Earth:Allen Formation
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| Allen Formation Stratigraphic range: Mid Campanian-Maastrichtian ~73–66 Ma | |
|---|---|
 Outcrop of the Allen and Anacleto Formations at Auca Mahuida | |
| Type | Geological formation |
| Unit of | Malargüe Group |
| Underlies | Jagüel Formation |
| Overlies | Anacleto Formation |
| Thickness | up to 70 m (230 ft) |
| Lithology | |
| Primary | Mudstone, sandstone |
| Other | Limestone |
| Location | |
| Coordinates | [ ⚑ ] : 40°00′S 66°36′W / 40.0°S 66.6°W |
| Paleocoordinates | [ ⚑ ] 42°48′S 52°12′W / 42.8°S 52.2°W |
| Region | Neuquén, Río Negro & La Pampa Provinces |
| Country | Argentina |
| Extent | Neuquén Basin |
| Type section | |
| Named by | Uliana & Dellapé |
| Year defined | 1981 |
  Allen Formation (Argentina) | |
The Allen Formation is a geological formation in Argentina whose strata date back to the Late Cretaceous (middle Campanian to early Maastrichtian.[1] Dinosaur remains are among the fossils that have been recovered from the formation.[2] Indeterminate chelid remains and other vertebrates have also been discovered in this formation.[3]
Description
Uliana and Dellapé defined the formation's stratotype in 1981 in the eastern area of the Bajo de Añelo, where the relation between the base and top is clearly exposed. The deposits are mostly clastic, interbedded with banks of limestone and layers of anhydrite, which were defined as continental and shallow marine facies associated with semiarid conditions.[4]
The interpreted sedimentary paleoenvironments range from purely continental such as ephemeral lacustrine, aeolian and fluvial systems to coastal marine paleoenvironments with development of estuaries and tidal flats, followed by a lagoon sedimentary stage from marsh to sea with carbonate precipitation in an area protected from waves, ending with a retraction leading to the accumulation of evaporites.[4]
Armas and Sánchez performed a detailed facies analysis of the formation in 2015, where the authors concluded the formation represents a hybrid coastal system of tidal flats, dominated by Atlantic ingressions, with a large storm influence in some areas linked to aeolian systems.[5]
A study of pollen found in outcrops of the middle member of the Allen Formation supported a late Maastrichtian age for these layers.[6]
Fossil content
Dinosaurs
Template:Paleobiota-key-compact Dinosaur eggs are known from the formation.[7]
Ornithischians
- Ankylosaurs
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
|---|---|---|---|---|---|---|
| Ankylosauria[8] | Indeterminate | Arriagada Farm | Two teeth, five osteoderms, and a partial sacrum | Fossil remains possibly belonging to a parankylosaur distinct from Patagopelta | ||
| Patagopelta | P. cristata | Salitral Moreno locality | Lower | Tooth, three posterior dorsal vertebrae, caudal vertebrae, two caudal centra, right femur, partial cervical half ring, and osteoderms | A possible parankylosaur[9] |  |
- Hadrosaurs
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
|---|---|---|---|---|---|---|
| Bonapartesaurus | B. rionegrensis | Salitral Moreno and Islas Malvinas. | Lower | A partial skeleton. | A hadrosaur |  |
| Kelumapusaura | K. machi | Cerro Matadero, Arriagada Farm | Upper | Partial skull, a cervical vertebrae, several sacrals, sternal rib and sternal plate, and multiple referred specimens found in a bonebed | A saurolophine hadrosaur[10] |  |
| Lapampasaurus | L. cholinoi | Islas Malvinas | Lower | Elements of the axial and appendicular skeleton of a subadult individual | A hadrosaur[11] | |
| Willinakaqe | W. salitralensis | Salitral Moreno site. | Lower | A right premaxilla. | A saurolophine hadrosaur[12] |
Saurischians
- Sauropods
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
|---|---|---|---|---|---|---|
| Aeolosaurus | Indeterminate | Lower | A titanosaur[7] |     | ||
|
B.reigi[13] |
