WThis is a list of fossiliferous stratigraphic units in Ecuador.
WThe Biblián Formation is an Early Miocene geologic formation of the Cuenca Basin in Ecuador. Fossils of Xenastrapotherium aequatorialis have been found in the formation.
WThe Cangahua Formation is a Late Pleistocene geologic formation of the Pichincha Province in north-central Ecuador.
WThe Canoa Formation is a Piacenzian to Calabrian geologic formation in Ecuador. The sandstones were deposited in a coastal environment. The formation is correlated to the Charco Azul Formation of western Panama and southeastern Costa Rica.
WThe Cazaderos Formation is an Albian geologic formation in southern Ecuador.
WThe Dos Bocas Formation is a Chattian, about 26 to 24 Ma, geologic formation of the Progreso Basin in southwestern Ecuador.
WThe Letrero Formation is a Late Miocene geologic formation in south-central Ecuador. The formation comprises lacustrine sediments with strong fluvial clastic input and contains siltstones and fine-grained sandstones.
WThe Onzole Formation is an Early Pliocene geologic formation in the Borbón Basin of northwestern Ecuador. The formation consists of a shallow marine sandstone member containing many fish fossils, among which megalodon, and a deep water member comprising tuffaceous shales and mudstones containing gastropods, bivalves and scaphopods.
WThe Seca Formation is a Late Eocene geologic formation of the Progreso Basin in southwestern Ecuador. The shales of the formation have provided fossils of the marine snake Pterosphenus sheppardi.
WThe Tablazo Formation is a Middle Pleistocene geologic formation of Santa Elena Province in western Ecuador. The claystones and sandstones were deposited in an estuarine environment.
WThe Viche Formation is a Langhian geologic formation of the Borbón Basin in northwestern Ecuador. The formation underlies the Angostura Formation. Fossils of Ziphiidae indet. have been found in the formation.