PBDB Collection

Rio Rosario (Miocene of Bolivia)

Where: Tarija, Bolivia (21.9° S, 65.4° W: paleocoordinates 22.2° S, 62.2° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Honda Group, Laventan (13.8 - 11.0 Ma)

• The local correlation between the Quebrada Honda and Rio Rosario sections, which are separated by about 6 km, is difficult because of several factors including: (1) the lack of demonstrable lateral continuity of persistent units, like the tuffaceous horizons; (2) significant facies changes between sections; (3) radiometric calibrations only available for Quebrada Honda; and (4) the fact that the magnetic polarity time scale is very "busy" during the Miocene, thereby resulting in numerous small polarity events. Nevertheless, due to the flat-lying nature of the sediments and the presence of generally similar fossil mammals in both sections, it is suggested that Quebrada Honda and Rio Rosario are roughly contemporaneous (MacFadden et al. 1990).

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•(From Brandoni et al., 2018): MacFadden et al. (1990) estimated the age of Río Rosario fossils at roughly 13.0–12.5 Ma. Based on Ogg (2012), this would correspond to roughly 13.2–12.8 Ma.

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Environment/lithology: fluvial; lithified, silty, sandy claystone

• Both the Quebrada Honda and Rio Rosario sections have been mapped as belonging to the Honda Group by GEOBOL (Servicio Geol6gico de Bolivia). These sections consist of about 300 m of principally fine-grained fluviatile sediments with predominant lithologies reddish brown and yellowish-green silty clays, silts, and fine sands. There are also coarser, lenticular channel sands and gravels, but these are localized. Several interbedded tuffaceous horizons occur within both the Quebrada Honda and Rio Rosario sections.

Size classes: macrofossils, mesofossils

Reposited in the MNHN (La Paz)

• McGrath et al 2020: new proterotheriid remains from the Quebrada Honda region that have been collected in recent years through a research collaboration between Case Western Reserve University (Cleveland, Ohio, USA) and the Universidad Autónoma ‘Tomás Frías’ (Potosí, Bolivia) as well as remains collected by earlier expeditions (Hoffstetter, 1977; Takai et al., 1984)

Primary reference: D. A. Croft. 2007. The middle Miocene (Laventan) Quebrada Honda fauna, southern Bolivia and description of its notoungulates. Palaeontology 50(1):277-303 [C. Jaramillo/A. Cardenas ]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 133664: authorized by Carlos Jaramillo, entered by Andrés Cárdenas on 21.09.2012, edited by Jelle Zijlstra, Grace Varnham and Miranta Kouvari

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names

Mammalia
Polydolopimorphia - Argyrolagidae	Hondalagus altiplanensis⁶ Hondalagus altiplanensis⁶ Villarroel and Marshall 1988 metatherian MNHN-Pal-BolV-006330, skull and jaws
Paucituberculata - Palaeothentidae	Acdestis maddeni n. sp.³ Acdestis maddeni n. sp.³ Goin et al. 2003 marsupial Holotype: MNHN-Pal-Bol-V-4000, partial skull; MNHN-Pal-Bol-V-003689 maxillary fragment
Panameriungulata - Proterotheriidae	Olisanophus sp.⁵, Olisanophus akilachuta⁵, Olisanophus riorosarioensis n. gen. n. sp.⁵ Olisanophus sp.⁵ McGrath et al. 2020 placental UATF-V-001562, UATF-V-001907 Olisanophus akilachuta⁵ McGrath et al. 2020 placental UATF-V-00967, UATF-V-00978, UATF-V-001613 Olisanophus riorosarioensis n. gen. n. sp.⁵ McGrath et al. 2020 placental Holotype: UATF-V- 001287
Panameriungulata - Macraucheniidae	Llullataruca shockeyi n. gen. n. sp.⁴ Llullataruca shockeyi n. gen. n. sp.⁴ McGrath et al. 2018 placental UATF-V-002818 (type)
Rodentia -	Guiomys unica¹, Acarechimys sp.¹ Guiomys unica¹ Pérez 2010 caviomorph specimens UATF-V-000962, UATF-V-000981, UATF-V-001038, UF 236852, UF 236852, UF 236853, UF 236853, UF 236859, UF 236859, UF 236860, UF 236860, UATF-V-000971, UATF-V-000973, UATF-V-001008, UATF-V-001017, UF 66003, UF 236854, UF 236854, UF 236858 Acarechimys sp.¹ Patterson 1965 caviomorph
Rodentia - Chinchillidae	Miochinchilla plurinacionalis n. sp.², Prolagostomus sp.¹ Miochinchilla plurinacionalis n. sp.² Croft et al. 2021 chinchilid UATF-V-001911, UATF-V-001580, UATF- V-001631 Prolagostomus sp.¹ Ameghino 1887 chinchilid
Notoungulata - Toxodontidae	Toxodontidae indet. Toxodontidae indet. Scott 1873 notoungulate specimen MNHN 6543
Notoungulata - Mesotheriidae	Plesiotypotherium minus Plesiotypotherium minus Croft 2007 notoungulate specimen MNHN 6510

¹Croft et al. 2011; ²Croft et al. 2021; ³Goin et al. 2003; ⁴McGrath et al. 2018; ⁵McGrath et al. 2020; ⁶Sánchez-Villagra et al. 2000