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Journal ArticleDOI

The Great Ordovician Biodiversification Event (GOBE): The palaeoecological dimension

TL;DR: The "great Ordovician Biodiversification Event" (GOBE) as mentioned in this paper was a spectacular increase in marine biodiversity at all taxonomic levels largely within the phyla established much earlier during the so-called Cambrian Explosion.
About: This article is published in Palaeogeography, Palaeoclimatology, Palaeoecology.The article was published on 2010-08-15. It has received 276 citations till now. The article focuses on the topics: Evolutionary fauna & Ordovician.
Citations
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Journal ArticleDOI
TL;DR: It is shown that limited phosphorus and nitrogen availability are likely to jointly reduce future carbon storage by natural ecosystems during this century and if phosphorus fertilizers cannot be made increasingly accessible, the crop yields projections of the Millennium Ecosystem Assessment imply an increase of the nutrient deficit in developing regions.
Abstract: Bioavailable nitrogen is increasing due to human activity, rapidly outpacing increases in another essential nutrient, phosphorous. Penuelas et al. show that this increasing imbalance between these nutrients is likely to significantly affect life and limit carbon storage in this century.

959 citations

Journal ArticleDOI
TL;DR: The authors reviewed the relationships of the three major biotic events to chemical and physical processes occurring in the ocean and atmosphere during the Ordovician and Silurian, including sea-level changes, geochemical proxies (δ13C, δ18O, 87Sr/86Sr) of the ocean waters, and the evolution of the atmosphere (oxygen and carbon dioxide content).

315 citations


Cites background from "The Great Ordovician Biodiversifica..."

  • ...events (taking place at different times on different continents within different phyla) that covered the entire Ordovician and were part of a wider Cambrian–Ordovician radiation (Servais et al., 2010)....

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Book ChapterDOI
01 Jan 2012
TL;DR: A prolonged "hot-house" climate through Early Ordovician, cooling through Middle Ordovian and changing to ''ice-house'' conditions in Late Ordovicians, global glaciation, oceanic turnover and mass extinction at end of period, strong fluctuations in eustatic sea level, appearance and diversification of pandemic planktonic graptolites and conodonts important for correlation, moderate to strong benthic faunal provincialism, re-organization and rapid migration of tectonic plates surrounding the Iapetus Ocean and migration of
Abstract: Rapid and sustained biotic diversification reached its highest levels in the Paleozoic. A prolonged “hot-house” climate through Early Ordovician, cooling through Middle Ordovician and changing to “ice-house” conditions in Late Ordovician, global glaciation, oceanic turnover and mass extinction at end of period, strong fluctuations in eustatic sea level, appearance and diversification of pandemic planktonic graptolites and conodonts important for correlation, moderate to strong benthic faunal provincialism, re-organization and rapid migration of tectonic plates surrounding the Iapetus Ocean and migration of the South Pole from North Africa to central Africa all characterize the Ordovician Period. All seven Ordovician stages have formalized GSSPs.

232 citations

Journal ArticleDOI
TL;DR: The end Ordovician (Hirnantian) extinction was the first of the five big Phanerozoic extinction events, and the first that involved metazoan-based communities as mentioned in this paper.

217 citations


Cites background from "The Great Ordovician Biodiversifica..."

  • ...Environmental conditions on the planet were quite unique during the Ordovician, very different from those today (e.g., Jaanusson, 1984; Servais et al., 2010)....

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Journal ArticleDOI
TL;DR: A new ecological-severity ranking of the major Phanerozoic biodiversity crises is proposed in this paper, in which the Capitanian crisis is ranked lesser than the Frasnian (Late Devonian) but greater than the Serpukhovian (end-mississippian), and the Famennian crisis was ranked as equal in ecological impact to the Hirnantian (ending-Ordovician).

190 citations


Cites background from "The Great Ordovician Biodiversifica..."

  • ...In the mobile-epifaunal-detritivore megaguild (Table 5) the benthic trilobites, ostracods and gastropods were dominant in the Late Ordovician (Servais et al., 2010)whereas in the LateDevonian the jawlessfishes were the dominant vagrant detritivores (McGhee, 1996)....

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  • ...Detritivorous jawless fishes are present in the Late Ordovician (Pteraspidomorphi: Astraspida, Arandaspida, and Heterostraci; Benton, 2005) but apparently they were rare and not ecologically prominent (Servais et al., 2010)....

