Rodeo Colorado, 92.5 m (Ordovician of Argentina)

Where: Salta, Argentina (22.7° S, 65.2° W: paleocoordinates 45.6° S, 128.5° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Kainella teiichii trilobite zone, Santa Rosita Formation, Tremadocian (485.4 - 477.7 Ma)

• Kainella teiichii zone spans uppemost Cordylodus angulatus and lowermost Paltodus deltifer conodont zones

• bed-level stratigraphic resolution

Environment/lithology: offshore; lithified, shelly/skeletal, gray, green, calcareous sandstone

• Facies 3 indicate sudden short-term change from low- to moderately high-energy conditions. These facies record sedimentation above storm wave base, on a platform affected by fair weather and storm waves. The presence of combined-flow ripple cross-lamination, symmetrical to near-symmetrical ripples, and flute and gutter casts in Facies 3 reflects deposition from combined and purely oscillatory flows.
• Dark gray to greenish gray, fine to very fine sandstone and calcareous sandstone beds containing bioclastic concentrations [Facies 3]. The sandstone beds are 3–15 cm thick and exhibit tabular or lenticular geometry, undulating and erosive bases, and undulating tops with symmetrical or nearsymmetrical ripples. Internally, the beds usually display either parallel-lamination or small-scale combined-flow ripple crosslamination. Scour marks (flute and gutter casts) are common at

•the bases of these layers. Additionally, small load casts are locally present. The top of some sandstone packages exhibit weak indications of bioturbation.

Size classes: macrofossils, mesofossils

Primary reference: M. F. Tortello and S. B. Esteban. 2016. Early Ordovician trilobites from the Iruya area (Cordillera Oriental, northwestern Argentina) and their stratigraphic significance. Journal of Paleontology 90(5):923-958 [M. Hopkins/M. Hopkins]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 208304: authorized by Melanie Hopkins, entered by Melanie Hopkins on 27.03.2020

Creative Commons license: CC BY (attribution)

Taxonomic list

Trilobita
 Asaphida - Asaphidae
Asaphellus clarksoni Tortello and Esteban 2016 trilobite
Asaphellus isabelae Meroi Arcerito et al. 2015 trilobite
 Asaphida - Remopleurididae
Kainella teiichii Vaccari and Waisfeld 2010 trilobite
Apatokephalus rugosus Tortello and Esteban 2016 trilobite
 Olenida - Olenidae
Leptoplastides marianus Hoek 1912 trilobite