The El Molino Formation is a

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval from ...

geologic

formation Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondar ...

pertaining to the Puca Group of central Bolivia. The formation comprises fine-grained

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

s and sandy

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

s with

stromatolite Stromatolites () or stromatoliths () are layered sedimentary formations (microbialite) that are created mainly by photosynthetic microorganisms such as cyanobacteria, sulfate-reducing bacteria, and Pseudomonadota (formerly proteobacteria). The ...

s deposited in a shallow marine to

lacustrine A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much larger ...

environment Environment most often refers to: __NOTOC__ * Natural environment, all living and non-living things occurring naturally * Biophysical environment, the physical and biological factors along with their chemical interactions that affect an organism or ...

. The formation has provided fossils of '' Dolichochampsa minima'',Buffetaut, 1987 and

ichnofossil A trace fossil, also known as an ichnofossil (; from el, ἴχνος ''ikhnos'' "trace, track"), is a fossil record of biological activity but not the preserved remains of the plant or animal itself. Trace fossils contrast with body fossils, ...

s of Ankylosauria indet., Ornithopoda indet., Theropoda indet. and Titanosauridae indet.Lockley et al., 2002, p.389 The tracksite of

Cal Orcko Cal Orck’o is a fossil bed in Bolivia. It is located in a quarry approximately 4.4 km northwest of Sucre (Chuquisaca Department, Bolivia) in the Cordillera Oriental (Bolivia), Altiplano/Cordillera Oriental, in the El Molino Formation (Maa ...

is the best known example of the ichnofossil locations of the formation. The ichnofossil of '' Ligabueichnum bolivianum'' may be attributed to an ankylosaur.Leonardi, 1994, p.39 The fossil fish species ''

Dasyatis molinoensis ''Dasyatis'' (Greek δασύς ''dasýs'' meaning rough or dense and βατίς ''batís'' meaning skate) is a genus of stingray in the family Dasyatidae that is native to the Atlantic, including the Mediterranean. In a 2016 taxonomic revisio ...

'' is named after the formation.

Fossil content

Other fossils retrieved from the formation are:Pajcha Pata
at

Fossilworks Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...

.org * '' Coelodus toncoensis'' * '' Dagetella sudamericana'' * ''

Dasyatis branisai ''Dasyatis'' (Greek δασύς ''dasýs'' meaning rough or dense and βατίς ''batís'' meaning skate) is a genus of stingray in the family Dasyatidae that is native to the Atlantic, including the Mediterranean. In a 2016 taxonomic revisio ...

'', '' D. molinoensis'', '' D. schaefferi'' * '' Gasteroclupea branisai'' * '' Ischyrhiza hartenbergeri'' * '' Latinopollia suarezi'' * '' Lepidotyle enigmatica'' * '' Ligabueichnum bolivianum'' * '' Noterpeton bolivianum'' * '' Phaerodusichthys taverni'' * '' Pucabatis hoffstetteri'' * '' Pucapristis branisi'' * '' Stephanodus minimus'' * '' Lepidosiren cf. paradoxa'' * '' Andinichthys sp.'' * '' Ceratodus sp.'' * '' Enchodus sp.'' * '' Lepisosteus sp.'' * '' Pucalithus sp.''Leonardi, 1994, p.40 * '' 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.

References

Bibliography

* * * {{cite LSA , last=Lockley , first=M.G. , last2=Schulp , first2=A.S. , last3=Meyer , first3=C.A. , last4=Leonardi , first4=G. , last5=Mamani , first5=D.K. , year=2002 , title=Titanosaurid trackways from the Upper Cretaceous of Bolivia: evidence for large manus, wide-gauge locomotion and gregarious behaviour , url=https://www.researchgate.net/publication/222695396_Titanosaurid_trackways_from_the_Upper_Cretaceous_of_Bolivia_Evidence_for_large_manus_wide-gauge_locomotion_and_gregarious_behaviour , journal=

Cretaceous Research ''Cretaceous Research'' is a bimonthly peer-reviewed scientific journal published by Elsevier. The journal focuses on topics dealing with the Cretaceous period and the Cretaceous–Paleogene boundary. Abstracting and indexing The journal is abst ...

, volume=23 , pages=383–400 , accessdate=2019-03-03 Geologic formations of Bolivia Upper Cretaceous Series of South America Cretaceous Bolivia Maastrichtian Stage of South America Sandstone formations Limestone formations Lacustrine deposits Shallow marine deposits Ichnofossiliferous formations Fossiliferous stratigraphic units of South America Paleontology in Bolivia Formations Formations Formations

Fossil content

See also

References

Bibliography