The Quebrada del Barro Formation formed within arift basin during a period of renewed fracturing. It encompasses 600 to 1,400 metres (2,000 to 4,600 ft) of redsandstones, fineconglomerates, anddiamictites.[3] Early hypotheses on the depositional environment proposed that the sediments formed in analluvial fan orbraided river system, while a newer proposal outlines how four differentfacies within the formation can be used to reconstruct a meanderingsemiarid floodplain deposited bymudflows and discharging inheterolithicterminal splays.[6]
The fauna of Quebrada del Barro is similar to that of the neighboringLos Colorados Formation which is considered to be from theNorian stage of the Late Triassic.[7] Both formations preserve fossils from groups such assauropodomorphdinosaurs,cynodonts, andtestudinatans. However, Quebrada del Barro is more abundant insphenodontians (Sphenotitan),tritheledontid cynodonts, andcoelophysoid dinosaurs (Lucianovenator), while sauropodomorphs are somewhat less common andaetosaurs are completely absent, in contrast to the Los Colorados Formation.[3] Sphenodontians and cynodonts are also abundant in microfossil assemblages.[6] In addition, the Quebrada del Barro Formation preserves some of the onlypterosaur andDromomeron specimens known from Triassic strata in Argentina. Although the sphenodontian and cynodont-dominated fauna of Quebrada del Barro is akin to that of the Faxinal del Sotorno assemblage of theBrazilianCaturrita Formation, the fauna of the Faxinal del Sotorno assemblage is otherwise indicative of an older part of the Triassic than the Quebrada del Barro Formation.[3]
^Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Triassic, South America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 527–528.ISBN0-520-24209-2.
^Ricardo N. Martínez; Cecilia Apaldetti (2017). "A late Norian-Rhaetian coelophysid neotheropod (Dinosauria, Saurischia) from the Quebrada del Barro Formation, northwestern Argentina". Ameghiniana. in press.doi:10.5710/AMGH.09.04.2017.3065.
^"Riojasaurus." In: Dodson, Peter & Britt, Brooks & Carpenter, Kenneth & Forster, Catherine A. & Gillette, David D. & Norell, Mark A. & Olshevsky, George & Parrish, J. Michael & Weishampel, David B.The Age of Dinosaurs. Publications International, LTD. p. 41.ISBN0-7853-0443-6.
^Ricardo N. Martínez; Cecilia Apaldetti; Gustavo A. Correa; Diego Abelín (2016). "A Norian lagerpetid dinosauromorph from the Quebrada del Barro Formation, northwestern Argentina".Ameghiniana.53 (1):1–13.doi:10.5710/AMGH.21.06.2015.2894.S2CID131613066.
Argentina
