scholarly journals Early diversifications of angiosperms and their insect pollinators: Were they unlinked?

2021 ◽  
Author(s):  
Yasmin Asar ◽  
Simon Y. W. Ho ◽  
Hervé Sauquet
Keyword(s):  
Mass Extinction ◽  
Evolutionary History ◽  
Molecular Dating ◽  
Insect Pollination ◽  
Early Angiosperm ◽  
Insect Pollinators ◽  
Extinction Event ◽  
History Of ◽  
Mass Extinction Event

The present-day ubiquity of angiosperm-insect pollination has led to the hypothesis that these two groups coevolved early in their evolutionary history. However, recent fossil discoveries and fossil-calibrated molecular dating analyses challenge the notion that early diversifications of angiosperms and insects were inextricably linked. In this article we examine (i) the discrepancies between dates of emergence for major clades of angiosperm and insect lineages; (ii) the long history of gymnosperm–insect pollination modes, which likely shaped early angiosperm–insect pollination mutualisms; and (iii) how the K–Pg mass extinction event was vital in propelling modern angiosperm-insect mutualisms. We posit that the early diversifications of angiosperms and their insect pollinators were largely decoupled, until the end of the Cretaceous.

3. The origin of mammals

2017 ◽  
pp. 34-44
Author(s):  
T. S. Kemp
Keyword(s):  
Mass Extinction ◽  
Fossil Record ◽  
Evolutionary History ◽  
Middle Permian ◽  
Upper Carboniferous ◽  
Developmental Progress ◽  
The World ◽  
Extinction Event ◽  
History Of ◽  
Mass Extinction Event

‘The origin of mammals’ considers the evolutionary history of mammals using the fossil record to chart their developmental progress. It looks at a group of ‘pre-mammals’, the Synapsids—mammal-like reptiles—including pelycosaurs from 320 mya in the Upper Carboniferous. Then came the therapsids from c.260 mya in the Middle Permian, when the world was increasingly arid. Then 250 mya a mass extinction event wiped out over 90 per cent of animals and plants. Miraculously, a few therapsids survived including the burrowing dicynodont called Lystrosaurus and cynodonts that evolved throughout the Triassic and gave rise to mammals. The earliest mammal was a mouse-sized animal called Morganucodon from 200 mya.

scholarly journals Divergence rates of subviral pathogens of angiosperms abruptly decreased at the Cretaceous-Paleogene boundary

2019 ◽  
Vol 4 ◽  
pp. 89-101 ◽  
Author(s):  
Piotr Bajdek
Keyword(s):  
Mass Extinction ◽  
Continental Drift ◽  
Time Calibration ◽  
Extinction Event ◽  
Drift Theory ◽  
History Of ◽  
Probable Impact ◽  
Mass Extinction Event ◽  
Extinction Events ◽  
First Time

Biogeographic distribution of infected plants and the continental drift theory allow a tentative time calibration of the phylogenetic tree of Pospiviroidae. Hypothetically, viroids evolved in the late Early Cretaceous shortly after the appearance of angiosperms, which constitute their only known hosts. No decline in the estimated divergence rates of Pospiviroidae is observed during the Late Cretaceous but it appears that they abruptly decreased at the Cretaceous-Paleogene boundary. However, an adaptive radiation of Pospiviroidae which occurred in the late Paleocene may reflect a recovery from the Cretaceous-Paleogene (K–Pg) mass extinction. It seems that the evolutionary history of viroids has been in part shaped by radiation and extinction events of angiosperms. Herein, for the first time I show the probable impact of a mass extinction event on the divergence rates of subviral pathogens, which are the simplest known “lifeforms”.

scholarly journals Simultaneous radiation of bird and mammal lice following the K-Pg boundary

2018 ◽  
Vol 14 (5) ◽  
pp. 20180141 ◽  
Author(s):  
Kevin P. Johnson ◽  
Nam-phuong Nguyen ◽  
Andrew D. Sweet ◽  
Bret M. Boyd ◽  
Tandy Warnow ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Single Copy ◽  
Orthologous Genes ◽  
Extinction Event ◽  
Single Host ◽  
History Of ◽  
Rapid Diversification ◽  
Mass Extinction Event ◽  
Host Parasite ◽  
Diverse Groups

The diversification of parasite groups often occurs at the same time as the diversification of their hosts. However, most studies demonstrating this concordance only examine single host–parasite groups. Multiple diverse lineages of ectoparasitic lice occur across both birds and mammals. Here, we describe the evolutionary history of lice based on analyses of 1107 single-copy orthologous genes from sequenced genomes of 46 species of lice. We identify three major diverse groups of lice: one exclusively on mammals, one almost exclusively on birds and one on both birds and mammals. Each of these groups radiated just after the Cretaceous–Paleogene (K-Pg) boundary, the time of the mass extinction event of the dinosaurs and rapid diversification of most of the modern lineages of birds and mammals.