Lower | Braincases, caudal vertebrae, and several limb elements | A titanosaur[13] | |||
| Menucocelsior | M. arriagadai | Lower | Seventeen caudal vertebrae and several appendicular bones: a right humerus, a left fibula and some metapodial. | A titanosaur[14] | ||
| Panamericansaurus | P. schroederi | "Five tail vertebrata, sacral vertebrae, left humerus and rib fragments" | A titanosaur[7][15] | |||
| Pellegrinisaurus? | P. powelli | Lower (if it is from the formation) | "Dorsal and caudal vertebrae, partial femur" | A titanosaur[7][15] | ||
| Rocasaurus | R. muniozi | Middle | "Partial postcranial skeleton" | A titanosaur[7][16] |
Theropods
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
|---|---|---|---|---|---|---|
| Austroraptor | A. cabazai | Lower | A fragmentary skeleton including parts of the skull, lower jaw, a few neck and torso vertebrae, some ribs, a humerus, and assorted bones from both legs | A dromaeosaurid |  | |
| Bonapartenykus | B. ultimus | Upper | A holotype consists of a mid-dorsal vertebra, both scapulocoracoids, left tibia and femur, left pubis articulated with the pubic peduncle of the ilium, the anterior blade of the left ilium, and two partially preserved eggs. | An alvarezsauroid | .png) | |
| Lamarqueavis | L. australis | Lower | "Right coracoid with damaged sternal and omal extremities, and lacking acrocoracoidal process" | An ornithuran[17] | ||
| Limenavis | L. patagonica | Lower | "Partial forelimb" | An ornithuran[7][18] | ||
| Niebla | N. antiqua | Upper | Braincase, fragmentary jaw and teeth, relatively complete scapulocoracoid, dorsal ribs, and incomplete vertebrae. | An abelisaurid[19] |  | |
| Quilmesaurus | Q. curriei | Upper | Femur and distal tibia | An abelisaurid[7][20] |  |
Pterosaurs
Fragmentary fossils are known from the formation.[7]
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
|---|---|---|---|---|---|---|
| Aerotitan | A. sudamericanus | Bajo de Arriagada | Upper | Partial rostrum | The first unambiguous azhdarchid from South-America[21] |  |
Fish
| Genus[3] | Species | Location | Stratigraphic position | Material | Notes | Images |
|---|---|---|---|---|---|---|
| Atlantoceratodus | A. patagonicus | 3 tooth plates | A ceratorontiform lungfish[22] | |||
| Belonostomus | B. lamarquensis | A aspidorhynchid fish[23] | ||||
| Chondrichthyes | indeterminate | 11 vertebral centra | ||||
| Diplomystidae | indeterminate | 4 incomplete pectoral spines | ||||
| Siluriformes | indeterminate | 5 incomplete pectoral spines | ||||
| Lepisosteidae | indeterminate | 6 vertebral centra | ||||
| Teleostei | indeterminate | 10 isolated teeth | ||||
| cf. Percichthyidae | indeterminate | 19 fragmentary vertebrae |
Squamata
| Genus[3][24] | Species | Location | Stratigraphic position | Material | Notes | Images |
|---|---|---|---|---|---|---|
| Patagoniophis | P. parvus | incomplete trunk vertebra | ||||
| Alamitophis | A. argentinus | incomplete trunk vertebra | ||||
| Madtsoiidae | indeterminate | incomplete trunk vertebra | ||||
| ?Scincoidea | indeterminate | incomplete left maxilla | ||||
| Pleurodonta | indeterminate | incomplete left maxilla | ||||
| Teiioidea | indeterminate | incomplete right maxilla |
Turtles
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
|---|---|---|---|---|---|---|
| Iaremys | I. batrachomorpha | A chelid turtle[25] | ||||
| Trapalcochelys | T. sulcata | A meiolaniform turtle[26] | ||||
| Yaminuechelys | Y. gasperinii | A chelid turtle |
Rhynchocephalia
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
|---|---|---|---|---|---|---|
| Lamarquesaurus | L. cabazai | Cerro Tortuga | [27] |
Plesiosauria
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
|---|---|---|---|---|---|---|
| Kawanectes | K. lafquenianum | Quarry of the “Bentonitas Patagónicas” company | Upper | A partial skeleton consists of six cervical vertebrae, three dorsal vertebrae, three sacral vertebrae, nine caudal vertebrae, right femur, right humerus, ilium, one 216 mesopodial element, one caudal phalanx and one caudal rib . | An elasmosaur. |  |
