Antarctic Peninsular cryosphere: Early Oligocene (
            <i>c.</i>
            30 Ma) initiation and a revised glacial chronology

Dingle, R. V.; Lavelle, M.

doi:10.1144/gsjgs.155.3.0433

Cited by 108 publications

(77 citation statements)

References 14 publications

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“…This interpretation may be supported by the occurrence of middle Eocene (alpine?) glacial deposits on King George Island in the South Shetland Islands (14), although equivalent age deposits on Seymour Island show no evidence for glaciation at that time (15).…”

mentioning

confidence: 99%

Progressive Cenozoic cooling and the demise of Antarctica’s last refugium

Anderson

Warny

Askin³

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

126

117

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The Antarctic Peninsula is considered to be the last region of Antarctica to have been fully glaciated as a result of Cenozoic climatic cooling. As such, it was likely the last refugium for plants and animals that had inhabited the continent since it separated from the Gondwana supercontinent. Drill cores and seismic data acquired during two cruises (SHALDRIL I and II) in the northernmost Peninsula region yield a record that, when combined with existing data, indicates progressive cooling and associated changes in terrestrial vegetation over the course of the past 37 million years. Mountain glaciation began in the latest Eocene (approximately 37–34 Ma), contemporaneous with glaciation elsewhere on the continent and a reduction in atmospheric CO 2 concentrations. This climate cooling was accompanied by a decrease in diversity of the angiosperm-dominated vegetation that inhabited the northern peninsula during the Eocene. A mosaic of southern beech and conifer-dominated woodlands and tundra continued to occupy the region during the Oligocene (approximately 34–23 Ma). By the middle Miocene (approximately 16–11.6 Ma), localized pockets of limited tundra still existed at least until 12.8 Ma. The transition from temperate, alpine glaciation to a dynamic, polythermal ice sheet took place during the middle Miocene. The northernmost Peninsula was overridden by an ice sheet in the early Pliocene (approximately 5.3–3.6 Ma). The long cooling history of the peninsula is consistent with the extended timescales of tectonic evolution of the Antarctic margin, involving the opening of ocean passageways and associated establishment of circumpolar circulation.

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mentioning

confidence: 99%

Progressive Cenozoic cooling and the demise of Antarctica’s last refugium

Anderson

Warny

Askin³

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

126

117

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“…The oldest reported fossil mysticete is the archaic toothed Llanocetus denticrenatus, dated at about 34.2 Myr B.P. (45)(46)(47) The rapid radiation of extant cetaceans predicted by SINE methods is elucidated by geological processes. Fossil cetaceans are rare in the interval from 34 to 29 -30 Myr B.P., probably because changing global sea levels (caused by a f luctuating Antarctic ice-cap) eroded bone-rich strata (5,51).…”

Section: Discussionmentioning

confidence: 99%

Retroposon analysis of major cetacean lineages: The monophyly of toothed whales and the paraphyly of river dolphins

Nikaido

Matsuno

Hamilton

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

233

164

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SINE (short interspersed element) insertion analysis elucidates contentious aspects in the phylogeny of toothed whales and dolphins (Odontoceti), especially river dolphins. Here, we characterize 25 informative SINEs inserted into unique genomic loci during evolution of odontocetes to construct a cladogram, and determine a total of 2.8 kb per taxon of the flanking sequences of these SINE loci to estimate divergence times among lineages. We demonstrate that: (i) Odontocetes are monophyletic; (ii) Ganges River dolphins, beaked whales, and ocean dolphins diverged (in this order) after sperm whales; (iii) three other river dolphin taxa, namely the Amazon, La Plata, and Yangtze river dolphins, form a monophyletic group with Yangtze River dolphins being the most basal; and (iv) the rapid radiation of extant cetacean lineages occurred some 28 -33 million years B.P., in strong accord with the fossil record. The combination of SINE and flanking sequence analysis suggests a topology and set of divergence times for odontocete relationships, offering alternative explanations for several long-standing problems in cetacean evolution.SINE ͉ evolution ͉ divergence times

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“…The age of the formation is determined by K−Ar radiometrically dated basalt lavas of the underlying Sherrat Bay Formation and transverse dikes, as well as by biostratigraphic studies, which indicate its deposition during the earliest Miocene glaciation in the Antarctic Peninsula region, the Melville Glaciation (see Birkenmajer et al 1983;Birkenmajer 1987Birkenmajer , 1995Birkenmajer , 2001Dingle and Lavelle 1998;Troedson and Riding 2002). …”

Section: Geological Settingmentioning

confidence: 99%

Early Cambrian bradoriide and phosphatocopide arthropods from King George Island, West Antarctica: Biogeographic implications

Wrona¹

2009

PPRes

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Arthropod carapaces have been recovered from the Early Cambrian fossiliferous limestone erratics (dropstones) in the Early Miocene glaciomarine Cape Melville Forma− tion of King George Island (South Shetland Islands), West Antarctica. The arthropod fauna comprises the bradoriide carapaces of Albrunnicola bengtsoni Hinz−Schallreuter, Liang− shanella birkenmajeri sp. nov., Melvillella corniculata gen. et sp. nov., Mongolitubulus squamifer Missarzhevsky, ?Zepaera sp., the phosphatocopid ?Dabashanella sp., and one problematic taxon. With the exception of M. squamifer, all described species are recorded from Antarctica for the first time. The described Antarctic bradoriide assemblage attests to a close relationship with similar faunas from South Australia and South China, but also in− cludes more widely distributed taxa extending the relationship to the palaeocontinents of Siberia, Baltica and Laurentia.

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Antarctic Peninsular cryosphere: Early Oligocene ( c. 30 Ma) initiation and a revised glacial chronology

Cited by 108 publications

References 14 publications

Progressive Cenozoic cooling and the demise of Antarctica’s last refugium

Progressive Cenozoic cooling and the demise of Antarctica’s last refugium

Retroposon analysis of major cetacean lineages: The monophyly of toothed whales and the paraphyly of river dolphins

Early Cambrian bradoriide and phosphatocopide arthropods from King George Island, West Antarctica: Biogeographic implications

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