Cerro La Bota: Huayquerian, Argentina
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Geography
| Country: | Argentina | State/province: | La Pampa | County: | Utracán |
| Coordinates: | 37.4° South, 65.5° West (view map) | ||||
| Paleocoordinates: | 36.9° South, 63.9° West (Wright 2013) | ||||
| Basis of coordinate: | stated in text | ||||
| Geographic resolution: | outcrop |
Time
| Period: | Neogene |
| 10 m.y. bin: | Cenozoic 6 |
| Key time interval: | Huayquerian |
| Age range of interval: | 8 - 5 m.y. ago |
| Age estimate: | 7.944 to 7.332 Ma (other) |
Stratigraphy
| Formation: | Cerro Azul | ||||
| Stratigraphy comments: Early late Miocene
The stratotype is the lower level of the Cerro Azul Formation outcropping at this locality Montalvo et al. 2019: The revision of the vertebrate assemblage from this locality, as well as new geomorphologic and sedimentological interpretations of the Cerro Azul Formation in the area, confirms the previous assignation to the Chasicoan age. Prevosti et al. 2023: Between 9 and ca. 7.7 Ma, there is a transitional fauna, represented by the assemblages retrieved from Cerro Patagua, Cerro La Bota, and Algarrobo del Águila, with taxa already recorded in the Chasicoan fauna and the appearance of four taxa ca. 8 Ma that reach at least 7.3 Ma. These are “Orthomyctera”, Proeuphractus limpidus, Macrochorobates scalabrinii, and Tetrastylus laevigatus, possibly representing the first instances of the beginning of the “Huayquerian” fauna. We did not consider Cerro La Bota as part of the Chasicoan fauna but as representative of a transition between the Chasicoan fauna and the “Huayquerian” fauna, together with Cerro Patagua and Algarrobo del Águila (cf. Contreras et al., 2013). |
Lithology and environment
| Primary lithology: | massive,very fine,red lithified sandy siltstone |
| Secondary lithology: | current ripples,"cross stratification",medium lithified sandy conglomerate |
| Includes fossils? | Y |
| Lithology description: The Cerro Azul formation is composed of massive brown reddish sandy silts, with loessic erosion. A detailed description of the geology and stratigraphy of this formation can be seen in Linares et al. (1980) and Goin et al. (2000). Montalvo et al. 2019: The FA1 crops out in the lower part of the studied section and is 1.7 m thick (Fig. 2). It includes sheet-like strata with non-erosive bases, composed of massive and commonly very fine-grained siltstones (facies Fsm) with root traces (facies P).The FA2 is 2.2 m thick and overlays FA1 deposits with erosive contact (Fig. 2). It is constituted by a lateral and vertical erosive superposition of sandstone (facies St) and conglomeratic (facies Gt) bodies. | |
| Environment: | fluvial indet. |
| Geology comments: Montalvo et al. 2019: Sedimentological and stratigraphic descriptions of the Cerro Azul Formation at Cerro La Bota locality were originally performed by Goin et al. (2000). These authors interpreted that the levels cropping out in this site represent ephemeral fluvial deposits. We propose here a new interpretation (Fig. 2) by recognizing two facies associations: loess-palaeosol association (FA1) and fluvial deposits association (FA2).
The amalgamated conglomeradic–sandy bodies suggest the episodic development of perennial streams without flow division on a loessic substrate. Schmidt et al. 2018: Levels of Cerro Azul formation at Cerro La Bota represent an ephemeral fluvial event (Goin et al. 2000; Verzi et al. 2008). | |
Taphonomy
| Modes of preservation: | body |
| Size of fossils: | macrofossils,mesofossils |
| Preservation of anatomical detail: | good |
| Fragmentation: | frequent |
Collection methods and comments
| Collection methods: | survey of museum collection |
| Reason for describing collection: | biostratigraphic analysis |
| Collection method comments: Montalvo et al. 2019: specimens recovered belong to the Paleontological Collection of the Facultad de Ciencias Exactas y Naturales, Universidad Nacional de La Pampa (La Pampa Province, Argentina).
