Huincul Formation
Geological formation in Argentina
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The Huincul Formation is a geologic formation of Late Cretaceous (Cenomanian to Early Turonian) age of the Neuquén Basin that outcrops in the Mendoza, Río Negro and Neuquén Provinces of northern Patagonia, Argentina.[1] It is the second formation in the Río Limay Subgroup, the oldest subgroup within the Neuquén Group. Formerly, that subgroup was treated as a formation, and the Huincul Formation was known as the Huincul Member.[2]
| Huincul Formation | |
|---|---|
| Stratigraphic range: Late Cenomanian-Early Turonian ~ | |
| Type | Geological formation |
| Unit of | Neuquén Group Río Limay Subgroup |
| Underlies | Lisandro Formation |
| Overlies | Candeleros Formation |
| Thickness | 250 m (820 ft) |
| Lithology | |
| Primary | Sandstone |
| Other | Claystone |
| Location | |
| Coordinates | 39.4°S 69.0°W |
| Approximate paleocoordinates | 46.1°S 46.0°W |
| Region | Mendoza, Río Negro & Neuquén Provinces |
| Country | Argentina |
| Extent | Neuquén Basin |
| Type section | |
| Named for | Plaza Huincul |
| Named by | Keidel |
| Year defined | 1929 |
  Huincul Formation (Argentina) | |
Description
The type locality of the Huincul Formation is near the town of Plaza Huincul in Neuquén Province after which the formation was named by Wichmann in 1929.[3] This formation conformably 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 streams.[4] In some areas, it is up to 250 metres (820 ft) thick. It is mainly composed of green and yellow sandstones 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.[2][5]
Paleobiota
Dinosaur fossils are frequently found in the Huincul Formation. The titanosaurian sauropod Argentinosaurus huinculensis, one of the largest known land animals, is named after the formation.[2] Another noteworthy Huincul dinosaur is the carcharodontosaurid theropod Mapusaurus roseae, which is regarded as one of the largest known terrestrial predators.[4]
Dinosaurs
Apart from sauropods and theropods, rare fossils of iguanodonts and other ornithopods have been recorded in the formation.[6] Ichnofossils (footprints) of abelisaurid theropods and hadrosaurs are also known.[7]
Ornithischians
Color key
|
Notes Uncertain or tentative taxa are in small text; |
| Ornithischians of the Huincul Formation | ||||||
|---|---|---|---|---|---|---|
| Taxa | Species | Locality | Stratigraphic unit | Material | Notes | Images |
| Chakisaurus[8] | C. nekul | Pueblo Blanco Natural Reserve | Lower[9][10] | Multiple partial skeletons belonging to individuals of different ages | An elasmarian ornithopod; the first ornithischian named from the Huincul Formation |  |
Sauropods
Color key
|
Notes Uncertain or tentative taxa are in small text; |
| Sauropods of the Huincul Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Locality | Stratigraphic unit | Material | Notes | Images |
| Argentinosaurus | A. huinculensis | Las Overas | Upper | Seven dorsal vertebrae, partial sacrum, partial dorsal rib, fibula, and potentially other hindlimb bones | One of the largest titanosaurs sauropod known from relatively complete remains |  |
| Astigmasaura[11] | A. genuflexa | El Orejano | Lower | A partial articulated skeleton including tail vertebrae, the pelvic girdle, and both hindlimbs | A rebbachisaurid sauropod |  |
| Bustingorrytitan | B. shiva | Villa El Chocón | Lower | Four specimens are known, including dentary and postcranial skeleton parts. | A titanosaurian sauropod |  |
| Cathartesaura | C. anaerobica[12] | La Buitrera | Lower | A partial skeleton consisting of vertebrae and limb bones. | A rebbachisaurid sauropod |
|
| Choconsaurus | C. baileywillisi[13] | Villa El Chocón | Lower | Partial skeleton without a skull, MMCh-PV 44/10. | A titanosaurian sauropod |  |
