Where: Buenos Aires, Argentina (39.0° S, 61.7° W: paleocoordinates 39.1° S, 60.3° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Montehermosan (5.0 - 3.8 Ma)

• Coastal deposits form a three km marine cliff, 15 m maximum height, in which fossil-bearing Neogene sediments of the Monte Hermoso Formation are exposed. The complete sedimentary sequence includes three stratigraphic units (Zavala, 1993): the Monte Hermoso Formation (Lower–Middle Pliocene), Puerto Belgrano Formation (Upper Pleistocene) and Punta Tejada Formation (Upper Pleistocene–Middle Holocene).

•The Monte Hermoso Formation (Zavala, 1993) crops out at the abrasion platform and the lower part of the cliff, along its entire extension, with a maximum thickness of up to 6 m. Several authors (e.g. Wichmann, 1916; Kantor, 1922; Vignati, 1925; Kraglievich, 1946) recognized in this formation the existence of two levels, differentiated by color and separated by a discontinuity. They proposed that these levels are temporarily different. With regard to this, Cione and Tonni (1995, 1996, 2001, 2005) published revisions of the biostratigraphy and biochronology of Monte Hermoso Formation at Farola Monte Hermoso. These authors recognized two chronologically successive biozones, the Biozone of Trigodon gaudryi, biostratigraphic basis of the Montehermosan Stage/Age (late Miocene–early Pliocene), and the Biozone of Neocavia depressidens, biostratigraphic basis of the Lower Chapadmalalan Stage/Age (early Pliocene). However, other authors (e.g. Frenguelli, 1928; Bonaparte, 1960; Deschamps et al., 2012; Olivares et al., 2012; Tomassini, 2012) emphasized that the stratigraphic and paleontological differences are minimal, so it would not be possible to define with certainty two levels with different ages.

Environment/lithology: "channel"; lithified, massive breccia

Size classes: macrofossils, mesofossils, microfossils

Preservation: original phosphate

Collection methods: Fossil remains are deposited in the “Museo Municipal de Ciencias Naturales Carlos Darwin” collection (Punta Alta, Buenos Aires), under the acronym MD-FM.

Primary reference: R. L. Tomassini and C. I. Montalvo. 2013. Taphonomic modes on fluvial deposits of the Monte Hermoso Formation (early Pliocene), Buenos Aires province, Argentina. Palaeogeography, Palaeoclimatology, Palaeoecology 369:282-294 [C. Jaramillo/A. Cardenas ]more details

Purpose of describing collection: taphonomic analysis

PaleoDB collection 152064: authorized by Carlos Jaramillo, entered by Andrés Cárdenas on 05.11.2013

Creative Commons license: CC BY (attribution)