The Iscayachi Formation, in older literature also referred to as Guanacuno Formation, is an extensive Tremadocian geologic formation of western and southern Bolivia. The shales and sandstones were deposited in a shallow marine to pro-delta environment.Suárez Riglos et al., 2018, p.37Quebrada de Rota at Fossilworks.orgPalqui at Fossilworks.orgTres Cruces at Fossilworks.orgIscayachi Formation at Fossilworks.org The formation reaches a thickness of .

Fossil content The formation has provided the following fossils:

Akoldinoidia sinuosaSuárez Riglos et al., 2018, p.52 Altiplanelaspis palquiensisSuárez Riglos et al., 2018, p.43 Angelina hyeronimi, A. punctalineataSuárez Riglos et al., 2018, p.48 Asaphellus communis, A. riojanas Deltacare prosops Conophrys erquensisSuárez Riglos et al., 2018, p.53 Golasaphus palquiensis Jujuyaspis keideli Kainella andina, K. meridionalis Kvania lariensis Leptoplastides mariana Macrocystella bavarica Micragnostus hoeki Onychopyge branisaiSuárez Riglos et al., 2018, p.45 Parabolinella argentinensis, P. boliviana Pharostomina alvarezi, P. trapezoidalisSuárez Riglos et al., 2018, p.42 Rhabdinopora flabelliformis Rhadinopleura incaica Rossaspis rossi Saltaspis steinmanniSuárez Riglos et al., 2018, p.51 Shumardia erquensis Leptoplastides cf. granulosaSuárez Riglos et al., 2018, p.47 Altiplanelaspis sp. Araiopleura sp. Broeggeria sp. Ctenodonta sp. Dictyonema sp. Koldinioidia sp. Leiostegium sp. Nanorthis sp. Onychopyge sp. Palquiella sp. Parabolina sp. Saltaspis sp. Sphaerocare sp. Trilobitarum sp. Tropidodiscus sp.

See also List of fossiliferous stratigraphic units in Bolivia

References

Bibliography

Further reading J. L. Benedetto. 2007. New Upper Cambrian-Tremadoc rhynchonelliformean brachiopods from northwestern Argentina: evolutionary trends and early diversification of plectorthoideans in the Andean Gondwana. Journal of Paleontology 81(2):261-285 A. Pribyl and J. Vanek. 1980. Ordovician trilobites of Bolivia. Rozpravy Ceskoslovenske Akademie Ved. Rada Matematickych a Prirodnich Ved. Academia Praha, Prague, Czechoslovakia 90(2):1-90 R. Suárez Soruco. 1976. El sistema ordovícico en Bolivia. Revista Tecnica YPF Bolivia 5(2):111-123