La Ciénega Formation, Bolivia

La Ciénega Formation is a Sandbian to Katian geologic formation of south-central Bolivia. The formation comprises silty, clayey, micaceous, fine-grained sandstones with thin intercalations of grey-green to light grey shales.

Fossil content
The formation has provided the following fossils:
 * Dinorthis sp.
 * Lingula sp.
 * Lingulepis sp.
 * Orbiculoidea sp.
 * Orthoceras sp.