Ischigualasto
Description
Source: Wikipédia
The Ischigualasto Formation is a Late Triassic geological formation in the Ischigualasto-Villa Unión Basin of southwestern La Rioja Province and northeastern San Juan Province in northwestern Argentina. The formation dates to the late Carnian and early Norian stages of the Late Triassic (around 231.7 to 225 Ma), according to radiometric dating of ash beds.
The Ischigualasto Formation is part of the Agua de la Peña Group, overlying the Los Rastros Formation and overlain by the Los Colorados Formation. The formation is typically subdivided into four members, from old to young; La Peña, Cancha de Bochas, Valle de la Luna and Quebrada de la Sal. The sandstones, mudstones, conglomerates and tuffs of the formation were deposited in an fluvial (river-dominated) floodplain environment, characterized by cool temperatures and strongly seasonal rainfall. The formation is most well-studied in Ischigualasto Provincial Park, a protected area established in San Juan Province in 1967 and designated a UNESCO World Heritage Site in 2000. Sites in La Rioja Province, such as Cerro Las Lajas and Cerro Bola, are less investigated but potentially even more stratigraphically extensive.
The Ischigualasto Formation is an important paleontological unit, considered a konzentrat-lagerstätte due to its density of fossils. It preserves a diverse assortment of Late Triassic synapsids, temnospondyls, and reptiles, including some of the earliest unambiguous dinosaur fossils. Herbivorous rhynchosaurs and cynodonts (especially the rhynchosaur Hyperodapedon sanjuanensis and the cynodont Exaeretodon argentinus) are by far the predominant findings among the tetrapod fossils in the formation. Herrerasaurus ischigualastensis is both the most numerous dinosaur and most abundant carnivore of the formation. Another important dinosaur with primitive characteristics is Eoraptor lunensis, found in Ischigualasto in the early 1990s. Coprolites, burrows, petrified wood, and plant compressions have also been found in the formation.
Découvertes
Source: The Paleobiology Database
Site(s) correspondant(s) à cette formation: 19
northeast edge, Cancha de Bochas : San Juan - ? 6971 34067 48936 NE edge, Cancha de Bochas, Valle de la Luna, Ischigualasto-Villa Unión Basin, San Juan Province, Argentina- Arroyo de Agua : San Juan - ? 6972 12426 77266 1 km NW of Arroyo de Agua, San Juan, Argentina
- Agua de Las Catas, Ischigualasto : La Rioja - General Lavalle 7278 13922 31985 32304 59610 60797 61518 63573 73941 "Agua de las Catas" (or Hoyada del Cerro Las Lajas), Cerro Bola area, in front of km 461 on National Route no. 40. Province of La Rioja. Coordinates for Ischigualasto Provincial Park.
- Valle Pintado (upper), coprolites : San Juan - ? 12507 Valle Pintado, Ischigualasto-Via Union Basin, within Ischigualasto Provincial Park
- 3 km east-southeast of Aguada de la Peña : San Juan - Valle Fertíl 11823 3 km ESE of Aguada de la Peña, Ischigualasto Valley
- Valle Pintado : San Juan - Valle Fertíl 11823 59610 Valle Pintado, a few km ESE of Aguada de la Peña, Ischigualasto Valley
- Arroyo de la Pintada : San Juan - Valle Fertíl 11823 6 km WNW of Aguada de la Peña, 200 m right of dry river bed of Arroyo de la Pintada, Ischigualasto Valley
- Ischigualasto Valley (MLP) : San Juan - Valle Fertíl 11823 Ischigualasto Valley
- 3.7 km east-southeast of Aguada de la Peña (MACN) : San Juan - Valle Fertíl 11823 13755 59610 3.7 km ESE of Aguada de la Peña, Ischigualasto Valley
- 4 km east-southeast of Aguada de la Peña : San Juan - Valle Fertíl 11823 13755 4 km ESE of Aguada de la Peña, Ischigualasto Valley
- 3.5 km east-southeast of Aguada de la Peña : San Juan - Valle Fertíl 11823 60797 3.5 km ESE of Aguada de la Peña, Ischigualasto Valley
- left bank, Río La Chilca, Ischigualasto : San Juan - Valle Fértil 13755 13756 left bank of Río La Chilca, 12 km before the Puerta de La Chilca, NW sector of Hoyada de Ischigualasto
- Valle Pintado, Ischigualasto : San Juan - ? 29302 34067 60798 Valle Pintado, Hollada de Ischigualasto, Ischigualasto Provincial Park; Ischigualasto–Villa Unión Basin
- Herrera de la base, La Gallinita : San Juan - ? 34067 "Herrera de la base" locality, at La Gallinita, 3 km NW of Cancha de Bochas. Ischigualasto Provincial Park, Ischigualasto-Villa Unión Basin
- Eodromaeus type, Valle de la Luna : San Juan - ? 34767 30°04'04"S, 67°56'11"W; Valle de la Luna, southern Ischigualasto Provincial Park, San Juan,
- Cancha de Bochas, Valle Pintado : San Juan - ? 42426 48934 90830 Cancha de Bochas, Valle Pintado, southern outcrops of Ischigualasto Fm.