THE RECORD OF ENVIRONMENTAL CHANGE IN NORTHEASTERN PANTHALASSA DIRECTLY PRECEDING THE END-TRIASSIC MASS EXTINCTION EVENT

2019 ◽  
Author(s):  
Ekaterina Larina ◽  
◽  
David J. Bottjer ◽  
Frank A. Corsetti ◽  
William M. Berelson ◽  
...  
Keyword(s):  
Environmental Change ◽  
Mass Extinction ◽  
Extinction Event ◽  
Mass Extinction Event

SEDIMENTARY MERCURY CONCENTRATIONS AND ISOTOPES ACROSS THE END-CRETACEOUS MASS EXTINCTION EVENT FROM NEW JERSEY

2020 ◽  
Author(s):  
Marisa D. Knight ◽  
◽  
Runsheng Yin ◽  
Clara L. Meier ◽  
James V. Browning ◽  
...  
Keyword(s):  
New Jersey ◽  
Mass Extinction ◽  
Extinction Event ◽  
Mass Extinction Event

scholarly journals Dinosaurs in decline tens of millions of years before their final extinction

2016 ◽  
Vol 113 (18) ◽  
pp. 5036-5040 ◽  
Author(s):  
Manabu Sakamoto ◽  
Michael J. Benton ◽  
Chris Venditti
Keyword(s):  
Mass Extinction ◽  
Marked Reduction ◽  
Evolutionary Dynamics ◽  
General Pattern ◽  
Extinction Rate ◽  
Catastrophic Event ◽  
Extinction Event ◽  
Mass Extinction Event ◽  
First Time

Whether dinosaurs were in a long-term decline or whether they were reigning strong right up to their final disappearance at the Cretaceous–Paleogene (K-Pg) mass extinction event 66 Mya has been debated for decades with no clear resolution. The dispute has continued unresolved because of a lack of statistical rigor and appropriate evolutionary framework. Here, for the first time to our knowledge, we apply a Bayesian phylogenetic approach to model the evolutionary dynamics of speciation and extinction through time in Mesozoic dinosaurs, properly taking account of previously ignored statistical violations. We find overwhelming support for a long-term decline across all dinosaurs and within all three dinosaurian subclades (Ornithischia, Sauropodomorpha, and Theropoda), where speciation rate slowed down through time and was ultimately exceeded by extinction rate tens of millions of years before the K-Pg boundary. The only exceptions to this general pattern are the morphologically specialized herbivores, the Hadrosauriformes and Ceratopsidae, which show rapid species proliferations throughout the Late Cretaceous instead. Our results highlight that, despite some heterogeneity in speciation dynamics, dinosaurs showed a marked reduction in their ability to replace extinct species with new ones, making them vulnerable to extinction and unable to respond quickly to and recover from the final catastrophic event.

scholarly journals New Biochronological Scales of Planktic Foraminifera for the Early Danian Based on High-Resolution Biostratigraphy

Geosciences ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 479
Author(s):  
Ignacio Arenillas ◽  
Vicente Gilabert ◽  
José A. Arz
Keyword(s):  
High Resolution ◽  
Mass Extinction ◽  
Quantitative Data ◽  
Qualitative Data ◽  
Rapid Evolution ◽  
Planktic Foraminifera ◽  
Middle Latitudes ◽  
Evolutionary Radiation ◽  
Extinction Event ◽  
Mass Extinction Event

After the Cretaceous/Paleogene boundary (KPB) catastrophic mass extinction event, an explosive evolutionary radiation of planktic foraminifera took place in consequence of the prompt occupation of empty niches. The rapid evolution of new species makes it possible to establish high-resolution biozonations in the lower Danian. We propose two biostratigraphic scales for low-to-middle latitudes spanning the first two million years of the Danian. The first is based on qualitative data and includes four biozones: the Guembelitria cretacea Zone (Dan1), the Parvularugoglobigerina longiapertura Zone (Dan2), the Parvularugoglobigerina eugubina Zone (Dan3), and the Parasubbotina pseudobulloides Zone (Dan4). The latter two are divided into several sub-biozones: the Parvularugoglobigerina sabina Subzone (Dan3a) and the Eoglobigerina simplicissima Subzone (Dan3b) for the Pv. eugubina Zone, and the Praemurica taurica Subzone (Dan4a), the Subbotina triloculinoides Subzone (Dan4b), and the Globanomalina compressa Subzone (Dan4c) for the P. pseudobulloides Zone. The second scale is based on quantitative data and includes three acme-zones (abundance zones): the Guembelitria Acme-zone (DanAZ1), the Parvularugoglobigerina-Palaeoglobigerina Acme-zone (DanAZ2), and the Woodringina-Chiloguembelina Acme-zone (DanAZ3). Both biozonations are based on high-resolution samplings of the most continuous sections of the lower Danian worldwide and have been calibrated with recent magnetochronological and astrochronological dating.

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