Unquillosaurus is a genus of large theropod dinosaur from the Late Cretaceous Los Blanquitos Formation of Salta Province, Argentina. Its precise classification is uncertain, but most researchers consider it as a maniraptoran. The genus contains a single species, U. ceibalii, known only from a single fossilized pubis.
Protypotherium is an extinct genus of notoungulate mammals native to South America during the Oligocene and Miocene epochs. A number of closely related animals date back further, to the Eocene. Fossils of Protypotherium have been found in the Deseadan Fray Bentos Formation of Uruguay, Muyu Huasi and Nazareno Formations of Bolivia, Cura-Mallín and Río Frías Formations of Chile, and Santa Cruz, Salicas, Ituzaingó, Aisol, Cerro Azul, Cerro Bandera, Cerro Boleadoras, Chichinales, Sarmiento and Collón Curá Formations of Argentina.
Brontornis is an extinct genus of giant bird that inhabited Argentina during the Early to Middle Miocene. Its taxonomic position is highly controversial, with authors alternatively considering it to be a cariamiform, typically a phorusrhacid or an anserimorph.
Cramauchenia is an extinct genus of litoptern South American ungulate. Cramauchenia was named by Florentino Ameghino. The name has no literal translation. Instead, it is an anagram of the name of a related genus Macrauchenia. This genus was initially discovered in the Sarmiento Formation in the Chubut Province, in Argentina, and later it was found in the Chichinales Formation in the Río Negro Province and the Cerro Bandera Formation in Neuquén, also in Argentina, in sediments assigned to the SALMA Colhuehuapian, as well as the Agua de la Piedra Formation in Mendoza, in sediments dated to the Deseadan. In 1981 Soria made C. insolita a junior synonym of C. normalis. A specimen of C. normalis was described in 2010 from Cabeza Blanca in the Sarmiento Formation, in sediments assigned to the Deseadan SALMA.
Opisthodactylus is an extinct genus of rhea from the Early to Middle Miocene Santa Cruz and Chichinales Formations and the Late Miocene (Montehermosan) Andalhuala Formation of Argentina. Three species are described: the type species, O. patagonicus, O. kirchneri and O. horacioperezi. The species O. kirchneri was described in 2017 by Noriega et al. Fossils of O. horacioperezi were found together with fossils of Patagorhacos terrificus.
Patagornis is a genus of extinct flightless predatory birds of the family Phorusrhacidae. Known as "terror birds", these lived in what is now Argentina during the Early and Middle Miocene; the Santa Cruz Formation in Patagonia contains numerous specimens. Patagornis was an agile, medium sized Patagornithine and was likely a pursuit predator.
The South American land mammal ages (SALMA) establish a geologic timescale for prehistoric South American fauna beginning 64.5 Ma during the Paleocene and continuing through to the Late Pleistocene. These periods are referred to as ages, stages, or intervals and were established using geographic place names where fossil materials where obtained.
The Santacrucian age is a period of geologic time within the Early Miocene epoch of the Neogene, used more specifically with SALMA classification in South America. It follows the Colhuehuapian and precedes the Friasian age.
Neuquén Basin is a sedimentary basin covering most of Neuquén Province in Argentina. The basin originated in the Jurassic and developed through alternating continental and marine conditions well into the Tertiary. The basin bounds to the west with the Andean Volcanic Belt, to the southeast with the North Patagonian Massif and to the northeast with the San Rafael Block and to the east with the Sierra Pintada System. The basin covers an area of approximately 120,000 square kilometres (46,000 sq mi). One age of the SALMA classification, the Colloncuran, is defined in the basin, based on the Collón Curá Formation, named after the Collón Curá River, a tributary of the Limay River.
Austrocheirus is an extinct genus of theropod dinosaur that lived during the Late Cretaceous period. It was named and described by Martin Ezcurra, Federico Agnolin and Fernando Novas in 2010. It contains the type species Austrocheirus isasii. The generic name means "southern hand". The specific epithet honours discoverer and preparator Marcelo Pablo Isasi.
