Seccion de la Loma de Los Piojos. Layer 1 (Silurian of Argentina)

Where: San Juan, Argentina (30.3° S, 68.8° W: paleocoordinates 34.2° S, 135.1° W)

• coordinate based on nearby landmark

• local area-level geographic resolution

When: Atavograptus atavus graptolite zone, La Chilca Formation, Rhuddanian (443.4 - 440.8 Ma)

• Age based on fact that beds containing the brachiopods are interbedded with or above beds of Atovograptus atavus Biozone.

• group of beds-level stratigraphic resolution

Environment/lithology: marine; shelly/skeletal sandstone and shale

• Precordillera. Occurrences generally in dense shell accumulations; valves generally fragmented and disarticulated, indicating turbulence, possibly due to storms. In other instances the valves are articulated, less fragmented. Some cases of partial or total silicification.
• Lower part of shale and Sst...Upper part of fine-grained Sst [the part with fossils]...high-angle cross beds...hummocky cross beds...

Size class: macrofossils

Preservation: replaced with silica

Collection methods: Brachiopods studied and listed; other higher taxa simply mentioned; graptolites listed for two of the sections that contain them. See location details.

Primary reference: J. L. Benedetto. 1995. Braquiopodos del Silurica temprano malvinocafrico (Formacion La Chilca), Precordillera Argentina. GĂ©obios 28(4):425-457 [M. Foote/M. Foote/J. Alroy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 185893: authorized by Pete Wagner, entered by Pete Wagner on 23.05.2017

Creative Commons license: CC BY (attribution)

Taxonomic list

 Strophomenida - Leptostrophiidae
Aphanomena chilcaensis Benedetto 1995
 Strophomenida - Rafinesquinidae
Rafinesquina relicua n. sp. Benedetto 1995
 Athyridida - Rhynchospirinidae
 Orthida - Proschizophoriidae