| Sella Formation | |
|---|---|
| Stratigraphic range: Dapingian-Darriwilian ~478–450 Ma PreꞒ Ꞓ O S D C P T J K Pg N | |
| Type | Geological formation |
| Lithology | |
| Primary | Siltstone, sandstone |
| Other | Shale, limestone, coquina |
| Location | |
| Coordinates | 21°24′S 64°36′W / 21.4°S 64.6°W / -21.4; -64.6 |
| Approximate paleocoordinates | 42°48′S 131°36′W / 42.8°S 131.6°W / -42.8; -131.6 |
| Region | Tarija Department |
| Country | Bolivia |
  Sella Formation (Bolivia) | |
The Sella Formation is a Dapingian to Darriwilian geologic formation of southern Bolivia. The grey to green bioturbated siltstones interbedded with thin sandstone layers bear lenticular shell beds. Other parts of the formation contain yellow-green limy shales and grey sandy limestones. Coquinas often fill gutter casts and included brachiopods, trilobites, bivalves and nautiloids. The sediments were deposited in an open marine environment. The species Coxiconchia sellaensis was named after the formation.
Fossil content
The formation has provided the following fossils:
- Baltograptus minutus
- Coxiconchia sellaensis
- Desmorthis segnis
- Glyptorthis imbrex
- Hemiprionodonta lusitanica
- Lingulocystis boliviensis
- Natasia boliviensis
- Pliomeridius sulcatus
- Redonia riojana
- Ribeiria spinosa
- Peelerophon cf. oehlerti
- Ampyx sp.
- Boeckaspis sp.
- Branisaspis sp.
- Bucania sp.
- Colpocoryphe sp.
- Cosmogoniophorina sp.
- Ctenodonta sp.
- Cyptendoceras sp.
- Didymograptus sp.
- Endoceras sp.
- Eothinoceras sp.
- Famatinolithus sp.
- Haploprimitia sp.
- Hoekaspis sp.
- Lecanospira sp.
- Lonchodomas sp.
- Maclurites sp.
- Quadrilobella sp.
- Parapyxion sp.
- Protocycloceras sp.
- Sibiritella sp.
- Suriaspis sp.
- Synhomalonotus sp.
- Technophorus sp.
- Trinucleus sp.
See also
References
- Sella C at Fossilworks.org
- Pantipampa, 3 kilometers east of Belle Vista at Fossilworks.org
- Sella, Bed 1 at Fossilworks.org
- Sella at Fossilworks.org
- Sella Bed 4 at Fossilworks.org
- Suárez Riglos et al., 2018, p.64
Bibliography
- Suárez Riglos, Mario; Dalenz Farjat, Alejandra; Pérez Leyton, Miguel Ángel (2018), Fósiles y Facies de Bolivia (PDF), Sincronía Diseño & Publicidad, Santa Cruz de la Sierra, pp. 1–146, ISBN 978-99974-79-68-6, retrieved 2019-03-03
Further reading
- C. Babin and L. Branisa. 1987. Ribeiria, Peelrophon y otros molluscos del Ordovícico de Bolivia. 4˚ Congreso Latinoamericano de Paleontología 1:119-129
- L. Branisa. 1965. Los fosiles guias de Bolivia: I. Paleozoico. Boletin de Servicio Geologico de Bolivia. La Paz, Bolivia 6:1-282
- V. Havlicek and L. Branisa. 1980. Ordovician brachiopods of Bolivia: Succession of assemblages, climate control, affinity to Anglo-French and Bohemian provinces. Rozpravy Ceskoslovenske Akademie Ved. Rada Matematickych a Prirodnich Ved. Academia Praha, Prague, Czechoslovakia 90(1):1-54
- T. M. Sánchez and C. Babin. 2005. Lower Ordovician bivalves from southern Bolivia: paleobiogeographic affinities. Ameghiniana 42(3):559-566
- R. Suárez Soruco. 1976. El sistema ordovícico en Bolivia. Revista Tecnica YPF Bolivia 5(2):111-123