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 younger 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 ''creta'', the ...

( Early Cenomanian to Late Turonian) age of the

Neuquén Basin Neuquén Basin ( es, Cuenca Neuquina) 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 bas ...

that

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

s in the Mendoza, Río Negro and

Neuquén Province Neuquén () is a 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 meets La Pampa Province a ...

s of northern

Patagonia Patagonia () refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and gl ...

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, th ...

.Huincul Formation
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 It is the second formation in the Río Limay Subgroup, the oldest subgroup within the

Neuquén Group The Neuquén Group is a 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 is itself over ...

. 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 igne ...

overlies the Candeleros Formation, and it is in turn overlain by the Lisandro Formation. 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 stream ...

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 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 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

Fossil content

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 preserved ...

bones are rarely found in the Huincul Formation. However, remains of ''

Argentinosaurus huinculensis ''Argentinosaurus'' 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 the largest known land animals o ...

'', one of the largest land animals known, were found in the Huincul Formation, and this species is named after it. One of the largest

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

s known, ''

Mapusaurus ''Mapusaurus'' () was a giant carcharodontosaurid carnosaurian dinosaur from the early Late Cretaceous (early Turonian stage), approximately 93.9 to 89.6 million years ago, of what is now Argentina. Discovery ''Mapusaurus'' was excavated b ...

'', has also been recovered from a bonebed in this formation. Fossils found in the Huincul Formation include those of dinosaurs: * several

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

sauropods 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 ...

(including ''

Argentinosaurus ''Argentinosaurus'' 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 the largest known land animals o ...

'' and ''

Choconsaurus ''Choconsaurus'' is an extinct genus of herbivorous sauropod dinosaur belonging to the group Titanosauriformes, which lived in the area of present-day Argentina at the end of the Cretaceous. Discovery and naming The holotype (specimen MMCh-P ...

'') * rebbachisaurid sauropods (including '' Cathartesaura'' and '' Limaysaurus'') *

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

theropods Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally ca ...

(including ''

''Canale ''et al.,'' 2012'',

Meraxes ''Meraxes'' is a genus of carcharodontosaurid theropod dinosaur from the Late Cretaceous Huincul Formation of Argentine Patagonia. The genus contains a single species, ''Meraxes gigas''. Discovery and naming The holotype of ''Meraxes'', prev ...

'' and ''

Taurovenator ''Taurovenator'' is a medium-sized carcharodontosaurid theropod from the late Cretaceous of Argentina. Discovered by Matias Motta in 2005 and formally described in 2016, it is represented by an isolated right postorbital. Etymology The ''tauro ...

'') * a possible

neovenatorid Neovenatoridae is a proposed clade of carcharodontosaurian dinosaurs uniting some primitive members of the group such as ''Neovenator'' with the Megaraptora, a group of theropods with controversial affinities. Other studies recover megaraptorans ...

theropod (''

Gualicho ''Gualicho'' (named in reference to the gualichu) is a genus of theropod dinosaur. The type species is ''Gualicho shinyae''. It lived in what is now northern Patagonia, on what was then a South American island continent split off from the superco ...

'') * a

megaraptora Megaraptora is a clade of carnivorous Tetanurae, tetanuran theropod dinosaurs with controversial relations to other theropods. Its Derived (phylogenetics), derived members, the Megaraptoridae are noted for their elongated hand claws and proporti ...

n theropod (''

Aoniraptor ''Aoniraptor'' is a megaraptoran theropod from the Late Cretaceous of Argentina (Huincul Formation). Discovery and naming The holotype, MPCA-Pv 804/1 to 804/25, which consists of the last sacral vertebra, six proximal caudal vertebrae, four mid ...

'') * several

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 (including ''

Skorpiovenator ''Skorpiovenator'' ("scorpion hunter") is a genus of abelisaurid theropod dinosaur from the Late Cretaceous (Cenomanian to Turonian) Huincul Formation of Argentina. It is one of the most complete and informative abelisaurids yet known, describe ...

'', ''

Tralkasaurus ''Tralkasaurus'' (meaning "thunder lizard") is a genus of abelisaurid dinosaur from the Huincul Formation from Río Negro Province in Argentina. The type and only species is ''Tralkasaurus cuyi'', named in 2020 by Mauricio Cerroni and colleagues ...

'' and '' Ilokelesia'') * an elaphrosaurine theropod ('' Huinculsaurus'') * a

paravian Paraves are a widespread group of theropod dinosaurs that originated in the Middle Jurassic period. In addition to the extinct dromaeosaurids, troodontids, anchiornithids, and possibly the scansoriopterygids, the group also contains the aviala ...

theropod (''

Overoraptor ''Overoraptor'' (meaning "piebald thief") is a genus of paravian theropod dinosaurs, which was closely related to ''Rahonavis'', from the Late Cretaceous (Cenomanian) Huincul Formation of Gondwana, present-day Argentina. It includes one species ...

'') * several

iguanodonts Iguanodontia (the iguanodonts) is a clade of herbivorous dinosaurs that lived from the Middle Jurassic to Late Cretaceous. Some members include '' Camptosaurus'', ''Dryosaurus'', ''Iguanodon'', '' Tenontosaurus'', and the hadrosaurids or "duck-bi ...

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

s and

hadrosaur Hadrosaurids (), 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 family, which includ ...

idsLeonardi, 1994, p.30

References

Bibliography

* * * * * * {{cite LSA , 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

Description

Fossil content

See also

References

Bibliography