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

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”.

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Speciation rates of subviral pathogens of angiosperms abruptly decreased at the Cretaceous–Paleogene boundary

10.7287/peerj.preprints.27469 ◽

2019 ◽

Author(s):

Piotr Bajdek

Keyword(s):

Mass Extinction ◽

Continental Drift ◽

Time Calibration ◽

Drift Theory ◽

Speciation Rates ◽

History Of ◽

Probable Impact ◽

Mass Extinction Event ◽

Extinction Events ◽

First Time

Biogeographic distribution of infected plants and the continental drift theory allow a time calibration of the phylogenetic tree of Pospiviroidae. Viroids evolved in the late Early Cretaceous shortly after the appearance of angiosperms, which constitute their only known hosts. No decline in the estimated speciation rates of Pospiviroidae is observed during the Late Cretaceous but 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 K–Pg mass extinction. 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 speciation rates of subviral pathogens, which are the simplest known lifeforms.

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Speciation rates of subviral pathogens of angiosperms abruptly decreased at the Cretaceous–Paleogene boundary

10.7287/peerj.preprints.27469v1 ◽

2019 ◽

Author(s):

Piotr Bajdek

Keyword(s):

Mass Extinction ◽

Continental Drift ◽

Time Calibration ◽

Drift Theory ◽

Speciation Rates ◽

History Of ◽

Probable Impact ◽

Mass Extinction Event ◽

Extinction Events ◽

First Time

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

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1521478113 ◽

2016 ◽

Vol 113 (18) ◽

pp. 5036-5040 ◽

Cited By ~ 38

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.

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Testing for a mass extinction without selecting taxa

Paleobiology ◽

10.1666/0094-8373(2000)026<0647:tfamew>2.0.co;2 ◽

2000 ◽

Vol 26 (4) ◽

pp. 647-650 ◽

Cited By ~ 16

Author(s):

Andrew R. Solow ◽

Woollcott K. Smith

Keyword(s):

Statistical Inference ◽

Mass Extinction ◽

Extinction Event ◽

Mass Extinction Event ◽

Extinction Events ◽

Mass Extinction Events ◽

Stratigraphic Height ◽

Selection Of

Statistical inference about mass extinction events is commonly based on the pattern of fossil finds among a group of taxa. An important issue for existing methods is the selection of taxa for inclusion in the analysis. A common approach is to select taxa on the basis of the stratigraphic height of their uppermost finds. This approach creates a bias in favor of detecting a mass extinction event. This paper describes and illustrates an approach that avoids this problem.

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Astronomical calibration of paleoclimatic and planktic foraminiferal events of the Cretaceous-Paleogene transition at Zumaia, Spain

10.5194/egusphere-egu21-8008 ◽

2021 ◽

Author(s):

Vicente Gilabert ◽

Sietske J. Batenburg ◽

Ignacio Arenillas ◽

José A. Arz

Keyword(s):

