfaddenia boliviensis

|2={{clade

|1=Archaeophylus patrius

|2=Progaleopithecus tournoueri

|3=Argyrohyrax proavus

|4={{clade

|1=Interatherium robustum

|2=Cochilius volvens }}

|5={{clade

|1=Protypotherium australe

|2={{clade

|1=Protypotherium endiadys

|2={{clade

|1=Protypotherium distinctum

|2=Protypotherium sinclairi

|3=Miocochilius federicoi

|4=Miocochilius anamopodus

|5={{clade

|1=Protypotherium minutum

|2=Protypotherium colloncurensis

}} }} }} }} }} }} }} }} }} }}

{{clearleft}}

The following species of Protypotherium have been described:[https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=43422 Protypotherium] at Fossilworks.org

{{div col|colwidth=20em}}

• P. altum {{small|Ameghino 1891}}
• P. antiquum {{small|Ameghino 1882}}
• P. attenuatum {{small|Ameghino 1887}}
• P. australe {{small|Moreno 1882}}
• P. claudum {{small|Ameghino 1889}}
• P. colloncurensis {{small|Vera et al. 2017}}
• P. diastematum {{small|Ameghino 1891}}
• P. distinctum {{small|Cabrera & Kraglievich 1931}}
• P. endiadys {{small|Roth 1898}}
• P. minutum {{small|Cabrera & Kraglievich 1931}}
• P. praerutilum {{small|Ameghino 1887}}
• P. sinclairi {{small|Kramarz et al. 2015}}

{{div col end}}

• P. concepcionensis {{small|Solórzano et al. 2019}}

{{clearboth}}

File:Protypotherium australe.jpg]]

Protypotherium was slightly larger than a rabbit, measuring about {{convert|40|cm|ft}} in length. The body and legs as well as the tail of this animal were relatively long, while its neck was short. It probably resembled a rodent, possessing slender limbs with four, digitigrade clawed feet.{{Cite journal |last1=Croft |first1=Darin A. |last2=Lorente |first2=Malena |date=2021-08-17 |title=No evidence for parallel evolution of cursorial limb adaptations among Neogene South American native ungulates (SANUs) |journal=PLOS ONE|language=en |volume=16 |issue=8 |pages=e0256371 |doi=10.1371/journal.pone.0256371 |issn=1932-6203 |pmc=8370646 |pmid=34403434|bibcode=2021PLoSO..1656371C |doi-access=free }} Its rat-like skull contained a set of 44 unspecialized teeth.

From the shape of its claws, Protypotherium would have been adept at digging and likely took over the burrows of other animals.{{cite book |editor=Palmer, D.|year=1999 |title= The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals|publisher= Marshall Editions|location=London|page= 251|isbn= 1-84028-152-9}}

File:Protypotherium endiadys - lower dentition - Collón Curá Formation, Argentina.jpgFile:Protypotherium colloncurensis - lower and upper dentition - Collón Curá Formation, Argentina.jpg

The skull of Protypotherium was about halfway up the cranial vault, was slightly descending in the anterior part; the posterior part, on the other hand, lowered abruptly, in contrast to similar forms such as Cochilius (whose cranial vault was not inclined). The orbit was in a nearly median position, very open posteriorly, and the nasal bones were very advanced. The orbital arch was robust and was the direct extension of the lambdoid ridges. The maxillary bone alone formed the lower margin of the skull. At the back of the skull, the squamous bone and mastoid were highly developed. Seen from above, the skull had an oval outline but narrowed sharply at the beginning of the snout.{{Cite journal |last=Ameghino |first=Florentino |date=1891 |title=Nuevos restos de mamíferos fósiles descubiertos por Carlos Ameghino en el Eoceno inferior de la Patagonia austral. — Especies nuevas, adiciones y correcciones |url=https://www.biodiversitylibrary.org/part/76088 |journal=Revista argentina de historia natural |volume=1 |pages=289–328 |access-date=2022-11-17 |archive-date=2022-10-05 |archive-url=https://web.archive.org/web/20221005190540/https://www.biodiversitylibrary.org/part/76088 |url-status=live }} The temporal fossa continued backward in a deep reinforcement between the lambdoid and sagittal ridges. The auditory region was characterized by a hypotympanic sinus much smaller than the tympanic cavity. In some species, the inner wall of the tympanic membrane was thick and filled with a fine spongy tissue. The epitympanic sinus was of medium size. The two branches of the mandible were firmly joined in the anterior part; the posterior part of the mandible was very elevated.

File:Protypotherium endiadys - skull and upper dentition - Collón Curá Formation, Argentina.jpg

The dentition is complete, with the mandible having 44 teeth and no diastema. The upper incisors were rooted and provided with enamel on the outer surface. The canines were incisor-shaped, while the premolars had weak roots. The molars had two ribs on the outer wall. An internal groove divided the tooth into two almost equal lobes. An unworn molar showed an ectoloph, two convex inner crescents, and a ridge departing from the ectoloph. The anterior margin of each crescent joined the ectoloph. The lower incisors were divided longitudinally by a deep groove and resembled those of present-day hyraxes. The teeth were partially overlapping: one molar covered the posterior-external margin of the previous molar. An opposite outer and inner groove divided the molars into two lobes; the posterior lobe was shorter. A slight anterior-internal groove disappeared over time as tooth wear progressed.

File:Protypotherium endiadys - dentition detail - Collón Curá Formation, Argentina.jpg

The upper incisors of Protypotherium are characterized by a three-layered schmelzmuster represented by outer radial enamel. The prism diameter is ~6 μm. The Hunter-Schreger bands are thin (20–50 μm thick) and oblique. The interprismatic matrix forms closed coats near the outer enamel service and interrow sheets near the enamel dentine junction, and is intermediate to modified in the Hunter-Schreger bands. Lower incisors of Protypotherium are characterized by a one-layered schmelzmuster with Hunter-Schreger bands. Prism diameter is ~6 μm. Hunter-Schreger Bands are generally oblique and steady, even if they present a low decussation on both sections and are less discernible on some transverse sections. The interprismatic matrix forms closed coats in the entire thickness, but it is also slightly anastomosing near the enamel dentine junction. The thickness of its dentition suggest that it was a grazer, eating mainly grass.{{Cite journal |last1=Filippo |first1=Andréa |last2=Kalthoff |first2=Daniela C. |last3=Billet |first3=Guillaume |last4=Gomes Rodrigues |first4=Helder |date=2020-06-01 |title=Evolutionary and Functional Implications of Incisor Enamel Microstructure Diversity in Notoungulata (Placentalia, Mammalia) |journal=Journal of Mammalian Evolution |language=en |volume=27 |issue=2 |pages=211–236 |doi=10.1007/s10914-019-09462-z |issn=1573-7055 |doi-access=free}}50x50px Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License

