Short Note: Second Jurassic marine reptile from the Antarctic Peninsula

2008 ◽  
Vol 21 (2) ◽  
pp. 169-170 ◽  
Author(s):  
Daniel C.H. Hikuroa
Keyword(s):  
Antarctic Peninsula ◽  
Short Note ◽  
Marine Reptiles ◽  
Neuquen Basin ◽  
The Rich ◽  
Neuquén Basin ◽  
Marine Reptile ◽  
The Antarctic

Except for the rich record from the Neuquen Basin (e.g. Gasparini & Fernández 2006), Jurassic southern Gondwanan marine reptiles are relatively rare. A tooth discovered in the Bean Peaks, Ellsworth Land, Antarctic Peninsula (Fig. 1) represents the southernmost, and only the second record of Jurassic marine reptiles from the Antarctic Peninsula. Comprising a single, incomplete tooth, the specimen is unable to be assigned to a species, but the paucity of Gondwanan Jurassic marine reptile material means this find adds significant palaeobiogeographical information.

High-concentration sediment plumes, Horseshoe Island, western Antarctic Peninsula

2021 ◽  
pp. 1-4
Author(s):  
CRISTIAN RODRIGO ◽  
ANDRÉS VARAS-GÓMEZ ◽  
ADRIÁN BUSTAMANTE-MAINO ◽  
EMILIO MENA-HODGES
Keyword(s):  
Antarctic Peninsula ◽  
Short Note ◽  
Sediment Concentration ◽  
Change Scenario ◽  
High Concentration ◽  
Tidewater Glaciers ◽  
Marguerite Bay ◽  
Southern Side ◽  
Reported Data ◽  
The Antarctic

The variability in sediment concentration and spatial distribution of meltwater discharges from tidewater glaciers can be used to elucidate climatic evolution and glacier behaviour due to the association between sediment yield and glacier retreat (e.g. Domack & McClennen 1996). In an accelerated deglaciation environment, higher sediment concentrations in the water column can change the glacimarine costal dynamics and affect productivity and sea floor ecosystems (e.g. Marín et al. 2013). In the Antarctic Peninsula Region, meltwater or turbid plumes were previously believed to be rare or without an important role in the sedimentary glacimarine environment (e.g. Griffith & Anderson 1989), but recent studies have shown that this is a common phenomenon in subpolar and transition polar climates (Yoo et al. 2015, Rodrigo et al. 2016). In the current climate change scenario, accelerated glacier retreats and mass losses can produce an increasing input of glacial meltwater into the fjord regions, a situation that is not yet well evaluated in the Antarctic Peninsula. In this short note, after in situ observation of an unusual waterfall from the southern side of the main western tidewater glacier (Shoesmith Glacier) of Horseshoe Island (Lystad Bay), Marguerite Bay (Fig. 1), we report high turbidity values associated with plumes from the glacier, whose values were higher than reported data from subpolar/transition polar Antarctic climates.

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).

Campanian and Maastrichtian mosasaurs from Antarctic Peninsula and Patagonia, Argentina

2012 ◽  
Vol 183 (2) ◽  
pp. 93-102 ◽  
Author(s):  
Marta S. Fernández ◽  
Zulma Gasparini
Keyword(s):  
Antarctic Peninsula ◽  
La Plata ◽  
Northern Patagonia ◽  
Neuquen Basin ◽  
Neuquén Basin ◽  
Stratigraphic Range

Abstract Mosasaurs from Antarctica have been recovered from the late Campanian and early and late Maastrichtian in James Ross, Vega and Seymour Islands within the James Ross basin. Tylosaurinae are represented by the late Campanian-early Maastrichtian remains of Taniwhasaurus antarcticus [Novas et al., 2002] and by late Maastrichtian Tylosaurinae indet.; Plioplatecarpinae by late Maastrichtian Plioplatecarpus sp.; and Mosasaurinae by late Maastrichtian “Liodon” sp., Mosasaurus sp. and Mosasaurinae indet. Materials from Cape Lamb, recently identified in the Museo de La Plata collection (Argentina), suggest that the stratigraphic range of Plioplatecarpus and “Liodon” within the James Ross basin extends back to the early Maastrichtian. At present, the holotype of T. antarcticus is the most complete specimen exhumed from Antarctica. In northern Patagonia, mosasaurs have been recovered from the late Maastrichtian of the Jagüel Formation, Neuquén basin. Patagonian mosasaurs are represented by Mosasaurus sp. aff. M. hoffmanni, Plioplatecarpus sp., Prognathodon sp., and Mosasaurinae indet. Presently, no Tylosaurinae have been found in Patagonia. Both in the James Ross and Neuquén basins, Mosasaurus sp. and Plioplatecarpus sp. occurred close to the K/Pg. boundary.

