Cerro Azul Formation

Cerro Azul Formation
Cerro Azul Formation
Stratigraphic range: Tortonian (Huayquerian); ~ Aqu. Burdig. Lan. Ser. Tortonian M Z P
	Fossil burrow fills in the Cerro Azul Formation
Type	Geological formation
Underlies	alluvium
Overlies	Arroyo Chasicó Formation or; Crystalline basement
Thickness	54 m (177 ft) (outcrop); 180 m (590 ft) (subsurface)
Lithology
Primary	Siltstone, sandstone
Other	Conglomerate
Location
Coordinates	35°42′S 64°42′W / 35.7°S 64.7°W / -35.7; -64.7
Approximate paleocoordinates	35°54′S 62°42′W / 35.9°S 62.7°W / -35.9; -62.7
Region	Buenos Aires & La Pampa Provinces
Country	Argentina
Extent	Colorado Basin
Type section
Named for	Cerro Azul, Epecuén Lake
Named by	Linares et al.
Year defined	1980
	Cerro Azul Formation (Argentina)

The Cerro Azul Formation (Spanish: Formación Cerro Azul), also described as Epecuén Formation, is a geological formation of Late Miocene (Tortonian, or Huayquerian in the SALMA classification) age in the Colorado Basin of the Buenos Aires and La Pampa Provinces in northeastern Argentina.¹²

The fluvial and aeolian siltstones, sandstones and tuffs of the formation contain many mammals, such as Thylacosmilus and Huayqueriana, reptiles, amphibians and fossils of terror birds as well as Argentavis, the largest flying bird ever discovered.

Description

Sedimentary logs of the Cerro Azul Formation source ↗

The Cerro Azul Formation crops out in patches in the southwestern Buenos Aires Province and southeastern Pampa Province. The Epecuén Formation has been correlated to the Cerro Azul Formation in the early 2000s. The Cerro Azul and Epecuén Formations were named after the Cerro Azul ("Blue Hill") and Epecuén Lake where the formation crops out.³ The formation overlies crystalline basement or the Arroyo Chasicó Formation.⁴ The mammal assemblage of the Cerro Azul-Epecuén unit is the most diverse for the Huayquerian Late Miocene age, possibly ranging into the Pliocene.⁵ The formation is considered contemporaneous with the Río Negro Formation of the Colorado Basin.⁶⁷

Outcrop map of the Cerro Azul Formation source ↗

The unit is characterized by a monotonous succession of loess containing moderately developed paleosols. In particular, the formation is considered to represent the interval between 10 and 5.7 Ma. The maximum exposed thickness in outcrop is 54 metres (177 ft), although the unit reaches about 180 metres (590 ft) in the subsurface.⁸

The Cerro Azul Formation deposits were described by Linares et al. in 1980.³ They are discontinuous along the whole occupied area in the provinces of La Pampa and Buenos Aires. They are composed of silts, sandy silts, and very thin silty sands, reddish and brown colored, with a homogeneous and compact general aspect, and frequent carbonate nodules and evidence of pedogenic processes. Visconti et al. (2010) interpreted them as eolian deposits characterized by loessic materials, with a high percentage of lithic fragments and volcaniclastic sediments.⁹

The sediments and their fauna belong to a sedimentary and faunal cycle, which followed the withdrawal (around 10 Ma) of a widespread marine transgression that extended from central Argentina to western Uruguay and southern Paraguay and Brazil, the "Paraná Sea" or mar paranense in Spanish.¹⁰

Large cylindrical sediment-filled structures, 115 of which are interpreted as mammal burrows, occur within the loess-paleosol sequence of the formation.¹¹

Fossil content

The following fossils have been recovered from the formation:¹

Locations:

La Pampa

Barrancas Coloradas - Cerro Azul Formation - La Pampa
Caleufú - Cerro Azul Formation - La Pampa
Cerro El Chancho - Cerro Azul Formation - La Pampa
Cerro Patagua - Cerro Azul Formation - La Pampa
Estancia Don Mariano - Cerro Azul Formation - La Pampa
Estancia El Recado - Cerro Azul Formation - La Pampa
Estancia Ré - Cerro Azul Formation - La Pampa
El Guanaco - Cerro Azul Formation - La Pampa
Huayquerías de San Carlos - Cerro Azul Formation - La Pampa
Laguna Chillhué - Cerro Azul Formation - La Pampa
Laguna Guatraché - Cerro Azul Formation - La Pampa
Quehué - Cerro Azul Formation - La Pampa
Salinas Grandes de Hidalgo - Cerro Azul Formation - La Pampa
Telen - Cerro Azul Formation - La Pampa

Buenos Aires

Bajo Giuliani - Cerro Azul Formation - Buenos Aires
Barrancas de Sarmiento - Cerro Azul Formation - Buenos Aires
Eduardo Castex - Cerro Azul Formation - Buenos Aires
Estancia los Médanos - Cerro Azul Formation - Buenos Aires
Estancia Quiñi-Malal - Cerro Azul Formation - Buenos Aires
Grünbein Cantera Seminario - Cerro Azul Formation - Buenos Aires
Grünbein Cantera Seminario Level 2 - Cerro Azul Formation - Buenos Aires
Laguna Epecuén - Cerro Azul Formation - Buenos Aires
Laguna La Paraguaya - Cerro Azul Formation - Buenos Aires
Puesto Colorado - Cerro Azul Formation - Buenos Aires
Ruta 14 - Cerro Azul Formation - Buenos Aires
Arroyo Guaminí - Epecuén Formation - Buenos Aires
Carhué - Epecuén Formation - Buenos Aires
Laguna de los Paraguayos - Epecuén Formation - Buenos Aires
Robilote Field - SE of Epecuén lagoon & E of Laguna de Epecuén - Epecuén Formation - Buenos Aires
Salinas Grandes de Hidalgo - Epecuén Formation - Buenos Aires

Amphibians

Taxa	Species	Presence	Abundance	Description	Images	Notes
Ceratophrynidae	C. sp.	Quehué				¹²
Lepidobatrachus	L. sp.	Quehué				¹²

Birds

Cathartid

Taxa	Species	Presence	Abundance	Description	Images	Notes
Argentavis	A. magnificens	Carhué	An associated partial skeleton with portions of the skull, right quadrate, and parts of the legs and arms.	A giant teratornithidae bird	source ↗	¹³

Phorusrhacids

Taxa	Species	Presence	Images	Notes
Devincenzia	D. pozzi	Carhué		¹⁴
Procariama	P. simplex	Salinas de Hidalgo	source ↗	¹⁵
Phorusrhacidae	indet.			¹⁴

Tinamou

Taxa	Species	Presence	Abundance	Description	Images	Notes
Eudromia	E. sp.	Salinas de Hidalgo				¹⁴
Nothura	N. sp.	Bajo Giuliani El Guanaco Salinas de Hidalgo				¹⁴

Rheidae

Taxa	Species	Presence	Abundance	Description	Images	Notes
Rhea	R. sp.	Salinas de Hidalgo				¹⁴

Mammals

Carnivora

Taxa	Species	Presence	Description	Notes
Cyonasua	C. brevirostris	Salinas de Hidalgo	A procyonid mammal.	¹³
	C. prebrevirostris	Salinas de Hidalgo		¹³
	C.sp.	Telén		¹⁶

Sparassodonts

Taxa	Species	Presence	Abundance	Description	Images	Notes
Borhyaenidium	B. musteloides	Salinas de Hidalgo				¹³
Dimartinia	D. pristina	Arroyo Chasicó	A left dentary and its associated teeth	A thylacosmiliform		¹⁷
Thylacosmilus	T. atrox	El Guanaco Quehué Salinas de Hidalgo		A saber-toothed thylacosmilid	source ↗	¹³¹⁸
Borhyaenidae	indeterminate.	Telén				¹⁶

