MD-67: Burdigalian - Langhian, Peru

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Mammalia - Rodentia - Acaremyidae
Acaremyidae indet. (Wood 1949)
Mammalia - Rodentia
Boivin et al. 2021
MUSM 1974, MUSM 1975
Mammalia - Rodentia - Dinomyidae
Scleromys sp. Ameghino 1887
Mammalia - Rodentia
Mammalia - Cingulata - Glyptodontidae
Mammalia - Didelphimorphia
Mammalia - Sparassodonta
Sipalocyon sp. Ameghino 1887
see common names

Geography
Country:Peru State/province:Cuzco County:Pilcopata
Coordinates: 12.7° South, 71.3° West (view map)
Paleocoordinates:12.0° South, 67.0° West (Wright 2013)
Basis of coordinate:stated in text
Altitude:428 meters
Geographic resolution:outcrop
Time
Period: Neogene Epoch: Miocene
Stage: Burdigalian - Langhian 10 m.y. bin: Cenozoic 5
Key time interval: Burdigalian - Langhian
Age range of interval: 20.45 - 13.82 m.y. ago
Age estimate: 17.1 ± 2.4 Ma (fission track)
Stratigraphy
Formation:Yahuarango
Stratigraphy comments: The fossiliferous outcrop dips 35 SW with a N130 strike. It crops out in the southern flank of the Pantiacolla anticline and was originally mapped as part of the PaleoceneeEocene Yahuarango Formation, based on sedimentary facies, but without any biostratigraphic constraint (Vargas and Hipólito, 1998). The Yahuarango Formation (northern Perú) is poorly dated and it consists mainly of red siltstones and mudstones forming distal fluvial deposits (see Roddaz et al., 2010 for a review).

Antoine et al., 2013: Apatite Fission Track provides a detrital age (17.1 ± 2.4 Ma) for the vertebrate-yielding locality, slightly older than its inferred biochronological age (Colloncuran-early Laventan South American Land Mammal Ages: ∼15.6–13.0 Ma). Be as it may, the middle Miocene age of the concerned outcrop is fully contradictory to its original assignment to the Paleocene-Eocene Yahuarango Formation (Vargas and Hipólito, 1998).
Lithology and environment
Primary lithology:red lithified silty siltstone
Secondary lithology:red lithified muddy mudstone
Includes fossils?Y
Includes fossils?Y
Lithology description: The Yahuarango Formation (northern Perú) is poorly dated and it consists mainly of red siltstones and mudstones forming distal fluvial deposits (see Roddaz et al., 2010 for a review).
Environment:wet floodplain Tectonic setting:foreland basin
Geology comments: Lithology of the fossil-bearing beds (i.e., channel-iron deposits, with Fe-rich pisolite gravels) provides valuable information on the depositional environment and associated diagenetic processes: pisolites might have formed in the ground by alteration and concretion of highly ferruginous groundwater solutions under warm, humid, and seasonally-contrasted conditions (Tardy, 1992). Accordingly, isotopic analyses performed on coeval mollusc shells from the Iquitos area (w1000 km more to the North) show the region was experiencing a seasonal water influx under a monsoonal-like tropical climate by that time (Kaandorp et al., 2006; Wesselingh et al., 2006). Both proxies are therefore in good agreement.
One of the striking features of the Miocene of Amazonia is the presence of a large and long-lasting “mega-wetland”. The Amazonian mega-wetland reached its maximum extent during the Middle Miocene (also called “Pebas phase” sensu Hoorn et al., 2010) and it consisted of a complex mosaic of lakes, embayments, swamps, rivers, and fluvio-tidal environments (see review in Hoorn et al., 2010). Our data suggest the absence of this megawetland in the Amazonian Madre de Dios Subandean Zone of Perú (Fig. 4), while other coeval localities such as IQ-26 and NA069 (nearby Iquitos; Antoine et al., 2006; Pujos et al., 2009) or the Fitzcarrald Local Fauna (Antoine et al., 2007; Goillot et al., 2011) were under its influence during the same period (Fig. 4). This environmental contrast might in turn have played some role in the faunal discrepancies as observed in middle Miocene times between Northern and Southern South America (Madden et al., 1997).
Taphonomy
Modes of preservation:body,original phosphate
Size of fossils:macrofossils,mesofossils
Collection methods and comments
Collection methods:field collection
Reason for describing collection:taxonomic analysis
Collection method comments: Repository: Museo de Natural de la Uni- versidad Nacional Mayor San Marcos, Lima, Perú
Metadata
Database number:144513
Authorizer:C. Jaramillo, J. Carrillo Enterer:A. Cárdenas, K. Pino
Modifier:M. Kouvari
Created:2013-05-09 01:51:55 Last modified:2025-02-22 15:12:02
Access level:authorizer only Released:2015-05-09 01:51:55
Creative Commons license:CC0
Reference information

Primary reference:
46731. P. O. Antoine, M. Roddaz, S. Brichau, J. Tejada-Lara, R. Salas-Gismondi, A. Altamirano, M. Louterbach, L. Lambs, T. Otto and S. Brusset. 2013. Middle Miocene vertebrates from the Amazonian Madre de Dios Subandean zone, Peru. Journal of South American Earth Sciences 42:91-102 [C. Jaramillo/A. Cárdenas]

Secondary references:

85340 M. Boivin, L. Marivaux, W. Aguirre-Diaz, A. Benites-Palomino, G. Billet, F. Pujos, R. Salas-Gismondi, N. S. Stutz, J. V. Tejada-Lara, R. M. Varas-Malca, A. H. Walton and P.-O. Antoine. 2021. Late middle Miocene caviomorph rodents from Tarapoto, Peruvian Amazonia. PLoS ONE 16(11):e0258455 [J. Carrillo/K. Pino/P. Mannion]