Estancia Pampa Grande, East of Route 9, between Bordo and Toro Rivers (Eocene of Argentina)

Where: Salta, Argentina (25.8° S, 65.5° W: paleocoordinates 28.4° S, 54.8° W)

• coordinate based on political unit

• local area-level geographic resolution

When: Vacan mammal zone, Lumbrera Formation (Salta Group), Ypresian (56.0 - 47.8 Ma)

• 5 m below the "Lower Green Level" of the Lumbrera Formation (Salta Group, Santa Barbara Subgroup)

•Lower Lumbrera assemblage, Vacan SELMA

•Powell et al., 2011: Recently, geologic and paleontologic evidence allowed the correlation of the upper levels of Lumbrera with Geste, Casa Grande, and Quebrada de los Colorados Formations. Additionally, these levels were referred to the late-middle Eocene (Casamayoran SALMA -South American Land Mammal Age-, Barrancan subage) by an U/Pb dating of 39.9 Ma . The lower levels of the Lumbrera Formation are here referred to the Vacan subage of the Casamayoran SALMA.

•Fernicola et al. 2021 obtained an 238U-206Pb isochron age of 46.2 +/- 7.3 Ma for samples from the Lower Lumberer Fm, suggesting that the Lower section of the formation was deposited between 55–46Ma. "According to different authors, the fossiliferous levels of the lower section of the Lumbrera Fm. are equivalent to the Vacan Subage (del Papa et al. 2010; Powell et al. 2011; García-López et al. 2019). However, this biochronology is not supported by the absolute dating provided in this work. The top of the LSLF is now established by radioisotopy at 46. 2 ± 7.3 Ma (early Lutetian), and the record of the EECO and ETM2 in the first 150 m of the LSLF set the initial deposition of the sec- tion in the early Eocene (early Ypresian). With these new constraints, the species based on specimens recovered on the lower levels of the LSLF (this work) are chronologi- cally equivalent to the Itaboraian SALMA (56.1–51.4 Ma; Woodburne et al. 2014; Krause et al. 2017)."

Environment/lithology: terrestrial; ferruginous, peloidal, red, sandy mudstone and marl

• Pelite and marl, predominantly brick red in color with a bit of sandstone.

Size class: macrofossils

Reposited in the MLP

Primary reference: R. Pascual. 1980. Nuevos y singulares tipos ecologicos de marsupiales extinguidos de America del Sur (Paleoceno Tardio o Eoceno Temprano) del Noroeste Argentina . Actas del Segundo congreso argentino de paleontologia y bioestratigrafia y Primer congreso latinoamericano de paleontologia 2:151-173 [J. Alroy/J. Wertheim/M. Uhen]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 20983: authorized by John Alroy, entered by Jill Wertheim on 13.06.2002, edited by John Alroy, Jelle Zijlstra and Philip Mannion

Creative Commons license: CC BY (attribution)

Taxonomic list

 Squamata -
Amaru scagliai n. gen. n. sp.1
Amaru scagliai n. gen. n. sp.1 Albino 2018 snake
MMP 4660-M - holotype
 Squamata - Teiidae
Lumbrerasaurus scagliai n. gen. n. sp.3
Lumbrerasaurus scagliai n. gen. n. sp.3 Donadio 1985 squamates
MMP 1418, various bones, holotype
 Loricata - Sebecidae
? Sebecus sp.2 Stirton 1953 crocodilian
M.L.P. 79-XI-22-17 (tooth)
 Polydolopimorphia -
Prepidolops didelphoides n. gen. n. sp.
Prepidolops didelphoides n. gen. n. sp. metatherian