Anseriformes is an order of birds also known as waterfowl that comprises about 180 living species of birds in three families: Anhimidae, Anseranatidae, and Anatidae, the largest family, which includes over 170 species of waterfowl, among them the ducks, geese, and swans. Most modern species in the order are highly adapted for an aquatic existence at the water surface. With the exception of screamers, males have penises, a trait that has been lost in the Neoaves. Due to their aquatic nature, most species are web-footed.
Phorusrhacids, colloquially known as terror birds, are an extinct clade of large carnivorous flightless birds that were one of the largest species of apex predators in South America during the Cenozoic era; their conventionally accepted temporal range covers from 62 to 0.1 million years (Ma) ago.
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 flightless terror birds (Phorusrhacidae) that inhabited Argentina during the Early to Middle Miocene. Certainly the heaviest of the Phorusrhacidae family, and the birds from the Americas as a whole, it is one of the largest birds that has ever existed. In 2021, a study found the genus to be closely related to mihirungs in the anserimorph order Gastornithiformes.
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.
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.
Macranhinga is a genus of extinct darters belonging to the Anhingidae. The type species is M. paranensis, which was described on the basis of complete tarsometatarsi and several dissociated skeletal elements. All the specimens come from the Ituzaingó Formation that crops out discontinuously along the eastern cliffs of the Paraná River in northeastern Argentina, the river from which the specific epithet is derived. The most striking feature of this bird is its large size, much greater than in all other known fossil or extant anhingas.
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.
Lamarqueavis is an extinct genus of prehistoric birds from the Cimolopterygidae known from Late Cretaceous-aged rocks from Argentina, Canada, and the United States. The type species, L. australis, was named in 2010 and is based on the holotype MML 207, a partial right coracoid found in the Allen Formation, Argentina. Two other species, L. minima, based on the holotype UCMP 53976, a right coracoid found in the Lance Formation, Wyoming, and L. petra, based on the holotype AMNH 21911, a left coracoid also found in the Lance Formation, Wyoming, were transferred over from Cimolopteryx to Lamarqueavis in 2010. A third unnamed species is known from the Dinosaur Park Formation of Alberta, Canada.
Huallasaurus is an extinct genus of saurolophine hadrosaur from the Late Cretaceous Los Alamitos Formation of Patagonia in Argentina. The type and only species is H. australis. Originally named as a species of Kritosaurus in 1984, it was long considered a synonym of Secernosaurus before being recognized as its own distinct genus in a 2022 study, different from other members of Kritosaurini.
Kelumapusaura is a genus of saurolophine hadrosaur from the Late Cretaceous Allen Formation in what is now Patagonia in Argentina. The type and only species is K. machi, known from a bonebed of various individuals.
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.
Maip is a genus of large megaraptorid theropod dinosaur from the Late Cretaceous (Maastrichtian) Chorrillo Formation of Santa Cruz, Argentina. The genus contains a single species, M. macrothorax, known from an incomplete, disarticulated skeleton. Maip may represent the largest megaraptorid known from South America, and possibly the world.
Proadinotherium is an extinct genus of toxodontid. It lived between the Late Oligocene and the Early Miocene in what is now South America.
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.