Protypotherium has euhypsodont (well high-crowned) premolars and molars, and premolariform premolars. The upper molars have a lingual sulcus that separates the protolophs from the metalophs. The third and fourth premolars have a sub-triangular shape, with the mesio-distal length shorter than the labio-lingual breadth and a smaller size than the first and second molars. The first and third incisors are compact (i.e. lacking spaces between the teeth) and are imbricated another mesiodistally. The second premolar has a shorter talonid than the trigonid. The third and fourth premolars are relatively smaller than the first and second molars. The first and third molars have sub-triangular trigonids, while the first and second molars have longer talonids than the trigonids.{{Cite journal |last1=Vizcaino |first1=Sergio F. |last2=Bargo |first2=M. Susana |last3=Pérez |first3=M. Encarnación |last4=Aramendía |first4=Inés |last5=Cuitiño |first5=José I. |last6=Monsalvo |first6=Eduardo S. |last7=Vlachos |first7=Evangelos |last8=Noriega |first8=Jorge I. |last9=Kay |first9=Richard F. |date=2022-09-30 |title=Fossil vertebrates of the early-middle Miocene Cerro Boleadoras Formation, northwestern Santa Cruz Province, Patagonia, Argentina |url=http://www.andeangeology.cl/index.php/revista1/article/view/V49n3-3425 |url-status=live |journal=Andean Geology |language=en |volume=49 |issue=3 |pages=382–422 |doi=10.5027/andgeoV49n3-3425 |issn=0718-7106 |archive-url=https://web.archive.org/web/20221002152643/http://andeangeology.cl/index.php/revista1/article/view/V49n3-3425 |archive-date=2022-10-02 |access-date=2022-11-17 |doi-access=free}}50x50px Material was copied from this source, which is available under a Creative Commons Attribution 3.0 International License

File:Protypotherium sinclairi.png

Compared with the related Interatherium and Cochilius, Protypotherium had well-differentiated third and fourth premolars compared to molars, and numerous other dental features. In contrast to Miocochilius, moreover, Protypotherium possessed the canine-shaped lower first premolar and shorter lower third molar.

The species Protypotherium sinclairi can be distinguished from other species of Protypotherium by its dentition, with all teeth having a thick cementum covering. The third and fourth premolar both have a shorter anteroposterior diameter of the talonid than the trigonid, while the first and second premolars are short and non-molariform. The teeth of this species are smaller than those of P. australe, but larger than those of P. praerutilum and P. attenuatum, all of which are Santacrucian in age. The posterior lower premolars show proportionally larger buccolingual diameter of the talonid than those in the Santacrucian species.

File:ProtypotheriumSinclair 1.jpg

The skeleton of Protypotherium is well known, especially regarding the species Protypotherium australe. Fifteen dorsal vertebrae, seven lumbar vertebrae and five sacral vertebrae were probably present. The tail was long, with at least eighteen vertebrae.

The scapula possessed a slightly convex coracoid margin. The scapular spine was tall and narrow, with a small apophysis of the acromion and a large metacromion. The humerus was very stout in the proximal region, with two low tuberosities; the distal end was enlarged, with the entepicondyle developed and provided with a large foramen. The radius was strongly curved antero-posteriorly and rather gracile; the ulna, on the other hand, was curved laterally. The hand was tetradactylous, as opposed to the related Miocochilius, which had only three fingers, two of which were functional, with an alternating structure of the carpus and relationships between the metacarpals. The weight was discharged between the second and third metacarpals, which were almost equal in length, while the fourth was shorter and the fifth was much reduced. The scaphoid bone had a strong articulation for the radius and rested on the greater trochanter and the trapezoid. In the outer part, the scaphoid articulated with the lunar bone by means of a small facet of the apophysis related to the great bone. The lunate bone was in contact distally with the great bone and the hamate, and laterally it was in contact with the cuneiform bone via a large surface. The joints of the first phalanges were limited to the plantar and distal surfaces. The phalanges nail joints were laterally compressed and provided with a small incision at the end.

File:Protypotherium endiadys - post-cranial bones - Collón Curá Formation, Argentina.jpg

The ischium was broad posteriorly, and the pubical area was small. The femur was straight and somewhat flattened anteroposteriorly. The greater trochanter slightly exceeded the articular head, while the third trochanter was well developed and in a fairly proximal position. The condyles were large. The tibia and fibula were usually separated, but sometimes distal co-ossification was present. The distal joint of the tibia was divided by a prominent ridge into two equal cavities. The fibula was thin. The trochlea of the astragalus was long and medium deep; the ridges of the talus were equal to each other, the neck long and the head globular. The calcaneus did not articulate with the navicular bone and had a large facet for the fibula. The phalanges possessed the same structure as those of the hand, but were larger. It is likely that the feet of Protypotherium were digitigrade.

Protypotherium was mainly a herbivore, but it is possible that Protypotherium fed occasionally on carrion as well. The legs clearly show robust nail phalanges, thanks to which the animal could dig burrows or modify those abandoned by other animals.

A 2021 study concerning numerous fossils of the teeth of various species of Protypotherium showed that there is a trend in the preservation of tooth pattern, increase in size and decrease in number of species over time. This could be correlated with a global trend of cooling temperatures, indicating a deterioration of paleoenvironmental conditions during the Miocene. There also appears to have been a latitude shift in the distributional range of these animals: from Lower Miocene Patagonia to northern areas of South America towards the end of the Miocene.