- Cerro Rajado tracksite : La Rioja - ? 17074 Cerro Rajado, Ischigualasto-Villa Unión Basin. Very close to border with San Juan province
- Herrerasaurus PVSJ 407 (PROXY) : San Juan - ? 10521 12426 unspecified locality in the Ischigualasto-Villa Unión Basin, San Juan, Argentina
- Hoyada de Ischigualasto, Ischigualasto Provincial Park : San Juan - ? 17306 35572 45398 93285 Ischigualasto Provincial Park, Hoyada de Ischigualasto, San Juan Province, Argentina (30° 04′ S, 67° 56′ W).
Publication(s)
La base comprend 31 publication(s).
Source: The Paleobiology Database
- ↑1 2 P. C. Sereno, C. A. Forster, and R. R. Rogers, A. M. Monetta. 1993. Primitive dinosaur skeleton from Argentina and the early evolution of Dinosauria. Nature 361:64-66 (https://doi.org/10.1038/361064a0)
- ↑1 2 3 4 O. A. Alcober and R. N. Martínez. 2010. A new herrerasaurid (Dinosauria, Saurischia) from the Upper Triassic Ischigualasto Formation of northwestern Argentina. Zookeys 63:55-81 (https://doi.org/10.3897/zzokeys.66.550)
- ↑1 P. C. Sereno, R. N. Martínez, and O. A. Alcober. 2013. Osteology of Eoraptor lunensis (Dinosauria, Sauropodomorpha). Basal Sauropodomorphs and the Vertebrate Fossil Record of the Ischigualasto Formation (Late Triassic: Carnian–Norian) of Argentina. Society of Vertebrate Paleontology Memoir 12. Journal of Vertebrate Paleontology 32(6 (s1)):83-179 (https://doi.org/10.1080/02724634.2013.820113)
- ↑1 2 D. B. Brinkman and H.-D. Sues. 1987. A staurikosaurid dinosaur from the Upper Triassic Ischigualasto Formation of Argentina and the relationships of the Staurikosauridae. Palaeontology 30(3):493-503
- ↑1 2 P. C. Sereno and F. E. Novas. 1994. The skull and neck of the basal theropod Herrerasaurus ischigualastensis. Journal of Vertebrate Paleontology 13(4):451-476 (https://doi.org/10.1080/02724634.1994.10011525)
- ↑1 J. d. S. Bittencourt and A. W. A. Kellner. 2009. The anatomy and phylogenetic position of the Triassic dinosaur Staurikosaurus pricei Colbert, 1970. Zootaxa 2079(1):1-56 (https://doi.org/10.11646/zootaxa.2079.1.1)
- ↑1 2 R. M. Casamiquela. 1967. Un nuevo dinosaurio ornitisquio triasico (Pisanosaurus mertii; Ornithopoda) de la Formación Ischigualasto, Argentina [A new Triassic ornithischian dinosaur (Pisanosaurus mertii; Ornithopoda) from the Ischigualasto Formation, Argentina]. Ameghiniana 4(2):47-64
- ↑1 J. F. Bonaparte. 1976. Pisanosaurus mertii Casamiquela and the origin of the Ornithischia. Journal of Paleontology 50(5):808-820
- ↑1 M. C. Langer, M. D. Ezcurra, and J. S. Bittencourt, F. E. Novas. 2010. The origin and early evolution of dinosaurs. Biological Reviews 85:55-110 (https://doi.org/10.1111/j.1469-185X.2009.00094.x)
- ↑1 R. B. Irmis, W. G. Parker, and S. J. Nesbitt, J. Liu. 2007. Early ornithischian dinosaurs: the Triassic record. Historical Biology 19(1):3-22 (https://doi.org/10.1080/08912960600719988)
