Drusilasaura deseadensis gen. et sp. nov., un nuevo titanosaurio (Dinosauria-Sauropoda), de la Formación Bajo Barreal, Cretácico Superior del norte de Santa Cruz, Argentina

Navarrete, César; Casal, Gabriel; Martı́nez, Rubén D.

doi:10.4072/rbp.2011.1.01

Cited by 29 publications

(24 citation statements)

References 12 publications

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“…The existence of a lithologic unconformity at the contact between the Bajo Barreal Formation and the overlying Salamanca Formation, as well as the lack of evidence for a reversed polarity interval that could correspond to Chron 29r (which spans the K-Pg boundary), makes it almost certain that the normal polarity associated with those two units represents different chrons separated by a hiatus. The Bajo Barreal Formation is poorly constrained in time but is generally thought to be Cenomanian-Turonian in age based on 40 Ar/ 39 Ar ages reported from it and the overlying Laguna Palacios Formation (Bridge et al, 2000), as well as its dinosaur fauna (Lamanna et al, 2002;Casal et al, 2009;Navarrete et al, 2011). Our results indicate a reverse-to-normal polarity transition in the uppermost Bajo Barreal in the study area.…”

Section: Chronostratigraphymentioning

confidence: 59%

New age constraints for the Salamanca Formation and lower Rio Chico Group in the western San Jorge Basin, Patagonia, Argentina: Implications for Cretaceous-Paleogene extinction recovery and land mammal age correlations

Clyde

Wilf

Iglesias

et al. 2014

Geological Society of America Bulletin

110

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The Salamanca Formation of the San Jorge Basin (Patagonia, Argentina) preserves critical records of Southern Hemisphere Paleo cene biotas, but its age remains poorly resolved, with estimates ranging from Late Cretaceous to middle Paleocene. We report a multidisciplinary geochronologic study of the Salamanca Formation and overlying Río Chico Group in the western part of the basin. New constraints include (1) an 40 Ar/ 39 Ar age determination of 67.31 ± 0.55 Ma from a basalt fl ow underlying the Salamanca Formation, (2) micropaleontological results indicating an early Danian age for the base of the Salamanca Formation, (3) laser ablation HR-MC-ICP-MS (high resolutionmulti collector-inductively coupled plasmamass spectrometry) U-Pb ages and a high-resolution TIMS (thermal ionization mass spectrometry) age of 61.984 ± 0.041(0.074) [0.100] Ma for zircons from volcanic ash beds in the Peñas Coloradas Formation (Río Chico Group), and (4) paleomagnetic results indicating that the Salamanca Formation in this area is entirely of normal polarity, with reversals occurring in the Río Chico Group. Placing these new age constraints in the context of a sequence stratigraphic model for the basin, we correlate the Salamanca Formation in the study area to Chrons C29n and C28n, with the Banco Negro Inferior (BNI), a mature widespread fossiliferous paleosol unit at the top of the Salamanca Formation, corresponding to the top of Chron C28n. The diverse paleo botanical assemblages from this area are here assigned to C28n (64.67-63.49 Ma), ~2-3 million years older than previously thought, adding to growing evidence for rapid Southern Hemisphere fl oral recovery after the Cretaceous-Paleogene extinction. Important Peligran and "Carodnia" zone vertebrate fossil assemblages from coastal BNI and Peñas Coloradas exposures are likely older than previously thought and correlate to the early Torrejonian and early Tiffanian North American Land Mammal Ages, respectively.

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Section: Chronostratigraphymentioning

confidence: 59%

New age constraints for the Salamanca Formation and lower Rio Chico Group in the western San Jorge Basin, Patagonia, Argentina: Implications for Cretaceous-Paleogene extinction recovery and land mammal age correlations

Clyde

Wilf

Iglesias

et al. 2014

Geological Society of America Bulletin

110

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“…For ex- ample, in Drusilasaura the ventral surface of Cd4? exhibits a pair of large elliptical openings which were considered autapomorphic for this species (Navarrete et al, 2011). Similarly, Salgado (1996) reported on caudals 2 through 4 of Pellegrinisaurus the presence of small holes on each side of the centrum.…”

Section: Sauropoda Marsh 1878mentioning

confidence: 76%

“…On proximal caudals, the excavations are relatively large (i.e., 5 cm long in a centrum 22 cm long), but are reduced or absent in more distal caudals. Such excavations are randomly distributed over centrum surface, being different from the symmetrical ventral perforations present in some titanosaurs, such as Pellegrinisaurus and Drusilasaura (Salgado, 1996;Navarrete et al, 2011). Clearly, the perforations do not invade the vertebral centrum.…”

Section: Riga Et Al 2019)mentioning

confidence: 92%

“…In the case of Drusilasaura, the few overlapping elements preclude proper comparisons with Nullotitan. Both taxa share proximal caudals strongly anteroposteriorly compressed with awllike transverse processes that extend towards the vertebral centrum, a longitudinal ventral groove delimited by thick ridges, and distal caudals dorsoventrally compressed (Navarrete et al, 2011). However, Drusilasaura apomorphically shows two large ventral foramina that are absent in Nullotitan.…”

Section: Riga Et Al 2019)mentioning

confidence: 98%

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Paleontological discoveries in the Chorrillo Formation (upper Campanian-lower Maastrichtian, Upper Cretaceous), Santa Cruz Province, Patagonia, Argentina

