Also known as Telén

Where: La Pampa, Argentina (36.3° S, 65.5° W: paleocoordinates 36.5° S, 63.3° W)

• coordinate stated in text

• small collection-level geographic resolution

When: Cerro Azul Formation, Huayquerian (8.0 - 5.0 Ma)

• The Cerro Azul Formation crops out in most of La Pampa Province, except in the southern region (Linares et al., 1980). It is a continental, nearly flat-lying unit composed of massive, pale red to pinkish siltstones and fine-grained sandstones with interbedded, poorly developed palaeosols (e.g., Linares et al., 1980; Goin et al., 2000). This lithostratigraphic unit is considered the distal portion of a clastic wedge related to the late Cenozoic Andean fold and thrust belt that is well developed in the neighbouring Mendoza Province. The maximum outcropping thickness is about 40 m, although the exposures are generally less than 5 m thick. The Cerro Azul Formation has yielded numerous vertebrate remains, specially mammals, which are referred to the Huayquerian land mammal age, which is of late Miocene age (Pascual and Bondesio, 1982; Montalvo and Casadío, 1988; Goin et al., 2000; Verzi et al., 1991, 1994, 1995, 1999, 2003, 2004; Montalvo et al., 1995, 1996, 1998; Esteban et al., 2001; Cerdeño and Montalvo, 2001, 2002). The base of the Cerro Azul Formation is covered and its top is overlain by Pliocene and younger (mostly aeolian) sediments or is composed of a discontinuous calcrete crust that forms a resistant layer responsible for the preservation from erosion of the unit. In the subsurface, the unit reaches ~370 m thick overlying older Cenozoic sediments or basement rocks (De Elorriaga and Tullio, 1998).

•Schmidt et al. 2018: Figure 2 illustrates the stratigraphic distribution of the locality giving a general age estimate of 7.2-7.5Ma

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•Romano et al. 2023: The presented 40Ar/39Ar “escoria” age estimate for Telén (average of 7.09 Ma) is contained in the older range of our previous inference.

• group of beds-level stratigraphic resolution

Environment/lithology: "floodplain"; lithified, paleosol/pedogenic, brown, gray, calcareous siltstone and lithified, fine-grained sandstone

Size classes: mesofossils, microfossils

Preservation: original phosphate

Collection methods: bulk, sieve,

• The collection includes all materials from surface prospecting. The low gradient of the modern margin of the depression favoured the erosive action by physical processes that loosened the fossils from the host material. For this reason, bone remains are frequently found in small concentrations produced by running water during rains. During a single visit to the site, 1955 specimens were recovered, 94.53% of them loose, and just 5.47% within the host material. Both the loose and in situ remains appeared throughout the exposed surface of the two palaeosol levels, randomly distributed, disarticulated and dispersed. The in situ material was found scattered in the host siltstone as well as in calcite concretions.

Primary reference: C. I. Montalvo, R. N. Melchor, G. Visconti and E. Cerdeño. 2008. Vertebrate taphonomy in loess-palaeosol deposits: A case study from the late Miocene of Central Argentina. Geobios 41:133-143 [C. Jaramillo/A. Cardenas ]more details

Purpose of describing collection: taphonomic analysis

PaleoDB collection 152061: authorized by Carlos Jaramillo, entered by Andrés Cárdenas on 05.11.2013, edited by Grace Varnham, Miranta Kouvari, Philip Mannion and Kateryn Pino

Creative Commons license: CC BY (attribution)