New gastropods from the Jurassic of Orville Coast, eastern Ellsworth Land, Antarctica

2007 ◽  
Vol 19 (1) ◽  
pp. 115-124 ◽  
Author(s):  
Daniel C.H. Hikuroa ◽  
Andrzej Kaim
Keyword(s):  
Southern Hemisphere ◽  
Antarctic Peninsula ◽  
Late Jurassic ◽  
Gastropod Mollusc ◽  
Ancestral Group

The Latady Group (southern Antarctic Peninsula) hosts the most diverse assemblage of Jurassic molluscs from this continent. A new gastropod mollusc, Silberlingiella latadyensis sp. nov. and three forms assigned to Rissoidae, Pseudomelaniidae and Bullinidae from the Middle-Late Jurassic, Bathonian–Kimmeridgian Hauberg Mountains Formation, Ellsworth Land, Antarctic Peninsula are described here. Silberlingiella is transferred to Eustomatidae and is the first confirmed record of this family in the Southern Hemisphere, indicating a much more widespread Jurassic distribution. The Triassic and Jurassic species of Silberlingiella are compared with the coeval European genus Diatinostoma. Eustomatidae is proposed as an ancestral group for Potamididae and Batillariidae. The composition of the gastropod association described herein differs markedly from the only other Antarctic Jurassic fauna from Alexander Island.

Palynology of the Lachman Crags Member, Santa Marta Formation (Upper Cretaceous) of north-west James Ross Island

1992 ◽  
Vol 4 (3) ◽  
pp. 293-304 ◽  
Author(s):  
J.M. Keating
Keyword(s):  
Southern Hemisphere ◽  
Antarctic Peninsula ◽  
Late Jurassic ◽  
Upper Cretaceous ◽  
Undescribed Species ◽  
Dinoflagellate Cyst ◽  
North West ◽  
James Ross Island

Palynomorph assemblages from the Lachman Crags Member of the Santa Marta Formation, north-west James Ross Island, Antarctic Peninsula are described. By basis of comparison with other Southern Hemisphere localities, particularly southern Australia, an early Santonian–early Campanian age is indicated. The results broadly corroborate previous stratigraphical interpretations based on macrofaunal evidence, although the presence of a significant thickness of Santonian strata, not previously recognized, is suggested. The dinoflagellate cyst floras allow the recognition of the local equivalents of the Australian Odontochitina porifera, Isabelidinium cretaceum, Nelsoniella aceras and Xenikoon australis Interval Zones. Some recycling of mid Cretaceous (and possibly Late Jurassic) taxa is also indicated. The miospore flora is composed of relatively long-ranging species, although the local appearance of certain taxa may be of stratigraphical significance. Ranges recorded support previous interpretations of heterochroneity in Southern Hemisphere floras. The palynoflora comprises 76 dinoflagellate cyst, 40 miospore and 7 acritarch, prasinophyte and chlorophyte taxa. Six undescribed species of dinoflagellate cyst are recorded and placed in open nomenclature.

scholarly journals The oldest hexanchiform shark from the Southern Hemisphere (Neoselachii; Early Cretaceous, Antarctica)

2009 ◽  
Vol 21 (5) ◽  
pp. 501-504 ◽  
Author(s):  
Alberto Luis Cione ◽  
Francisco Medina
Keyword(s):  
Southern Hemisphere ◽  
Antarctic Peninsula ◽  
Early Cretaceous ◽  
The Other ◽  
James Ross Island

AbstractThe oldest record of the hexanchiform sharks from the Southern Hemisphere and the second chondrichthyan report known from Carboniferous to Early Cretaceous beds in Antarctica is given. The material was collected in late Aptian rocks of the Kotick Point Formation outcropping in the western part of James Ross Island, near Antarctic Peninsula. It consists of an isolated tooth assignable to a hexanchiform different from the other described genera. The tooth shows putative plesiomorphic cusp (few cusps, no serrations) and apomorphic root characters (relatively deep, quadrangular). It could be related to a species close to the origin ofHexanchus(unknown in beds older than Cenomanian).