| Chucarosaurus | C. diripienda | Violante farm. | Lower[9][10] | A complete left humerus, partial left radius, complete left metacarpal II, left ischium, partial left femur and fibula, partial right tibia, and partial indeterminate metapodial.[14] | A titanosaurian sauropod |  |
| Cienciargentina | C. sanchezi[15] | Villa El Chocon | Lower | Multiple partial skeletons, including several vertebrae and limb bones | A rebbachisaurid sauropod |  |
| Limaysaurus | L. tessonei | Villa El Chocón | Lower | A partial articulated skeleton composed of two sacra, the first six caudals, pubis and ischium. | A rebbachisaurid sauropod |  |
| Sidersaura | S. marae | Barda Atravesada de Las Campanas | Lower | Multiple partial skeletons, including partial pelvic and pectoral girdles, limb bones, and vertebrae | A rebbachisaurid sauropod |  |
Theropods
| Theropods of the Huincul Formation | ||||||
|---|---|---|---|---|---|---|
| Taxa | Species | Locality | Stratigraphic unit | Material | Notes | Images |
| Aoniraptor | A. liberataem | Violante Farm | Lower[9][10] | Sacral vertebra, six proximal caudal vertebrae, four mid-caudal vertebrae.[16] | Possibly a megaraptoran |  |
| Gualicho | G. shinyae | Violante Farm | Lower[9][10] | A partial skeleton lacking the skull along with several veterbraes, ribs, the left shoulder girdle, the left forelimb, the right lower arm, the lower ends of both pubic bones, thighbones, shinbones, calf bones, metatarsi and three toes of the right foot (Holotype MPCN PV 0001). | A theropod of uncertain affinities |  |
| Huinculsaurus | H. montesi | Aguada Grande | Upper | Several vertebrae[17] | A noasaurid |  |
| Ilokelesia | I. aguadagrandensis | Aguada Grande | Upper | Fragmented skull and the axial, appendicular skeleton. | An abelisaurid |  |
| Mapusaurus[18] | M. roseae | Cañadón del Gato | Upper (middle section of formation)[19] | A partial skull consisting of an isolated right nasal, along with twelve paratypes based on additional isolated skeletal elements | A carcharodontosaurid |  |
| Meraxes | M. gigas[19] | Las Campanas Creek | Lower | A nearly complete skull, pectoral and pelvic elements, partial forelimbs, complete hindlimbs, fragmentary ribs, and cervical and dorsal vertebrae, a sacrum, and several complete caudal vertebrae. | A carcharodontosaurid |  |
| Overoraptor | O. chimentoi[20] | Violante Farm | Lower[9][10] | Skeletal specimen consists of two phalanges and a metacarpal of the right hand, two hemal arches, the right scapula, the right ulna, a partial ilium, a partial pubis, two metatarsals from each foot, and several phalanges and unguals from the left foot. | A paravian |  |
| Skorpiovenator | S. bustingorryi | Bustingorry's Farm | Lower | A partial skeleton | An abelisaurid |  |
| Taurovenator[16] | T. violantei[16] | Violante Farm | Lower[9][10] | An isolated right postorbital and a referred partial skeleton. | A carcharodontosaurid |  |
| Tralkasaurus | T. cuyi | Violante Farm | Lower [9][10] | An incomplete skeleton ( MPCA-Pv 815), which comprises a maxilla; dorsal, sacral, and caudal vertebrae; cervical ribs; and a badly-preserved pubis. | An abelisaurid | |
Other reptiles
Apart from the taxa named here, fossils of unnamed squamates and neosuchian crocodyliforms have been discovered in the formation.[21]
| Non-dinosaur reptiles of the Huincul Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Locality | Stratigraphic unit | Material | Notes | Images |
| Kaikaifilusaurus | K. sp. | Violante's Farm | Lower | Incomplete right dentary[9] | An eilenodontine rhynchocephalian | |
| Patagosphenos[9] | P. watuku | Violante's Farm | Lower | Disarticulated skull with shoulder and limb fragments | An eilenodontine rhynchocephalian | |
