PBDB Collection

Yauri city (Pliocene of Peru)

Also known as Locality ESP9-1

Where: Espinar, Peru (14.8° S, 71.4° W: paleocoordinates 15.0° S, 70.5° W)

• coordinate stated in text

When: C Member (Descanso Formation), Early/Lower Pliocene (5.3 - 3.6 Ma)

• Salas-Gismondi et al. (2023): The Andes are home to numerous intermontane basins containing thick continental successions, with the Descanso-Yauri basin in southern Peru being one of the best-known in the southern Peruvian region. It contains a 1.8 km-thick Mio–Pliocene sequence associated with the Descanso Formation. These exposures consist of three lithostratigraphic units, in ascending order: Member A, Member B, and Member C (Carlotto, 2013; Cerpa et al., 2002). Fossil remains discussed in this collection were collected from the latter unit. The age of Member C was recently assessed as latest Miocene to Early Pliocene (5.43.9 Ma; Kar et al., 2016; Martínez et al., 2020). In this study, a 3 m-thick ash outcropping on the NW margin of the Yauri city, near the area of the first paleontological discoveries, was further analyzed for U/Pb radiometric dating (sample E19-14; 14°784′S, 71°418′W;Figs. 1 ,S1–S3). U/Pb analyses of zircons from this ash yielded an age of 4.75 ± 0.5 Ma (see Supplementary Data 1, Table S1). Mammal remains described herein are correlated with sedimentary levels from the Versalles area (Martínez et al., 2020; 3907 m a.s.l.), but are considered at least 1 My older than those outcropping at Cerro Púcara (Garbage Pit locality, 3937 m a.s.l.; Vélez et al., 2018).

Environment/lithology: lacustrine - small; conglomeratic sandstone

• Salas-Gismondi et al. (2023): It represents a N-NE flowing fluvial system that gradually gave rise to lacustrine and palustrine environments (Cerpa et al., 2002), preserving abundant plant (pollen, leaves, wood), invertebrate (ostracods), and vertebrate (fish, mammal) remains.

• Salas-Gismondi et al. (2023): It contains a 1.8 km-thick Mio–Pliocene sequence associated with the Descanso Formation. These exposures consist of three lithostratigraphic units, in ascending order: Member A, Member B, and Member C (Carlotto, 2013; Cerpa et al., 2002). Fossil remains discussed in this paper were collected from the latter unit. Member C is composed of finely laminated fossiliferous diatomaceous silt- and sandstones, interbedded with massive to cross-bedded sandstone and conglomerate beds, as well as local syndepositional ash beds.

Size class: macrofossils

Primary reference: R. Salas-Gismondi, D. Ochoa, J. Gamarra, F. Pujos, D.A. Foster and J. V. Tejada. 2023. Pliocene Pre-GABI herbivorous mammals from Espinar, Peruvian Andean Plateau. Journal of Vertebrate Paleontology e2237079 [J. Carrillo/K. Pino/P. Mannion]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 231812: authorized by Juan Carrillo, entered by Kateryn Pino on 13.09.2023

Creative Commons license: CC BY (attribution)

Taxonomic list

• Fossil mammals are housed in the Dirección Desconcentrada de Cultura de Cusco (Cusco, Peru) and the Museo Municipal de Espinar (MUESP; Espinar, Peru). Remains of the new glyptodontine (MUESP 4) are described and compared with other members of the clade.

Show authors, comments, and common names

Mammalia
Notoungulata - Toxodontidae	Posnanskytherium viscachanense Posnanskytherium viscachanense Saint-André 1999 notoungulate MUESP 15, adult individual, rostrum and palatal region with most cheek teeth, but broken at the alveolar series level; and MUESP 17, young individual, partial jaws
- Mylodontidae	Simomylodon uccasamamensis Simomylodon uccasamamensis Saint-André et al. 2010 edentate MUESP 16, Partial skull, left mandible, and ulna; and MUESP 11, juvenile individual, partial skull, fragmentary jaw, cervical vertebrae.