New trigonioid bivalves from the Early Jurassic to earliest Cretaceous of the Antarctic Peninsula region: systematics and austral paleobiogeography

1995 ◽  
Vol 69 (1) ◽  
pp. 66-84 ◽  
Author(s):  
Simon R. A. Kelly
Keyword(s):  
New Zealand ◽  
Antarctic Peninsula ◽  
Southern Africa ◽  
Late Jurassic ◽  
Early Jurassic ◽  
South Shetland Islands ◽  
Shetland Islands ◽  
Livingston Island ◽  
History Of ◽  
The Antarctic

New discoveries of trigonioid bivalves are documented from three areas in the Antartic Peninsula: the Fossil Bluff Group of Alexander Island, the Latady Formation of the Orville Coast, and the Byers Group of Livingston Island, South Shetland Islands. Eleven taxa are described, representing six genera or subgenera. The faunas are characterized by genera including Vaugonia (Vaugonia), the first Early Jurassic trigonioid recognized on the continent; Vaugonia (V.) and V. (Orthotrigonia?) in the Late Jurassic; and Iotrigonia (Iotrigonia), Myophorella (Scaphogonia), and Pterotrigonia (Pterotrigonia), which span the Jurassic–Cretaceous boundary, reaching the Berriasian stage. The following species are new: Pterotrigonia (P.) cramei n. sp., Pterotrigonia (P.) thomsoni n. sp., Vaugonia (V.) orvillensis n. sp., and V. (Orthotrigonia?) quiltyi n. sp. The faunas show affinities with those of New Zealand and southern Africa. Trigonioids characterize the shallower marine biofacies in the Jurassic of the Antarctic and reflect the principal shallowing events in the history of the region.

First pachycormiform (Actinopterygii, Pachycormiformes) remains from the Late Jurassic of the Antarctic Peninsula and remarks on bone alteration by recent bioeroders

2018 ◽  
Vol 38 (5) ◽  
pp. e1524384 ◽  
Author(s):  
Soledad Gouiric-Cavalli ◽  
Luciano L. Rasia ◽  
Gonzalo J. Márquez ◽  
Vilma Rosato ◽  
Roberto A. Scasso ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Late Jurassic ◽  
The Antarctic

Dinoflagellate cysts from an allochthonous block of Nordenskjöld Formation (Upper Jurassic), north-west James Ross Island

1992 ◽  
Vol 4 (3) ◽  
pp. 267-278 ◽  
Author(s):  
Michael G. Snape
Keyword(s):  
New Species ◽  
Papua New Guinea ◽  
Antarctic Peninsula ◽  
Late Jurassic ◽  
New Genus ◽  
Upper Jurassic ◽  
Dinoflagellate Cysts ◽  
Dinoflagellate Cyst ◽  
North West ◽  
James Ross Island

An allochthonous block of the Nordenskjöld Formation from north-west James Ross Island, Antarctic Peninsula has yielded a diverse marine palynoflora. Dinoflagellate cyst assemblages from the 185 m thick sequence are described and compared with similar microfloras previously described from Australia, Papua New Guinea and Madagascar. A mid Tithonian (Late Jurassic) age is suggested for the section. One new genus, Helbydinium gen. nov. and four new species, Helbydinium scabratum sp. nov., Leptodinium acneum sp. nov., Leptodinium posterosulcatum sp. nov. and Rhynchodiniopsis foveata sp. nov. are described.

scholarly journals Stratospheric gravity waves at Southern Hemisphere orographic hotspots: 2003–2014 AIRS/Aqua observations

2016 ◽  
Vol 16 (14) ◽  
pp. 9381-9397 ◽  
Author(s):  
Lars Hoffmann ◽  
Alison W. Grimsdell ◽  
M. Joan Alexander
Keyword(s):  
Gravity Wave ◽  
Southern Hemisphere ◽  
Antarctic Peninsula ◽  
Gravity Waves ◽  
General Circulation ◽  
Wave Activity ◽  
Small Scale ◽  
Mountain Wave ◽  
Kerguelen Islands ◽  
The Antarctic

Abstract. Stratospheric gravity waves from small-scale orographic sources are currently not well-represented in general circulation models. This may be a reason why many simulations have difficulty reproducing the dynamical behavior of the Southern Hemisphere polar vortex in a realistic manner. Here we discuss a 12-year record (2003–2014) of stratospheric gravity wave activity at Southern Hemisphere orographic hotspots as observed by the Atmospheric InfraRed Sounder (AIRS) aboard the National Aeronautics and Space Administration's (NASA) Aqua satellite. We introduce a simple and effective approach, referred to as the “two-box method”, to detect gravity wave activity from infrared nadir sounder measurements and to discriminate between gravity waves from orographic and other sources. From austral mid-fall to mid-spring (April–October) the contributions of orographic sources to the observed gravity wave occurrence frequencies were found to be largest for the Andes (90 %), followed by the Antarctic Peninsula (76 %), Kerguelen Islands (73 %), Tasmania (70 %), New Zealand (67 %), Heard Island (60 %), and other hotspots (24–54 %). Mountain wave activity was found to be closely correlated with peak terrain altitudes, and with zonal winds in the lower troposphere and mid-stratosphere. We propose a simple model to predict the occurrence of mountain wave events in the AIRS observations using zonal wind thresholds at 3 and 750 hPa. The model has significant predictive skill for hotspots where gravity wave activity is primarily due to orographic sources. It typically reproduces seasonal variations of the mountain wave occurrence frequencies at the Antarctic Peninsula and Kerguelen Islands from near zero to over 60 % with mean absolute errors of 4–5 percentage points. The prediction model can be used to disentangle upper level wind effects on observed occurrence frequencies from low-level source and other influences. The data and methods presented here can help to identify interesting case studies in the vast amount of AIRS data, which could then be further explored to study the specific characteristics of stratospheric gravity waves from orographic sources and to support model validation.