Novas¹,

Agnolín²,

Rozadilla³

et al. 2019

MACN

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The first fossil remains of vertebrates, invertebrates, plants and palynomorphs of the Chorrillo Formation (Austral Basin), about 30km to the SW of the town of El Calafate (Province of Santa Cruz), are described. Fossils include the elasmarian (basal Iguanodontia) Isasicursor santacrucensis gen. et sp. nov., the large titanosaur Nullotitan glaciaris gen. et sp. nov., both large and small Megaraptoridae indet., and fragments of sauropod and theropod eggshells. The list of vertebrates is also composed by the Neognathae Kookne yeutensis gen. et sp. nov., two isolated caudal vertebrae of Mammalia indet., and isolated teeth of a large mosasaur. Remains of fishes, anurans, turtles, and snakes are represented by fragmentary material of low taxonomical value, with the exception of remains belonging to Calyptocephalellidae. On the other hand, a remarkable diversity of terrestrial and freshwater gastropods has been documented, as well as fossil woods and palinological assemblages. The Chorrillo Formation continues south, in the Las Chinas River valley, southern Chile, where it is called Dorotea Formation. Both units share in their lower two thirds abundant materials of titanosaurs, whose remains cease to appear in the upper third, registering only elasmarians (Chorrillo Formation) and hadrosaurs (Dorotea Formation). Above both units there are levels with remains of invertebrates and marine reptiles. It is striking that the dinosaurs of the lower two thirds of the Chorrillo and Dorotea formations are represented by large basal titanosaurs and Megaraptoridae coelurosaurs, being the Saltasaurinae and Aeolosaurinae sauropods and Abelisauridae theropods totally absent. In contrast, these taxa are dominant components in sedimentary units of central and northern Patagonia (e.g., Allen, Los Alamitos, La Colonia formations). Such differences could reflect, in part, a greater antiquity (i.e., late Campanian-early Maastrichtian) for the Chorrillo fossils, or, more probably, different environmental conditions. Thus, knowledge of the biota of the southern tip of Patagonia is expanded, particularly those temporarily close to the K-Pg boundary.

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“…The Bajo Barreal Formation was deposited in a fluvial to lacustrine environment (e.g., Paredes et al, 2016). This unit has been assigned to the Cenomanian-Turonian based on 40 Ar/ 39 Ar ages ranging from 95.6 to 91 Myr (Bridge et al, 2000), dinosaur 10.1029/2018TC005173 Tectonics fauna (e.g., Casal et al, 2009;Navarrete et al, 2011), and a recent sensitive high-resolution ion microprobe U/Pb age of 99.7 ± 0.7 Ma (Suárez et al, 2014). However, Clyde et al (2014) suggested that in certain areas this unit could be younger based on the presence of a reverse-to-normal polarity transition in strata of the Bajo Barreal Formation that they interpreted as being Campanian or younger.…”

Section: Geological Overviewmentioning

confidence: 99%

Cretaceous Intraplate Contraction in Southern Patagonia: A Far‐Field Response to Changing Subduction Dynamics?

et al. 2018

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The origin, extent, and timing of intraplate contraction in Patagonia are among the least understood geological processes of southern South America. Particularly, the intraplate Deseado fold‐thrust belt (FTB), located in the Patagonian broken foreland (47°–48°30′S), is one of the most enigmatic areas. In this belt, time constraints on tectonic events are limited and synorogenic deposits have not been documented so far. Furthermore, the driving mechanism for intraplate contraction remains unknown. In this study, we carried out a structural and sedimentological analysis. We report the first syntectonic deposits in this area in the Baqueró (Aptian) and Chubut (Cenomanian/Campanian) groups and a newly found unit referred to as the Albian beds (109.9 ± 1.5 Ma). Thus, several contractional stages in late Aptian, Albian, and Cenomanian‐Campanian are then inferred. We suggest that the Deseado FTB constituted the southernmost expression of the early Patagonian broken foreland in Cretaceous times. Additionally, we analyzed the spatiotemporal magmatic arc behavior as a proxy of dynamic changes in the Andean subduction during determined stages of intraplate contraction. We observe a significant arc broadening from ~121 to 82 Myr and magmatic quiescence after ~67 Ma. This is interpreted as a slab shallowing to flattening process. Far‐field tectonic forces would have been produced by increased plate coupling linked to the slab flattening as indirectly indicated by the correlation between Cretaceous arc expansion and intraplate contraction. Finally, the tectonic evolution of the Deseado FTB favors studies supporting inception of Andean shortening since Cretaceous times.

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Drusilasaura deseadensis gen. et sp. nov., un nuevo titanosaurio (Dinosauria-Sauropoda), de la Formación Bajo Barreal, Cretácico Superior del norte de Santa Cruz, Argentina

Cited by 29 publications

References 12 publications

New age constraints for the Salamanca Formation and lower Rio Chico Group in the western San Jorge Basin, Patagonia, Argentina: Implications for Cretaceous-Paleogene extinction recovery and land mammal age correlations

New age constraints for the Salamanca Formation and lower Rio Chico Group in the western San Jorge Basin, Patagonia, Argentina: Implications for Cretaceous-Paleogene extinction recovery and land mammal age correlations

Paleontological discoveries in the Chorrillo Formation (upper Campanian-lower Maastrichtian, Upper Cretaceous), Santa Cruz Province, Patagonia, Argentina

Cretaceous Intraplate Contraction in Southern Patagonia: A Far‐Field Response to Changing Subduction Dynamics?

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