Frogs
Unnamed frogs belonging to the family Calyptocephalellidae and Leptodactylidae, and those with no family designation were also found.[28][3]
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
|---|---|---|---|---|---|---|
| Calyptocephalella | C. satan | Cerro Tortuga | Lower | A right incomplete maxilla. | A calyptocephalellid frog[29] | |
| Kuruleufenia | K. xenopoides | Cerro Tortuga, Bajo Santa Rosa, and Cerro Bonaparte | Lower | An almost complete sphenethmoid. | Pipid frog[30] |
Mammals
The mammal fauna of the Allen Formation is known from seven teeth, which document the presence of several species.[31]
| Genus | Species | Location | Material | Notes | Images |
|---|---|---|---|---|---|
| Mesungulatum | M. lamarquensis | Cerro Tortuga | Two upper molars and a fragmentary lower molar | A dryolestoid | |
| Groebertherium | G. stipanicici | Cerro Tortuga | One upper molar | A dryolestoid | |
| cf. Brandonia | sp. | Cerro Tortuga | One lower molar | A dryolestoid | |
| Barberenia | B. allenensis | Cerro Tortuga | One upper molariform | A dryolestoid | |
| Solanutheirum | S. walshi | Cerro Tortuga | A right lower molar and left dentary fragment. | A meridiolestid.[32] | |
| Trapalcotherium | T. matuastensis | Cerro Tortuga | One first lower molar | A gondwanathere |
Plants
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
|---|---|---|---|---|---|---|
| Podocarpoxylon | P. mazzonii | Valcheta Petrified Forest, Río Negro Province.[33] | Lower | Fossil wood[33] | A conifer tree |
See also
- List of dinosaur-bearing rock formations
- Adamantina Formation
- La Colonia Formation
- Lecho Formation
- Los Alamitos Formation
- Los Llanos Formation
- Marília Formation
References
- ↑ Salgado et al. 2007.
- ↑ Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, South America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 600-604. ISBN 0-520-24209-2.
- ↑ 3.0 3.1 3.2 3.3 Martinelli, Agustín; Forasiepi, Analía (2004). "Late Cretaceous vertebrates from bajo de Santa Rosa (Allen Formation), Río Negro province, Argentina, with the description of a new sauropod dinosaur (Titanosauridae)". Revista del Museo Argentino de Ciencias Naturales 6 (2): 257–305. doi:10.22179/REVMACN.6.88. https://revista.macn.gob.ar/index.php/RevMus/article/view/88.
- ↑ 4.0 4.1 Armas & Sánchez 2015, p. 101.
- ↑ Armas & Sánchez 2015, p. 110.
- ↑ Pincheira, Egly Pérez; Garrido, Alberto Carlos (November 2024). "Palynostratigraphy from the Allen and Jagüel formations at the Cerro Gutiérrez locality, Lago Pellegrini area, South Argentina". Journal of South American Earth Sciences 148. doi:10.1016/j.jsames.2024.105139. Bibcode: 2024JSAES.14805139P.
- ↑ 7.0 7.1 7.2 7.3 7.4 7.5 7.6 7.7 Weishampel et al., 2004, p.604
- ↑ Álvarez Nogueira, Rodrigo; Agnolín, Federico L.; Rozadilla, Sebastián; Aranciaga-Rolando, Mauro; Novas, Fernando E. (2 January 2025). "Ankylosaurian remains from a new Campanian–Maastrichtian locality in Northern Patagonia, Argentina". Alcheringa: An Australasian Journal of Palaeontology 49 (1): 69–78. doi:10.1080/03115518.2025.2467462. Bibcode: 2025Alch...49...69A.
- ↑ Soto Acuña, Sergio; Vargas, Alexander O.; Kaluza, Jonatan (2024). "A new look at the first dinosaur discovered in Antarctica: reappraisal of Antarctopelta oliveroi (Ankylosauria: Parankylosauria)". Advances in Polar Science 35 (1): 78–107. doi:10.12429/j.advps.2023.0036.
- ↑ Rozadilla, Sebastián; Brissón-Egli, Federico; Agnolín, Federico Lisandro; Aranciaga-Rolando, Alexis Mauro; Novas, Fernando Emilio (2 September 2021). "A new hadrosaurid (Dinosauria: Ornithischia) from the Late Cretaceous of northern Patagonia and the radiation of South American hadrosaurids". Journal of Systematic Palaeontology 19 (17): 1207–1235. doi:10.1080/14772019.2021.2020917. Bibcode: 2021JSPal..19.1207R.
- ↑ Coria, Riga & Casadío 2012.
