Where: Mendoza, Argentina (33.3° S, 69.1° W: paleocoordinates 33.5° S, 66.9° W)

• coordinate stated in text

When: Huayquerian mammal zone, Río de los Pozos Formation, Huayquerian (8.0 - 5.0 Ma)

• Cerdeño et al. 2023: Fossils from the Río de los Pozos Formation were first assigned to the Late Miocene–Pliocene (Huayquerian–Montehermosan Stages/Ages); Irigoyen et al. (2000) later stated a Huayquerian age, according to their origin from sediments close to the dated levels of Tobas La Angostura. Recently, two samples from the lower third of this formation at the La Pilona Anticline (~20 km NNW from the Tupungato Anticline) were dated. The U-Pb zircon age supplied from that area for the Río de los Pozos Formation was 7.41 + 1.3 Ma (Upper Miocene, late Tortonian–early Messinian Stages, roughly equivalent to the Huayquerian Stage/Age; e.g., see Prevosti et al., 2021, fig. 2) for maximum depositional age; samples of tuff from the underlying Tobas La Angostura gave values of 8.39 + 0.42 Ma and 8.31 + 0.48 Ma U-Pb (Buelow et al., 2018: 385), older within the Tortonian. Then, these chronological data support a Late Miocene age and the latest Chasicoan or mostly Huayquerian Stage/Age for the faunal content, at least in the inferior part of the sequence.

Environment/lithology: terrestrial; lithology not reported

Size class: macrofossils

Collection methods: The recovered fossils mostly come from the two inferior thirds of the Río de los Pozos Formation (Fig. 2), but some come from outcrops at the most eastern part of the Piedras Coloradas creek (Fig. 1). Following Yrigoyen (1993b) and Ramos et al. (2010), the eastern part of the Piedras Coloradas creek would correspond to the Mogotes Formation. However, no lithologic differentiation has been observed in the field. The upper third of the section has more conglomeratic intercalations, which likely led Ramos et al. (2010) to propose the limit between formations. However, the section is still dominated by fine-grained facies (Fig. 2), being different from the limit observed at the western flank of the Tupungato Anticline (Fig.1), clearly dominated by conglomeratic facies and without fossil remains. Therefore, we conclude that the whole studied section, with fossil records, corresponds to only one unit that we recognize as the Río de los Pozos Formation.

Primary reference: E. Cerdeño , C. I. Montalvo, S. H. Del Pino, J. Suriano, M. R. Ciancio, F. Pujos, G. I. Schmidt and J. S. Salgado Ahumada. 2023. Late Miocene–Early Pliocene mammals from the Tupungato–Piedras Coloradas Anticlines, Mendoza, Argentina. Journal of South American Earth Sciences 104497 [J. Carrillo/K. Pino/P. Mannion]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 231327: authorized by Juan Carrillo, entered by Kateryn Pino on 16.08.2023

Creative Commons license: CC BY (attribution)