Allen Formation
Allen Formation | |
---|---|
Stratigraphic range: Mid Campanian-Maastrichtian ~73–69 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓ | |
![]() 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 | ![]() ![]() 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
![](http://upload.wikimedia.org/wikipedia/commons/thumb/4/48/Allen_Formation_Fauna.png/220px-Allen_Formation_Fauna.png)
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]
Fossil content
![](http://upload.wikimedia.org/wikipedia/commons/thumb/6/68/Quilmesaurus_hunting_Bonapartesaurus_version_2.jpg/220px-Quilmesaurus_hunting_Bonapartesaurus_version_2.jpg)
Dinosaurs
Color key
| Notes Uncertain or tentative taxa are in small text; |
Dinosaur eggs are known from the formation.[6]
Ornithischians
Color key
| Notes Uncertain or tentative taxa are in small text; |
- Ankylosaurs
Ankylosaurs reported from the Allen Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
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 parankylosaur of uncertain affinities. [7][8] | ![]() |
- Hadrosaurs
Color key
| Notes Uncertain or tentative taxa are in small text; |
Hadrosaurs reported from the Allen Formation | ||||||
---|---|---|---|---|---|---|
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 | Upper | Partial skull, a cervical vertebrae, several sacrals, sternal rib and sternal plate, and multiple referred specimens found in a bonebed | A saurolophine hadrosaur. [9] | ![]() | |
Lapampasaurus | L. cholinoi | Lower | Elements of the axial and appendicular skeleton of a subadult individual | A hadrosaur. [10] | ||
Willinakaqe | W. salitralensis | Salitral Moreno site. | Lower | A right premaxilla. | A saurolophine hadrosaur. [11] |
Saurischians
- Sauropods
Color key
| Notes Uncertain or tentative taxa are in small text; |
Sauropods reported from the Allen Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Aeolosaurus | Indeterminate | Lower | A titanosaur. [6] | ![]() | ||
B.reigi[12] | Lower | Braincases, caudal vertebrae, and several limb elements | A titanosaur. [12] | |||
Menucocelsior | M. arriagadai | Lower | Seventeen caudal vertebrae and several appendicular bones: a right humerus, a left fibula and some metapodial. | A titanosaur. [13] | ||
Panamericansaurus | P. schroederi | "Five tail vertebrata, sacral vertebrae, left humerus and rib fragments" | A titanosaur. [6][14] | |||
Pellegrinisaurus? | P. powelli | Lower (if it is from the formation) | "Dorsal and caudal vertebrae, partial femur" | A titanosaur. [6][14] | ![]() | |
Rocasaurus | R. muniozi | Lower | "Partial postcranial skeleton" | A titanosaur. [6][15] |
Theropods
Theropods reported from the Allen Formation | ||||||
---|---|---|---|---|---|---|
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. | ![]() | |
Lamarqueavis | L. australis | Lower | "Right coracoid with damaged sternal and omal extremities, and lacking acrocoracoidal process" | An ornithuran. [16] | ||
Limenavis | L. patagonica | Lower | "Partial forelimb" | An ornithuran. [6][17] | ||
Niebla | N. antiqua | Upper | Braincase, fragmentary jaw and teeth, relatively complete scapulocoracoid, dorsal ribs, and incomplete vertebrae. | An abelisaurid[18] | ![]() | |
Quilmesaurus | Q. curriei | Upper | Femur and distal tibia | An abelisaurid. [6][19] | ![]() |
Pterosaurs
Fragmentary fossils are known from the formation.[6]
Pterosaurs reported from the Allen Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Aerotitan | A. sudamericanus | Bajo de Arriagada | Upper | Partial rostrum | The first unambiguous azhdarchid from South-America[20] | ![]() |
Fish
Fish reported from the Allen Formation[3] | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Ceratodontiformes | indeterminate | 3 tooth plates | ||||
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
Squamates reported from the Allen Formation[3] | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Patagoniophis | P. parvus | incomplete trunk vertebra | ||||
Alamitophis | A. argentinus | incomplete trunk vertebra | ||||
Madtsoiidae | indeterminate | incomplete trunk vertebra |
Rhynchocephalia
Rhynchocephalia reported from the Allen Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Lamarquesaurus | L. cabazai | Cerro Tortuga | [21] |
Plesiosauria
Plesiosaurs reported from the Allen Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Kawanectes | K. lafquenianum |
Frogs
Unnamed frogs belonging to the family Calyptocephalellidae and Leptodactylidae, and those with no family designation were also found.[22][3]
Frogs reported from the Allen Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Kuruleufenia | K. xenopoides | Pipid frog.[23] |
Mammals
The mammal fauna of the Allen Formation is known from seven teeth, which document the presence of several species.[24]
Mammals reported from the Allen Formation | |||||
---|---|---|---|---|---|
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.[25] | |
Trapalcotherium | T. matuastensis | Cerro Tortuga | One first lower molar | A gondwanathere |
Plants
Plants reported from the Allen Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Podocarpoxylon | P. mazzonii | Valcheta Petrified Forest, Río Negro Province.[26] | Fossil wood.[26] |
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.