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  • ...…pelagic-carnivore megaguild (Table 5) the nautiloid orthocerid, lithulitid, and tarphyncerid cephalopods were dominant carnivores in the Late Ordovician (Servais et al., 2010), whereas in the Late Devonian the ammonoid cephalopods and placoderm fishes were the dominant carnivores (McGhee, 1996)....

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References
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Journal ArticleDOI
01 May 1972-Taxon

4,445 citations

Journal ArticleDOI
25 Nov 2005-Science
TL;DR: Long-term sea level peaked at 100 ± 50 meters during the Cretaceous, implying that ocean-crust production rates were much lower than previously inferred, and presents a new sea-level record for the past 100 million years.
Abstract: We review Phanerozoic sea-level changes [543 million years ago (Ma) to the present] on various time scales and present a new sea-level record for the past 100 million years (My). Long-term sea level peaked at 100 ± 50 meters during the Cretaceous, implying that ocean-crust production rates were much lower than previously inferred. Sea level mirrors oxygen isotope variations, reflecting ice-volume change on the 10 4 - to 10 6 -year scale, but a link between oxygen isotope and sea level on the 10 7 -year scale must be due to temperature changes that we attribute to tectonically controlled carbon dioxide variations. Sea-level change has influenced phytoplankton evolution, ocean chemistry, and the loci of carbonate, organic carbon, and siliciclastic sediment burial. Over the past 100 My, sea-level changes reflect global climate evolution from a time of ephemeral Antarctic ice sheets (100 to 33 Ma), through a time of large ice sheets primarily in Antarctica (33 to 2.5 Ma), to a world with large Antarctic and large, variable Northern Hemisphere ice sheets (2.5 Ma to the present).

2,740 citations

Journal ArticleDOI
TL;DR: In this article, a total of 2128 calcitic and phosphatic shells, mainly brachiopods with some conodonts and belemnites, were measured for their δ 18 O, δ 13 C and 87 Sr / 86 S values.

2,241 citations

Journal ArticleDOI
TL;DR: In this article, the GEOCARB model has been updated with an emphasis on factors affecting CO2 uptake by continental weathering, including the role of plants in chemical weathering and the application of GCMs to study the long-term carbon cycle.
Abstract: Revision of the GEOCARB model (Berner, 1991, 1994) for paleolevels of atmospheric CO2, has been made with emphasis on factors affecting CO2 uptake by continental weathering. This includes: (1) new GCM (general circulation model) results for the dependence of global mean surface temperature and runoff on CO2, for both glaciated and non-glaciated periods, coupled with new results for the temperature response to changes in solar radiation; (2) demonstration that values for the weathering-uplift factor fR(t) based on Sr isotopes as was done in GEOCARB II are in general agreement with independent values calculated from the abundance of terrigenous sediments as a measure of global physical erosion rate over Phanerozoic time; (3) more accurate estimates of the timing and the quantitative effects on Ca-Mg silicate weathering of the rise of large vascular plants on the continents during the Devonian; (4) inclusion of the effects of changes in paleogeography alone (constant CO2 and solar radiation) on global mean land surface temperature as it affects the rate of weathering; (5) consideration of the effects of volcanic weathering, both in subduction zones and on the seafloor; (6) use of new data on the d 13 C values for Phanerozoic limestones and organic matter; (7) consideration of the relative weather- ing enhancement by gymnosperms versus angiosperms; (8) revision of paleo land area based on more recent data and use of this data, along with GCM-based paleo-runoff results, to calculate global water discharge from the continents over time. Results show a similar overall pattern to those for GEOCARB II: very high CO2 values during the early Paleozoic, a large drop during the Devonian and Carbonifer- ous, high values during the early Mesozoic, and a gradual decrease from about 170 Ma to low values during the Cenozoic. However, the new results exhibit considerably higher CO2 values during the Mesozoic, and their downward trend with time agrees with the independent estimates of Ekart and others (1999). Sensitivity analysis shows that results for paleo-CO2 are especially sensitive to: the effects of CO2 fertilization and temperature on the acceleration of plant-mediated chemical weathering; the quantitative effects of plants on mineral dissolution rate for constant temperature and CO2; the relative roles of angiosperms and gymnosperms in accelerating rock weather- ing; and the response of paleo-temperature to the global climate model used. This emphasizes the need for further study of the role of plants in chemical weathering and the application of GCMs to study of paleo-CO2 and the long term carbon cycle.

1,842 citations

Journal ArticleDOI
TL;DR: In this article, a total of 2128 calcitic and phosphatic shells, mainly brachiopods with some conodonts and belemnites, were measured for their δ 18 O, δ 13 C and 87 Sr / 86 S values.

1,801 citations