- ↑1 2 3 J. F. Bonaparte. 1978. El Mesozoico de America de Sur y sus Tetrapodos [The Mesozoic of South America and its tetrapods]. Opera Lilloana 26:1-596
- ↑1 2 A. Lecuona, M. D. Ezcurra, and R. B. Irmis. 2016. Revision of the early crocodylomorph Trialestes romeri (Archosauria, Suchia) from the lower Upper Triassic Ischigualasto Formation of Argentina: one of the oldest-known crocodylomorphs. Papers in Palaeontology 2(4):585-622 (https://doi.org/10.1002/spp2.1056)
- ↑1 D. B. Weishampel and J. B. Weishampel. 1983. Annotated localities of ornithopod dinosaurs: implications to Mesozoic paleobiogeography. The Mosasaur 1:43-87
- ↑1 J. F. Bonaparte. 1984. I dinosauri dell’Argentina [. Sulle Orme dei Dinosauri
- ↑1 J. B. Desojo, L. E. Fiorelli, and M. D. Ezcurra, A. G. Martinelli, J. Ramezani, Á. A. S. Da Rosa, M. Belén von Baczko, M. Jimena Trotteyn, F. C. Montefeltro, M. Ezpeleta, M. C. Langer. 2020. The Late Triassic Ischigualasto Formation at Cerro Las Lajas (La Rioja, Argentina): fossil tetrapods, high‑resolution chronostratigraphy, and faunal correlations. Scientific Reports 10:12782:1-34 (https://doi.org/10.1038/s41598-020-67854-1)
- ↑1 2 K. T. Hollocher, O. A. Alcober, and C. E. Colombi, T. C. Hollocher. 2005. Carnivore coprolites from the Upper Triassic Ischigualasto Formation, Argentina: chemistry, mineralogy, and evidence for rapid initial mineralization. Palaios 20(1):51-63 (https://doi.org/10.2110/palo.2003.p03-98)
- ↑1 2 3 4 5 6 7 8 9 10 11 12 13 14 O. A. Reig. 1963. La presencia de dinosaurios saurisquios en los "Estratos de Ischigualasto" (Mesotriasico Superior) de las provincias de San Juan y La Rioja (República Argentina) [The presence of saurischian dinosaurs in the "Ischigualasto beds" (upper Middle Triassic) of San Juan and La Rioja Provinces (Argentine Republic)]. Ameghiniana 3(1):3-20
- ↑1 2 3 F. E. Novas. 1994. New information on the systematics and postcranial skeleton of Herrerasaurus ischigualastensis (Theropoda: Herrerasauridae) from the Ischigualasto Formation (Upper Triassic) of Argentina. Journal of Vertebrate Paleontology 13(4):400-423 (https://doi.org/10.1080/02724634.1994.10011523)
- ↑1 2 F. E. Novas. 1986. Un probable teropodo (Saurischia) de la Formacion Ischigualasto (Triasico Superior), San Juan, Argentina [A probable theropod (Saurischia) from the Ischigualasto Formation (Upper Triassic), San Juan, Argentina]. IV Congreso Argentino de Paleontologia y Bioestratigrafia 1:1-6
- ↑1 2 R. N. Martínez and O. A. Alcober. 2009. A basal sauropodomorph (Dinosauria: Saurischia) from the Ischigualasto Formation (Triassic, Carnian) and the early evolution of Sauropodomorpha. PLoS ONE 4(2 (e4397)):1-12 (https://doi.org/10.1371/journal.pone.0004397)
- ↑1 R. N. Martínez, C. Apaldetti, and G. A. Correa, D. Abelín. 2016. A Norian lagerpetid dinosauromorph from the Quebrada del Barro Formation, northwestern Argentina. Ameghiniana 53(1):1-13 (https://doi.org/10.5710/AMGH.21.06.2015.2894)