Didelphimorphs

Taxa	Species	Presence	Notes
Didelphinae	indet.	Telén	¹⁶
Hyperdidelphys	H. pattersoni	El Guanaco Telén	¹⁸¹⁶
Hyperdidelphys	H. sp.	Salinas Grandes de Hidalgo	¹⁹
Lutreolina	L. sp.	Salinas de Hidalgo	¹³
Sparassocynidae	indet.	Telen	¹⁸¹⁶
Thylamys	T. pinei	Laguna Chillhué	²⁰
Thylamys	T. zetti	Estancia Ré Arroyo Guaminí	²¹²²
Thylatheridium	T. dolgopolae	El Guanaco Quehué Telén	²³¹⁶
	T. hudsoni	Bajo Giuliani Telén	¹⁸¹⁶
	T. sp.	Estancia Ré Telén	²¹¹⁶
Zygolestes	Z. tatei	Bajo Giuliani	¹⁸²⁰

Polydolopimorphia

Taxa	Species	Presence	Notes
Argyrolagus	A. rusconii	Bajo Giuliani El Guanaco Barrancas Coloradas	¹⁸
Argyrolagidae	indet.	Telén	¹⁶
Pliolestes	P. venetus	Bajo Giuliani Laguna Chillhué	¹⁸

Rodents

Taxa	Species	Presence	Notes
Abrocoma	A. antiqua	Estancia Ré	²¹
Cardiatherium	C. aff. orientalis	Laguna Chillhué Laguna Guatraché	²⁴
Cardiomys	C. sp.	Salinas de Hidalgo	¹³
Chasichimys	C. bonaerense	Cerro Patagua	²⁵
	C. scagliai	Laguna Chillhué
	C. sp.	Bajo Giuliani
Caviidae	indet.	Barrancas de Sarmiento	²⁶
Clyomys	C. aff. sp.	Barrancas Coloradas	²⁰
Ctenomyidae	indet.	Telén	¹⁶
Dolicavia	D. sp.	Grünbein Cantera Seminario	²⁶
Echimyidae	indet.	Telén	¹⁶
Hydrochoeridae	indet.	Salinas de Hidalgo	¹⁸
Neocavia	N. pampeana	Estancia El Recado	²⁷
Lagostomus	L. pretrichodactyla	Salinas de Hidalgo	¹³
Lagostomus	L. (Lagostomopsis) sp.	Grünbein Cantera Seminario Barrancas de Sarmiento Estancia Ré Salinas de Hidalgo	¹³²¹²⁶
Neocavia	N. sp.	Grünbein Cantera Seminario	²⁶
Neophanomys	N. pristinus	Estancia Don Mariano Quehué	²⁸
Neophanomys	N. sp.	Estancia Ré	²⁹
Palaeocavia	P. sp.	Grünbein Cantera Seminario Barrancas de Sarmiento Estancia Ré	¹³²¹²⁶
Palaeoctodon	P. aff. simplicidens	Bajo Giuliani	³⁰²⁰
Pampamys	P. emmonsae	Laguna Chillhué Bajo Giuliani Estancia Ré	²⁰³¹
Phtoramys	P. hidalguense	Barrancas Coloradas Salinas de Hidalgo	²⁰³²
	P. cf. hidalguense	Grünbein Cantera Seminario	²⁶
	P. sp.	Estancia Ré	²¹
Proctenomys	P. simpsoni	El Guanaco Barrancas Coloradas	³³
Protabrocoma	P. chasicoensis	Telén	¹⁶³⁴
Octodontoidea	indet.	Estancia Ré	²⁹
Orthomyctera	O. sp.	Grünbein Cantera Seminario Salinas de Hidalgo	²⁶¹³
Reigechimys	R. octodontiformis	Bajo Giuliani Estancia Ré	³⁵
	R. plesiodon	Laguna Chillhué	³⁶
	R. simplex	Bajo Giuliani	³⁵
Tetrastylus	T. araucanus	Salinas de Hidalgo	¹³
Tetrastylus	Tetrastylus sp.	Telén	¹⁶
Theridomysops	T. parvulus	Telén	¹⁶
Xenodontomys	X. ellipticus	Grünbein Cantera Seminario Barrancas de Sarmiento	²⁶