Late Jurassic (Kimmeridgian-Tithonian) macrofossil assemblage from Jason Peninsula, Graham Land: evidence for a significant northward extension of the Latady Formation

1997 ◽  
Vol 9 (4) ◽  
pp. 434-442 ◽  
Author(s):  
T.R. Riley ◽  
J.A. Crame ◽  
M.R.A. Thomson ◽  
D.J. Cantrill
Keyword(s):  
Antarctic Peninsula ◽  
Late Jurassic ◽  
Volcanic Rocks ◽  
Sedimentary Rocks ◽  
Coarse Grained ◽  
Areal Extent ◽  
South Eastern ◽  
Back Arc ◽  
The Antarctic ◽  
Major Sequence

New exposures of fossiliferous sedimentary rocks at Cape Framnes, Jason Peninsula (65°57′S, 60°33′W) are assigned to the Middle–Late Jurassic Latady Formation of the south-eastern Antarctic Peninsula region. A sequence of fine to coarse-grained sandstones of unknown thickness has yielded a molluscan and plant macrofossil assemblage rich in the following elements: perisphinctid ammonites, belemnopseid belemnites, oxytomid, trigoniid and astartid bivalves, and bennettitalean fronds and fructifications. The overwhelming age affinities are with the Kimmeridgian–early Tithonian part of the Latady Formation, as exposed on the Orville and Lassiter coasts. The Cape Framnes sedimentary rocks help to constrain the age of a major sequence of acid volcanic rocks on Jason Peninsula, and show that the Latady Basin was geographically much more extensive than recognized previously. It was the principal depositional centre of Middle–Late Jurassic sedimentation in the Antarctic Peninsula back-arc region and in areal extent may have rivalled the essentially Cretaceous Larsen Basin.

Late Mesozoic bipolar bivalve faunas

1986 ◽  
Vol 123 (6) ◽  
pp. 611-618 ◽  
Author(s):  
J. A. Crame
Keyword(s):  
Southern Hemisphere ◽  
Late Cretaceous ◽  
High Latitude ◽  
Late Jurassic ◽  
Temperature Gradients ◽  
Late Mesozoic ◽  
Cool Temperate

AbstractBipolar bivalve genera probably existed through the greater part of late Mesozoic (i.e. late Jurassic–late Cretaceous) time. Of the various theories put forward to account for their presence, those based on some form of global climatic zonation seem most appropriate. Although equatorial–polar temperature gradients were substantially less in late Mesozoic time than at the present day, high latitude regions were subjected to temperate (or even cool-temperate) climatic regimes. Macrobenthonic marine faunas may have been more susceptible to differentiation in response to these climatic patterns than nektonic ones. This is particularly so in the late Mesozoic strata of the Southern Hemisphere.

scholarly journals Post-cranial remains of ‘coelurosaurs’ (Dinosauria, Theropoda) from the Late Jurassic of Tanzania

2005 ◽  
Vol 142 (1) ◽  
pp. 97-107 ◽  
Author(s):  
OLIVER W. M. RAUHUT
Keyword(s):  
Southern Hemisphere ◽  
Middle Jurassic ◽  
Late Jurassic ◽  
East African ◽  
Faunal Element

Small theropod post-cranial material from Tendaguru, Tanzania, the only known Late Jurassic theropod locality in the Southern Hemisphere, is reviewed. Material originally described as ‘coelurosaurs’ includes at least one taxon of basal tetanuran and one taxon of small abelisauroid. Together with the abelisauroid Elaphrosaurus and the presence of a larger ceratosaur in Tendaguru, this material indicates that ceratosaurs were an important faunal element of Late Jurassic East African theropod faunas. One bone furthermore shares derived characters with the holotype of the poorly known Middle Jurassic Australian theropod Ozraptor and allows the identification of the latter as the oldest known abelisauroid, thus indicating an early divergence of ceratosaurids and abelisauroids within ceratosaurs. Abelisauroids might have originated in Gondwana and represent important faunal elements of Cretaceous Gondwanan theropod faunas in general.

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