Cyonasua

Cyonasua (meaning "dog-coati" in Greek) is an extinct genus of procyonid from the Late Miocene to Middle Pleistocene of South America. Fossils of Cyonasua have been found in Argentina (Ituzaingó, Epecuén, Huayquerías, Monte Hermoso, Chapadmalal, Maimará, Ensenada, La Playa, Chiquimil, Andalhuala, and Cerro Azul Formations), Bolivia (Tariquía Formation), Uruguay (Camacho Formation), and Venezuela (San Gregorio Formation). The oldest well-dated fossils of Cyonasua are approximately 7.3 million years old. Most fossils of Cyonasua are late Miocene to early late Pliocene (Huayquerian to Chapadmalalan SALMAs, 7.3-3 million years old) in age, but a single early Pleistocene specimen (the holotype and only known specimen of Cyonasua meranii) indicates that members of this genus survived until at least 0.99 million years ago (the fossil layer where this specimen was collected dating to the Jaramillo Chron).

Cyonasua is the oldest terrestrial carnivoran known from South America, and represents the earliest undisputed southward mammalian migrants of the Great American Interchange. Cyonasua appears in the fossil record much earlier than other North American immigrant groups, most of which did not appear until 3 million years ago, including other carnivorans, many of which did not appear in South America until the early Pleistocene (about 1.2 million years ago). The next oldest remains of carnivorans in South America are rare specimens of Lycalopex and Galictis from the Barrancalobian (~2.9 million years old), nearly 4.4 million years after the first appearance of Cyonasua in South America. The ancestors of Cyonasua are thought to have arrived from Central America by island hopping before the formation of the Isthmus of Panama.