- ↑ Juárez Valieri et al., 2010
- ↑ 13.0 13.1 "63.10 Provincia de Río Negro, Argentina; 4. Río Colorado Formation," in Weishampel, et al. (2004). Page 604.
- ↑ Rolando et al., 2022
- ↑ 15.0 15.1 "Table 13.1," in Weishampel, et al., 2004, p.269
- ↑ "Table 13.1," in Weishampel, et al., 2004, p.270
- ↑ Agnolin, 2010
- ↑ "Table 11.1," in Weishampel, et al., 2004, p.215
- ↑ Aranciaga Rolando, Mauro; Cerroni, Mauricio A.; Garcia Marsà, Jordi A.; Agnolín, Federico l.; Motta, Matías J.; Rozadilla, Sebastián; Brisson Eglí, Federico; Novas, Fernando E. (January 2021). "A new medium-sized abelisaurid (Theropoda, Dinosauria) from the late cretaceous (Maastrichtian) Allen Formation of Northern Patagonia, Argentina". Journal of South American Earth Sciences 105. doi:10.1016/j.jsames.2020.102915. Bibcode: 2021JSAES.10502915A.
- ↑ "Table 4.1," in Weishampel, et al., 2004, p.77
- ↑ Novas et al. 2012.
- ↑ Federico Agnolin (2010). "A new species of the genus Atlantoceratodus (Dipnoiformes: Ceratodontoidei) from the Uppermost Cretaceous of Patagonia and a brief overview of fossil dipnoans from the Cretaceous and Paleogene of South America". Brazilian Geographical Journal: Geosciences and Humanities Research Medium 1 (2): 162–210. http://dialnet.unirioja.es/servlet/articulo?codigo=3638695.
- ↑ Sergio Bogan; Louis Taverne; Federico L. Agnolin (2011). "Description of a new aspidorhynchid fish, Belonostomus lamarquensis sp. nov. (Halecostomi, Aspidorhynchiformes), from the continental Upper Cretaceous of Patagonia, Argentina". Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, Sciences de la Terre 81: 235–245.
- ↑ Garberoglio, F. F.; Gómez, R. O.; Apesteguía, S.; Rougier, G. W. (2024). "A Late Cretaceous lizard assemblage from the Allen Formation, northern Patagonia, Argentina". Historical Biology: An International Journal of Paleobiology 37 (4): 950–962. doi:10.1080/08912963.2024.2344789.
- ↑ Agnolín, F. L.; Aranciaga-Rolando, A. M.; Ortiz, R. (2024). "New chelid turtle with a flattened skull from the Late Cretaceous of Northern Patagonia, Argentina". Alcheringa: An Australasian Journal of Palaeontology 49: 79–84. doi:10.1080/03115518.2024.2427261.
- ↑ Sterli, Juliana; Fuente, Marcelo S. De La; Cerda, Ignacio A. (April 2013). "A New Species of Meiolaniform Turtle and a Revision of the Late Cretaceous Meiolaniformes of South America". Ameghiniana 50 (2): 240–256. doi:10.5710/amgh.16.01.2013.582. Bibcode: 2013Amegh..50..240S.
- ↑ Apesteguía & Rougier, 2007, p.3
- ↑ Suazo Lara, F.; Gómez, R.O. (March 2022). "In the shadow of dinosaurs: Late Cretaceous frogs are distinct components of a widespread tetrapod assemblage across Argentinean and Chilean Patagonia". Cretaceous Research 131. doi:10.1016/j.cretres.2021.105085. Bibcode: 2022CrRes.13105085S.
- ↑ Federico Agnolin (2012). "A new Calyptocephalellidae (Anura, Neobatrachia) from the Upper Cretaceous of Patagonia, Argentina, with comments on its systematic position". Studia Geologica Salmanticensia 48 (2): 129–178. http://revistas.usal.es/index.php/0211-8327/article/view/12820.
- ↑ Gómez, Raúl O. (July 2016). "A new pipid frog from the Upper Cretaceous of Patagonia and early evolution of crown-group Pipidae". Cretaceous Research 62: 52–64. doi:10.1016/j.cretres.2016.02.006. Bibcode: 2016CrRes..62...52G.
- ↑ Rougier et al., 2009
- ↑ Connelly, B. E.; Cardozo, M. S.; Montgomery, J. D.; Rougier, G. W. (2024). "New mammals from the Upper Cretaceous Allen Formation (Patagonia, Argentina) and reassessment of meridiolestidan diversity". Cretaceous Research 162. doi:10.1016/j.cretres.2024.105935. Bibcode: 2024CrRes.16205935C.
