Friasian

The Friasian age is a period of geologic time (16.3–15.5 Ma) within the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification of South America. It follows the Santacrucian and precedes the Colloncuran age.^[1]

Etymology

The age is named after the Río Frías Formation in the Aysén Basin, Patagonia, Chile.

Formations

Locations of Friasian formations

Formation bold is type	Country	Basin	Notes
Río Frías Formation	Chile	Aysén Basin	[2][3]
Castilletes Formation	Colombia	Cocinetas Basin	[4]
Cerdas Beds	Bolivia	Altiplano Basin	[5]
Chilcatay Formation	Peru	Pisco Basin	[6][7]
Cura-Mallín Group	Chile	Cura-Mallín Basin	[8]
Gran Bajo del Gualicho Formation	Argentina	Colorado Basin	[9]
Parángula Formation	Venezuela	Barinas-Apure Basin	[10]
Pebas Formation	Brazil  Colombia  Ecuador  Peru	Amazon Basin	[11][12]
Río Foyel Formation	Argentina	Patagonian Andes	[13][14]
Río Yuca Formation	Venezuela	Barinas-Apure Basin	[15]

Fossils

Group	Fossils	Formation	Notes
Mammals	Abderites aisenense, A. meridionalis, Alloiomys friasensis, Astrapotherium hesperinum, Borhyaena tuberata, Cladosictis patagonica, Megathericulus friasensis, Microbiotherium tehuelchum, Parabderites bicrispatus, Palaeothentes intermedius, P. lemoinei, P. minutus, Pichipilus halleuxi, Pitheculites rothi, Prothylacinus patagonicus, Prototrigodon rothi, Sipalocyon gracilis, Adinotherium sp., Homalodotherium sp., Neonematherium sp., Nesodon sp., Pachyrukhos sp., Phoenixauchenia sp., ?Propalaehoplophorus sp., Protypotherium sp., Prozaedyus sp., Theosodon sp., Trachytypotherium sp., Platyrrhini indet.	Río Frías	[16] [17][18]
	Lycopsis padillai, ?Hyperleptus sp., Astrapotheriidae, Odontoceti, Mysticeti, Glyptodontidae, Pampatheriidae, Macraucheniidae, Proterotheriidae, Leontinidae, Toxodontidae, Interatheriidae, Megatheriidae, Dinomyidae, Sirenia, Sparassodonta	Castilletes	[19][20] [21]
	Hegetotherium cerdasensis, Juchuysillu arenalesensis, Llullataruca cf. shockeyi, Microtypotherium cf. choquecotense, Protypotherium cf. attenuatum, "Plesiotypotherium" minus, Palyeidodon obtusum, Mcdonaldocnus bondesioi, Borhyaenoidea indet., Euphractini indet., Lagostominae indet., Macraucheniidae indet., Megatheriinae indet., Mesotheriinae indet., Peltephilidae indet., Uruguaytheriinae indet.	Cerdas	[22][23]
	Adinotherium sp., Peltephilidae indet.	Río Yuca	[24]
Reptiles	Chelus colombiana, Chelonoidis sp., cf. Crocodylus sp., cf. Mourasuchus sp., cf. Purussaurus sp., Alligatoridae indet., Boidae indet., Eusuchia indet., Gavialoidea indet., Podocnemididae indet.	Castilletes	[21] [25][26]
	Barinasuchus arveloi	Parángula	[27]
	Purussaurus sp.	Río Yuca	[24]
Birds	Aves indet.	Castilletes	[21]
	Palaeospheniscus bergi, Spheniscidae indet.	Río Foyel	[28]
Fish	Megalodon, Characidae, Serrasalmidae, Sciaenidae, Sparidae, Sphyraenidae, Ariidae, Callichthyidae, Doradidae, Pimelodidae, Carcharhinidae, Hemigaleidae, Sphyrnidae, Lamnidae, Otodontidae, Dasyatidae, Myliobatidae, Rhinopteridae, Ginglymostomatidae, Pristiophoridae, Pristidae, Rhynchobatidae, Rhynobatidae, Lepidosirenidae	Castilletes	[21][29]
	Carcharodon hastalis	Río Foyel	[28]
	Phractocephalus sp., Platysilurus sp.	Río Yuca	[24]