Aerotitan is a genus of large azhdarchid pterosaur known from the Late Cretaceous period of what is now the Allen Formation of the Neuquén Basin in northern Patagonia, Argentina.
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, which were the dominant mammals in 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. Its morphology suggests that it was a digging, subterranean-dwelling mole-like mammal that fed on invertebrates.
Hegetotherium is an extinct genus of mammals from the Early to Middle Miocene of South America. Fossils of this genus have been found in the Cerro Bandera, Cerro Boleadoras, Chichinales, Collón Curá, Santa Cruz and Sarmiento Formations of Argentina, the Nazareno Formation of Bolivia, and the Galera and Río Frías Formations of Chile.
Thegornis is an extinct genus of herpetotherine falconid that lived during the Miocene of South America. The genus was erected by Florentino Ameghino in 1895 based on two species, T. musculosus and T. debilis. However, T. debilis was later suggested to be an invalid species, with the differences between it and T. musculosus being due to sexual dimorphism. Two additional species, T. spivacowi and T. sosae, were subsequently named in later years by Federico Agnolín. Its skull and postcranial morphology are similar to the laughing falcon and forest falcon, which together form the clade Herpetotherinae. The seriema Noriegavis's holotype was transferred to this genus and the well-preserved specimen described in 2015 attributed to Noriegavis has been classified into Miocariama.
Kaikaifilusaurus is an extinct genus of rhynchocephalians in the family Sphenodontidae from the Late Cretaceous of South America. Fossils of the genus were found in Cenomanian sediments of the Candeleros Formation and Turonian layers of the Huincul Formation, both of the Neuquén Basin and the Albian strata of the Cerro Barcino Formation in the Cañadón Asfalto Basin, all in Patagonia, Argentina. The genus contains two species, K. minimus and the type species K. calvoi.
Niebla is a genus of abelisaurid theropod dinosaur from the Late Cretaceous Period (Campanian-Maastrichtian) of Río Negro province, Argentina. The genus contains a single species, Niebla antiqua, and is known from a partial, non-articulated skeleton. The holotype, found in the Allen Formation, represents an adult individual about nine years old in minimum age.
Patagorhacos is an extinct genus of medium-sized phorusrhacid from the early Miocene of Patagonia. Currently only the single species Patagorhacos terrificus is known, which is represented by two highly fragmentary specimen, one belonging to the back of the skull and the other being the distal end of a leg bone. It was described together with the contemporary rheid Opisthodactylus horacioperezi.
Colpodon is an extinct genus of herbivorous mammal, belonging to the order Notoungulata. It lived during the Early Miocene, in what is today Argentina and Chile, in South America.
The Santa Cruz Formation is a geological formation in the Magallanes/Austral Basin in southern Patagonia in Argentina and in adjacent areas of Chile. It dates to the late Early Miocene epoch, and is contemporaneous with eponymous Santacrucian SALMA. The formation extends from the Andes to the Atlantic coast. In its coastal section it is divided into two members, the lower, fossil rich Estancia La Costa Member, which has a lithology predominantly consisting of tuffaceous deposits and fine grained sedimentary claystone and mudstone, and the upper fossil-poor Estancia La Angelina Member, which consists of sedimentary rock, primarily claystone, mudstone, and sandstone. The environment of deposition is interpreted to have been mostly fluvial, with the lowermost part of the Estancia La Costa Member being transitional between fluvial and marine conditions. The environment of the Estancia La Costa Member is thought to have been relatively warm and humid, but likely became somewhat cooler and drier towards the end of the sequence. The Santa Cruz Formation is known for its abundance of South American native ungulates, as well as an abundance of rodents, xenarthrans, and metatherians.
Yatenavis is an extinct genus of enantiornithine bird from the Late Cretaceous Chorrillo Formation of Santa Cruz Province, Argentina. The genus contains a single species, Y. ieujensis, known from a partial humerus.