Xenarthrans

Cingulata

Taxa	Species	Presence	Images	Notes
Aspidocalyptus	A. castroi	Robilote Field Salinas de Hidalgo		¹³³⁷
	A. sp.	Telén		¹⁶
	A. cf. sp.	Grünbein Cantera Relleno Sanitario Level 2		²⁶
Chasicotatus	C. ameghinoi	Laguna Chillhué Estancia Don Mariano Cerro Patagua Cerro El Chancho Cerro de los Guanacos Puesto Colorado Estancia Quiñi-Malal Bajo Giuliani El Guanaco Telen El Recado Laguna Guatraché Loventué Quehué Barrancas Coloradas Estancia Ré Salinas de Hidalgo		¹⁶³⁸ ³⁹⁴⁰
	C. cf. peiranoi	Grünbein Cantera Relleno Sanitario Level 2		²⁶
	C. sp.	El Recado		²⁶⁴⁰
Chorobates	C. villosissimus	Laguna Chillhué Estancia Don Mariano Grünbein Cantera Relleno Sanitario Level 2 Puesto Colorado Ruta 14 Estancia Quiñi-Malal El Guanaco Telen El Recado Loventué Quehué Estancia Ré Salinas de Hidalgo		¹³²⁶³⁸ ³⁹⁴⁰
Chorobates	Chorobates sp.	Grünbein Cantera Seminario		²⁶
Coscinocercus	C. brachyurus	Robilote Field Salinas de Hidalgo		¹³³⁷
	C. marcalaini	Robilote Field Salinas de Hidalgo		¹³³⁷
	C. sp.	Telén		¹⁶
Doellotatus	D. chapadmalensis	El Recado Salinas de Hidalgo		¹³⁴⁰
	D. inornatus	Laguna Chillhué Estancia Don Mariano Grünbein Cantera Seminario Puesto Colorado Ruta 14 El Guanaco El Recado Laguna Guatraché Loventué Quehué Barrancas Coloradas Estancia Ré Telén Salinas de Hidalgo		¹³²⁶ ³⁸³⁹ ⁴⁰¹⁶
	D. cf. praecursor	Grünbein Cantera Seminario		²⁶
	D. sp.	Laguna La Paraguaya		⁴⁰
Eosclerocalyptus	E. sp.	Laguna La Paraguaya	source ↗	⁴¹
Eumysops	E. sp.	Laguna Chillhué		²⁰
Glyptodontidae	indet.	Laguna La Paraguaya Salinas Grandes de Hidalgo		⁴¹
Hoplophorus	H. sp.	Telén		¹⁶
Hoplophractus	H. tapinocefalus	Laguna de los Paraguayos Salinas de Hidalgo		¹³⁴²
Hoplophractus	H. sp.	Telén		¹⁶
Macrochorobates	M. chapalmalensis	El Guanaco Barrancas Coloradas		³⁸
Macrochorobates	M. scalabrinii	Laguna Chillhué Estancia Don Mariano Telen Loventué Quehué Salinas de Hidalgo		¹³³⁸ ³⁹¹⁶
Macroeuphractus	M. morenoi	Grünbein Cantera Relleno Sanitario Level 2 Puesto Colorado Laguna Chillhué Telen El Recado Laguna Guatraché Loventué Quehué Barrancas Coloradas Estancia Ré Salinas de Hidalgo		¹³²⁶ ³⁸³⁹ ⁴⁰¹⁶
	M. retusus	Salinas de Hidalgo		¹³
	M. sp.	Grünbein Cantera Relleno Sanitario Level 2 El Recado		²⁶⁴⁰
Paleuphractus	P. sp.	Salinas de Hidalgo		¹³
Plohophorus	P. araucanus	Salinas de Hidalgo		¹³
Proeuphractus	P. limpidus	Laguna Chillhué Telén		³⁸¹⁶
Proeuphractus	P. sp.	Laguna Chillhué Cerro Patagua Telen El Recado Laguna Guatraché Quehué Salinas de Hidalgo		¹³³⁸ ³⁹⁴⁰ ¹⁶
Pseudoplohophorus	P. cf. sp.	Grünbein Cantera Relleno Sanitario Level 2		²⁶
Vetelia	V. perforata	Cerro Patagua Cerro de los Guanacos Telén		³⁸³⁹¹⁶
Zaedyus	Z. pichiy	Laguna Chillhué Telen Quehué	source ↗	³⁹

