The Lagarcito Formation is an
Albian
The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous Epoch/ Series. Its approximate time range is 113.0 ± 1.0 Ma to 100.5 ± ...
geologic
formation
Formation may refer to:
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Mathematics and science
* Cave formation or speleothem, a secondary ...
in
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, t ...
.
Pterosaur
Pterosaurs (; from Greek ''pteron'' and ''sauros'', meaning "wing lizard") is an extinct clade of flying reptiles in the Order (biology), order, Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cre ...
fossils have been recovered from the formation. The formation overlies the
La Cruz Formation and is overlain by the
San Roque Formation. The
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
mudstones of the formation were deposited in a
fluvial
In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluv ...
and mostly
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:
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* Natural environment, all living and non-living things occurring naturally
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.
[Gardini et al., 2009, p.554] The fossil association and the geological evidence indicate that the Lagarcito Formation represents a perennial shallow lake situated in an
alluvial plain
An alluvial plain is a largely flat landform created by the deposition of sediment over a long period of time by one or more rivers coming from highland regions, from which alluvial soil forms. A floodplain is part of the process, being the s ...
where detrital sedimentation and semiarid climatic conditions predominated.
Fossil content
The following fossils have been found in the Lagarcito Formation:
Loma del Pterodaustro
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.org
* '' Neosemionotus puntanus''
* '' Lepidotes pusillus''
* ''Pterodaustro guinazui
''Pterodaustro'' is a genus of ctenochasmatid pterodactyloid pterosaur from South America. Its fossil remains dated back to the Early Cretaceous period, about 105 million years ago. The most distinctive characteristic that separates ''Pter ...
''
* '' Treptichnus pollardi''
* '' Cyzicus aff. codoensis''
* '' Darwinula sp.''
* '' Copytus sp.''
* '' Bisulcocypris sp.''
* '' Candonopsis sp.''
* Anura indet.
* Magnoliophyta indet.
* Pleuropholidae indet.
* Trichoptera indet.
See also
* List of pterosaur-bearing stratigraphic units
This is a list of stratigraphic units, where pterosaur fossils have been recovered from. Units listed are all either formation rank or higher (e.g. group).
See also
* Pterosaur
* List of fossil sites
References
Further reading
*
Ext ...
References
Bibliography
* {{cite LSA , last=Gardini , first=Carlos , last2=Rivarola , first2=David , last3=Agüera , first3=Maximiliano , last4=Candela , first4=Gerónimo , year=2009 , title=Estructura de la región Sierra de Guayaguas-Marayes, Provincias de San Juan y San Luis , url=http://www.scielo.org.ar/pdf/raga/v65n3/v65n3a12.pdf , journal=Revista de la Asociación Geológica Argentina
The ''Revista de la Asociación Geológica Argentina'' is an open access peer-reviewed scientific journal
In academic publishing, a scientific journal is a periodical publication intended to further the progress of science, usually by repor ...
, volume=65 , pages=551–565 , accessdate=2018-09-08
Further reading
* A. López-Arbarello and L. Codorniú. 2007. Semionotids (Neopterygii, Semionotiformes) from the Lower Cretaceous Lagarcito Formation, San Luis Province, Argentina. Journal of Vertebrate Paleontology 27(4):811-826
Geologic formations of Argentina
Cretaceous Argentina
Albian Stage
Sandstone formations
Mudstone formations
Fluvial deposits
Lacustrine deposits
Ichnofossiliferous formations
Fossiliferous stratigraphic units of South America
Paleontology in Argentina
Geology of San Luis Province