Fossils of Protypotherium have been found in various fossiliferous stratigraphic units in South America. Several specimens come from the Santa Cruz Formation in the Austral Basin in southern Patagonia, Argentina,{{Cite journal |last1=Cuitiño |first1=José I. |last2=Vizcaíno |first2=Sergio F. |last3=Bargo |first3=M. Susana |last4=Aramendía |first4=Inés |date=2019-05-31 |title=Sedimentology and fossil vertebrates of the Santa Cruz Formation (early Miocene) in Lago Posadas, southwestern Patagonia, Argentina |url=http://www.andeangeology.cl/index.php/revista1/article/view/V46n2-3128 |url-status=live |journal=Andean Geology |language=en |volume=46 |issue=2 |pages=383–420 |doi=10.5027/andgeoV46n2-3128 |issn=0718-7106 |archive-url=https://web.archive.org/web/20221001040203/http://www.andeangeology.cl/index.php/revista1/article/view/V46n2-3128 |archive-date=2022-10-01 |access-date=2022-11-17 |doi-access=free|hdl=11336/96343 |hdl-access=free }}{{Cite journal |last1=Zurita-Altamirano |first1=Daniel |last2=Buffetaut |first2=Eric |last3=Forasiepi |first3=Analía M. |last4=Kramarz |first4=Alejandro |last5=Carrillo |first5=Juan D. |last6=Aguirre-Fernández |first6=Gabriel |last7=Carlini |first7=Alfredo A. |last8=Scheyer |first8=Torsten M. |last9=Sánchez-Villagra |first9=Marcelo R. |date=2019 |title=The Allemann collection from the Santa Cruz Formation (late early Miocene), Argentina, in Zurich, Switzerland |journal=Swiss Journal of Palaeontology |language=en |volume=138 |issue=2 |pages=259–275 |doi=10.1007/s13358-019-00185-5 |issn=1664-2384 |doi-access=free|bibcode=2019SwJP..138..259Z |hdl=11336/120785 |hdl-access=free }} with other finds from the Cerro Azul,{{Cite journal |last1=Montalvo |first1=C. I. |last2=Tomassini |first2=R. L. |last3=Sostillo |first3=R. |last4=Cerdeño |first4=E. |last5=Verzi |first5=D. H. |last6=Visconti |first6=G. |last7=Folguera |first7=A. |last8=Schmidt |first8=G. I. |date=2019-11-01 |title=A Chasicoan (late Miocene) vertebrate assemblage from Cerro Azul Formation, central Argentina. Geomorphological and biochronological considerations |url=https://www.sciencedirect.com/science/article/pii/S0895981119301518 |journal=Journal of South American Earth Sciences |language=en |volume=95 |pages=102218 |bibcode=2019JSAES..9502218M |doi=10.1016/j.jsames.2019.102218 |issn=0895-9811 |s2cid=189976661}} Cerro Boleadoras, Ituzaingó,{{Cite journal |last=Schmidt |first=Gabriela I. |date=2013 |title=Los ungulados nativos (Litopterna y Notoungulata: Mammalia) del "Mesopotamiense" (Mioceno Tardío) de Entre Ríos, Argentina |url=https://www.peapaleontologica.org.ar/index.php/peapa/article/view/45 |url-status=live |journal=Publicación Electrónica de la Asociación Paleontológica Argentina |language=en |volume=14 |issue=1 |issn=2469-0228 |archive-url=https://web.archive.org/web/20221115033531/https://www.peapaleontologica.org.ar/index.php/peapa/article/view/45 |archive-date=2022-11-15 |access-date=2022-11-17}} Cerro Bandera, Chichinales, Collón Curá Formations, and the Sarmiento Formations of the Colorado, Austral, Paraná, Neuquén, Cañadón Asfalto, and Golfo San Jorge Basins, as well as the Aisol and Salicas Formations of the same country.{{cite journal |last1=Forasiepi |first1=Analía M. |last2=Martinelli |first2=Agustín G. |last3=De la Fuente |first3=Marcelo S. |last4=Dieguez |first4=Sergio |last5=Bond |first5=Mariano |year=2011 |title=Paleontology and stratigraphy of the Aisol Formation (Neogene), San Rafael, Mendoza |url=http://naturalis.fcnym.unlp.edu.ar/repositorio/_documentos/sipcyt/bfa002518.pdf |url-status=live |journal=Cenozoic Geology of the Central Andes of Argentina, SCS Publisher, Salta |pages=135–154 |archive-url=https://web.archive.org/web/20220522170431/http://naturalis.fcnym.unlp.edu.ar/repositorio/_documentos/sipcyt/bfa002518.pdf |archive-date=2022-05-22 |access-date=2022-11-17}}{{cite journal |last1=Brandoni |first1=Diego |last2=Schmidt |first2=Gabriela I. |last3=Candela |first3=Adriana M. |last4=Noriega |first4=Jorge I. |last5=Brunetto |first5=Ernesto |last6=Fiorelli |first6=Lucas E. |year=2012 |title=Mammals from the Salicas Formation (Late Miocene), La Rioja Province, Northwestern Argentina: Paleobiogeography, age and paleoenvironment |url=http://naturalis.fcnym.unlp.edu.ar/repositorio/_documentos/sipcyt/bfa004294.pdf |url-status=live |journal=Ameghiniana |volume=49 |issue=3 |pages=1–13 |doi=10.5710/AMGH.v49i3(467) |archive-url=https://web.archive.org/web/20170823131229/http://naturalis.fcnym.unlp.edu.ar/repositorio/_documentos/sipcyt/bfa004294.pdf |archive-date=2017-08-23 |access-date=2019-03-13 |s2cid=55646353}} Furthermore, fossil finds of Protypotherium have been found in other countries, such as the Fray Bentos Formation of Uruguay, also in the Paraná Basin, the Muyu Huasi Formation of the Muyu Huasi Basin in Bolivia, the Nazareno Formation in the same country, of the Tupiza Basin,{{Cite journal |last1=Croft |first1=Darin Andrew |last2=Anaya |first2=Federico |last3=Auerbach |first3=David |last4=Garzione |first4=Carmala |last5=MacFadden |first5=Bruce J. |date=2009-09-01 |title=New Data on Miocene Neotropical Provinciality from Cerdas, Bolivia |url=https://doi.org/10.1007/s10914-009-9115-0 |url-status=live |journal=Journal of Mammalian Evolution |language=en |volume=16 |issue=3 |pages=175–198 |doi=10.1007/s10914-009-9115-0 |issn=1573-7055 |archive-url=https://web.archive.org/web/20230206215116/https://link.springer.com/article/10.1007/s10914-009-9115-0 |archive-date=2023-02-06 |access-date=2022-11-17 |s2cid=16210582}} and the Cura-Mallín Formation of the Cura Mallín Basin of Argentina and Chile and the Río Frías Formation of the Magallanes Basin in Chile.{{cite journal |last1=Bostelmann |first1=J.E. |last2=Bobe |first2=René |last3=Carrasco |first3=G. |last4=Alloway |first4=Brent V. |last5=Malnis |first5=Paula Santi |last6=Mancuso |first6=Adriana Cecilia |last7=Agüero |first7=B. |last8=Zeresenay |first8=Alemseged |last9=Godoy |first9=Y. |year=2012 |title=The Alto Río Cisnes Fossil Fauna (Río Frías Formation, Early-Middle Miocene, Friasian SALMA): A keystone and paradigmatic vertebrate assemblage of the South American Fossil Record |url=https://www.researchgate.net/publication/306123402 |publisher=III Simposio Paleontología en Chile |pages=44–45 |accessdate=2019-03-13}}

In the Chichinales Formation, which is known for its local mammal fauna, Protypotherium would have coexisted with astrapotheres, the notoungulates Cochilius volvens, Colpodon, Hegetotheriopsis sulcatus and Hegetotherium,{{Cite journal |last1=Kramarz |first1=Alejandro Gustavo |last2=Paz |first2=Ernesto Rodrigo |date=2013 |title=Un Hegetotheriidae (Mammalia, Notoungulata) basal del Mioceno temprano de Patagonia |url=http://www.scielo.org.mx/scielo.php?script=sci_abstract&pid=S1026-87742013000100013&lng=es&nrm=iso&tlng=es |journal=Revista Mexicana de Ciencias Geológicas |language=es |volume=30 |issue=1 |pages=186–195 |issn=1026-8774 |access-date=2022-11-17 |archive-date=2022-10-29 |archive-url=https://web.archive.org/web/20221029041100/https://www.scielo.org.mx/scielo.php?script=sci_abstract&pid=S1026-87742013000100013&lng=es&nrm=iso&tlng=es |url-status=live }} the litoptern Cramauchenia, the rodents Australoprocta, Caviocricetus, Eoviscaccia, and Willidewu esteparius,{{Cite book |last1=Madden |first1=Richard H. |chapter-url=https://books.google.com/books?id=oY7wkK6lV4cC&q=Colhuehuapian+rodents+from+Gran+Barranca+and+other+Patagonian+localities%3A+the+state+of+the+art.&pg=PA206 |chapter=Colhuehuapian rodents from Gran Barranca and other Patagonian localities: the state of the art. |title=The Paleontology of Gran Barranca: Evolution and Environmental Change Through the Middle Cenozoic of Patagonia |last2=Carlini |first2=Alfredo A. |last3=Vucetich |first3=Maria Guiomar |last4=Kay |first4=Richard F. |date=2010-06-17 |publisher=Cambridge University Press |isbn=978-0-521-87241-6 |language=en |access-date=2022-11-17 |archive-date=2022-10-02 |archive-url=https://web.archive.org/web/20221002174237/https://books.google.com/books?id=oY7wkK6lV4cC&q=Colhuehuapian+rodents+from+Gran+Barranca+and+other+Patagonian+localities:+the+state+of+the+art.&pg=PA206 |url-status=live }} the armadillos Proeutatus and Stenotatus, and the sparassodont Cladosictis. Bird remains from the formation are comparatively poor. A part of a tibiotarsus has previously been classified as an undetermined species of psilopterine phorusrhacid. Other birds include an undetermined wading bird, Opisthodactylus horacioperezi, a species of rhea, and Patagorhacos, a phorusrhacid. During the Miocene the area likely consisted of open but wooded environment with temperate climate and a proximity to freshwater.

