The Angostura Colorada Formation is a
Campanian
The Campanian is the fifth of six ages of the Late Cretaceous epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campa ...
to
Maastrichtian
The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...
geologic
formation of the
Neuquén Basin and
North Patagonian Massif in the
Río Negro Province
Río Negro (, ''Black River'') is a province of Argentina, located in northern Patagonia. Neighboring provinces are from the south clockwise Chubut, Neuquén, Mendoza, La Pampa and Buenos Aires. To the east lies the Atlantic Ocean.
Its cap ...
of
Argentina
Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...
.
Dinosaur
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...
remains diagnostic to the
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
level are among the fossils that have been recovered from the formation.
[Weishampel, et al. (2004). "Dinosaur distribution." Pp. 517-607.]
Description
The Angostura Colorada Formation was defined by Volkhaimer in 1973 and unconformably overlies the
Late Triassic
The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch a ...
volcanics of the
Sañicó Formation. The formation is partly overlain by the
Huitrera and
Collón Cura Formations,
[Prez & Massaferro, 2013, p.223] and in other parts by the
Coli Toro Member
The Coli Toro Member is a Campanian geologic member (geology), member in Argentina. Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus.Weishampel, et al. (2 ...
of the
Los Alamitos Formation.
[Ottone, 2009, p.377] The formation, outcropping south of
Comallo, comprises
sandstone
Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...
s,
claystone
Mudrocks are a class of fine-grained siliciclastic sedimentary rocks. The varying types of mudrocks include siltstone, claystone, mudstone and shale. Most of the particles of which the stone is composed are less than and are too small to ...
s and
conglomerates deposited in a
fluvial
A river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it ru ...
environment.
[Prez & Massaferro, 2013, p.225]
Paleofauna
* ''
Aeolosaurus rionegrinus''
*
Hadrosauridae
Hadrosaurids (), also hadrosaurs or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod fam ...
indet.
*
Saltasaurinae indet.
*
Lithostrotia
Lithostrotia is a clade of derived titanosaur sauropods that lived during the Early Cretaceous and Late Cretaceous. The group was defined by Upchurch ''et al.'' in 2004 as the most recent common ancestor of ''Malawisaurus'' and ''Saltasaurus'' an ...
indet.
See also
*
List of dinosaur-bearing rock formations
This list of dinosaur-bearing rock formations is a list of geologic formations in which dinosaur fossils have been documented.
* List of stratigraphic units with dinosaur body fossils
* List of stratigraphic units with dinosaur trace fossils
** ...
**
List of stratigraphic units with few dinosaur genera
References
Bibliography
*
*
*
*
* {{Cite journal , last1=Zurriaguz, first1=Virginia, last2=Martinelli, first2=Agustín, last3=Rougier, first3=Guillermo W. , last4=Ezcurra, first4=Martín D., last5=Manabe, first5=Makoto, last6=Tsuihiji, first6=Takanobu, last7=Novas, first7=Fernando E., year=2017 , title=A saltasaurine titanosaur (Sauropoda: Titanosauriformes) from the Angostura Colorada Formation (upper Campanian, Cretaceous) of northwestern Patagonia, Argentina, url=https://www.sciencedirect.com/science/article/abs/pii/S0195667122003160, journal=Cretaceous Research, volume=75, pages=101–114, doi=10.1016/j.cretres.2017.03.016, bibcode=2017CrRes..75..101Z , accessdate=2023-01-29, hdl=11336/65494, hdl-access=free
Further reading
* J. E. Powell. 1987. The Late Cretaceous fauna of Los Alamitos, Patagonia, Argentina part VI—the titanosaurids. Revista del Museo Argentina de Ciencias Naturales "Bernardino Rivadavia" e Instituto Nacional de Investigacion de las Ciencias Naturales: Paleontología 3(3):147-153
Geologic formations of Argentina
Upper Cretaceous Series of South America
Cretaceous Argentina
Campanian Stage
Maastrichtian Stage of South America
Sandstone formations
Shale formations
Conglomerate formations
Fluvial deposits
Formations
Geology of Río Negro Province