Quebrada Chalala, ~1 kilometer northwest of Purmamarca ( of Argentina)

Where: Jujuy, Argentina (23.8° S, 65.5° W: paleocoordinates 44.5° S, 128.8° W)

• coordinate estimated from map

• local area-level geographic resolution

When: Upper Member (Coquena Formation), Tremadoc (486.5 - 477.7 Ma)

• Upper Tremadoc

• group of beds-level stratigraphic resolution

Environment/lithology: shoreface; shelly/skeletal mudstone

• The upper member is mainly composed of bioturbated mudstones interbedded with some lenticular shell beds from which the bivalves Cienagomya bidentata n. gen. and sp., Lipanella purmamarcensis n. gen. and sp., Coxiconchia babini n. sp., and Ribeiria pojetai n. sp. were obtained (Table 1 ). Associated fossils are gastropods, nautiloids, brachiopods, and trilobites. The lower sandy succession has been interpreted as storm-dominated shoreface and inner platform deposits, whereas the fine-grained upper member was deposited in an open shelf, the coquinites probably representing distal storm deposits (Benedetto and Carrasco, 2002).

Size class: macrofossils

Primary reference: T. M. Sánchez. 2005. New Bivalvia and Rostroconchia from the Early Ordovician (Late Tremadoc - Middle Arenig) of northwestern Argentina. Journal of Paleontology 79(3):532-541 [P. Wagner/P. Wagner]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 57210: authorized by Pete Wagner, entered by Pete Wagner on 12.12.2005

Creative Commons license: CC BY (attribution)

Taxonomic list

Bivalvia
 Actinodontida - Intihuarellidae
Cienagomya bidentata Sánchez 2005 clam
 Cardioni - Coxiconchiidae
Coxiconchia babini n. sp. Sánchez 2005 clam
 Heteroconchia - Lipanellidae
Lipanella purmamarcensis n. gen. n. sp.
Lipanella purmamarcensis n. gen. n. sp. Sánchez 2005 clam
Rostroconchia
 Ribeirioida - Technophoridae
Ribeiria pojetai n. sp. Sánchez 2005