PBDB Collection

Laguna Chillhué (Neogene of Argentina)

Also known as Zone of Chasichimys scagliai

Where: La Pampa, Argentina (37.3° S, 64.2° W: paleocoordinates 37.5° S, 61.9° W)

• coordinate stated in text

• local area-level geographic resolution

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

• Age: Late Chasicoan or Early Huayquerian? (Late Miocene)

•The stratotype is recognized in the lower levels of the Cerro Azul Formation in this locality.

•

•Verzi et al. 1994 & Schmidt et al., 2018: Huayquerian

•

•Romano et al. 2023: Biochronological methods were useful in ordering and estimating the age of the different faunas of the Cerro Azul Formation, ranging from ca. 8 to ca. 5.7 Ma. Some appear to be transitional between Chasicoan and “Huayquerian” faunas (Cerro La Bota, Cerro Patagua, and Algarrobo del Águila), and other three (Barrancas Coloradas, El Guanaco, and Caleufú) cover the latest Miocene, even some of them could have reached the earliest Pliocene. The Cerro Azul Formation localities cover the range between ca. 8 to ca. 5.7 Ma (late Tortonian–Messinian; Late Miocene; Fig. 3; Supplementary Online Information 1, Tab. S8). 7.190 Ma (7.016 - 7.657 Ma) for Laguna Chilhué.

• formation-level stratigraphic resolution

Environment/lithology: fluvial-lacustrine; massive, red, sandy siltstone

• 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).

Size classes: macrofossils, mesofossils

Primary reference: 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]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 152065: authorized by Carlos Jaramillo, entered by Maria Vallejo on 05.11.2013, edited by Miranta Kouvari and Kateryn Pino

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names

Mammalia
Didelphimorphia - Didelphidae	Thylamys pinei Thylamys pinei Goin et al. 2000 fat-tailed mouse opossum
Cingulata - Dasypodidae	Proeuphractus sp.³, Proeuphractus limpidus³, Chorobates villosissimus³, Chasicotatus ameghinoi³, Doellotatus inornatus³, Macrochorobates scalabrinii³ Proeuphractus sp.³ Ameghino 1886 armadillo Proeuphractus limpidus³ Ameghino 1886 armadillo Chorobates villosissimus³ Reig 1958 armadillo Chasicotatus ameghinoi³ Scillato-Yané 1977 armadillo Doellotatus inornatus³ Rovereto 1914 armadillo Macrochorobates scalabrinii³ Moreno and Mercerat 1891 armadillo
Rodentia - Chinchillidae	Lagostomus pretrichodactyla¹, Lagostomus telenkechanum¹ Lagostomus pretrichodactyla¹ Rovereto 1914 viscacha GHUNLPam 2171 right mandible with p4-m1, GHUNLPam 5634 left mandible with p4-m3, GHUNLPam 5664 left mandible with i and p4-m3, GHUNLPam 5566 left M3, GHUNLPam 8400 right mandible with i and p4-m3, GHUNLPam 8401 right maxilla with M1-3, GHUNLPam Lagostomus telenkechanum¹ Rasia and Candela 2017 viscacha GHUNLPam 5454 left mandible with i and p4-m2, GHUNLPam 5635 right mandible with p4-m1, GHUNLPam 8418 left mandible with i and p4, GHUNLPam 8559 right mandible with broken m1-3, GHUNLPam 18799 left mandible with p4-m1 and broken m2-m3, GHUNLPam 21734 right mandible with p4-m1.
Rodentia - Dinomyidae	Tetrastylus laevigatus² Tetrastylus laevigatus² Ameghino 1886 caviomorph GHUNLPam 147
Rodentia - Echimyidae	Reigechimys plesiodon n. sp.⁴, Eumysops sp., Pampamys emmonsae Reigechimys plesiodon n. sp.⁴ Verzi et al. 1994 spiny rat Holotype: GHUNLPam 306 Eumysops sp. Ameghino spiny rat Pampamys emmonsae Verzi et al. 1995 spiny rat

¹Montalvo et al. 2023; ²Sostillo et al. 2022; ³Urrutia et al. 2008; ⁴Verzi et al. 1994