The Huincul Formation is a

geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

(

Cenomanian The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretace ...

to Early Turonian) age of the

Neuquén Basin Neuquén Basin () is a sedimentary basin covering most of Neuquén Province in Argentina. The basin originated in the Jurassic and developed through alternating continental and marine conditions well into the Tertiary. The basin bounds to the wes ...

that

outcrop An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth and other terrestrial planets. Features Outcrops do not cover the majority of the Earth's land surface because in most p ...

s in the Mendoza, Río Negro and

Neuquén Province Neuquén () is a Provinces of Argentina, province of Argentina, located in the west of the country, at the northern end of Patagonia. It borders Mendoza Province to the north, Rio Negro Province to the southeast, and Chile to the west. It also me ...

s of northern

Patagonia Patagonia () is a geographical region that includes parts of Argentina and Chile at the southern end of South America. The region includes the southern section of the Andes mountain chain with lakes, fjords, temperate rainforests, and glaciers ...

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 ...

.Huincul Formation
at

Fossilworks Fossilworks was a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world. History Fossilworks was cr ...

.org It is the second formation in the

Río Limay Subgroup The Río Limay Subgroup is a geological unit of the Neuquén Group in the Neuquén Basin of Neuquén, Mendoza and Río Negro Provinces, northern Patagonia, Argentina. The strata date back to the Late Cretaceous ( Early Cenomanian to Early Turon ...

, the oldest subgroup within the

Neuquén Group The Neuquén Group is a geologic unit, group of geologic formations found in Argentina. Rocks in the Neuquén Group fall within the Cenomanian to early Campanian stages of the Late Cretaceous Period. It overlies the older Lohan Cura Formation and ...

. Formerly, that subgroup was treated as a formation, and the Huincul Formation was known as the Huincul Member.Sánchez ''et al.'', 2006

Description

The type locality of the Huincul Formation is near the town of

Plaza Huincul Plaza Huincul is a small city in Neuquen province, with a population of around 13,000 people, located in southwestern Argentina. It is approximately south-west from the capital, Buenos Aires. Plaza Huincul is located in the middle of the desert ...

in Neuquén Province after which the formation was named by Wichmann in 1929. This formation

conformably Lithostratigraphy is a sub-discipline of stratigraphy, the geological science associated with the study of strata or rock layers. Major focuses include geochronology, comparative geology, and petrology. In general, strata are primarily igneous ...

overlies the

Candeleros Formation The Candeleros Formation is a geologic formation that outcrop, crops out in the Rio Negro Province, Río Negro, Neuquen Province, Neuquén, and Mendoza Province, Mendoza provinces of northern Patagonia, Argentina. It is the oldest formation in the ...

, and it is in turn overlain by the

Lisandro Formation __NOTOC__ The Lisandro Formation, alternatively known as the Cerro Lisandro Formation, is a Late Cretaceous ( Late Cenomanian to Early Turonian) geologic formation with outcrops in the Neuquén, Río Negro and Mendoza Provinces of Argentina. It ...

. The Huincul Formation is thought to represent an arid environment with ephemeral or seasonal

stream A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a strea ...

s.Coria & Currie, 2006 In some areas, it is up to thick. It is mainly composed of green and yellow

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 and can easily be differentiated from the overlying Lisandro Formation, which is red in color. The Candeleros Formation, underlying the Huincul, is composed of darker sediments, making all three formations easily distinguishable.Leanza ''et al.'', 2004, p.68

Paleobiota

Dinosaur

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

s are frequently found in the Huincul Formation. The

titanosauria Titanosaurs (or titanosaurians; members of the group Titanosauria) were a diverse group of Sauropoda, sauropod dinosaurs, including genera from all seven continents. The titanosaurs were the last surviving group of long-necked sauropods, with tax ...

sauropod Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their b ...

