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Divisaderan

The Divisaderan age is a South American land mammal age, covering a period of geologic time within the Middle or Late Eocene epochs of the Paleogene. It follows the Mustersan age and is followed by the Tinguirirican age.

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The Divisaderan age is a South American land mammal age, covering a period of geologic time within the Middle or Late Eocene epochs of the Paleogene (>36.0 Ma). It follows the Mustersan age and is followed by the Tinguirirican age.1

The Divisaderan is named after the Divisadero Largo Formation of Divisadero Largo, Mendoza, Argentina. It was originally distinguished by an unusual combination of archaic mammals and more recent-looking notoungulate fossils. However, more recent studies argue that the distinctive notoungulates reported from the Divisadero Largo Formation may actually be sourced from the younger (Miocene-age) Mariño Formation. Without these fossils, the Divisaderan may be too poorly-distinguished to stay in use compared to other middle-late Eocene SALMAs.2

Formations

Locations of Divisaderan formations
Formation
bold is type
Country Basin Notes
Divisadero Largo Formation  Argentina Cuyo Basin
Abanico Formation  Chile Abanico Basin
Andesitas Huancache Formation  Argentina Golfo San Jorge Basin
Chota Formation  Peru Bagua Basin
Guabirotuba Formation  Brazil Curitiba Basin
Leticia Formation  Argentina Austral Basin
Loreto Formation  Chile Magallanes Basin
Paracas Group  Peru Pisco Basin
Pozo Formation  Peru Ucayali Basin
Sarmiento Formation  Argentina Golfo San Jorge Basin
Soncco Formation  Peru Eastern Peruvian Andes
Yumaque Formation  Peru Pisco Basin

Fossils

Group Fossils Formation Notes
Mammals Acamana ambiguus, Adiantoides leali, Allalmeia atalaensis, Brachystephanus postremus, Groeberia minoprioi, G. pattersoni, Phoradiadius divortiensis, Xenostephanus chiottii, Trigonostylops sp., ?Notoungulata indet. Divisadero
Largo
Proeocoleophorus carlinii, Machlydotherium sp., Meteutatus sp., Nemolestes sp., Parutaetus sp., Utaetus sp., Argyrolagoidea indet., Astegotheriini indet., Astrapotheria indet., Euphractinae indet., Notopithecidae indet., Oldfieldthomasiidae indet., Palaeothentoidea indet. Guabirotuba
Ocucajea picklingi, Supayacetus muizoni, Basilosauridae indet. Paracas
Cachiyacuy contamanensis, C. kummeli, Canaanimys maquiensis, Eobranisamys javierpradoi, Eocoleophorus glyptodontoides, Pozomys ucayaliensis, Pseudostegotherium chubutanum, cf. Eoespina sp., cf. Griphodon sp., cf. Perulestes sp., Rumiodon sp., Sasawatsu sp., Stegosimpsonia sp., ?Trigonostylops sp., Wamradolops sp., Archaeohyracidae indet., Bonapartherioidea indet., Borhyaenidae indet., Chinchilloidea indet., Cingulata indet., Didelphimorphia indet., Interatheriinae indet., Litopterna indet., Microchiroptera indet., Molossidae indet., Phyllostomatidae indet., Polydolopimorphia indet., ?Sudamericidae indet., Toxodontia indet. Pozo
Pseudocladosictis determinabile, Patene coluapiensis, Angelocabrerus daptes, Arminiheringia auceta, Caroloameghinia mater, C. tenuis, Coona gaudryi, Rosendolops primigenium, Polydolops crassus, P. serra, P. thomasi, Amphidolops serrula, Eudolops tetragonus, Pseudolops princeps, Progarzonia notostylopense, Ideodelphys microscopicus, Tonostylops spissus, Thomashuxleya rostrata, Coelostylodon caroloameghinoi, C. florentinoameghinoi, Acoelohyrax complicatissimus, Isotemnus colhuehuapiensis, I. primitivus, Anisotemnus distentus, Pleurostylodon crassiramis, P. modicus, P. similis, Homalostylops parvus, Notostylops bicinctus, N. murinus, Isostylops fretus, Catastylops deflexus, Eohyrax isotemnoides, E. praerusticus, Archaeopithecus fossulatus, A. rogeri, Maxschlosseria consumata, Oldfieldthomasia debilitata, O. parvidens, O. transversa, Ultrapithecus rutilans, Paginula parca, Transpithecus obtentus, Antepithecus brachystephanus, A. innexus, Notopithecus adapinus, Henricosbornia ?lophodonta, Acoelodus proclivus, Proectocion argentinus, P. precisus, Didolodus magnus, D. minor, D. multicuspis, Paulogervaisia inusta, P. mamma, P. porca, Ernestokokenia nitida, Albertogaudrya unica, ?Trigonostylops duplex, T. wortmani, Parutaetus chicoensis, P. clusus, P. signatus, Meteutatus percarinatus, Pseudostegotherium chubutanum, Prostegotherium astrifer, P. notostylopianum, Utaetus buccatus, U. deustus, U. lenis, Machlydotherium sparsum, Rutimeyeria conulifera Guilielmofloweria plicata, Anisolambda fissidens, Proplanodus adnepos, Periphragnis exauctus, Mazzoniphractus ingens Sarmiento
Mystacodon selenensis Yumaque
Reptiles &
amphibians
Cunampaia simplex, Ilchunaia parva, Barinasuchus sp. Divisadero
Largo
?Balanerodus sp., cf. Sebecus sp., Anilioidea indet., Anura indet., Booidea indet., Caimaninae indet., ?Chelidae indet., Gavialoidea indet., Pipidae indet., ?Platynota indet. Pozo
Eocaiman cavernensis, ?Boa sp., ?Madtsoia sp., Crocodylomorpha indet. Sarmiento
Birds Spheniscidae indet. Loreto
Fishes Ischyodus dolloi, Striatolamia macrota, Elasmobranchii indet. Loreto
Potamotrygon ucayalensis, ?Colossoma sp., cf. Leporinus sp., cf. Hydrolycus sp., Actinopterygii indet., Characiformes indet. Pozo
Flora Chara (Grambastichara) tornata, Nitellopsis (Tectochara) latispira Pozo
References

