San Benito Formation, Bolivia

The San Benito Formation is a Katian geologic formation of central Bolivia. The formation belongs to the Cochabamba Group, overlies the Anzaldo Formation and is overlain by the Cancañiri Formation. The 500 m thick formation comprises a succession of shallow water quartzitic sandstones with minor interbeds of dark grey micaceous siltstones. Shelly fossils have been found at few horizons and consist mainly of linguliformean brachiopods, bivalves, and a few homalonotid trilobite remains. Poorly preserved graptolites occur occasionally in the shaly beds.

Fossil content
The formation has provided the following fossils:


 * Desmochitina minor
 * Rafinesquina pseudoloricata
 * Tunariorthis cardocanalis
 * Villosacapsula setosapellicula
 * Ancyrochitina cf. ancyrea
 * Hirnantia cf. transgrediens
 * Rhabdochitina cf. magna
 * Bistramia sp.
 * Ctenodonta sp.
 * Lingula sp.