- ^ a b c d Martinelli, A. and Forasiepi, A.M. (2004). "Late Cretaceous vertebrates from Bajo de Santa Rosa (Allen Formation), Rio Negro province, Argentina, with the description of a new sauropod dinosaur (Titanosauridae)". Revista del Museo Argentino de Ciencias Naturales 6(2): 257–305.
- ^ a b Armas & Sánchez, 2015, p.101
- ^ Armas & Sánchez, 2015, p.110
- ^ a b c d e f g h Weishampel et al., 2004, p.604
- ^ Arbour, Victoria M.; Currie, Philip J. (2016-05-03). "Systematics, phylogeny and palaeobiogeography of the ankylosaurid dinosaurs". Journal of Systematic Palaeontology. 14 (5): 385–444. Bibcode:2016JSPal..14..385A. doi:10.1080/14772019.2015.1059985. ISSN 1477-2019. S2CID 214625754.
- ^ Riguetti, Facundo; Pereda-Suberbiola, Xabier; Ponce, Denis; Salgado, Leonardo; Apesteguía, Sebastián; Rozadilla, Sebastián; Arbour, Victoria (2022-12-31). "A new small-bodied ankylosaurian dinosaur from the Upper Cretaceous of North Patagonia (Río Negro Province, Argentina)". Journal of Systematic Palaeontology. 20 (1): 2137441. Bibcode:2022JSPal..2037441R. doi:10.1080/14772019.2022.2137441. ISSN 1477-2019. S2CID 254212751.
- ^ Rozadilla, S.; Brissón-Egli, F.; Agnolín, F.L.; Aranciaga-Rolando, A.M.; Novas, F.E. (2022). "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. S2CID 247122005.
- ^ Coria et al., 2012
- ^ Juárez Valieri et al., 2010
- ^ a b "63.10 Provincia de Río Negro, Argentina; 4. Río Colorado Formation," in Weishampel, et al. (2004). Page 604.
- ^ Rolando et al., 2022
- ^ a b "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. (2020-10-14). "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: 102915. doi:10.1016/j.jsames.2020.102915. hdl:11336/150468. ISSN 0895-9811. S2CID 225123133.
- ^ "Table 4.1," in Weishampel, et al., 2004, p.77
- ^ Novas et al., 2012
- ^ Apesteguía & Rougier, 2007, p.3
- ^ Suazo Lara, F.; Gómez, R. O. (2022-03-01). "In the shadow of dinosaurs: Late Cretaceous frogs are distinct components of a widespread tetrapod assemblage across Argentinean and Chilean Patagonia". Cretaceous Research. 131: 105085. Bibcode:2022CrRes.13105085S. doi:10.1016/j.cretres.2021.105085. ISSN 0195-6671. S2CID 243482426.