- ↑ 33.0 33.1 Passalia, M.G.; Garrido, A.; Iglesias, A.; Vera, E.I. (February 2023). "The Valcheta Petrified Forest (Upper Cretaceous), northern Patagonia, Argentina: A geological and paleobotanical survey". Cretaceous Research 142. doi:10.1016/j.cretres.2022.105395. Bibcode: 2023CrRes.14205395P.
Bibliography
- Agnolin, Federico L (2010), "An avian coracoid from the Upper Cretaceous of Patagonia, Argentina", Studia Geologica Salmanticensia 46 (2): 99–119, http://campus.usal.es/~revistas_trabajo/index.php/0211-8327/article/view/7642/8861, retrieved 2019-02-16
- Apesteguía, Sebastián; Rougier, Guillermo W. (2007). "A Late Campanian Sphenodontid Maxilla from Northern Patagonia". American Museum Novitates (3581): 1. doi:10.1206/0003-0082(2007)3581[1:ALCSMF2.0.CO;2]. https://www.biodiversitylibrary.org/bibliography/169185.
- Armas, Paula; Sánchez, María Lidia (30 January 2015). "Márgenes costeros híbridos de la Cuenca Neuquina (Formación Allen, Cretácico Superior, Argentina)". Andean Geology 42 (1). doi:10.5027/andgeoV42n1-a06. Bibcode: 2015AndGe..42a...6A.
- Coria, Rodolfo A.; Riga, Bernardo González; Casadío, Silvio (December 2012). "Un Nuevo Hadrosáurido (Dinosauria, Ornithopoda) de la Formación Allen, Provincia de la Pampa, Argentina". Ameghiniana 49 (4): 552–572. doi:10.5710/AMGH.9.4.2012.487. Bibcode: 2012Amegh..49..552C.
- Juárez Valieri, Rubén; Haro, José; Fiorelli, Lucas; Calvo, Jorge (2010). "A new hadrosauroid (Dinosauria: Ornithopoda) from the Allen Formation (Late Cretaceous) of Patagonia, Argentina". Revista del Museo Argentino de Ciencias Naturales 12: 217–231. doi:10.22179/REVMACN.12.242.
- Novas, Fernando E.; Kundrat, Martin; Agnolín, Federico L.; Ezcurra, Martín D.; Ahlberg, Per Erik; Isasi, Marcelo P.; Arriagada, Alberto; Chafrat, Pablo (November 2012). "A new large pterosaur from the Late Cretaceous of Patagonia". Journal of Vertebrate Paleontology 32 (6): 1447–1452. doi:10.1080/02724634.2012.703979. Bibcode: 2012JVPal..32.1447N.
- Rougier, Guillermo W.; Chornogubsky, Laura; Casadio, Silvio; Arango, Natalia Paéz; Giallombardo, Andres (February 2009). "Mammals from the Allen Formation, Late Cretaceous, Argentina". Cretaceous Research 30 (1): 223–238. doi:10.1016/j.cretres.2008.07.006. Bibcode: 2009CrRes..30..223R.
- Salgado, Leonardo; Coria, Rodolfo A.; Magalhaes Ribeiro, Claudia M.; Garrido, Alberto; Rogers, Raymond; Simón, María E.; Arcucci, Andrea B.; Rogers, Kristina Curry et al. (June 2007). "Upper Cretaceous dinosaur nesting sites of Río Negro (Salitral Ojo de Agua and Salinas de Trapalcó-Salitral de Santa Rosa), northern Patagonia, Argentina". Cretaceous Research 28 (3): 392–404. doi:10.1016/j.cretres.2006.06.007. Bibcode: 2007CrRes..28..392S.
- Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (2004), The Dinosauria, 2nd edition, Berkeley: University of California Press, pp. 1–880, ISBN 0-520-24209-2, https://books.google.com/books?id=vtZFDb_iw40C, retrieved 2019-02-21
Further reading
- O'gorman, José Patricio; Salgado, Leonardo; Gasparini, Zulma (March 2011). "Plesiosaurios de la Formación Allen (Campaniano-Maastrichtiano) en el Área del Salitral de Santa Rosa (Provincia de Río Negro, Argentina)". Ameghiniana 48 (1): 129–135. doi:10.5710/AMGH.v48i1(308). Bibcode: 2011Amegh..48..129O.
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