The Sarmiento Formation has provided a wide assemblage of mammals, consisting of pyroclastic deposits in an arid desert environment.{{Cite book |last=Madden |first=Richard H. |url=http://worldcat.org/oclc/499130096 |title=The paleontology of Gran Barranca : evolution and environmental change through the middle Cenozoic of Patagonia |date=2010 |publisher=Cambridge University Press |isbn=978-0-521-87241-6 |chapter=Loessic and fluvial sedimentation in Sarmiento Formation pyroclastics, middle Cenozoic of central Patagonia |oclc=499130096}} Among these mammals were the astrapotheres Astrapotherium and Parastrapotherium,{{Cite book |last1=Madden |first1=Richard H. |chapter-url=https://books.google.com/books?id=oY7wkK6lV4cC&dq=Colhuehuapian+Astrapotheriidae+%28Mammalia%29+from+Gran+Barranca+south+of+Lake+Colhue+Huapi.&pg=PA182 |title=The Paleontology of Gran Barranca: Evolution and Environmental Change Through the Middle Cenozoic of Patagonia |last2=Carlini |first2=Alfredo A. |last3=Vucetich |first3=Maria Guiomar |last4=Kay |first4=Richard F. |date=2010-06-17 |publisher=Cambridge University Press |isbn=978-0-521-87241-6 |language=en |chapter=Colhuehuapian Astrapotheriidae (Mammalia) from Gran Barranca south of Lake Colhue Huapi. |access-date=2022-11-17 |archive-date=2022-11-10 |archive-url=https://web.archive.org/web/20221110225518/https://books.google.com/books?id=oY7wkK6lV4cC&dq=Colhuehuapian+Astrapotheriidae+(Mammalia)+from+Gran+Barranca+south+of+Lake+Colhue+Huapi.&pg=PA182 |url-status=live }} the fellow notoungulates Argyrohippus,{{Cite book |last1=G.M López |chapter-url=https://books.google.com/books?id=oY7wkK6lV4cC&pg=PA143 |title=The Paleontology of Gran Barranca. Evolution and Environmental Change Through the Middle Cenozoic of Patagonia |last2=A.M. Ribeiro |last3=M. Bond |publisher=Cambridge University Press |year=2010 |isbn=978-0-521-87241-6 |editor-last=Richard H. Madden |pages=143–151 |chapter=The Notohippidae (Mammalia, Notoungulata) from Gran Barranca: preliminary considerations |editor-last2=Alfredo A. Carlini |editor-last3=Maria Guiomar Vucetich |editor-last4=Richard F. Kay |access-date=2022-11-17 |archive-date=2022-11-10 |archive-url=https://web.archive.org/web/20221110225317/https://books.google.com/books?id=oY7wkK6lV4cC&pg=PA143 |url-status=live }} Cochilius, Colpodon,{{Cite book |last1=Madden |first1=Richard H. |chapter-url=https://books.google.com/books?id=oY7wkK6lV4cC&dq=The+Leontiniidae+%28Mammalia%2C+Notoungulata%29+from+the+Sarmiento+Formation+at+Gran+Barranca%2C+Chubut+Province%2C+Argentina.&pg=PR5 |title=The Paleontology of Gran Barranca: Evolution and Environmental Change Through the Middle Cenozoic of Patagonia |last2=Carlini |first2=Alfredo A. |last3=Vucetich |first3=Maria Guiomar |last4=Kay |first4=Richard F. |date=2010-06-17 |publisher=Cambridge University Press |isbn=978-0-521-87241-6 |language=en |chapter=The Leontiniidae (Mammalia, Notoungulata) from the Sarmiento Formation at Gran Barranca, Chubut Province, Argentina. |access-date=2022-11-17 |archive-date=2022-11-10 |archive-url=https://web.archive.org/web/20221110225243/https://books.google.com/books?id=oY7wkK6lV4cC&dq=The+Leontiniidae+(Mammalia,+Notoungulata)+from+the+Sarmiento+Formation+at+Gran+Barranca,+Chubut+Province,+Argentina.&pg=PR5 |url-status=live }} Interatherium and Pachyrukhos, the litopterns Cramauchenia,{{cite journal |author1=Dozo, M.T. |author2=Vera, B. | year = 2010 | title = First skull and associated postcranial bones of Macraucheniidae (Mammalia, Litopterna) from the Deseadan SALMA (late Oligocene) of Cabeza Blanca (Chubut, Argentina) | journal = Journal of Vertebrate Paleontology | volume = 30 | issue = 6 | pages = 1818–1826 |url=https://www.researchgate.net/publication/233015768| doi=10.1080/02724634.2010.521534|bibcode=2010JVPal..30.1818D |s2cid=86291795 | hdl = 11336/93665 | hdl-access = free }} Lambdaconus, Paramacrauchenia, Proheptaconus,{{Cite journal |last1=Cifelli |first1=Richard |last2=Soria |first2=Miguel Fernando |date=1983 |title=Systematics of the Adianthidae (Litopterna, Mammalia). |url=https://digitallibrary.amnh.org/handle/2246/5255 |journal=American Museum Novitates |language=en-US |issue=2771 |pages=1–25 |hdl=2246/5255 |access-date=2022-11-17 |archive-date=2022-10-01 |archive-url=https://web.archive.org/web/20221001074728/https://digitallibrary.amnh.org/handle/2246/5255 |url-status=live }} Prolicaphrium,{{Cite journal |last1=Vera |first1=Bárbara Soledad |last2=Fornasiero |first2=Mariagabriella |last3=Del Favero |first3=Letizia |date=December 2015 |title=The Egidio Feruglio's collection in the Museum of Geology and Palaeontology of the University of Padova: its importance to the knowledge of Cenozoic mammals from South America |url=https://www.researchgate.net/publication/290430697 |journal=Museologia Scientifica |volume=9 |pages=35–44 |issn=1123-265X}} Pternoconius,{{Cite journal |last1=Cifelli |first1=Richard L. |last2=Soria |first2=Miguel F. |date=1983 |title=Notes on Deseadan Macraucheniidae |journal=Ameghiniana |url=https://ameghiniana.org.ar/index.php/ameghiniana/article/view/1799 |language=es |volume=20 |issue=1–2 |pages=141–153 |issn=1851-8044 |access-date=2022-11-17 |archive-date=2022-09-29 |archive-url=https://web.archive.org/web/20220929232212/https://ameghiniana.org.ar/index.php/ameghiniana/article/view/1799 |url-status=live }}{{Cite journal |last1=Soria (h) |first1=Miguel Fernando |last2=Hoffstetter |first2=Robert |date=1985 |title=Pternoconius tournoueri, nueva especie de Macraucheniidae (Mammalia; Litopterna) de edad Colhuehuapense (Oligoceno Tardio); Pcia. Del Chubut, República Argentina |journal=Ameghiniana |url=https://ameghiniana.org.ar/index.php/ameghiniana/article/view/1758 |language=es |volume=22 |issue=3–4 |pages=149–158 |issn=1851-8044 |access-date=2022-11-17 |archive-date=2022-10-04 |archive-url=https://web.archive.org/web/20221004213516/https://ameghiniana.org.ar/index.php/ameghiniana/article/view/1758 |url-status=live }}{{Cite journal |last1=Cheme-Arriaga |first1=Lucas |last2=Dozo |first2=MarÍa Teresa |last3=Gelfo |first3=Javier N. |date=2016-11-01 |title=A new Cramaucheniinae (Litopterna, Macraucheniidae) from the early Miocene of Patagonia, Argentina |url=https://doi.org/10.1080/02724634.2017.1229672 |journal=Journal of Vertebrate Paleontology |volume=36 |issue=6 |pages=e1229672 |doi=10.1080/02724634.2017.1229672 |bibcode=2016JVPal..36E9672C |s2cid=88586687 |issn=0272-4634|hdl=11336/30386 |hdl-access=free }} Tetramerorhinus

