Rio Gualo (2nd cycle) (Triassic of Argentina)

Where: La Rioja, Argentina (29.9° S, 67.8° W: paleocoordinates 46.5° S, 33.2° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Los Rastros Formation (Agua de la Peña Group), Carnian (237.0 - 228.0 Ma)

• Carnian age based on radiometric constraints from underlying Chañares Formation in Marsicano et al. (2015).

• group of beds-level stratigraphic resolution

Environment/lithology: lacustrine - large; lithified, black, carbonaceous claystone

• "The features observed in the facies assemblage A suggest that it was deposited in a deep off-shore lacustrine depositional environment. The claystones were deposited by suspension in distal-lake conditions…" Mancuso et al., 2007

•Ichigualasto–Villa Unión Basin, developed along the western Gondwana margin associated with extension focused along the northwest-trending Paleozoic sutures. This extension originated from the breakup of Pangaea during the end of Permian and start of the Triassic. Synrift phase II - accommodation space generated by tectonic subsidence.

• "This facies assemblage is dominated by dark gray to black carbonaceous claystones (Fl) interbedded with iron mudstones and very fine-grained sandstones (SFm) (figures 3, 4). The tabular beds form a laterally persistent succession with thickness that ranges from 2 to 5 m. The claystones are horizontally laminated, and formed by continuous microlamination with different grain sizes."

Size classes: macrofossils, mesofossils

• beetle specimens consist of 90% isolated elytra

Preservation: mold/impression

Collection methods: quarrying,

• Specimens kept in PULR-I – Invertebrate Paleontological Collection, Universidad Nacional de La Rioja, Argentina

Primary reference: R. G. Martins-Neto, O. F. Gallego, and A. C. Mancuso. 2006. The Triassic insect fauna from Argentina. Coleoptera from the Los Rastros Formation (Bermejo Basin), La Rioja Province. Ameghiniana 43(3):1-20 [M. Clapham/J. Karr]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 123047: authorized by Matthew Clapham, entered by Jered Karr on 10.01.2012, edited by Matthew Clapham

Creative Commons license: CC BY (attribution)

Taxonomic list

Insecta
 Coleoptera - Ademosynidae
Ademosyne arcucciae Martins-Neto and Gallego 2006 beetle
PULR-I 224a, b
Ademosyne punctuada Martins-Neto and Gallego 2006 beetle
PULRI 313a, c-e
 Coleoptera -
Argentinocupes pulcher n. gen. n. sp. Martins-Neto and Gallego 2006 beetle
PULR-I 299
Argentinocupes abdalai n. sp. Martins-Neto and Gallego 2006 beetle
PULR-I 310
 Coleoptera - Permosynidae
? Permosynidae indet. Tillyard 1924 beetle
CTES-PZ 7305b, PULR-I 332, 333
 Coleoptera -
Cardiosyne obesa Martins-Neto and Gallego 2006 beetle
PULR-I 325a
 Hemiptera - Corixidae
Corixidae indet.1 Leach 1815 water boatman
PULR-I 349
 Hemiptera - Scytinopteridae
"Gualoscytina mayae n. gen. n. sp." = Apheloscyta mayae2, "Argentinopheloscyta forsterae n. gen. n. sp." = Mesoscytina forsterae2
"Gualoscytina mayae n. gen. n. sp." = Apheloscyta mayae2 Martins-Neto and Gallego 2003 true bug
PULR-I 267
"Argentinopheloscyta forsterae n. gen. n. sp." = Mesoscytina forsterae2 Martins-Neto and Gallego 2003 true bug
PULR-I 268
 Hemiptera - Saaloscytinidae
Saaloscytina carmonae1 Martins-Neto et al. 2006 true bug
PULR-I 355
 Hemiptera - Mesojabloniidae
Fulgobole arcucciae1 Martins-Neto and Gallego 2001 true bug
PULR-I 353