Pilosans

Taxa	Species	Presence	Notes
Mylodontidae	indet.	Telén	¹⁶
Plesiomegatherium	P. sp.	Salinas de Hidalgo	¹³
Proscelidodon	P. gracillimus	Estancia Don Mariano Huayquerías de San Carlos Laguna Epecuén Bajo Giuliani Laguna Chillhué Loventué Salinas Grandes de Hidalgo Quehué Barrancas Coloradas Estancia Ré Arroyo Guaminí Laguna de los Paraguayos Carhué	⁴³⁴⁴ ²²⁴⁵

Litopterns

Taxa	Species	Presence	Description	Notes
Brachytherium	B. cf. cuspidatum	Telén Salinas de Hidalgo		¹³¹⁶
Diplasiotherium	D. pampa	Bajo Giuliani Laguna Chillhué Salinas de Hidalgo	A litoptern.	¹³⁴⁶
Eoauchenia	E. cingulata	Robilote Field Salinas de Hidalgo		¹³³⁷
Eoauchenia	E. primitiva	El Guanaco		⁴⁶
Epecuenia	E. thoatherioides	Robilote Field Salinas de Hidalgo		¹³³⁷
Huayqueriana	H. cristata	Robilote Field Salinas de Hidalgo	Previously called as Macrauchenia latidens.	³⁷¹³⁴⁷
Litopterna	indet.	Telén		¹⁶
Neobrachytherium	N. sp.	Bajo Giuliani Salinas de Hidalgo		¹³⁴⁶
Promacrauchenia	P. sp.	Grünbein Cantera Relleno Sanitario Level 2 Salinas de Hidalgo		¹³²⁶
Proterotheriidae	indet.	Bajo Giuliani Telén		⁴⁶¹⁶

Notoungulate

Taxa	Species	Presence	Description	Notes
Hemihegetotherium	H. achataleptum	Cerro Patagua Eduardo Castex Cerro de los Guanacos Puesto Colorado Bajo Giuliani Laguna Chillhué Loventué Salinas de Hidalgo	A hegetotheriidae notoungulate.	⁴⁸³⁹ ³⁸⁴⁹
Hemihegetotherium	H. lazai	Salinas de Hidalgo	A hegetotheriidae notoungulate.	¹³
Mesotheriinae	indet.	Laguna La Paraguaya Telén		¹⁶⁴¹
Paedotherium	P. bonaerense	Barrancas de Sarmiento	A notoungulate.	²⁶
	P. minor	Laguna La Paraguaya Estancia Ré Salinas de Hidalgo		¹³⁴¹
	P. cf. minor	Grünbein Cantera Seminario		²⁶
	P. sp.	Bajo Giuliani Laguna Chillhué Estancia Ré		²⁹
Pisanodon	P. nazari	Salinas de Hidalgo	A toxodont.	¹³
Pseudotypotherium	P. carhuense	Robilote Field Salinas de Hidalgo	A mesotheriidae notoungulate.	¹³³⁷
Tremacyllus	T. impressus	Grünbein Cantera Seminario Bajo Giuliani Laguna Chillhué Salinas Grandes de Hidalgo Quehué Barrancas Coloradas	A hegetotheriidae notoungulate.	²⁶⁴⁹
Typotheriodon	T. grandis	Robilote Field		³⁷
Typotheriopsis	T. minimus	Robilote Field	A Mesotheriidae notoungulate.	³⁷

Reptiles

Taxa	Species	Presence	Notes
Tupinambis	T. sp.	Telén	¹⁶
Chelidae	indet.	Telén	¹⁶
Testudinidae	indet.	Salinas de Hidalgo	⁵⁰