and Theosodon,{{Cite journal |last1=Kramarz |first1=Alejandro G. |last2=Bond |first2=Mariano |date=2005 |title=Los Litopterna (Mammalia) de la Formación Pinturas, Mioceno Temprano-Medio de Patagonia |url=https://www.ameghiniana.org.ar/index.php/ameghiniana/article/view/928 |language=es |volume=42 |issue=3 |pages=611–625 |issn=1851-8044 |access-date=2022-11-17 |archive-date=2022-09-26 |archive-url=https://web.archive.org/web/20220926214926/https://www.ameghiniana.org.ar/index.php/ameghiniana/article/view/928 |url-status=live }} the xenarthrans Hapaloides, Holomegalonyx, Nematherium, Peltephilus, Proeutatus, Proschismotherium, Prozaedyus, Stegotherium, and Stenotatus,{{Cite book |last1=Carlini |first1=Alfredo Armando |url=https://www.researchgate.net/publication/233955405 |title=The Paleontology of Gran Barranca. Evolution and Environmental Change Through the Middle Cenozoic of Patagonia |last2=Ciancio |first2=Martin R. |last3=Scillato-Yané |first3=G. 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|pages=228–234 |doi=10.1671/18.1 |bibcode=2004JVPal..24..228D |s2cid=86327308 |issn=0272-4634 |access-date=2022-11-17 |archive-date=2023-02-06 |archive-url=https://web.archive.org/web/20230206215125/https://www.tandfonline.com/doi/abs/10.1671/18.1 |url-status=live |hdl=11336/103980 |hdl-access=free }}{{Cite journal |last1=Patterson |first1=B. |last2=Pascual |first2=R. |date=1968 |title=New echimyid rodents from the Oligocene of Patagonia, and a synopsis of the family |url=https://www.biodiversitylibrary.org/part/31522 |journal=Breviora |volume=301 |pages=1–14 |issn=0006-9698 |access-date=2022-11-17 |archive-date=2022-10-02 |archive-url=https://web.archive.org/web/20221002201111/https://www.biodiversitylibrary.org/part/31522 |url-status=live }}{{Cite journal |last1=Arnal |first1=Michelle |last2=Kramarz |first2=Alejandro G. |date=2011-09-01 |title=First complete skull of an octodontoid (Rodentia, Caviomorpha) from the Early Miocene of South America and its bearing in the early evolution of Octodontoidea |url=https://www.sciencedirect.com/science/article/pii/S0016699511000532 |journal=Geobios |language=en |volume=44 |issue=5 |pages=435–444 |doi=10.1016/j.geobios.2010.12.003 |bibcode=2011Geobi..44..435A |issn=0016-6995|hdl=11336/69014 |hdl-access=free }}{{Cite journal |last1=Álvarez |first1=Alicia |last2=Arnal |first2=Michelle |date=2015-12-01 |title=First Approach to the Paleobiology of Extinct Prospaniomys (Rodentia, Hystricognathi, Octodontoidea) Through Head Muscle Reconstruction and the Study of Craniomandibular Shape Variation |url=https://doi.org/10.1007/s10914-015-9291-z |journal=Journal of Mammalian Evolution |language=en |volume=22 |issue=4 |pages=519–533 |doi=10.1007/s10914-015-9291-z |s2cid=16937577 |issn=1573-7055 |access-date=2022-11-17 |archive-date=2023-02-06 |archive-url=https://web.archive.org/web/20230206215128/https://link.springer.com/article/10.1007/s10914-015-9291-z |url-status=live |hdl=11336/19056 |hdl-access=free }}{{Cite journal |last1=Busker |first1=Felipe |last2=Pérez |first2=María E. |last3=Dozo |first3=María T. |date=2019-07-01 |title=A new chinchilloid (Rodentia, Hystricognathi) from the early Miocene of the localities of Bryn Gwyn and Gran Barranca (Patagonia, Argentina) |journal=Comptes Rendus Palevol |language=en |volume=18 |issue=5 |pages=525–540 |doi=10.1016/j.crpv.2019.05.003 |s2cid=202185808 |issn=1631-0683|doi-access=free |bibcode=2019CRPal..18..525B }} and the primates Homunculus, Mazzonicebus and Tremacebus.{{Cite journal |last=Hershkovitz |first=Philip |date=1981-01-31 |title=Comparative Anatomy of Platyrrhine Mandibular Cheek Teeth dpm4, pm4, m1 with Particular Reference to Those of Homunculus (Cebidae), and Comments on Platyrrhine Origins |url=https://brill.com/view/journals/ijfp/35/2-3/article-p179_5.xml |journal=Folia Primatologica |volume=35 |issue=2–3 |pages=179–217 |doi=10.1159/000155972 |pmid=7021372 |issn=0015-5713 |access-date=2022-11-17 |archive-date=2022-10-05 |archive-url=https://web.archive.org/web/20221005070016/https://brill.com/view/journals/ijfp/35/2-3/article-p179_5.xml |url-status=live }}{{Cite journal |last1=Novo |first1=Nelson M. |last2=Tejedor |first2=Marcelo F. |last3=Ruiz |first3=Laureano R. González |date=2018-11-08 |title=Previously unknown fossil platyrrhines (Primates) of Patagonia from the Tournouër collection at the Muséum national d'Histoire naturelle, Paris |journal=Geodiversitas |volume=40 |issue=4 |pages=529–535 |doi=10.5252/geodiversitas2018v40a22 |issn=1280-9659 |doi-access=free|hdl=11336/82708 |hdl-access=free }}{{Cite journal |last=Hershkovitz |first=Philip |date=1974 |title=A New Genus of Late Oligocene Monkey (Cebidae, Platyrrhini) with Notes on Postorbital Closure and Platyrrhine Evolution |url=https://www.karger.com/Article/FullText/155594 |journal=Folia Primatologica |language=english |volume=21 |issue=1 |pages=1–35 |doi=10.1159/000155594 |issn=0015-5713 |pmid=4210697 |access-date=2022-11-17 |archive-date=2023-02-06 |archive-url=https://web.archive.org/web/20230206215141/https://www.karger.com/Article/Abstract/155594 |url-status=live }} The late-surviving meridiolestidan Necrolestes was also present.{{Cite journal |last1=Goin |first1=Francisco J. |last2=Abello |first2=María Alejandra |date=February 2013 |title=Los Metatheria Sudamericanos de Comienzos Del Neógeno (Mioceno Temprano, Edad MamÍFero Colhuehuapense): Microbiotheria y Polydolopimorphia |journal=Ameghiniana |volume=50 |issue=1 |pages=51–78 |doi=10.5710/AMGH.9.11.2012.570 |issn=0002-7014 |doi-access=free|hdl=11336/76812 |hdl-access=free }}

