Mesonychia is an extinct taxon of small- to large-sized carnivorous ungulates related to artiodactyls. Mesonychians first appeared in the early Paleocene, went into a sharp decline at the end of the Eocene, and died out entirely when the last genus, Mongolestes, became extinct in the early Oligocene. In Asia, the record of their history suggests they grew gradually larger and more predatory over time, then shifted to scavenging and bone-crushing lifestyles before the group became extinct.
South American native ungulates, commonly abbreviated as SANUs, are extinct ungulate-like mammals of controversial affinities that were indigenous to South America prior to the Great American Biotic Interchange. They comprise five major groups conventionally ranked as orders—Astrapotheria, Litopterna, Notoungulata, Pyrotheria, and Xenungulata—as well as the primitive "condylarth" groups Didolodontidae and Kollpaniinae. It has been proposed that some or all of the members of this group form a clade, named Meridiungulata, though the relationships of South American ungulates remain largely unresolved. The two largest groups of South American ungulates, the notoungulates and the litopterns, were the only groups to persist beyond the mid Miocene. Only a few of the largest species of notoungulates and litopterns survived until the end-Pleistocene extinction event around 12,000 years ago where they became extinct with most other large mammals in the Americas, shortly after the first arrival of humans into the region.
Pyrotheriidae is the only family in the order Pyrotheria, provided one does not include the Paleocene genus, Carodnia. These extinct, elephant-like ungulates include the genera Baguatherium, Carolozittelia, Griphodon, Propyrotherium, and Pyrotherium. Fossils of the family have been found in Argentina, Brazil, Bolivia and Peru.
Xenungulata is an order of extinct and primitive South American hoofed mammals that lived from the Late Paleocene to Early Eocene. Fossils of the order are known from deposits in Brazil, Argentina, Peru, and Colombia. The best known member of this enigmatic order is the genus Carodnia, a tapir-like and -sized animal with a gait similar to living African elephants.
Pyrotherium is an extinct genus of South American ungulate, of the order Pyrotheria, that lived in what is now Argentina and Bolivia, during the Late Oligocene. It was named Pyrotherium because the first specimens were excavated from an ancient volcanic ash deposit. Fossils of the genus have been found in the Deseado and Sarmiento Formations of Argentina and the Salla Formation of Bolivia.
Carodnia is an extinct genus of South American ungulate known from the Early Eocene of Brazil, Argentina, and Peru. Carodnia is placed in the order Xenungulata together with Etayoa and Notoetayoa.
Astrapotheria is an extinct order of South American and Antarctic hoofed mammals that existed from the late Paleocene to the Middle Miocene, 59 to 11.8 million years ago. Astrapotheres were large, rhinoceros-like animals and have been called one of the most bizarre orders of mammals with an enigmatic evolutionary history.
Coryphodontidae is an extinct family of pantodont mammals known from the Late Paleocene to the Middle Eocene of Eurasia and North America.
Hyaenodonta is an extinct order of hypercarnivorous placental mammals of clade Pan-Carnivora from mirorder Ferae. Hyaenodonts were important mammalian predators that arose during the early Paleocene in Europe and persisted well into the late Miocene.
Colombitherium is an extinct mammal from Late Eocene Colombia. It has originally been assigned to the order Pyrotheria and the family Colombitheriidae, although a later detailed analysis of the fossil questions that classification. A fossil jawbone of approximately 9 centimetres (3.5 in) length of Colombitherium has been found by Texas Petroleum in 1945, in the Upper Eocene strata of the middle Gualanday Group in the department of Tolima, Central Ranges of the Colombian Andes.
Lamegoia is an extinct genus of mammals, belonging to the family Didolodontidae. It contains a single species, Lamegoia conodonta, which lived during the Late Paleocene in what is now South America.
Proticia is an extinct genus of mammals belonging to the order Pyrotheria. It lived during the Early Eocene, and its fossilized remains were discovered in South America.
Baguatherium is an extinct genus of herbivorous mammal, belonging to the order Pyrotheria. It lived during the Early Oligocene, and its fossilized remains were discovered in Peru.
Notoetayoa is an extinct genus of mammal, from the order Xenungulata. It contains a single species, Notoetayoa gargantuai, which lived during the Middle Paleocene. Its fossilized remains were discovered in South America.
Rodcania is an extinct genus of mammal, belonging to the order Xenungulata. It contains a single species, Rodcania kakan, which lived during the Paleocene. Its remains were found in South America. The genus name is an anagram of Carodnia.
Carolozittelia is an extinct genus of mammals, belonging to the order Pyrotheria. It contains the single species Carolozittelia tapiroides which lived during the Early Eocene. Its fossilized remains were found in South America.
Griphodon is an extinct genus of mammals, belonging to the order Pyrotheria. It lived during the Middle Eocene, in what is now Peru.
Propyrotherium is an extinct genus of mammals, belonging to the order Pyrotheria. It lived during the Late Eocene, in what is now South America.
Moqueguahippus is an extinct genus of notohippid notoungulates that lived during the Late Oligocene of what is now Peru. Fossils of this genus have been found in the Moquegua Formation of Peru, which it was named after.
Protobradys is an extinct genus of mammal of unknown affinities from the Early Eocene of Chubut Province, Argentina. It was described in 1902 by prolific Argentine paleontologist Florentino Ameghino on the basis of an isolated left maxilla and an erroneously referred tooth. Ameghino described the genus as the earliest known member of Pilosa (sloths), though this assessment has not been supported and later authors believe that it is a nomen vanum of uncertain affinities within Mammalia.
