End Ordovician extinctions: A coincidence of causes

Harper, David A. T.; Hammarlund, Emma U.; Rasmussen, C. E.

doi:10.1016/j.gr.2012.12.021

Cited by 257 publications

(181 citation statements)

References 61 publications

Supporting

Mentioning

165

Contrasting

Unclassified

Order By: Relevance

“…However, substantial uncertainty remains regarding the mechanisms of extinction-there are many ways in which climatic transitions and associated oceanographic changes could potentially lead to elevated extinctions, particularly through habitat loss [5,8,11]. Previous studies of the LOME have implicated two major drivers of extinction: (i) loss of species inhabiting shallow cratonic seaways that drained as Gondwanan glaciers grew; and (ii) loss of species with narrow and/or relatively warm thermal tolerance ranges as the polar front advanced and the latitudinal temperature gradient steepened [12,13].…”

Section: Introductionmentioning

confidence: 99%

Biogeographic and bathymetric determinants of brachiopod extinction and survival during the Late Ordovician mass extinction

2016

View full text Add to dashboard Cite

The Late Ordovician mass extinction (LOME) coincided with dramatic climate changes, but there are numerous ways in which these changes could have driven marine extinctions. We use a palaeobiogeographic database of rhynchonelliform brachiopods to examine the selectivity of Late Ordovician -Early Silurian genus extinctions and evaluate which extinction drivers are best supported by the data. The first (latest Katian) pulse of the LOME preferentially affected genera restricted to deeper waters or to relatively narrow (less than 358) palaeolatitudinal ranges. This pattern is only observed in the latest Katian, suggesting that it reflects drivers unique to this interval. Extinction of exclusively deeper-water genera implies that changes in water mass properties such as dissolved oxygen content played an important role. Extinction of genera with narrow latitudinal ranges suggests that interactions between shifting climate zones and palaeobiogeography may also have been important. We test the latter hypothesis by estimating whether each genus would have been able to track habitats within its thermal tolerance range during the greenhouse -icehouse climate transition. Models including these estimates are favoured over alternative models. We argue that the LOME, long regarded as non-selective, is highly selective along biogeographic and bathymetric axes that are not closely correlated with taxonomic identity.

show abstract

Section: Introductionmentioning

confidence: 99%

Biogeographic and bathymetric determinants of brachiopod extinction and survival during the Late Ordovician mass extinction

2016

View full text Add to dashboard Cite

show abstract

“…Melott & Thomas 2009, Harper et al 2013, Baarli 2014. Because of their use in biostratigraphy, graptolites from strata near the Ordovician-Silurian boundary have been well studied from many localities worldwide.…”

mentioning

confidence: 99%

Earliest Silurian graptolites from Kalpin, western Tarim, Xinjiang, China

Wang¹,

Muir²,

Chen³

et al. 2015

Bull. Geosci.

View full text Add to dashboard Cite

“…Mucronaspis occurs throughout Hirnantian strata in the Oslo Region including the Kalvøya Member. This trilobite is common in the lower parts of Hirnantian strata in the East Baltic and there does not extend into the upper Hirnantian (Hints et al, 2012). However, it is found in the Leemon Formation in Illinois as part of the Edgewood fauna.…”

Section: Discussionmentioning

confidence: 96%

“…17). The change corresponds to a glaciation phase linked to a low stand in the subtropical regions just above the Katian-Hirnantian boundary (Bergström et al, 2014;Ghienne et al, 2014;Harper et al, 2014).…”

Section: Relative Sea-level Changesmentioning

confidence: 99%

Hirnantian (latest Ordovician) glaciations and their consequences for the Oslo Region, Norway, with a revised lithostratigraphy for the Langøyene Formation in the inner Oslofjorden area

Bockelie¹,

Baarli²,

Johnson³

2017

NJG

View full text Add to dashboard Cite

During the Hirnantian Age (Late Ordovician) the Oslo Region was located in a subtropical setting with siliciclastic input and carbonate production. At that time the sea level fluctuated in the Oslo Region during three regressive-transgressive episodes, some of which involved subaerial exposure and coastal valley erosion. The last major sea-level drop resulted in the formation of a conspicuous network of incised valleys that were subsequently filled with sediment during the transgression in the latest part of the Hirnantian. The continuing transgressive event rapidly flooded the exposed land areas in the central Oslo-Asker district. The areas towards the west in mainland Asker and Sylling in the adjacent Modum district were first transgressed in the late Rhuddanian (Early Silurian). Primarily eustatic processes affected the area, but synsedimentary faulting may also have been in play. There are two distinct palaeovalley trends: one at Hovedøya in Oslo more or less NW-SE, with narrow valley sides, the other at Kalvøya and surrounding areas trending approximately NE-SW, with one valley more than 10 km long. There may have been more than one filling phase. Sediment fill of the last-formed incised valleys were mapped and correlated across a large area of the Oslo-Asker district. Four new members of the Langøyene Formation are proposed: the Skaueren, Høyerholmen, Pilodden and Kalvøya members. Strata of the lateral Langåra Formation began deposition during the Katian. The rest of the formation as well as the Skaueren and Høyerholmen members contain fossils belonging to the cold-water Kosov fauna of early to mid Hirnantian age. The Pilodden and fossiliferous parts of the Kalvøya members include a mix of cold-water Kosov and warm-water Edgewood faunas of late Hirnantian age. Detailed descriptions of many incised valley fill sections in Oslo and Asker are included to show the spectrum of the sediment fill composition.

show abstract

End Ordovician extinctions: A coincidence of causes

Cited by 257 publications

References 61 publications

Biogeographic and bathymetric determinants of brachiopod extinction and survival during the Late Ordovician mass extinction

Biogeographic and bathymetric determinants of brachiopod extinction and survival during the Late Ordovician mass extinction

Earliest Silurian graptolites from Kalpin, western Tarim, Xinjiang, China

Hirnantian (latest Ordovician) glaciations and their consequences for the Oslo Region, Norway, with a revised lithostratigraphy for the Langøyene Formation in the inner Oslofjorden area

Contact Info

Product

Resources

About