Argentinosaurus huinculensis ''Argentinosaurus'' (meaning "lizard from Argentina") is a genus of giant sauropod dinosaur that lived during the Late Cretaceous period in what is now Argentina. Although it is only known from fragmentary remains, ''Argentinosaurus'' is one of ...

'', one of the largest known land animals, is named after the formation. Another noteworthy Huincul dinosaur is the

carcharodontosaurid Carcharodontosauridae (carcharodontosaurids; from the Greek καρχαροδοντόσαυρος, ''carcharodontósauros'': "shark-toothed lizards") is a group of carnivorous theropod dinosaurs. In 1931, Ernst Stromer named Carcharodontosauridae ...

theropod Theropoda (; from ancient Greek , (''therion'') "wild beast"; , (''pous, podos'') "foot"">wiktionary:ποδός"> (''pous, podos'') "foot" is one of the three major groups (clades) of dinosaurs, alongside Ornithischia and Sauropodom ...

'' Mapusaurus roseae'', which is regarded as one of the largest known terrestrial

predator Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...

Dinosaurs

Apart from sauropods and theropods, rare fossils of

iguanodonts Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (). They represent one of the most successful groups of herbivorous dinosaurs during the Cretaceous. The most primitive members of the group were bipedal and relatively sm ...

and other

ornithopods Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (). They represent one of the most successful groups of herbivore, herbivorous dinosaurs during the Cretaceous. The most primitive members of the group were bipedal and rel ...

have been recorded in the formation.Canudo, J. I., Salgado, L., Garrido, A., Carballido, J. L., Aragosaurus-IUCA, G., Lobo, I., Negro, R., & Olsacher, J. A. (2013). Primera evidencia de dinosaurios ornitópodos en la base de la Formación Huincul (Cenomaniense Superior-Turoniense, Cuenca Neuquina, Argentina) First evidence of ornithopod dinosaurs at the base of Huincul Formation (Cenomanian - Upper Turonian, Neuquén Basin, Argentina).

Ichnofossil A trace fossil, also called an ichnofossil (; ), is a fossil record of biological activity by lifeforms, but not the preserved remains of the organism itself. Trace fossils contrast with body fossils, which are the fossilized remains of part ...

s (footprints) of

abelisaurid Abelisauridae (meaning "Abel's lizards") is a family (or clade) of ceratosaurian theropod dinosaurs. Abelisaurids thrived during the Cretaceous period, on the ancient southern supercontinent of Gondwana, and today their fossil remains are foun ...

theropods and

hadrosaurs 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 fami ...

are also known.Leonardi, 1994, p.30

Ornithischians

Saurischians

= Sauropods

Rebbachisaurids

Titanosaurs

= Theropods

Abelisaurs

Carcharodontosaurids

Other theropods

Other reptiles

Apart from the taxa named here, fossils of unnamed

squamates Squamata (, Latin ''squamatus'', 'scaly, having scales') is the largest order of reptiles; most members of which are commonly known as lizards, with the group also including snakes. With over 11,991 species, it is also the second-largest order ...

and

neosuchia Neosuchia is a clade within Mesoeucrocodylia that includes all modern extant crocodilians and their closest fossil relatives. It is defined as the most inclusive clade containing all Crocodylomorpha, crocodylomorphs more closely related to ''Croc ...

crocodyliforms Crocodyliformes is a clade of crurotarsan archosaurs, the group often traditionally referred to as "crocodilians". They are the first members of Crocodylomorpha to possess many of the features that define later relatives. They are the only pseudo ...

have been discovered in the formation.

References

Bibliography

* * * * * * {{cite journal , last=Wichmann , first=R , year=1929 , title=Los Estratos con Dinosaurios y su techo en el este del Territorio del Neuquén ("The dinosaur-bearing strata and their upper limit in eastern Neuquén Territory") , journal=Dirección General de Geología, Minería e Hidrogeología Publicación , volume=32 , pages=1–9 Geologic formations of Argentina Cretaceous Argentina Sandstone formations Fluvial deposits Lacustrine deposits