- ↑1 2 R. N. Martinez, P. C. Sereno, and O. A. Alcober, C. E. Colombi, P. R. Renne, I. P. Montañez, B. S. Currie. 2011. A basal dinosaur from the dawn of the dinosaur era in southwestern Pangaea. Science 331(6014):206-210 (https://doi.org/10.1126/science.1198467)
- ↑1 2 M. D. Ezcurra and F. E. Novas. 2008. A review of the dinosaur diversity of the Ischigualasto Formation (Carnian, NW Argentina): insights on early dinosaur evolution. VI Simpósio Brasileiro de Paleontologia de Vertebrados. Paleontologia em Destaque 23(Ed.Es.):88-89
- ↑1 M. D. Ezcurra. 2010. A new early dinosaur (Saurischia: Sauropodomorpha) from the Late Triassic of Argentina: a reassessment of dinosaur origin and phylogeny. Journal of Systematic Palaeontology 8:371-425 (https://doi.org/10.1080/14772019.2010.484650)
- ↑1 R. N. Martínez, C. Apaldetti, and D. Abelin. 2013. Basal sauropodomorphs from the Ischigualasto Formation. Basal Sauropodomorphs and the Vertebrate Fossil Record of the Ischigualasto Formation (Late Triassic: Carnian–Norian) of Argentina. Society of Vertebrate Paleontology Memoir 12. Journal of Vertebrate Paleontology 32(6 (s1)):51-69 (https://doi.org/10.1080/02724634.2013.819361)
- ↑1 2 R. N. Melchor and S. de Valais. 2006. A review of Triassic tetrapod track assemblages from Argentina. Palaeontology 49(2):355-379 (https://doi.org/10.1111/j.1475-4983.2006.00538.x)
- ↑1 2 P. C. Sereno and F. E. Novas. 1992. The complete skull and skeleton of an early dinosaur. Science 258:1137-1140 (https://doi.org/10.1126/science.258.5085.1137)
- ↑1 R. N. Martínez, C. E. Colombi, and M. D. Ezcurra, D. O. Abelín, I. Cerda, O. A. Alcober. 2025. A Carnian theropod with unexpectedly derived features during the first dinosaur radiation. Nature Ecology & Evolution (https://doi.org/10.1038/s41559-025-02868-4)
- ↑1 L. L. Jacobs, O. Mateus, and M. J. Polcyn, A. S. Schulp, M. T. Antunes, M. L. Morais, T. S. Tavares. 2006. The occurrence and geological setting of Cretaceous dinosaurs, mosasaurs, plesiosaurs, and turtles in Angola. Journal of the Paleontological Society of Korea 22(1):91-110
- ↑1 O. M. Mateus, L. L. Jacobs, and A. S. Schulp, M. L. Polcyn, T. S. Tavares, A. B. Neto, M. L. Morais, M. T. Antunes. 2011. Angolatitan adamastor, a new sauropod dinosaur and the first record from Angola. Anais da Academia Brasileira de Ciências 83(1):221-233 (https://doi.org/10.1590/s0001-37652011000100012)
- ↑1 O. Mateus, M. J. Polcyn, and L. L. Jacobs, R. Arujo, A. S. Schulp, J. Marinheiro, B. Pereira, D. P. Vineyard. 2012. Cretaceous amniotes from Angola: dinosaurs, pterosaurs, mosasaurs, plesiosaurs, turtles. Actas de V Jornadas Internacionales sobre Paleontologia de Dinosaurios y su Entorno, Salas de los Infantes, Burgos
Galerie d'image
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