The El Molino Formation is a Maastrichtian geologic formation pertaining to the Puca Group of central Bolivia. The formation comprises fine-grained sandstones and sandy limestones with stromatolites deposited in a shallow marine to lacustrine environment. The formation has provided fossils of Dolichochampsa minima,[1] and ichnofossils of Ankylosauria indet., Ornithopoda indet., Theropoda indet. and Titanosauridae indet.[2][3][4] The tracksite of Cal Orcko is the best known example of the ichnofossil locations of the formation. The ichnofossil of Ligabueichnum bolivianum may be attributed to an ankylosaur.[5] The fossil fish species Dasyatis molinoensis is named after the formation.
| El Molino Formation | |
|---|---|
| Stratigraphic range: Maastrichtian ~ | |
| Type | Geological formation |
| Unit of | Puca Group |
| Underlies | Santa Lucía Formation |
| Overlies | Chaunaca Formation |
| Lithology | |
| Primary | Sandstone |
| Other | Limestone |
| Location | |
| Coordinates | 19°30′S 65°48′W / 19.5°S 65.8°W |
| Approximate paleocoordinates | 22°00′S 51°48′W / 22.0°S 51.8°W |
| Region | Cochabamba, Chuquisaca & Potosí Departments |
| Country |  Bolivia |
| Extent | Altiplano & Potosí Basins |
  El Molino Formation (Bolivia) | |
Fossil content
editOther fossils retrieved from the formation are:[6]
- Coelodus toncoensis
- Dagetella sudamericana
- Dasyatis branisai, D. molinoensis, D. schaefferi
- Gasteroclupea branisai
- Ischyrhiza hartenbergeri
- Latinopollia suarezi
- Lepidotyle enigmatica
- Ligabueichnum bolivianum[5]
- Noterpeton bolivianum
- Phaerodusichthys taverni
- Pucabatis hoffstetteri
- Pucapristis branisi
- Stephanodus minimus
- Lepidosiren cf. paradoxa
- Andinichthys sp.
- Ceratodus sp.
- Enchodus sp.
- Lepisosteus sp.
- Pucalithus sp.[7]
- Rhineastes sp.
- Santosius sp.
- Anura indet.
- Coelurosauria indet.
- Crocodylia indet.
- Dryolestidae indet.
- Eutheria indet.
- cf. Cyprinodontiformes indet.
- Gymnophiona indet.
- Heterotidinae indet.
- ?Madtsoiidae indet.
- Podocnemididae indet.
- Pycnodontidae indet.
- Sauropoda indet.
- Siluriformes indet.
- Tetragonopterinae indet.
See also
editReferences
edit- ^ Buffetaut, 1987
- ^ Lockley et al., 2002, p.389
- ^ La Palca village at Fossilworks.org
- ^ Cal Orcko tracksite at Fossilworks.org
- ^ a b Leonardi, 1994, p.39
- ^ Pajcha Pata[dead link] at Fossilworks.org
- ^ Leonardi, 1994, p.40
Bibliography
edit- Buffetaut, É (1987), "Occurrence of the crocodilian Dolichochampsa minima (Eusuchia, Dolichochampsidae) in the El Molino Formation of Bolivia", Bulletin de la Société Belge de Géologie, 96 (2): 195–199
- Leonardi, Giuseppe (1994), Annotated Atlas of South America Tetrapod Footprints (Devonian to Holocene) with an appendix on Mexico and Central America, Ministerio de Minas e Energia - Companhia de Pesquisa de Recursos Minerais, Geological Service of Brazil, pp. 1–248, retrieved 2019-03-25
- Lockley, M.G.; Schulp, A.S.; Meyer, C.A.; Leonardi, G.; Mamani, D.K. (2002), "Titanosaurid trackways from the Upper Cretaceous of Bolivia: evidence for large manus, wide-gauge locomotion and gregarious behaviour", Cretaceous Research, 23 (3): 383–400, Bibcode:2002CrRes..23..383L, doi:10.1006/cres.2002.1006, retrieved 2019-03-03