Exceptional preservation of a barred shoreline under forced‐regressive conditions (Lower Cretaceous, Neuquén Basin, Argentina)

Sedimentology ◽  
2021 ◽  
Author(s):  
Manuel F. Isla ◽  
Mariana S. Olivo ◽  
Jerónimo J. Zuazo ◽  
Ernesto Schwarz ◽  
Gonzalo D. Veiga
Keyword(s):  
Lower Cretaceous ◽  
Exceptional Preservation ◽  
Neuquen Basin ◽  
Neuquén Basin

First articulated stalked crinoids from the Mesozoic of South America: two new species from the Lower Cretaceous of the Neuquén Basin, west-central Argentina

2020 ◽  
Vol 94 (4) ◽  
pp. 716-733
Author(s):  
Darío G. Lazo ◽  
Graciela S. Bressan ◽  
Ernesto Schwarz ◽  
Gonzalo D. Veiga
Keyword(s):  
New Species ◽  
Lower Cretaceous ◽  
Carbonate Sediments ◽  
Exceptional Preservation ◽  
Central Argentina ◽  
West Central ◽  
Subaqueous Dunes ◽  
Neuquen Basin ◽  
Neuquén Basin ◽  
Slender Column

AbstractTwo new isocrinids are described from the Lower Cretaceous Agrio Formation of the Neuquén Basin, west-central Argentina. Isocrinus (Chladocrinus) covuncoensis new species is based on several beautifully preserved specimens from Valanginian beds of the Pilmatué Member. It is characterized by a small size, multiramose crown with six arm divisions, 240 arm tips, mostly isotomous branching, seven (or rarely eight) secundibrachials, smooth and stout column, short noditaxis, and pentalobate columnals. The species occurs in a 30 m thick interval of cross-bedded sandstones and mixed clastic-carbonate sediments that represent the migration of large, tidally influenced, subaqueous dunes developed in the offshore. Sudden burial of crinoids that dwelled on the dune toes and interdunes, possibly by the acceleration of the lee face migration, provided the exceptional preservation of specimens and thus this finding can be considered as a local crinoid Konservat Lagerstätte. Isocrinus (Chladocrinus) pehuenchensis new species is described from a single articulated specimen preserved in a silty calcareous concretion collected from a late Hauterivian concretion level of the Agua de la Mula Member. It is characterized by isotomous branching, eight or nine secundibrachials (IIBr), slender column ornamented with medial ridge of fine tubercles, interradius acuminated with fine tubercles on its tip, short noditaxis, and pentastellate columnals. It is associated with low-energy fall-out deposits in the offshore. The excellent state of preservation was due to an early cementation process by carbonate that enhanced lithification around the specimen.UUID: http://zoobank.org/4763ae70-9d0a-4015-b1c9-6a7ceeedfb1a

First plesiosaur remains from the lower Cretaceous of the Neuquén Basin, Argentina

2003 ◽  
Vol 77 (4) ◽  
pp. 784-789 ◽  
Author(s):  
Dario G. Lazo ◽  
Marcela Cichowolski
Keyword(s):  
Lower Cretaceous ◽  
Sister Group ◽  
Monophyletic Group ◽  
Phylogenetic Position ◽  
Crown Group ◽  
Marine Reptiles ◽  
Stem Group ◽  
Neuquen Basin ◽  
Neuquén Basin

Plesiosaurs constitute a monophyletic group whose stratigraphical range is uppermost Triassic to uppermost Cretaceous (Brown, 1981). They were large predatory marine reptiles, highly adapted for submarine locomotion, with powerful paddle-like limbs and heavily reinforced limb girdles (Saint-Seine, 1955; Romer, 1966; Carroll, 1988; Benton, 1990). The Plesiosauria clade belongs to the Sauropterygia, which has recently been hypothesized as the sister-group of the Ichthyosauria. Together with that clade they form the Euryapsida (Caldwell, 1997). The Sauropterygia can be subdivided into relatively plesiomorphic stem-group taxa from the Triassic (Placodonts, Nothosauroids, and Pistosauroids), and the obligatorily marine crown-group Plesiosauria (Rieppel, 1999). Plesiosaurs are traditionally divided into two superfamilies: Plesiosauroidea, with usually small heads and long necks; and Pliosauroidea, with larger heads and shorter necks (Welles, 1943; Persson, 1963; Brown, 1981). Plesiosauroidea contains three families: Plesiosauridae, Cryptoclididae, and Elasmosauridae (Brown, 1981; Brown and Cruickshank, 1994). The validity of the Polycotylidae Cope, 1869, has long been questioned and its phylogenetic position among Plesiosauria debated, as many consider it to be related to the Pliosauridae or to be a sister-group of the Elasmosauridae (Sato and Storrs, 2000; O'Keefe, 2001).

Depositional and postdepositional processes of an oil-shale analog at the microstructure scale: The Lower Cretaceous Agrio Formation, Neuquén Basin, northern Patagonia

AAPG Bulletin ◽  
2020 ◽  
Vol 104 (8) ◽  
pp. 1679-1705
Author(s):  
Marcos Comerio ◽  
Diana E. Fernández ◽  
Nicolás Rendtorff ◽  
Mariano Cipollone ◽  
Patricia E. Zalba ◽  
...  
Keyword(s):  
Lower Cretaceous ◽  
Oil Shale ◽  
Northern Patagonia ◽  
Neuquen Basin ◽  
Neuquén Basin

Lower Cretaceous (Berriasian-Aptian) biostratigraphy of the Neuquén Basin

2005 ◽  
Vol 252 (1) ◽  
pp. 57-81 ◽  
Author(s):  
M. Beatriz Aguirre-Urreta ◽  
Peter F. Rawson ◽  
G. Andrea Concheyro ◽  
Paul R. Bown ◽  
Eduardo G. Ottone
Keyword(s):  
Lower Cretaceous ◽  
Neuquen Basin ◽  
Neuquén Basin

Palaeodemecological Analysis of Infaunal Bivalves “Lebensspuren” from the Mulichinco Formation, Lower Cretaceous, Neuquén Basin, Argentina

Ameghiniana ◽  
2012 ◽  
Vol 49 (1) ◽  
pp. 47-59 ◽  
Author(s):  
Javier Echevarría ◽  
Susana E. Damborenea ◽  
Miguel O. Manceñido
Keyword(s):  
Lower Cretaceous ◽  
Neuquen Basin ◽  
Neuquén Basin
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