Pebas Formation
PeriodMiocene
AgeEarly Aquitanian-Tortonian
(Colhuehuapian-Huayquerian)
~
PrilithologySiltstone, mudstone
OtherlithologyCoal/lignite
NamedforPebas District
RegionAmazon Basin
CountryBrazil
Colombia
Ecuador
Peru
Coordinates7.4°S 75.0°W
Paleocoordinates8.4°S 70.6°W
UnderliesMarañón Formation
OverliesChambira Formation
Thickness~350–1,074 m (1,150–3,524 ft)
Area1,000,000 km2 (390,000 sq mi)

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]

Fossil content

Fish

TaxaSpeciesLocalityStratigraphic positionMaterialNotesImages

Anostomidae

[3]
Indeterminate
Hydrolycus[3]cf. H. sp.
Leporinus[3]L. sp.
Pristis[3]P. sp.
Potamotrygon[3]P. sp.

Insects

TaxaSpeciesLocalityStratigraphic positionMaterialNotesImages

Macroteleia

[4]
M. yaguarumA parasitoid wasp.
SycoraxS. peruensisRelatives of moth flies and sand flies.

Mammals

TaxaSpeciesLocalityStratigraphic positionMaterialNotesImages

Dinomyidae

[3]
indeterminateA hystricognath rodent.
OctodontoideaIndeterminate.A hystricognath rodent.
Neoepiblema[5]N. sp.A hystricognath rodent.
PebanistaP. yacurunaRio Napo.A nearly complete skull.A platanistid river dolphin.
PseudoprepotheriumP. sp.Rio NapoA ground sloth.
PotamarchusP. spA hystricognath rodent.
ParapropalaehoplophorusP. spa glyptodont

Reptiles

TaxaSpeciesLocalityStratigraphic positionMaterialNotesImages

Caiman

[3][6]
C. wannlangstoniLocality IQ26 and IQ114A well-preserved partial skull.An extinct caiman
GavialoideaIndeterminate.
GnatusuchusG. pebasensisLocality IQ114, IQ116, and IQ125UpperA nearly complete skull.A clam eating caiman.
GryposuchusG. pachakamueLocality IQ101A gavialid crocodilian.
KuttanacaimanK. iquitosensisLocality IQ26 and IQ116Middlenearly complete skull and mandibles.A small caiman.

Chelus

[3][6]
C. colombianusPieces of shell bones and scutesA slightly larger species of mata mata, reaching an estimated shell length of up to a meter.
MourasuchusM. atopusLocality IQ114
PaleosuchusP. sp.
PodocnemisP. sp.
PurussaurusP. neivensisLocality IQ26 and IQ114Skull and teeth.A giant caiman.

Correlations

Laventan

Laventan correlations in South America
FormationHondaHondaAisolCura-MallínPiscoIpururoPebasCapadareUrumacoInésParanáMap
BasinVSMHondaSan RafaelCalderaPiscoUcayaliAmazonFalcónVenezuelaParaná
Country
Boreostemma
Hapalops
Miocochilius
Theosodon
Xenastrapotherium
Mylodontidae
Sparassodonta
Primates
Rodents
Birds
Terror birds
Reptiles
megalodon
Flora
Insects
EnvironmentsFluvialFluvio-deltaicFluvio-lacustrineFluvio-deltaicFluvial

VolcanicYes

Huayquerian

Huayquerian correlations in South America
FormationCerro AzulItuzaingóParanáCamachoRaigónAndalhualaChiquimilLas FloresMaimaráPaloPebasMuyuRosaSaldungaraySalicasUrumacoMap
BasinColoradoParanáHualfínTontalAndesSaltaAmazonHuasiAltiplanoBAVelascoFalcón
Country
Cardiatherium
Lagostomus
Macroeuphractus
Proeuphractus
Pronothrotherium
Pseudotypotherium
Thylacosmilus
Xotodon
Macraucheniidae
Primates
Rodents
Reptiles
Birds
Terror birds
Flora
EnvironmentsAeolian-fluvialFluvio-deltaicFluvialFluvio-lacustrineFluvialFluvio-lacustrineFluvio-deltaic

VolcanicYes

References

  1. ^ Wesselingh et al., 2006
  2. ^ Sala Gismondi et al., 2006
  3. ^ CTA-45 at Fossilworks.org
  4. ^ Amazonian amber at Fossilworks.org
  5. ^ Rasia, Luciano L.; Candela, Adriana M. (2018-05-19). "Reappraisal of the giant caviomorph rodent Phoberomys burmeisteri (Ameghino, 1886) from the late Miocene of northeastern Argentina, and the phylogeny and diversity of Neoepiblemidae". Historical Biology. 30 (4): 486–495. doi:10.1080/08912963.2017.1294168. ISSN 0891-2963. S2CID 90381892.
  6. ^ IQ114 at Fossilworks.org

Bibliography

Further reading

  • Antoine, P.; Abello, J.A.; Adnet, S.; Altamirano Sierra, A.J.; Baby, P.; Billet, G.; Boivin, M.; Calderón, Y.; Candela and J. Chabain, F. Corfu, D. A. Croft, M. Ganerød, C. Jaramillo, S. Klaus, L. Marivaux, R. E. Navarrete, M. J. Orliac, F. Parra, M. E. Pérez, F. Pujos, J. Rage, Anthony Ravel, Céline Robinet, Martin Roddaz, Julia Victoria Tejada Lara, Jorge Vélez-Juarbe, Frank P. Wesselingh and Rodolfo Salas Gismondi, A.R. (2016), "A 60-million-year Cenozoic history of western Amazonian ecosystems in Contamana, eastern Peru", Gondwana Research. 31: 30–59, Bibcode:2016GondR..31...30A. doi:10.1016/j.gr.2015.11.001, retrieved 2020-03-19
  • Marcos C.Bissaro-Júnior, Leonardo Kerber, James L.Crowley, Ana M.Ribeiro, Renato P.Ghilardi, Edson Guilherme, Francisco R.Negri, Jonas P.Souza Filho, Annie S.Hsiou: "Detrital zircon U–Pb geochronology constrains the age of Brazilian Neogene deposits from Western Amazonia." Palaeogeography, Palaeoclimatology, Palaeoecology Volume 516, 15 February 2019, Pages 64–70 10.1016/j.palaeo.2018.11.032