Multiple species of Protypotherium lived during the Early Miocene in the Santa Cruz Formation of Argentina, which preserves mostly a coastal environment, but also forested and grassland regions.Croft, D. A. (2016). Horned armadillos and rafting monkeys: the fascinating fossil mammals of South America. Indiana University Press. The area had little rainfall, so forests developed around lakes and rivers, giving Santa Cruz a diverse environment. During the Miocene, the climate was similar to those of the coasts of Chile with semi-temperate forests and oceanic winds. Grasslands began spreading into Argentina during the Miocene, though much of inner Patagonia was still arid with small rainforests in between. Large, herbivorous, South American ungulates such as the astrapothere Astrapotherium, the toxodont notoungulates Adinotherium, Homalodotherium and Nesodon shared the niche of low browsers, along with the litopterns Adianthus, Anisolophus, Diadiaphorus, Tetramerorhinus, Theosodon, and Thoatherium,{{cite journal|last1=Schmidt|first1=Gabriela I.|last2=Ferrero|first2=Brenda S.|date=September 2014|title=Taxonomic Reinterpretation of Theosodon hystatus Cabrera and Kraglievich, 1931 (Litopterna, Macraucheniidae) and Phylogenetic Relationships of the Family|journal=Journal of Vertebrate Paleontology|url=https://www.tandfonline.com/doi/abs/10.1080/02724634.2014.837393|volume=34|issue=5|pages=1231–1238|doi=10.1080/02724634.2014.837393|bibcode=2014JVPal..34.1231S |s2cid=86091386|access-date=2022-11-22|archive-date=2022-10-06|archive-url=https://web.archive.org/web/20221006040309/https://www.tandfonline.com/doi/abs/10.1080/02724634.2014.837393|url-status=live|hdl=11336/18953|hdl-access=free}}{{Cite journal |last1=Schmidt |first1=Gabriela Ines |last2=Pino |first2=Santiago Hernández Del |last3=Muñoz |first3=Nahuel Antú |last4=Fernández |first4=Mercedes |date=2019-12-20 |title=Litopterna (Mammalia) From the Santa Cruz Formation (Early-Middle Miocene) At the Río Santa Cruz, Southern Argentina. |url=https://www.peapaleontologica.org.ar/index.php/peapa/article/view/290 |journal=Publicación Electrónica de la Asociación Paleontológica Argentina |language=en |volume=19 |issue=2 |doi=10.5710/PEAPA.13.08.2019.290 |issn=2469-0228 |doi-access=free |access-date=2022-11-22 |archive-date=2022-11-22 |archive-url=https://web.archive.org/web/20221122001101/https://www.peapaleontologica.org.ar/index.php/peapa/article/view/290 |url-status=live |hdl=11336/121536 |hdl-access=free }}{{Cite journal |last1=Fernández |first1=Mercedes |last2=Muñoz |first2=Nahuel Antu |date=2019-12-20 |title=Notoungulata and Astrapotheria (Mammalia, Meridiungulata) of the Santa Cruz Formation (Early-Middle Miocene) along the Río Santa Cruz, Argentine Patagonia. |url=https://www.peapaleontologica.org.ar/index.php/peapa/article/view/288 |journal=Publicación Electrónica de la Asociación Paleontológica Argentina |language=en |volume=19 |issue=2 |doi=10.5710/PEAPA.19.09.2019.288 |issn=2469-0228 |doi-access=free |access-date=2022-11-17 |archive-date=2022-11-17 |archive-url=https://web.archive.org/web/20221117002220/https://www.peapaleontologica.org.ar/index.php/peapa/article/view/288 |url-status=live |hdl=11336/120862 |hdl-access=free }}{{Cite journal |last1=Chimento |first1=Nicolás R. |last2=Agnolin |first2=Federico L. |year=2020 |title=Phylogenetic tree of Litopterna and Perissodactyla indicates a complex early history of hoofed mammals |journal=Scientific Reports |volume=10 |issue=1 |pages=13280 |doi=10.1038/s41598-020-70287-5 |issn=2045-2322 |pmc=7413542 |pmid=32764723 |bibcode=2020NatSR..1013280C |hdl-access=free |hdl=11336/135739|doi-access=free}}{{Cite journal |last1=MacPhee |first1=R. D. E. |last2=Pino |first2=Santiago Hernández Del |last3=Kramarz |first3=Alejandro |last4=Forasiepi |first4=Analía M. |last5=Bond |first5=Mariano |last6=Sulser |first6=R. Benjamin |date=2021-04-19 |title=Cranial Morphology and Phylogenetic Relationships of Trigonostylops wortmani, an Eocene South American Native Ungulate |journal=Bulletin of the American Museum of Natural History |volume=449 |issue=1 |pages=1–183 |doi=10.1206/0003-0090.449.1.1 |issn=0003-0090 |doi-access=free}} with the rabbit-like interatheres such as Interatherium and the hegetotheres Hegetotherium and Pachyrukhos being frugivorous.{{Cite journal |last=Cassini |first=Guillermo H. |date=2013 |title=Skull Geometric Morphometrics and Paleoecology of Santacrucian (Late Early Miocene; Patagonia) Native Ungulates (Astrapotheria, Litopterna, and Notoungulata) |url=https://bioone.org/journals/ameghiniana/volume-50/issue-2/AMGH.7.04.2013.606/Skull-Geometric-Morphometrics-and-Paleoecology-of-Santacrucian-Late-Early-Miocene/10.5710/AMGH.7.04.2013.606.full |journal=Ameghiniana |volume=50 |issue=2 |pages=193–216 |doi=10.5710/AMGH.7.04.2013.606 |s2cid=128999112 |issn=0002-7014 |access-date=2022-11-22 |archive-date=2023-02-06 |archive-url=https://web.archive.org/web/20230206215131/https://bioone.org/journals/ameghiniana/volume-50/issue-2/AMGH.7.04.2013.606/Skull-Geometric-Morphometrics-and-Paleoecology-of-Santacrucian-Late-Early-Miocene/10.5710/AMGH.7.04.2013.606.short |url-status=live |hdl=11336/26393 |hdl-access=free }}Townsend, K. B., & Croft, D. A. (2008). Diets of notoungulates from the Santa Cruz Formation, Argentina: new evidence from enamel microwear. Journal of Vertebrate Paleontology, 28(1), 217-230.{{Cite journal |last1=Cassini |first1=Guillermo H. |last2=Pino |first2=Santiago Hernández Del |last3=Muñoz |first3=Nahuel A. |last4=Acosta |first4=M. V. Walter G. |last5=Fernández |first5=Mercedes |last6=Bargo |first6=M. Susana |last7=Vizcaíno |first7=Sergio F. |date=2017 |title=Teeth complexity, hypsodonty and body mass in Santacrucian (Early Miocene) notoungulates (Mammalia) |journal=Earth and Environmental Science Transactions of the Royal Society of Edinburgh |language=en |volume=106 |issue=4 |pages=303–313 |doi=10.1017/S1755691016000153 |issn=1755-6910|doi-access=free|hdl=11336/48917 |hdl-access=free }} Both mammalian and avian carnivores inhabited the area, the largest being the phorusrhacid Phorusrhacos. Marsupials also lived in the region, including the large carnivorous sparassodonts Borhyaena and the smaller sparassodonts Acyon, Cladosictis, and Sipalocyon. Xenarthrans in the Santa Cruz Formation were fairly common, such as the ground sloths Analcimorphus, Analcitherium, Eucholoeops,{{Cite journal |last1=Iuliis |first1=Gerardo De |last2=Pujos |first2=François |last3=Toledo |first3=Nestor |last4=Bargo |first4=M. Susana |last5=Vizcaíno |first5=Sergio F. |date=2014 |title=Eucholoeops Ameghino, 1887 (Xenarthra, Tardigrada, Megalonychidae) from the Santa Cruz Formation, Argentine Patagonia: implications for the systematics of Santacrucian sloths |url=https://sciencepress.mnhn.fr/fr/periodiques/geodiversitas/36/2/eucholoeops-ameghino-1887-xenarthra-tardigrada-megalonychidae-de-la-formation-santa-cruz-de-patagonie-argentine-implications-pour-la-systematique-des-paresseux-santacruziens |journal=Geodiversitas |volume=36 |issue=2 |pages=209–255 |doi=10.5252/g2014n2a2 |hdl=11336/80624 |issn=1280-9659 |doi-access=free |access-date=2022-11-26 |archive-date=2022-06-20 |archive-url=https://web.archive.org/web/20220620012715/https://sciencepress.mnhn.fr/fr/periodiques/geodiversitas/36/2/eucholoeops-ameghino-1887-xenarthra-tardigrada-megalonychidae-de-la-formation-santa-cruz-de-patagonie-argentine-implications-pour-la-systematique-des-paresseux-santacruziens |url-status=live |hdl-access=free }} Hapalops, Hyperleptus, Nematherium, Megalonychotherium, Planops, Prepotherium, Schismotherium, Trematherium, and Xyophorus,{{Cite journal |last1=Toledo |first1=Néstor |last2=Cassini |first2=Guillermo Hernán |last3=Vizcaíno |first3=Sergio Fabián |last4=Bargo |first4=M. Susana |date=2014 |title=Mass Estimation of Santacrucian Sloths from the Early Miocene Santa Cruz Formation of Patagonia, Argentina |journal=Acta Palaeontologica Polonica |volume=59 |issue=2 |pages=267–280 |doi=10.4202/app.2012.0009 |issn=0567-7920|doi-access=free|hdl=11336/20506 |hdl-access=free }}{{Cite journal |last1=Bargo |first1=M. Susana |last2=Iuliis |first2=Gerardo De |last3=Toledo |first3=Néstor |date=2019-12-20 |title=Early Miocene Sloths (Xenarthra, Folivora) From the Río Santa Cruz Valley (Southern Patagonia, Argentina), Ameghino, 1887 Revisited |url=https://www.peapaleontologica.org.ar/index.php/peapa/article/view/297 |journal=Publicación Electrónica de la Asociación Paleontológica Argentina |language=en |volume=19 |issue=2 |doi=10.5710/PEAPA.06.08.2019.297 |issn=2469-0228 |doi-access=free |access-date=2022-11-17 |archive-date=2022-11-17 |archive-url=https://web.archive.org/web/20221117230201/https://www.peapaleontologica.org.ar/index.php/peapa/article/view/297 |url-status=live |hdl=11336/126223 |hdl-access=free }} and the armadillos Cochlops, Eucinepeltus, Proeutatus, Propalaehoplophorus, Prozaedyus, Stegotherium, and Stenotatus.{{Cite book |last1=Vizcaíno |first1=Sergio F. |title=Paleobiology of Santacrucian glyptodonts and armadillos (Xenarthra, Cingulata) |date=2012 |url=https://www.cambridge.org/core/books/early-miocene-paleobiology-in-patagonia/paleobiology-of-santacrucian-glyptodonts-and-armadillos-xenarthra-cingulata/58CB0068C890DBBD5F3E7AA03E423905 |chapter=Early Miocene Paleobiology in Patagonia: High-Latitude Paleocommunities of the Santa Cruz Formation |pages=194–215 |editor-last=Bargo |editor-first=M. Susana |place=Cambridge |publisher=Cambridge University Press |isbn=978-0-521-19461-7 |last2=Fernicola |first2=Juan C. |last3=Bargo |first3=M. Susana |editor2-last=Kay |editor2-first=Richard F. |editor3-last=Vizcaíno |editor3-first=Sergio F. |access-date=2022-11-17 |archive-date=2018-06-05 |archive-url=https://web.archive.org/web/20180605183127/https://www.cambridge.org/core/books/early-miocene-paleobiology-in-patagonia/paleobiology-of-santacrucian-glyptodonts-and-armadillos-xenarthra-cingulata/58CB0068C890DBBD5F3E7AA03E423905 |url-status=live }} In addition, fossils of rodents, such as Acarechimys, Acaremys, Adelphomys, Eocardia, Neoreomys, Perimys, Pliolagostomus, Prolagostomus,{{Cite journal |last1=Vizcaíno |first1=Sergio F. |last2=Bargo |first2=M. Susana |last3=Kay |first3=Richard F. |last4=Raigemborn |first4=M. Sol |date=2021-07-07 |title=The record of the typothere Pachyrukhos (Mammalia, Notoungulata) and the Chinchillid Prolagostomus (Mammalia, Rodentia) in the Santa Cruz Formation (early–middle Miocene) south to the Río Coyle, Patagonia, Argentina |url=https://www.peapaleontologica.org.ar/index.php/peapa/article/view/385 |journal=Publicación Electrónica de la Asociación Paleontológica Argentina |language=en |volume=21 |issue=2 |pages=1–15 |doi=10.5710/PEAPA.26.05.2021.385 |issn=2469-0228 |doi-access=free |access-date=2022-11-26 |archive-date=2022-11-22 |archive-url=https://web.archive.org/web/20221122020057/https://www.peapaleontologica.org.ar/index.php/peapa/article/view/385 |url-status=live |hdl=11336/147286 |hdl-access=free }} Schistomys, Scleromys, Spaniomys, and Stichomys are also known.{{Cite journal |last1=Arnal |first1=Michelle |last2=Pérez |first2=María Encarnación |last3=Deschamps |first3=Cecilia |date=2019-12-20 |title=Revision of the Miocene caviomorph rodents from the Río Santa Cruz (Argentinean Patagonia). |url=https://www.peapaleontologica.org.ar/index.php/peapa/article/view/299 |journal=Publicación Electrónica de la Asociación Paleontológica Argentina |language=en |volume=19 |issue=2 |doi=10.5710/PEAPA.25.09.2019.299 |issn=2469-0228 |doi-access=free |access-date=2022-11-17 |archive-date=2022-11-17 |archive-url=https://web.archive.org/web/20221117222229/https://www.peapaleontologica.org.ar/index.php/peapa/article/view/299 |url-status=live |hdl=11336/175184 |hdl-access=free }} There were also primates found in the formation, such as Carlocebus and Homunculus.{{Cite journal |last1=Fleagle |first1=John G. |last2=Gladman |first2=Justin T. |last3=Kay |first3=Richard F. |date=2022 |title=A New Humerus of Homunculus patagonicus, a Stem Platyrrhine from the Santa Cruz Formation (Late Early Miocene), Santa Cruz Province, Argentina |url=https://bioone.org/journals/ameghiniana/volume-59/issue-1/AMGH.29.09.2021.3447/A-New-Humerus-of-Homunculus-patagonicus-a-Stem-Platyrrhine-from/10.5710/AMGH.29.09.2021.3447.full |journal=Ameghiniana |volume=59 |issue=1 |pages=78–96 |doi=10.5710/AMGH.29.09.2021.3447 |s2cid=244330777 |issn=0002-7014 |access-date=2022-11-17 |archive-date=2023-02-06 |archive-url=https://web.archive.org/web/20230206215133/https://bioone.org/journals/ameghiniana/volume-59/issue-1/AMGH.29.09.2021.3447/A-New-Humerus-of-Homunculus-patagonicus-a-Stem-Platyrrhine-from/10.5710/AMGH.29.09.2021.3447.short |url-status=live }}{{Cite journal |last1=Kay |first1=Richard Frederick |last2=Perry |first2=Jonathan Marcus G. |date=2019-12-20 |title=New primates from the Río Santa Cruz and Río Bote (Early-Mid Miocene), Santa Cruz Province, Argentina |url=https://www.peapaleontologica.org.ar/index.php/peapa/article/view/289 |journal=Publicación Electrónica de la Asociación Paleontológica Argentina |language=en |volume=19 |issue=2 |doi=10.5710/PEAPA.24.08.2019.289 |issn=2469-0228 |doi-access=free |access-date=2022-11-17 |archive-date=2022-11-17 |archive-url=https://web.archive.org/web/20221117222229/https://www.peapaleontologica.org.ar/index.php/peapa/article/view/289 |url-status=live }}

