Guichón (water well): Cenomanian - Santonian, Uruguay
collected by C. Rusconi, J. Aznarez 1930

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Reptilia
Huene 1934 1 specimen
tooth "A2"
Mones 1972
Weishampel and Weishampel 1983
Soto et al. 2011
Soto & Cambiaso (2006)
Huene 1934 1 specimen
tooth "A1"
Weishampel and Weishampel 1983
Soto et al. 2011
Soto & Cambiaso (2006)
Huene 1934 1 specimen
tooth "B"
Soto et al. 2011
Soto & Cambiaso (2006)
Reptilia - Uruguaysuchidae
1 specimen
CA unnumbered - holotype (an approximately.1.2-m-long articulated adult individual (including a complete skull, mandible, right forelimb, 18 vertebrae, both ilia and partial right hindlimb, as well as a few associated osteoderms); 5 partial paratype skeletons also found, but now lost (Soto et al. 2011); FC-DPV 2320 - referred specimen (partial skull, a lower jaw and three cervical vertebrae)
1 specimen
CA unnumbered - type (a complete mandible and skull in articulation)
see common names

Geography
Country:Uruguay State/province:Paysandú
Coordinates: 32.3° South, 57.2° West (view map)
Paleocoordinates:33.0° South, 25.7° West (Wright 2013)
Basis of coordinate:based on nearby landmark
Geographic resolution:small collection
Time
Period: Cretaceous Epoch: Late Cretaceous
Stage: Cenomanian - Santonian 10 m.y. bin: Cretaceous 5 - Cretaceous 6
Key time interval: Cenomanian - Santonian
Age range of interval: 100.5 - 83.6 m.y. ago
Stratigraphy
Geological group:Paysandú Formation:Guichón
Stratigraphic resolution:bed
Stratigraphy comments: See discussion in Soto et al. (2011, 2012) regarding the age of the Guichón Formation. Also listed as Mercedes Formation.
Lithology and environment
Primary lithology: sandstone
Includes fossils?Y
Lithology description: Guichón Formation comprises mainly pink-greyish to reddish sandstones, which contain moderate to well-sorted, subrounded, fine to medium-sized grains in a pelitic matrix. These sandstones (which compositionally are feldspathic wackes) are either massive or may instead exhibit parallel lamination, cross-lamination and graded bedding.
Environment:fluvial indet.
Geology comments: These lithologies were deposited in southwest- trending alluvial–fluvial systems comprising low-sinuosity channels traversing through sandy plains. Subordinate to the already mentioned sandstones are conglomeratic and pelitic lithologies, interpreted as channel-fill and overbank deposits, respectively. It is inferred that the Guichón Formation was deposited in warm, semi-arid climatic conditions.
Taphonomy
Modes of preservation:body
Degree of concentration:concentrated
Size of fossils:macrofossils,mesofossils
Preservation of anatomical detail:medium
Associated major elements:some
Disassociated major elements:some
Disassociated minor elements:some
Collection methods and comments
Collection methods:salvage,selective quarrying,mechanical,field collection,survey of museum collection
Reason for describing collection:taxonomic analysis
Collectors:C. Rusconi, J. Aznarez Collection dates:1930s
Metadata
Also known as:Uruguaysuchus aznarezi type, Mones Loc. 10
Database number:65322
Authorizer:M. Carrano, P. Mannion Enterer:M. Carrano, P. Mannion
Modifier:M. Carrano Research group:vertebrate
Created:2006-09-21 06:19:39 Last modified:2025-02-22 15:12:02
Access level:the public Released:2006-09-21 06:19:39
Creative Commons license:CC0
Reference information

Primary reference:
78882. C. Rusconi. 1933. Sobre reptiles cretáceos del Uruguay (Uruguaysuchus aznarezi, n.g.n.sp.) y sus relaciones con los notosúquidos de Patagonia [On the Cretaceous reptiles of Uruguay (Uruguaysuchus aznarezi, n.g.n.sp.) and their relationships with the notosuchids of Patagonia]. Instituto de Geología y Perforaciones Boletín 19:1-64 [M. Carrano/M. Carrano/M. Carrano]

Secondary references:

75729 P. Cruzado-Caballero, L. S. Filippi, A. H. Méndez, A. C. Garrido, and I. Díaz-Martínez. 2018. First ornithopod remains from the Bajo de la Carpa Formation (Santonian, Upper Cretaceous), northern Patagonia, Argentina. Cretaceous Research 83:182-193 [M. Carrano/M. Carrano/M. Carrano]
79220 C. Goso Aguilar and D. Perea. 2004. El Cretácico post-basáltico y el Terciario Inferior de la Cuenca Litoral de Río Uruguay: geología y paleontología []. In G. Veroslavsky, M. Ubilla, & S. Martínez (eds.), Cuencas Sedimentarias de Uruguay. Geología, Paleontología y Recursos Naturales. Mesozoico 143-171 [M. Carrano/M. Carrano]
64844 F. v. Huene. 1934. Nuevos dientes de Saurios de cretáceo del Uruguay [New saurian teeth from the Cretaceous of Uruguay]. Boletín, Instituto de Geología y Perforaciones (Uruguay) 21:13-20 [M. Carrano/M. Carrano]
24360ETE F. v. Huene. 1934. Neue Saurier-Zähne aus der Kreide von Uruguay [New saurian teeth from the Cretaceous of Uruguay]. Centralblatt für Mineralogie, Geologie und Paläontologie, Abteilung B: Geologie und Paläontologie 1934(4):183-189 [M. Carrano/M. Carrano]
82857 R. Lambert. 1941. Estado actual de nuestros conocimientos sobra la geología de la República Oriental del Uruguay [Current state of our knowledge about the geology of the Oriental Republic of Uruguay]. Boletin del Instituto Geológico del Uruguay 29:1-89 [M. Carrano/M. Carrano]
18841ETE A. Mones. 1972. Lista de los vertebrados fosiles del Uruguay, I. Chondrichthyes, Osteichthyes, Reptilia, Aves [List of the fossil vertebrates of Uruguay, I. Chondrichthyes, Osteichthyes, Reptilia, Aves]. Comunicaciones Paleontologicas del Museo de Historia Natural de Montevideo 1(3):23-35 [M. Carrano/M. Carrano]
79333 Á Mones. 1997. Los vertebrados mesozoicos del Uruguay y sus relaciones con los de áreas vecinas [The Mesozoic vertebrates of Uruguay and their relationships with those of neighboring areas]. In J. Arroyo Cabrales & Ó. J. Polaco (ed.), Homenaje al Profesor Ticul Álvarez. Colección Científica (Instituto Nacional de Antropología e Historia (Mexico)) 357:205-222 [M. Carrano/M. Carrano]
42879 M. Soto, D. Perea, and A. Cambiaso. 2012. First sauropod (Dinosauria: Saurischia) remains from the Guichón Formation, Late Cretaceous of Uruguay. Journal of South American Earth Sciences 33(1):68-79 [P. Mannion/P. Mannion/M. Carrano]
39436 M. Soto, D. Pol, and D. Perea. 2011. A new specimen of Uruguaysuchus aznarezi (Crocodyliformes: Notosuchia) from the middle Cretaceous of Uruguay and its phylogenetic relationships. Zoological Journal of the Linnean Society 163:S173-S198 [P. Mannion/P. Mannion]
61518 D. B. Weishampel and J. B. Weishampel. 1983. Annotated localities of ornithopod dinosaurs: implications to Mesozoic paleobiogeography. The Mosasaur 1:43-87 [M. Carrano/M. Carrano]