PBDB Collection

Picos Gemelos (5th cycle) (Triassic of Argentina)

Where: La Rioja, Argentina (29.8° S, 67.6° W: paleocoordinates 46.4° S, 32.9° W)

• coordinate estimated from map

• 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

•The samples from the Los Rastros Formation were collected by OFG, A. Arcucci, C. Forster, C. May and R. Rogers during 1995 and by ACM, A. Arcucci and C. Marsicano in 1999,

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 123045: authorized by Matthew Clapham, entered by Jered Karr on 10.01.2012

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names

Insecta
Blattodea - Mancusoblattidae	? Hermosablatta sp., Hermosablatta crassatella ? Hermosablatta sp. Martins-Neto and Gallego 2005 cockroach PULR-I 275 Hermosablatta crassatella Martins-Neto and Gallego 2005 cockroach PULR-I 273
Blattodea - Argentinoblattidae	Condorblatta lutzae Condorblatta lutzae Martins-Neto and Gallego 2005 cockroach PULR-I 283(CTES-PZ 7298)
Dicondylia - Triassoblattidae	Triassoblatta argentina n. sp. Triassoblatta argentina n. sp. Martins-Neto and Gallego 2005 winged insect PULR-I 222, 290
Coleoptera - Schizocoleidae	Argentinosyne frenguellii, Argentinosyne losrastrosensis Argentinosyne frenguellii Martins-Neto and Gallego 2006 beetle PULR-I 225, 326a-c Argentinosyne losrastrosensis Martins-Neto and Gallego 2006 beetle PULR-I 343
Coleoptera - Ademosynidae	Ademosyne elongatus, Ademosyne arcucciae n. sp., Ademosyne hexacostata, Ademosyne punctuada n. sp. Ademosyne elongatus Martins-Neto and Gallego 2006 beetle PULR-I 304a-b Ademosyne arcucciae n. sp. Martins-Neto and Gallego 2006 beetle PULR-I 298, PULR-I 300a, b, c, d, CTES-PZ 7299 Ademosyne hexacostata Martins-Neto and Gallego 2006 beetle PULR-I 307 Ademosyne punctuada n. sp. Martins-Neto and Gallego 2006 beetle PULR-I 309, a; CTES-PZ 7298
Coleoptera -	Gemelina triangularis n. gen. n. sp., Cardiosyne obesa n. gen. n. sp. Gemelina triangularis n. gen. n. sp. Martins-Neto and Gallego 2006 beetle PULR-I 280a(CTES-PZ 7275a) Cardiosyne obesa n. gen. n. sp. Martins-Neto and Gallego 2006 beetle PULR-I 324(CTES-PZ 7300)