- ^ Gómez, Raúl O. (2016-07-01). "A new pipid frog from the Upper Cretaceous of Patagonia and early evolution of crown-group Pipidae". Cretaceous Research. 62: 52–64. Bibcode:2016CrRes..62...52G. doi:10.1016/j.cretres.2016.02.006. hdl:11336/59544. ISSN 0195-6671.
- ^ 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. 105935. doi:10.1016/j.cretres.2024.105935.
- ^ a b Passalia, M. G.; Garrido, A.; Iglesias, A.; Vera, E. I. (2022-10-14). "The Valcheta Petrified Forest (Upper Cretaceous), Northern Patagonia, Argentina: A Geological And Paleobotanical Survey". Cretaceous Research. 142: 105395. doi:10.1016/j.cretres.2022.105395. ISSN 0195-6671. S2CID 252964524.
Bibliography
- Agnolin, Federico L (2010), "An avian coracoid from the Upper Cretaceous of Patagonia, Argentina", Studia Geologica Salmanticensia, 46 (2): 99–119, retrieved 2019-02-16
- Apesteguía, Sebastián; Rougier, Guillermo W. (2007), "A Late Campanian Sphenodontid Maxilla from Northern Patagonia" (PDF), American Museum Novitates (3581): 1–12, doi:10.1206/0003-0082(2007)3581[1:ALCSMF]2.0.CO;2, retrieved 2019-03-30
- Armas, Paula; Sánchez, María Lidia (2015), "Hybrid coastal edges in the Neuquén Basin (Allen Formation, Upper Cretaceous, Argentina)" (PDF), Andean Geology, 42: 97–113, retrieved 2018-10-02
- Coria, Rodolfo A.; González Riga, Bernardo; Casadío, Silvio (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, retrieved 2019-02-16
- Juárez Valieri, Rubén D.; Haro, José A.; Fiorelli, Lucas E.; Calvo, Jorge O. (2010), "A new hadrosauroid (Dinosauria: Ornithopoda) from the Allen Formation (Late Cretaceous) of Patagonia, Argentina", Revista del Museo Argentino de Ciencias Naturales, New Series, 11 (2): 217–231, doi:10.22179/REVMACN.12.242, hdl:11336/147903, retrieved 2019-02-16
- Novas, F.E.; Kundrat, M.; Agnolín, F.L.; Ezcurra, M.N.D.; Ahlberg, P.E.; Isasi, M.P.; Arriagada, A.; Chafrat, P. (2012), "A new large pterosaur from the Late Cretaceous of Patagonia" (PDF), Journal of Vertebrate Paleontology, 32 (6): 1447, Bibcode:2012JVPal..32.1447N, doi:10.1080/02724634.2012.703979, hdl:11336/98097, retrieved 2019-02-16
- Rougier, G.W.; Chornogubsky, L.; Casadio, S.; Paéz Arango, N.; Giallombardo, A. (2009), "Mammals from the Allen Formation, Late Cretaceous, Argentina (subscription required)", Cretaceous Research, 30 (1): 223–238, Bibcode:2009CrRes..30..223R, doi:10.1016/j.cretres.2008.07.006, hdl:11336/103413, retrieved 2019-02-16
- Salgado, L.; Coria, R.A.; Magalheas Ribeiro, C.M.; Garrido, A.; Rogers, R.; Simon, M.E.; Arcucci, A.B.; Rogers, Carabajal, A. P., Apesteguia, S., Fernandez, M., Garcia, R. A., and Talevi, M., K.C. (2007), "Upper Cretaceous dinosaur nesting sites of Rio Negro (Salitral Ojo de Agua and Salinas de Trapalco-Salitral de Santa Rosa), northern Patagonia, Argentina", Cretaceous Research, 28 (3): 392–404, Bibcode:2007CrRes..28..392S, doi:10.1016/j.cretres.2006.06.007, hdl:11336/183909, retrieved 2019-02-16
{{citation}}
: CS1 maint: multiple names: authors list (link) - 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, retrieved 2019-02-21
Further reading
![](http://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png)
- O'Gorman, J. P., Salgado, L., y Gasparini, Z., 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