The Collón Curá Formation and the Colloncuran age of South America represent a time when more open environments with reduced plant covering predominated, similar to semiarid and temperate to warm, dry woodlands or bushlands. The open environment allowed more cursorial (adapted for running) and large animals to occur, contrasting with the earlier conditions during the late Early Miocene, with its well-developed forests with tree-dwelling animals. Forests would then have been restricted to valleys of the cordillera mountain ranges, with few tree-dwelling species. This change happened progressively during the earlier Friasian stage.{{cite book |last1=Tonni |first1=Eduardo P. |title=The Late Cenozoic of Patagonia and Tierra del Fuego |last2=Carlini |first2=Alfredo A. |publisher=Elsevier Science |year=2008 |isbn=978-0-08-055889-9 |editor=Rabassa, Jorge |pages=269–278 |chapter=Neogene vertebrates from Argentine Patagonia: their relationship with the most significant climatic changes}}{{cite journal |last1=Genise |first1=Jorge F. |last2=Bellosi |first2=Eduardo S. |last3=Cantil |first3=Liliana F. |last4=González |first4=Mirta G. |last5=Puerta |first5=Pablo |date=2022 |title=Middle Miocene climate transition as reflected by changes in ichnofacies and palaeosols from Patagonia, Argentina |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |volume=594 |pages=110932 |bibcode=2022PPP...59410932G |doi=10.1016/j.palaeo.2022.110932 |s2cid=247423841}} The transition towards more arid landscapes would have happened simultaneously with climate changes that corresponded to the Middle Miocene Climate Transition, a global cooling event which had a drying effect on continents.