References

  1. Divisaderan at Fossilworks.org
  2. Cerdeño, Esperanza; López, Guillermo M.; Reguero, Marcelo A. (2008-06-12). "Biostratigraphic considerations of the Divisaderan faunal assemblage". Journal of Vertebrate Paleontology. 28 (2): 574–577. doi:10.1671/0272-4634(2008)28[574:BCOTDF]2.0.CO;2. ISSN 0272-4634.
  3. Cerdeño & Guiomar, M2007, p.200
  4. Godoy et al., 2012
  5. Muñoz et al., 2006
  6. Tejedor et al., 2009, p.6
  7. Chacaltana et al., 2015, p.2
  8. Castro Medina, 2010, p.53
  9. Sedor et al., 2017, p.39
  10. Clarke et al., 2003
  11. Otero et al., 2012
  12. Clarke et al., 2007, p.11545
  13. Antoine et al., 2016, p.56
  14. Castro Medina, 2010, p.54
  15. Dozo et al., 2014, p.241
  16. Acosta & Tambussi, 2005, p.128
  17. Carlotto, 2016, p.522
  18. Solíz Mundaca, 2018, p.11
  19. Divisadero Hill at Fossilworks.org
  20. Sedor et al., 2017
  21. Guabirotuba fauna at Fossilworks.org
  22. Archaeocete Valley at Fossilworks.org
  23. Archaeocete Valley, Paracas, AV-17 at Fossilworks.org
  24. Archaeocete Valley, Paracas, AV-19 at Fossilworks.org
  25. Boivin et al., 2017
  26. CTA-27 at Fossilworks.org
  27. CTA-29 at Fossilworks.org
  28. CTA-51 at Fossilworks.org
  29. CTA-66 at Fossilworks.org
  30. Barranca south of Lago Colhue-Huapi, Gran Barranca at Fossilworks.org
  31. El Nuevo at Fossilworks.org
  32. Locality III, Tapera de López, Riconada de los López at Fossilworks.org
  33. Gran Barranca faunule 12 at Fossilworks.org
  34. Lambert et al., 2017
  35. Playa Media Luna at Fossilworks.org
  36. Eocaiman cavernensis holotype locality at Fossilworks.org
  37. Río de las Minos at Fossilworks.org
  38. CTA-73 at Fossilworks.org

Bibliography

General
Divisadero Largo Formation
Abanico Formation
Andesitas Huancache Formation
Chota Formation
Guabirotuba Formation
Leticia Formation
Loreto Formation
Paracas Group
Pozo Formation
Sarmiento Formation
Soncco Formation
Yumaque Formation