# Chasicoan

The Chasicoan (Spanish: Chasiquense or Spanish: Chasicoense) age is a period of geologic time from 10–9 Ma within the Late Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Mayoan and precedes the Huayquerian age.

## Etymology

The Chasicoan is named after the Arroyo Chasicó Formation of the Colorado Basin in northeastern Argentina.

## Formations

| Formation bold is type | Country | Basin |
| Arroyo Chasicó Formation | Argentina | Colorado Basin |
| Bahía Inglesa Formation | Chile | Caldera Basin |
| Caujarao Formation | Venezuela | Falcón Basin |
| Cerro Azul Formation | Argentina | Colorado Basin |
| Coquimbo Formation | Chile | Tongoy Bay |
| Loma de Las Tapias Formation | Argentina | Tulum Valley |
| Madre de Dios Formation | Peru | Madre de Dios Basin |
| Mauri Formation | Bolivia | Altiplano Basin |
| Navidad Formation | Chile | Chilean Coast Range |
| Puerto Madryn Formation | Argentina | Valdés Basin |
| Paraná Formation | Argentina | Paraná Basin |
| Pebas Formation | Brazil Colombia Ecuador Peru | Amazon Basin |
| Pisco Formation | Peru | Pisco Basin |
| Urumaco Formation | Venezuela | Falcón Basin |

## Fossil content

| Group | Fossils | Formation | Notes |
| Mammals | Cardiatherium chasicoense, Cardiomys leufuensis, Chasicobradys intermedius, Chasicostylus castroi, Chasicotatus ameghinoi, Epipeltephilus kanti, Lagostomus telenkechanum, Lycopsis viverensis, Paedotherium minor, Pisanodon nazari, Protomegalonyx chasicoensis, Pseudolycopsis cabrerai, Vetelia perforata, Kraglievichia sp., Orthomyctera sp., ?Parodimys sp., Proeuphractus sp., ?Tetrastylus sp., Typotheriopsis sp., Hegetotheriinae indet., Hoplophorini indet., Palaehoplophorini indet., Plohophorini indet., Proterotheriinae indet. | Arroyo Chasicó | [18][19] [20] [21][22] [23][24] |
| Mammals | Chasichimys bonaerense, Chasicotatus ameghinoi, Macrochorobates scalabrinii | Cerro Azul | |
| Mammals | Cardiatherium chasicoense, Contrerascynus borhyaenoides | Loma de las Tapias | [26] [27][28] |
| Mammals | Notiomastodon sp. | Madre de Dios | |
| Mammals | Bolivartherium urumaquensis, Bounodus enigmaticus, Ischyrorhynchus cf. vanbenedeni, Pseudoprepotherium urumaquensis, Urumaquia robusta, Gyrinodon sp., Neoepiblema sp., Potamarchus sp., Ribodon sp., Saurocetes sp. | Urumaco | [30][31] [32][33] [34][35] [36] |
| Birds | Psilopterus colzecus | Arroyo Chasicó | |
| Birds | Leptoptilos patagonicus | Puerto Madryn | |
| Reptiles & amphibians | Carlesia cf. pendolai, Anura indet., Testudines indet. | Arroyo Chasicó | |
| Reptiles & amphibians | Bairdemys venezuelensis, Caiman brevirostris, C. wannlangstoni, Charactosuchus mendesi, Globidentosuchus brachyrostris, Gryposuchus croizati, G. jessei, G. cf. pachakamue, Hesperogavialis cruxenti, Ikanogavialis gameroi, Melanosuchus fisheri, Mourasuchus arendsi, Purussaurus mirandai, Boinae indet. | Urumaco | [30][35] [36][38] [39][40] [41] |
| Fishes | Megalodon, Hemipristis serra, Carcharhinus sp., Galeocerdo sp., Rhinoptera sp., Sphyrna sp. | Caujarao | |
| Fishes | Ariidae indet., Carcharhinidae indet., Dasyatidae indet., Hemigaleidae indet., Heterodontidae indet., Lamnidae indet., Myliobatidae indet., Odontaspididae indet., Otodontidae indet., Physeteroidea indet., Rajidae indet., Sciaenidae indet., Sparidae indet., Sphyrnidae indet., Squatinidae indet. | Paraná | |
| Fishes | Megalodon, Arius couma, A. dowii, A. herzbergii, A. kessleri, A. quadriscutis, A. rugispinis, Bagre marinus, Carcharhinus caquetius, Epinephelus itajara, Galeocerdo cuvier, Hemipristis serra, Larimus henrii, L. steurbautti, Micropogonias coatesi, Phractocephalus nassi, Pristis pectinata, Carcharhinus sp., Cynoscion sp., Dasyatis sp., Equetus sp., Haemulon sp., Nebris sp., Rhinoptera sp., Sphyrna sp. | Urumaco | |