Short Note: Micropropagation of Antarctic Colobanthus quitensis

2008 ◽  
Vol 21 (2) ◽  
pp. 149-150 ◽  
Author(s):  
Gustavo E. Zúñiga ◽  
Pablo Zamora ◽  
Marcelo Ortega ◽  
Alberto Obrecht
Keyword(s):  
Seed Production ◽  
Plant Species ◽  
Antarctic Peninsula ◽  
Vascular Plant ◽  
Short Note ◽  
Falkland Islands ◽  
Maritime Antarctic ◽  
Colobanthus Quitensis ◽  
The Andes ◽  
The Antarctic

The Antarctic Pearlwort, Colobanthus quitensis (Kunth.) Bartl. (Caryophyllaceae) is one of the two native vascular plant species that have successfully colonized the maritime Antarctic during the Holocene (Smith 1984). Within the Antarctic biome, it is only found on the Antarctic Peninsula and on islands in the maritime Antarctic (Smith 1984). Its distribution also includes South Georgia (sub-Antarctic), the Falkland Islands, and sites along the Andes, reaching c. 10°N in Mexico (Moore 1970). Moore (1970) observed that C. quitensis is self-compatible and appears to be largely, if not entirely, self-pollinated. Convey (1996), found that maritime Antarctic C. quitensis showed lower allocation to seed production than plants from sub-Antarctic sites.

Short Note: New fossil turtle remains from the Eocene of the Antarctic Peninsula

2010 ◽  
Vol 22 (5) ◽  
pp. 531-532 ◽  
Author(s):  
Paula Bona ◽  
Marcelo S. de la Fuente ◽  
Marcelo A. Reguero
Keyword(s):  
Antarctic Peninsula ◽  
Short Note ◽  
The Antarctic

Short Note: An intriguing penguin bone from the Late Eocene of Seymour Island, Antarctic Peninsula

2008 ◽  
Vol 20 (6) ◽  
pp. 589-590 ◽  
Author(s):  
Piotr Jadwiszczak
Keyword(s):  
Antarctic Peninsula ◽  
Short Note ◽  
Late Eocene ◽  
New Genus And Species ◽  
Type Specimens ◽  
West Antarctic ◽  
Antarctic Convergence ◽  
La Meseta Formation ◽  
The Antarctic ◽  
Seymour Island

Penguins (Aves: Sphenisciformes) are interesting to both neontologists and palaeontologists (e.g. Davis & Renner 2003). The fossil record of these extremely specialized inhabitants of the Southern Hemisphere extends back to the Palaeocene epoch (Slack et al. 2006). Extinct penguins are known from localities within the range of their modern-day relatives (Fordyce & Jones 1990), and the oldest diverse assemblage comes from the Eocene La Meseta Formation of Seymour Island, Antarctic Peninsula, the only such locality south of the Antarctic Convergence (Myrcha et al. 2002, Jadwiszczak 2006a). Several collections amounting to over three thousand bones (mainly isolated skeletal elements) have been acquired since 1901 from that formation, and 15 penguin species have been erected so far (Jadwiszczak 2006a, table 1, Tambussi et al. 2006). Only ten of them (grouped into six genera) appear to be taxonomically distinct, and their type specimens are tarsometatarsi (Simpson 1971, Myrcha et al. 2002, Jadwiszczak 2006a, 2006b, p. 296). Individuals from six species belonging to four genera most probably were not larger than those of Aptenodytes forsteri G.R. Gray, 1844, the heaviest and tallest extant penguin (Jadwiszczak 2001, table 3). Interestingly, representatives of all ten species may have co-existed in the West Antarctic during the Late Eocene epoch, just prior to the final break-up of Gondwana (Jadwiszczak 2006a). Presented here is an intriguing partial tarsometatarsus of a small-sized penguin from the Late Eocene of Antarctic Peninsula, probably representing a new genus and species.

3D Seismic Petrophysical Evaluation of Complex Clastic-Carbonate Sequences in the Neuquen Basin, Argentina. A Case Study

2009 ◽  
Author(s):  
Pablo Andres Borghi ◽  
Erick Raciel Alvarez ◽  
Jaume Hernandez ◽  
Rafael Vela ◽  
Marco Antonio Vasquez ◽  
...  
Keyword(s):  
3D Seismic ◽  
Neuquen Basin ◽  
Neuquén Basin ◽  
Petrophysical Evaluation
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