Guichón (water well) (Cretaceous to of Uruguay)

Also known as Uruguaysuchus aznarezi type, Mones Loc. 10

Where: Paysandú, Uruguay (32.3° S, 57.2° W: paleocoordinates 38.8° S, 33.8° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: Guichón Formation (Paysandú Group), Cenomanian to Cenomanian (100.5 - 83.6 Ma)

• See discussion in Soto et al. (2011, 2012) regarding the age of the Guichón Formation. Also listed as Mercedes Formation.

• bed-level stratigraphic resolution

Environment/lithology: fluvial; sandstone

• 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.
• 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.

Size classes: macrofossils, mesofossils

Collected by C. Rusconi, J. Aznarez in the 1930s

Collection methods: salvage, quarrying, mechanical,

Primary reference: 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]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 65322: authorized by Matthew Carrano, entered by Matthew Carrano on 21.09.2006, edited by Philip Mannion

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Reptilia
 Theropoda -
Theropoda indet.
Theropoda indet. Marsh 1881 theropod
tooth "B"
 Ornithischia -
Iguanodontia indet., Iguanodontia indet.
Iguanodontia indet. Baur 1891 ornithopod
tooth "A2"
Iguanodontia indet. Baur 1891 ornithopod
tooth "A1"
 Loricata - Uruguaysuchidae
"Uruguaysuchus aznarezi n. gen. n. sp." = Uruguaysuchus aznarezi, "Uruguaysuchus terrai n. sp." = Uruguaysuchus aznarezi
"Uruguaysuchus aznarezi n. gen. n. sp." = Uruguaysuchus aznarezi Rusconi 1933 crocodilian
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)
"Uruguaysuchus terrai n. sp." = Uruguaysuchus aznarezi Rusconi 1933 crocodilian
CA unnumbered - type (a complete mandible and skull in articulation)