Journal ArticleDOI
The Ordovician Biodiversification: revolution in the oceanic trophic chain
Thomas Servais,Oliver Lehnert,Jun Li,Gary L. Mullins,Axel Munnecke,Alexander Nützel,Marco Vecoli +6 more
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The early Palaeozoic phytoplankton (acritarch) radiation paralleled a long-term increase in sea level between the Early Cambrian and the Late Ordovician as discussed by the authors.Abstract:
The Early Palaeozoic phytoplankton (acritarch) radiation paralleled a long-term increase in sea level between the Early Cambrian and the Late Ordovician. In the Late Cambrian, after the SPICE delta C-13(carb) excursion, acritarchs underwent a major change in morphological disparity and their taxonomical diversity increased to reach highest values during the Middle Ordovician (Darriwilian). This highest phytoplankton diversity of the Palaeozoic was possibly the result of palaeogeography (greatest continental dispersal) and major orogenic and volcanic activity, which provided maximum ecospace and large amounts of nutrients. With its warm climate and high atmospheric CO2 levels, the Ordovician was similar to the Cretaceous: a period when phytoplankton diversity was at its maximum during the Mesozoic. With increased phytoplankton availability in the Late Cambrian and Ordovician a radiation of zooplanktonic organisms took place at the same time as a major diversification of suspension feeders. In addition, planktotrophy originated in invertebrate larvae during the Late Cambrian-Early Ordovician. These important changes in the trophic chain can be considered as a major palaeoecological revolution (part of the rise of the Palaeozoic Evolutionary Fauna of Sepkoski). There is now sufficient evidence that this trophic chain revolution was related to the diversification of the phytoplankton, of which the organic-walled fraction is partly preserved.read more
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Journal ArticleDOI
Ordovician and Silurian sea–water chemistry, sea level, and climate: A synopsis
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).
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.
Book ChapterDOI
The Ordovician Period
Roger A. Cooper,Peter M. Sadler +1 more
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
Journal ArticleDOI
End Ordovician extinctions: A coincidence of causes
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.
Journal ArticleDOI
Fossil calibrations for the arthropod Tree of Life
TL;DR: A series of rigorously vetted calibration fossils for arthropod evolutionary history, taking into account recently published guidelines for best practice in fossil calibration are presented, resulting in 80 fossil calibrations for 102 clades.
References
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Journal ArticleDOI
Geocarb III: A Revised Model of Atmospheric CO2 over Phanerozoic Time
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.
Journal ArticleDOI
The Evolution of Modern Eukaryotic Phytoplankton
Paul G. Falkowski,Miriam E. Katz,Andrew H. Knoll,Antonietta Quigg,John A. Raven,Oscar Schofield,F. J. R. Taylor +6 more
TL;DR: The geological, geochemical, and biological processes that contributed to the rise of the dinoflagellates, coccolithophores, and diatoms all contain plastids derived from an ancestral red alga by secondary symbiosis are examined.
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Revised World maps and introduction
TL;DR: The authors reviewed the highlights of the 1988 Symposium on Palaeozoic Biogeography and Palaeogeography, and presented a revised set of 20 base maps that incorporate much of the new data presented at the symposium.
Journal ArticleDOI
Introduction: aspects of the geological evolution of the Eastern Mediterranean
TL;DR: In this paper, a new model of ophiolite genesis by asymmetrical spreading-ridge collapse was proposed to explain both arc-like ophiola chemistry prior to major volcanic arc edifice construction, and the synchroneity of sub-ophiolite metamorphic sole formation with Atlantic opening phases.
Journal ArticleDOI
A kinetic model of Phanerozoic taxonomic diversity; III, Post-Paleozoic families and mass extinctions
TL;DR: The good fit of this model to data on Phanerozoic familial diversity suggests that many of the large-scale patterns of diversification seen in the marine fossil record of animal families are simple consequences of nonlinear interrelationships among a small number of parameters that are intrinsic to the evolutionary faunas and are largely (but not completely) invariant through time.