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. The formation reaches a thickness of 1,000 metres (3,300 ft).

Fossil content

The formation has provided the following fossils:

  • Akoldinoidia sinuosa
  • Altiplanelaspis palquiensis
  • Angelina hyeronimi, A. punctalineata
  • Asaphellus communis, A. riojanas
  • Deltacare prosops
  • Conophrys erquensis
  • Golasaphus palquiensis
  • Jujuyaspis keideli
  • Kainella andina, K. meridionalis
  • Kvania lariensis
  • Leptoplastides mariana
  • Macrocystella bavarica
  • Micragnostus hoeki
  • Onychopyge branisai
  • Parabolinella argentinensis, P. boliviana
  • Pharostomina alvarezi, P. trapezoidalis
  • Rhabdinopora flabelliformis
  • Rhadinopleura incaica
  • Rossaspis rossi
  • Saltaspis steinmanni
  • Shumardia erquensis
  • Leptoplastides cf. granulosa
  • 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

Bibliography

  • Suárez Riglos, Mario; Dalenz Farjat, Alejandra; Pérez Leyton, Miguel Ángel (2018), (PDF), Sincronía Diseño & Publicidad, Santa Cruz de la Sierra, pp. 1–146, ISBN 978-99974-79-68-6, archived from (PDF) on 2019-03-08

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