Where: Aisén, Chile (46.9° S, 72.3° W: paleocoordinates 47.7° S, 66.6° W)

• coordinate estimated from map

• local area-level geographic resolution

When: Santacrucian mammal zone, Galera Formation, Burdigalian (20.4 - 16.0 Ma)

• "a thick stratigraphic sequence, locally exposed as a prominent butte... approximately 300 m. thick sequence"; unit is "an unnamed formation, possibly equivalent to the Río Zeballos Formation"; mammals are from "Nine major mammal-bearing horizons... though the sequence is fossiliferous throughout"; much material is from "the rich quarry sites at the base of the terrestrial section (level E-O)"

•McGrath et al 2020: The mammal-bearing beds have been variably Buenos Aires) and Lago Cochrane (¼ Lago Pueyrred?on; assigned to the R?ıo Zeballos (R. H. Niemeyer 1975), Santa Cruz (de la Cruz et al. 2004), Galera (J. Niemeyer et al. 1984), or Pampa Castillo (Scalabrino 2009) formations (see discussion in Flynn et al. [2002] and Folguera et al. [2018]). Pending formal naming, designation of a type section, and a published descrip- tion of the Pampa Castillo formation, we continue to refer these beds to the Galera Formation, consistent with previous work (Flynn et al. 2002). The sequence has been correlated stratigraphically and temporally to the Santa Cruz Formation in Argentina (J. Niemeyer et al. 1984; Flynn et al. 2002). Folguera et al. (2018) recently provided a U/Pb date of 18.7 ± 0.3 Ma for zir- cons from a reworked tuff about 10 m above the contact between the terrestrial fossil-bearing unit and the grada- tionally and conformably underlying marine Guadal Formation at Meseta Guadal. A U/Pb age of ?18Ma from a tuff within the fossil-bearing unit (Su?arez et al. 2015) is consistent with the known age range of the Santacrucian SALMA and Santa Cruz Formation depos- its and faunas (Flynn & Swisher 1995; Croft et al. 2004; Cuiti~no et al. 2016; and discussion below). No litopterns have been reported from the Galera Formation (Bostelmann & Buldrini 2012). The Pampa Castillo at Pampa Guadal, ?20km north-west of Pampa Castillo fauna is referred to the Santacrucian SALMA, although only the rodents (Dodson 1994; Chick et al. 2010) and palaeothentids (Flynn et al. 2002) have been described comprehensively. This study represents the first detailed assessment of the fauna’s SANUs.

•McGrath et al. 2022: Geochronological age estimates suggest that Pampa Castillo is also closer temporally to “Pinturan” faunas than either is to core Santacrucian faunas. Folguera et al. (2018) reported a U/Pb date of 18.7 +/-0.3 Ma from a reworked tuff directly below strata bearing the Pampa Castillo fauna. “Pinturan” faunas of the lmPF and Upper Fossil Zone at Gran Barranca are ~19.0–17.9 Ma (Perkins et al., 2012; Dunn et al., 2013), whereas core Santacrucian faunas are ~17.5–15.6 Ma (Cuitiño et al., 2016; Trayler et al., 2020).

• formation-level stratigraphic resolution

Environment/lithology: fluvial; sandstone and siltstone

Size class: macrofossils

Collection methods: surface (float),

Primary reference: J. J. Flynn, M. J. Novacek, H. E. Dodson, D. Frassinetti, M. C. McKenna, M. A. Norell, K. E. Sears, C. C. Swisher, III, and A. R. Wyss. 2002. A new fossil mammal assemblage from the southern Chilean Andes: implications for geology, geochronology, and tectonics. Journal of South American Earth Sciences 15(3):285-302 [J. Alroy/J. Alroy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 71843: authorized by John Alroy, entered by John Alroy on 14.05.2007, edited by Miranta Kouvari, Grace Varnham and Kateryn Pino

Creative Commons license: CC BY (attribution)