Esteban, et al. 2000: Todos los ejemplares analizados están depositados en la Cátedra de Geología Histórica de la Facultad de Ciencias Exactas y Naturales de la Universidad Nacional ele La Pampa, Argentina, cuyo acrónimo es GHUNLPam | |
Metadata
| Also known as: | Zone of Chasichimys bonaerense | ||
| Database number: | 152063 | ||
| Authorizer: | C. Jaramillo, P. Mannion, J. Carrillo | Enterer: | M. Vallejo, K. Pino, M. Kouvari, G. Varnham |
| Modifier: | K. Pino | Research group: | vertebrate |
| Created: | 2013-11-05 08:38:41 | Last modified: | 2025-02-22 15:12:02 |
| Access level: | group members | Released: | 2015-11-05 08:38:41 |
| Creative Commons license: | CC0 | ||
Reference information
Primary reference:
| 48750. | D. H. Verzi, C. I. Montalvo, and C. M. Deschamps. 2008. Biostratigraphy and biochronology of the Late Miocene of central Argentina: Evidence from rodents and taphonomy. Geobios 41:145-155 [C. Jaramillo/M. Vallejo] |
Secondary references:
| 73117 | E. Cerdeño and C. I. Montalvo. 2002. Los Hegetotheriinae (Hegetotheriidae, Notoungulata) del Mioceno superior de la provincia de La Pampa, Argentina. Revista del Museo Argentina de Ciencias Naturales 41(1):35-43 [P. Mannion/G. Varnham] | |
| 70059 | G. I. Esteban, N. L. Nasif, and C. I. Montalvo. 2000. Nuevos registros de Dasypodidae (Xenarthra) del Mioceno tardío de la provincia de La Pampa, Argentina. Revista Espanola de Paleontología 16(1):77-87 [P. Mannion/M. Kouvari] | |
| 85601 | C. I. Montalvo, R. Sostillo, and L. L. Rasia. 2023. New light on the late Middle Miocene–Early Pliocene representatives of Lagostomus (Chinchillidae, Rodentia) from Cerro Azul Formation, Argentina. Journal of South American Earth Sciences 128(104481) [J. Carrillo/K. Pino] | |
| 69136 | C. I. Montalvo, R. L. Tomassini, R. Sostillo, E. Cerdeño, D.H. Verzi, G. Visconti, A. Folguera and G.I. Schmidt. 2019. A chasicoan (late miocene) vertebrate assemblage from cerro azul formation, central Argentina. Geomorphological and biochronological considerations. Journal of South American Earth Sciences [P. Mannion/G. Varnham/G. Varnham] | |
| 81656 | C. I. Montalvo, R. L. Tomassini, E. Cerdeño and F. J. Fernández. 2023. A Late Miocene mammal assemblage reveals a complex taphonomic history in fluvial deposits of central Argentina. Historical Biology 35(5):645-660 [P. Mannion/G. Varnham/P. Mannion] | |
| 69166 | G. I. Schmidt, C. I. Montalvo, R. Sostillo and E. Cerdeño. 2018. Proterotheriidae (Mammalia, Litopterna) from the Cerro Azul Formation (late Miocene), La Pampa Province, Argentina. Journal of South American Earth Sciences 83:165-177 [P. Mannion/G. Varnham] | |
| 86911 | G. I. Schmidt, C. I. Montalvo, E. Cerdeño, R. Sostillo, R. L. Tomassini and R. A. Bonini. 2022. Updated data on Litopterna from the Huayquerian Stage/Age (Late Miocene-Early Pliocene) of central-east Argentina. Comptes Rendus Palevol 21(32):721-743 [P. Mannion/G. Varnham/P. Mannion] | |
| 84590 | R. Sostillo, C. I. Montalvo, E. Cerdeño, G. I. Schmidt, A. Folguera and M. C. Cardonatto. 2021. Updated knowledge on the Notoungulata (Mammalia) from the late Miocene Cerro Azul Formation, La Pampa Province, Argentina. Historical Biology An International Journal of Paleobiology 33(8):1247-1265 [J. Carrillo/K. Pino] | |
| 70799 | J. J. Urrutia, C. I. Montalvo, and G. J. Scillato-Yane. 2008. Dasypodidae (Xenarthra, Cingulata) de la Formación Cerro Azul (Mioceno tardío) de la provincia de La Pampa, Argentina. Ameghiniana 45(2):289-302 [P. Mannion/M. Kouvari] |