SALMA correlations

Huayquerian correlations in South America
Formation	Cerro Azul	Ituzaingó	Camacho	Raigón	Andalhuala	Las Flores	Maimará	Palo	Pebas	Muyu	Rosa	Saldungaray	Salicas	Urumaco	Map
Basin	Colorado	Paraná			Hualfín	Tontal	Andes	Salta	Amazon	Huasi	Altiplano	BA	Velasco	Falcón	Cerro Azul Formation (South America)
Country	Argentina		Uruguay		Argentina				Brazil Peru	Bolivia		Argentina		Venezuela
Cardiatherium
Lagostomus
Macroeuphractus
Proeuphractus
Pronothrotherium
Pseudotypotherium
Thylacosmilus
Xotodon
Macraucheniidae
Primates
Rodents
Reptiles
Birds
Terror birds
Flora
Environments	Aeolian-fluvial	Fluvio-deltaic		Fluvial					Fluvio-lacustrine	Fluvial			Fluvio-lacustrine	Fluvio-deltaic	Huayquerian volcanoclastics Huayquerian fauna Huayquerian flora
Volcanic					Yes

References

Cerro Azul Formation in the Paleobiology Database
Epecuén Formation in the Paleobiology Database
Visconti et al., 2010, p.259
Visconti et al., 2010, p.262
Carrillo et al., 2015, p.5
Pérez, 2012, p.11
Visconti et al., 2010, p.258
Cardonatto & Melchor, 2018, p.2
Caleufú at Fossilworks.org
Verzi & Montalvo, 2008, p.285
Cardonatto & Melchor, 2018, p.1
Nicoli, 2017
Vizcaino & Fariña, 1999
Cenizo et al., 2012
Vezzosi, 2012
Montalvo et al., 2008
Suarez, Catalina; Goin, Francisco J.; Montalvo, Claudia I.; Acosta, Walter; Cadena, Edwin-Alberto; Tomassini, Rodrigo L. (2025). "A small extinct biter: New South American metatherian predator (Sparassodonta) from the Late Miocene of Argentina". Journal of South American Earth Sciences. 155 105377. Bibcode:2025JSAES.15505377S. doi:10.1016/j.jsames.2025.105377. ISSN 0895-9811.
Goin et al., 2000
Goin & Pardiñas, 1996
Verzi et al., 2008
Montalvo et al., 2016
Goin, 1997
Goin & Montalvo, 1988
Vucetich et al., 2014
Verzi, 1999
Deschamps, 2005
Montalvo & Rocha, 2003
Verzi et al., 2011
Cerdeño et al., 2017
Montalvo & Casadio, 1988
Verzi et al., 1995
Pascual et al., 1965
Verzi et al., 1991
Olivares, A. I.; Verzi, D. H.; Kihn, R.; Montalvo, C. I.; Fernández Villoldo, J. A.; Álvarez, A.; Costa Filho, R. G.; Ré, G. H. (2025). "The fossil record of chinchilla rats (Abrocomidae, Hystricomorpha) from the Late Miocene–Early Pliocene of southern South America". Historical Biology: An International Journal of Paleobiology: 1–22. doi:10.1080/08912963.2025.2475209.
Sostillo et al., 2014
Verzi et al., 1994
Cabrera, 1939
Urrutia et al., 2008
Esteban et al., 2000
Esteban et al., 2003
Cardonatto & Melchor, 2018, p.16
Zurita & Aramayo, 2007
Montalvo et al., 2020
Rovereto, 1914
Ortega, 1967
Schmidt et al., 2018
Forasiepi, Analía M.; MacPhee, Ross D. E.; Del Pino, Santiago Hernández; Schmidt, Gabriela I.; Amson, Eli; Grohé, Camille (2016-06-22). "Exceptional Skull of Huayqueriana (Mammalia, Litopterna, Macraucheniidae) From the Late Miocene of Argentina: Anatomy, Systematics, and Paleobiological Implications". Bulletin of the American Museum of Natural History. 404: 1–76. doi:10.1206/0003-0090-404.1.1. ISSN 0003-0090.
Cerdeño & Montalvo, 2002
Sostillo et al., 2018
De la Fuente et al., 2018

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[PBDB-1] Cerro Azul Formation in the Paleobiology Database

