Middle Miocene vertebrates from the Amazonian Madre de Dios subandean zone, Peru

2013

Article référencé dans le Web of Science WOS:000315763100009

Antoine P. O., Roddaz M., Brichau Stéphanie, Tejada-Lara J., Salas-Gismondi R., Altamirano A., Louterbach M., Lambs L., Otto T., Brusset S.

Journal of South American Earth Sciences, 2013, 42, p. 91-102 ISSN 0895-9811

A new middle Miocene vertebrate fauna from Peruvian Amazonia is described. It yields the marsupials Sipalocyon sp. (Hathliacynidae) and Marmosa (Micoureus) cf. laventica (Didelphidae), as well as an unidentified glyptodontine xenarthran and the rodents Guiomys sp. (Caviidae), "Scleromys" sp., cf. quadrangulatus-schurmanni-colombianus (Dinomyidae), an unidentified acaremyid, and cf. Microsteiromys sp. (Erethizontidae). Apatite Fission Track provides a detrital age (17.1 +/- 2.4 Ma) for the locality, slightly older than its inferred biochronological age (Colloncuran-early Laventan South American Land Mammal Ages: similar to 15.6-13.0 Ma). Put together, both the mammalian assemblage and lithology of the fossil-bearing level point to a mixture of tropical rainforest environment and more open habitats under a monsoonal-like tropical climate. The fully fluvial origin of the concerned sedimentary sequence suggests that the Amazonian Madre de Dios Subandean Zone was not part of the Pebas mega-wetland System by middle Miocene times. This new assemblage seems to reveal a previously undocumented "spatiotemporal transition" between the late early Miocene assemblages from high latitudes (Patagonia and Southern Chile) and the late middle Miocene faunas of low latitudes (Colombia, Peru, Venezuela, and ?Brazil).

Géologie et formations superficielles [064] ; Sciences du monde animal [080] ; Etudes, transformation, conservation du milieu naturel [082]

PEROU

Fonds IRD [F B010060778]

fdi:010060778