MD-61 (Miocene of Peru)

Where: Cusco, Peru (12.9° S, 71.4° W: paleocoordinates 13.6° S, 67.5° W)

• coordinate stated in text

• small collection-level geographic resolution

When: Santacrucian (17.5 - 16.3 Ma)

• The MD-61 section is 30 m thick. It consists of individual or stacked brownish sandstone bodies (deposited in fluvial channels, point bars, stream floods, and/or waning flows) separated by reddish mudstones with carbonate nodules, further testifying to the presence of a floodplain with frequent subaerial exposure under oxidizing conditions (Fig. 1E). Fossil verte- brate remains are scattered within the lower 5-m thick sand body. This early Miocene sequence is unconformably overlain by unconsolidated Pleistocene terrace conglomerates.

Environment/lithology: "channel"; lithified, medium-grained, coarse, ferruginous, sandy sandstone

• All identifiable vertebrate remains from MD-61 were isolated and scattered all over the iron-pisolite-rich sand-and-gravel channel

Size class: macrofossils

Preservation: original phosphate

Collected in 2011

• MUSM: Museo de Historia Natural de la Universidad Nacional Mayor San Marcos, Lima, Perú

Primary reference: L. Marivaux, R. Salas-Gismondi, J. Tejada, G. Billet, M. Louterbach, JVink, J. Bailleul, M. Roddaz, and P.O. Antoine. 2012. A platyrrhine talus from the early Miocene of Peru (Amazonian Madre de Dios Sub-Andean Zone). Journal of Human Evolution 63:696-703 [C. Jaramillo/J. Ceballos/M. Uhen]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 145126: authorized by Carlos Jaramillo, entered by Juliana Ceballos on 27.05.2013, edited by Andrés Cárdenas

Creative Commons license: CC BY (attribution)

Taxonomic list

• Location MD-61 documents unambiguously a crane-sized gruiform bird and testifies to the proximity of water and the occurrence of swamps or extensive wetlands in the area by the time of deposition of the fossiliferous level. This specimen is not included in the list.
Show authors, comments, and common names
Mammalia
 Cingulata - Dasypodidae
Dasypodidae sp.
Dasypodidae sp. armadillo
osteoderm
 Megatherioidea - Megatheriidae
Megatherium sp.
Megatherium sp. Cuvier 1796 edentate
claw
 Placentalia -
Notoungulata sp.
Notoungulata sp. Roth 1903 notoungulate
 Rodentia - Dinomyidae
Scleromys quadrangulatus
Scleromys quadrangulatus Kramarz 2006 caviomorph
right M1, p4, and dp4
 Primates - Cebidae
cf. Saimiri sp.
cf. Saimiri sp. Voigt 1831 squirrel monkey
MUSM-2024: Its size approximates that of the talus of some living large marmosets or small tamarins (Cebidae, Callitrichinae). MUSM-2024 would thus document a tiny Saimiri-like cebine, with the body size of a large marmoset