[PBDBEpecuen-2] Epecuén Formation in the Paleobiology Database

[Visconti2010-p259-3] Visconti et al., 2010, p.259

[Visconti2010-p262-4] Visconti et al., 2010, p.262

[Carrillo2015-p5-5] Carrillo et al., 2015, p.5

[Perez2012-p11-6] Pérez, 2012, p.11

[Visconti2010-p258-7] Visconti et al., 2010, p.258

[Cardonatto2018-p2-8] Cardonatto & Melchor, 2018, p.2

[Caleufu-9] Caleufú at Fossilworks.org

[VerziMontalvo2008-p285-10] Verzi & Montalvo, 2008, p.285

[Cardonatto2018-p1-11] Cardonatto & Melchor, 2018, p.1

[Nicoli2017-12] Nicoli, 2017

[Vizcaino1999-13] Vizcaino & Fariña, 1999

[Cenizo2012-14] Cenizo et al., 2012

[Vezzosi2012-15] Vezzosi, 2012

[Montalvo2008-16] Montalvo et al., 2008

[Dimartinia-17] Suarez, Catalina; Goin, Francisco J.; Montalvo, Claudia I.; Acosta, Walter; Cadena, Edwin-Alberto; Tomassini, Rodrigo L. (2025). "A small extinct biter: New South American metatherian predator (Sparassodonta) from the Late Miocene of Argentina". Journal of South American Earth Sciences. 155 105377. Bibcode:2025JSAES.15505377S. doi:10.1016/j.jsames.2025.105377. ISSN 0895-9811.

[Goin2000-18] Goin et al., 2000

[Goin1996-19] Goin & Pardiñas, 1996

[Verzi2008-20] Verzi et al., 2008

[Montalvo2016-21] Montalvo et al., 2016

[Goin1997-22] Goin, 1997

[Goin1988-23] Goin & Montalvo, 1988

[Vucetich2014-24] Vucetich et al., 2014

[Verzi1999-25] Verzi, 1999

[Deschamps2005-26] Deschamps, 2005

[Montalvo2003-27] Montalvo & Rocha, 2003

[Verzi2011-28] Verzi et al., 2011

[Cerdeño2017-29] Cerdeño et al., 2017

[Montalvo1988-30] Montalvo & Casadio, 1988

[Verzi1995-31] Verzi et al., 1995

[Pascual1965-32] Pascual et al., 1965

[Verzi1991-33] Verzi et al., 1991

[34] Olivares, A. I.; Verzi, D. H.; Kihn, R.; Montalvo, C. I.; Fernández Villoldo, J. A.; Álvarez, A.; Costa Filho, R. G.; Ré, G. H. (2025). "The fossil record of chinchilla rats (Abrocomidae, Hystricomorpha) from the Late Miocene–Early Pliocene of southern South America". Historical Biology: An International Journal of Paleobiology: 1–22. doi:10.1080/08912963.2025.2475209.

[Sostillo2014-35] Sostillo et al., 2014

[Verzi1994-36] Verzi et al., 1994

[Cabrera1939-37] Cabrera, 1939

[Urrutia2008-38] Urrutia et al., 2008

[Esteban2000-39] Esteban et al., 2000

[Esteban2003-40] Esteban et al., 2003

[Cardonatto2018-p16-41] Cardonatto & Melchor, 2018, p.16

[Zurita2007-42] Zurita & Aramayo, 2007

[Montalvo2020-43] Montalvo et al., 2020

[Rovereto1914-44] Rovereto, 1914

[Ortega1967-45] Ortega, 1967

[Schmidt2018-46] Schmidt et al., 2018

[47] Forasiepi, Analía M.; MacPhee, Ross D. E.; Del Pino, Santiago Hernández; Schmidt, Gabriela I.; Amson, Eli; Grohé, Camille (2016-06-22). "Exceptional Skull of Huayqueriana (Mammalia, Litopterna, Macraucheniidae) From the Late Miocene of Argentina: Anatomy, Systematics, and Paleobiological Implications". Bulletin of the American Museum of Natural History. 404: 1–76. doi:10.1206/0003-0090-404.1.1. ISSN 0003-0090.

[Cerdeno2002-48] Cerdeño & Montalvo, 2002

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