Pebas Formation

Pebas Formation
Pebas Formation
Stratigraphic range: Early Aquitanian-Tortonian; (Colhuehuapian-Huayquerian); ~21–8 Ma PreꞒ Ꞓ O S D C P T J K Pg N
	The Pebas Mega-Wetland (or Lake Pebas), on the western side of this map, corresponds to the Pebas Formation
Underlies	Marañón Formation
Overlies	Chambira Formation
Area	1,000,000 km2 (390,000 sq mi)
Thickness	~350–1,074 m (1,148–3,524 ft)
Lithology
Primary	Siltstone, mudstone
Other	Coal/lignite
Location
Coordinates	7.4°S 75.0°W
Approximate paleocoordinates	8.4°S 70.6°W
Region	Amazon Basin
Country	Brazil; Colombia; Ecuador; Peru
Type section
Named for	Pebas District

The Pebas Formation is a lithostratigraphic unit of Miocene age, found in western Amazonia. The formation extends over 1,000,000 square kilometres (390,000 sq mi), including parts of Brazil, Peru, Ecuador and Colombia.^[1] It is interpreted as representing the deposits of a lake ("Lake Pebas") or series of lakes, formed within the foreland basin of the Andes mountain belt. It is known for its abundant fossil ostracods and molluscs and an unusually diverse group of crocodylians.^[2]

Quick Facts Underlies, Overlies ...

[1]

[2]

Taxa	Species	Locality	Stratigraphic position	Material	Notes	Images
Anostomidae ^[3]	Indeterminate
Hydrolycus^[3]	cf. H. sp.
Leporinus^[3]	L. sp.
Pristis^[3]	P. sp.
Potamotrygon^[3]	P. sp.

Taxa	Species	Locality	Stratigraphic position	Material	Notes	Images
Macroteleia ^[4]	M. yaguarum				A parasitoid wasp.
Sycorax	S. peruensis				Relatives of moth flies and sand flies.

Taxa	Species	Locality	Material	Notes
Dinomyidae ^[3]	D. sp.			A hystricognath rodent.
Octodontoidea	Indeterminate.			A hystricognath rodent.
Neoepiblema^[5]	N. sp.			A hystricognath rodent.
Pebanista	P. yacuruna	Rio Napo.	A nearly complete skull.	A platanistid river dolphin.
Pseudoprepotherium	P. sp.	Rio Napo		A ground sloth.
Potamarchus	P. sp			A hystricognath rodent.
Parapropalaehoplophorus	P. sp			a glyptodont

Taxa	Species	Locality	Stratigraphic position	Material	Notes
Caiman ^[3]^[6]	C. wannlangstoni	Locality IQ26 and IQ114		A well-preserved partial skull.	An extinct caiman
Gavialoidea	Indeterminate.
Gnatusuchus	G. pebasensis	Locality IQ114, IQ116, and IQ125	Upper	A nearly complete skull.	A clam eating caiman.
Gryposuchus	G. pachakamue	Locality IQ101			A gavialid crocodilian.
Kuttanacaiman	K. iquitosensis	Locality IQ26 and IQ116	Middle	nearly complete skull and mandibles.	A small caiman.
Chelus ^[3]^[6]	C. colombianus			Pieces of shell bones and scutes	A slightly larger species of mata mata, reaching an estimated shell length of up to a meter.
Mourasuchus	M. atopus	Locality IQ114
Paleosuchus	P. sp.
Podocnemis	P. sp.
Purussaurus	P. neivensis	Locality IQ26 and IQ114		Skull and teeth.	A giant caiman.

Formation	Honda	Honda	Aisol	Cura-Mallín	Pisco	Ipururo	Pebas	Capadare	Inés	Paraná	Map
Basin	VSM	Honda	San Rafael	Caldera	Pisco	Ucayali	Amazon	Falcón	Venezuela	Paraná	Pebas Formation (South America)
Country	Colombia	Bolivia	Argentina	Chile	Peru			Venezuela		Argentina
Boreostemma
Hapalops
Miocochilius
Theosodon
Xenastrapotherium
Mylodontidae
Sparassodonta
Primates
Rodents
Birds
Terror birds
Reptiles
megalodon
Flora
Insects
Environments	Fluvial			Fluvio-deltaic		Fluvio-lacustrine		Fluvio-deltaic		Fluvial	Laventan volcanoclastics Laventan fauna Laventan flora
Volcanic	Yes										Laventan volcanoclastics Laventan fauna Laventan flora

Pebas Formation

Fossil content

Fish

Insects

Mammals

Reptiles

Correlations

Laventan

Huayquerian

References

Further reading

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