The Collón Curá Formation of Argentina has provided a wide assemblage of mammals, including at least 24 taxa such as the xenarthrans Megathericulus, Prepotherium, Prozaedyus, and Paraeucinepeltus, the notoungulates Hegetotherium, Interatherium, and Pachyrukhos, the astrapothere Astrapotherium, the sparassodonts Patagosmilus and Cladosictis, the marsupial Abderites, the primate Proteropithecia, and rodents such as Maruchito, Protacaremys, Neoreomys, and Prolagostomus.{{cite journal |last1=Brandoni |first1=Diego |last2=Ruiz |first2=Laureano González |last3=Bucher |first3=Joaquín |date=2020 |title=Evolutive implications of Megathericulus patagonicus (Xenarthra, Megatheriinae) from the Miocene of Patagonia Argentina |url=https://link.springer.com/article/10.1007/s10914-019-09469-6 |journal=Journal of Mammalian Evolution |volume=27 |issue=3 |pages=445–460 |doi=10.1007/s10914-019-09469-6 |s2cid=163164163 |access-date=2022-11-17 |archive-date=2022-05-12 |archive-url=https://web.archive.org/web/20220512011629/https://link.springer.com/article/10.1007/s10914-019-09469-6 |url-status=live }}{{cite journal |last1=Kay |first1=Richard Frederick |last2=Johnson |first2=Derek |last3=Meldrum |first3=Don Jeffrey |date=1998 |title=A new pitheciin primate from the middle Miocene of Argentina. |url=https://www.researchgate.net/publication/13583562 |journal=American Journal of Primatology |volume=45 |issue=4 |pages=317–336 |doi=10.1002/(SICI)1098-2345(1998)45:4<317::AID-AJP1>3.0.CO;2-Z |pmid=9702279 |s2cid=22214720}}{{cite journal |last1=Echarri |first1=Sebastian |last2=Ulloa-Guaiquin |first2=Karen S. |last3=Aguirrezabala |first3=Guillermo |last4=Forasiepi |first4=Analia M. |date=2021 |title=Cladosictis patagonica (Metatheria, Sparassodonta) from the Collón Cura Formation (Middle Miocene), Río Negro, Argentina |journal=Ameghiniana |volume=58 |issue=6 |doi=10.5710/AMGH.06.08.2021.3439 |hdl=11336/171288 |s2cid=240529252|hdl-access=free }}{{cite journal |last1=Kramarz |first1=Alejandro |last2=Garrido |first2=Alberto |last3=Bond |first3=Mariano |date=2019 |title=Astrapotherium from the Middle Miocene Collón Cura Formation and the Decline of Astrapotheres in Southern South America |journal=Ameghiniana |volume=56 |issue=4 |pages=290 |doi=10.5710/AMGH.15.07.2019.3258 |s2cid=199099778}} In addition to the mammals that characterize sediments of this age, there are also a few fossils of birds, reptiles, amphibians, and fish.

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Category:Typotheres

Category:Prehistoric placental genera

Category:Chattian first appearances

Category:Messinian extinctions

Category:Oligocene mammals of South America

Category:Miocene mammals of South America

Category:Huayquerian

Category:Chasicoan

Category:Mayoan

Category:Laventan

Category:Colloncuran

Category:Friasian

Category:Santacrucian

Category:Colhuehuapian

Category:Deseadan

Category:Neogene Argentina

Category:Fossils of Argentina

Category:Neogene Bolivia

Category:Fossils of Bolivia

Category:Neogene Chile

Category:Fossils of Chile

Category:Oligocene Uruguay

Category:Fossils of Uruguay

Category:Fossil taxa described in 1882

Category:Taxa named by Florentino Ameghino

Category:Neuquén Basin

Category:Paraná Basin

Category:Golfo San Jorge Basin

Category:Austral or Magallanes Basin

Category:Cerro Azul Formation

Category:Cerro Bandera Formation

Category:Chichinales Formation

Category:Ituzaingó Formation

Category:Sarmiento Formation

Category:Santa Cruz Formation

Category:Fray Bentos Formation