| Prochelidella [22] | P. buitreraensis | La Buitrera | Upper | A partial skeleton with a skull, two cervical vertebrae, a partial left humerus, a partial left ulna, a partial left radius, a right pelvic girdle, a nuchal, and a right first costal. | A chelid turtle | |
Paleoflora
At least forty species of pollen specimens are derived from the taxons of angiosperms (monosulcate, tricolpate, tricolporoidate, and tricolporate), ferns, mosses and gymnosperms discovered within the El Zampa Section of Huincul Formation.[23]
Angiosperms
| Angiosperms of the Huincul Formation | ||||||
|---|---|---|---|---|---|---|
| Taxa | Species | Locality | Stratigraphic unit | Material | Notes | Images |
| Clavatipollenites | C. rotundus | El Zampal Section | Upper | A pollen | A chloranthaceae | |
| Cretacaeiporites | C. scabratus | Upper | A pollen | A trimeniaceae | ||
| Dryadopollis | D. argus | Upper | A pollen | A magnoliophyte | ||
| Fraxinoipollenites | F. fragilis | Upper | A pollen | A magnoliophyte | ||
| Nyssapollenites | N. lanosus | Upper | A pollen | A magnoliophyte | ||
| Retimonocolpites | R. peroreticulatus | Upper | A pollen | An angiosperm pollen morphotaxon of uncertain affinities | ||
Bryophytes (Moss)
| Mosses of the Huincul Formation | ||||||
|---|---|---|---|---|---|---|
| Taxa | Species | Locality | Stratigraphic unit | Material | Notes | Images |
| Foraminisporis | F. asymmetricus | El Zampa Section | Upper | A pollen | A moss | |
| F. wonthaggie | ||||||
| Interulobites | I. intrabverrucatus | Upper | A pollen | A moss | ||
| Tricolpites | T. variabilis | Upper | A pollen | A bryopside moss | ||
| T. sagax | Upper | A pollen | ||||
| Taurocusporites | T. segmenta | Upper | A pollen | A moss | ||
Gymnosperms
| Gymnosperms of the Huincul Formation | ||||||
|---|---|---|---|---|---|---|
| Taxa | Species | Locality | Stratigraphic unit | Material | Notes | Images |
| Araucariacites | A. australis | El Zampa Section | Upper | A pollen | An araucariaceae | |
| Callialasporites | C. dampieri | Upper | A pollen | A callialasporites | ||
| C. trilobatus | ||||||
| Classopollis | C. martinotti | Upper | A pollen | A cheirolepidiaceae | ||
| Cyclusphaera | C. psilata | Upper | A pollen | An araucariaceae | ||
| Cycadopites | C. nitidus | Upper | A pollen | A cycadophyte | ||
| Equisetosporites | E. evidens | Upper | A pollen | A cycadophyte | ||
| E. irregularis | A pollen | |||||
| E. ovatus | A pollen | |||||
| Microcachryidites | M. antarcticus | Upper | A pollen | A podocarpaceae | ||
| Singhia | S. multicostata | Upper | A pollen | A gymnospermopsida | ||
Ferns
| Ferns of the Huincul Formation | ||||||
|---|---|---|---|---|---|---|
| Taxa | Species | Locality | Stratigraphic unit | Material | Notes | Images |
| Biretisporites | B. poton | El Zampa Section | Upper | A pollen | A schizaeaceae | |
| Cicatricosisporites | C. dorogensis | Upper | A pollen | A schizaeaceae | ||
| Concavissimisporites | C. punctatus | Upper | A pollen | A pteridopsida | ||
| Cyathidites | C. australis | Upper | A pollen | A pteridopsida | ||
| Echinatisporis | E. longech | Upper | A pollen | A pteridopsida | ||
| E. sp | A pollen | |||||
| Microreticulatisporites | M. lacunosus | Upper | A pollen | A pteridophyte | ||
| "M. sp" | ||||||
| Polycingulatisporites | P. circulus | Upper | A pollen | A pteridophyte | ||
| P. cf. reduncus | ||||||
| Triporoletes | T. singularis | Upper | A pollen | A pteridophyte | ||
| T. reticula | ||||||
Other Plants
| Other plants of the Huincul Formation | ||||||
|---|---|---|---|---|---|---|
| Taxa | Species | Locality | Stratigraphic unit | Material | Notes | Images |
| Balmeiopsis | B. limbatus | El Zampa Section | Upper | A pollen | A pollen morphotaxon of uncertain affinities | |
| Elateroplicites | E. africaensis | Upper | A pollen | A pollen morphotaxon of uncertain affinities | ||
| Leptolepidites | L. proxigranulatus | Upper | A pollen | A lycopsid | ||