Mass Extinction ◽

Deccan Traps ◽

Deccan Volcanism ◽

Extinction Event ◽

First Occurrence ◽

Mass Extinction Event ◽

Environmental Events ◽

Chicxulub Impact ◽

First Time ◽

Intense Debate

The main trigger for the Cretaceous/Paleogene boundary (KPB) mass extinction is still subject of intense debate. The co-occurrence of the Chicxulub impact (Yucatan, Mexico) and massive Deccan Traps volcanism (India) during Chron C29r hinders disentangling their climatic and environmental effects. Unravelling the influence of Deccan volcanism on the KPB extinction and other Maastrichtian and Danian perturbations requires more accurate age calibrations and duration estimates of biotic and climatic events. Here we integrate existing astrochronologies of the Zumaia section, allowing us to produce a refined cyclostratigraphic calibration of the main planktic foraminiferal and paleoclimatic events recorded across the KPB in the well-know Zumaia section (NW, Spain).At Zumaia, the KPB is marked by a ~8 cm-thick dark clay bed, with low values of %CaCO3 and &#948;13C. The Chicxulub ejecta-rich airfall layer has been identified at the base of the dark clay bed, but it is partially masked within a 1&#8211;2 cm-thick diagenetic calcitic layer. At Zumaia, the KPB has been astronomically calibrated at 66 Ma (compatible with radioisotopic ages), and the duration of dark clay bed is estimated at ~10 kyr. The first appearances (FA) of the Danian planktic foraminiferal index-species Parvularugoglobigerina longiapertura, Parvularugoglobigerina eugubina, Eoglobigerina simplicissima, Parasubbotina pseudobulloides, Subbotina triloculinoides and Globanomalina compressa have been orbitally tuned at Zumaia, to have occurred at 8, 30, 45, 70, 210, and 475 kyr after the KPB. Specimens of Plummerita hantkeninoides have been identified for the first time in the Maastrichtian of Zumaia, and its first occurrence is dated at ~100 kyr before the KPB. Based on d13C data, we have identified the late Maastrichtian Warming Event (LMWE), the early Danian Dan-C2 and the Lower-C29N events. Additionally, a bloom of the eutrophic/opportunist genus&#160;Chiloguembelitria, interpreted as a period of environmental stress, has also been recognized above and separate from the KPB clay bed. Besides the KPB, the main paleoclimatic/paleoenvironmental events have been astronomically calibrated at Zumaia as follows: the LMWE between 270 and 120 kyr before the KPB, the Dan-C2 event between 205 and 305 kyr after the KPB, the Lower-C29N event between 520 and 595 kyr after the KPB, and the Chiloguembelitria bloom&#160;between 100 and 305 kyr after the KPB. According to this chronology, we conclude that the LMWE and early Danian Chiloguembelitria bloom seems to coincide in time with major volcanic pulses of the Deccan Traps, unlike the Dan-C2 and Lower-C29N events, which appear to have been driven by orbital forcing. Regardless of the cause of climatic and environmental events, all these perturbations appear unrelated to the KPB mass extinction event. It supports the hypothesis that the influence of Deccan volcanism on planktic foraminiferal assemblages during the Maastrichtian and Danian was limited.

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Dead clades walking are a pervasive macroevolutionary pattern

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2019208118 ◽

2021 ◽

Vol 118 (15) ◽

pp. e2019208118

Author(s):

B. Davis Barnes ◽

Judith A. Sclafani ◽

Andrew Zaffos

Keyword(s):

Mass Extinction ◽

Bayesian Method ◽

Marine Invertebrate ◽

Mass Extinctions ◽

Extinction Event ◽

Genus Richness ◽

Mass Extinction Event ◽

Extinction Events ◽

Mass Extinction Events

D. Jablonski [Proc. Natl. Acad. Sci. U.S.A. 99, 8139–8144 (2002)] coined the term “dead clades walking” (DCWs) to describe marine fossil orders that experience significant drops in genus richness during mass extinction events and never rediversify to previous levels. This phenomenon is generally interpreted as further evidence that the macroevolutionary consequences of mass extinctions can continue well past the formal boundary. It is unclear, however, exactly how long DCWs are expected to persist after extinction events and to what degree they impact broader trends in Phanerozoic biodiversity. Here we analyze the fossil occurrences of 134 skeletonized marine invertebrate orders in the Paleobiology Database (paleobiodb.org) using a Bayesian method to identify significant change points in genus richness. Our analysis identifies 70 orders that experience major diversity losses without recovery. Most of these taxa, however, do not fit the popular conception of DCWs as clades that narrowly survive a mass extinction event and linger for only a few stages before succumbing to extinction. The median postdrop duration of these DCW orders is long (>30 Myr), suggesting that previous studies may have underestimated the long-term taxonomic impact of mass extinction events. More importantly, many drops in diversity without recovery are not associated with mass extinction events and occur during background extinction stages. The prevalence of DCW orders throughout both mass and background extinction intervals and across phyla (>50% of all marine invertebrate orders) suggests that the DCW pattern is a major component of macroevolutionary turnover.

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Patterns of extinction and recovery of phacopid trilobites during the Frasnian–Famennian (Late Devonian) mass extinction event, Canning Basin, Western Australia

Geological Magazine ◽

10.1017/s0016756808005335 ◽

2008 ◽

Vol 146 (1) ◽

pp. 12-33 ◽

Cited By ~ 20

Author(s):

RAIMUND FEIST ◽

KENNETH J. MCNAMARA ◽

CATHERINE CRÔNIER ◽

RUDY LEROSEY-AUBRIL

Keyword(s):

Shallow Water ◽

Western Australia ◽

Mass Extinction ◽

New Genus ◽

Late Devonian ◽

Canning Basin ◽

Eye Size ◽

Extinction Event ◽

Mass Extinction Event ◽

First Time

AbstractA diverse fauna of phacopid trilobites is described from the Late Devonian (middle Frasnian to early Famennian) of the northern Canning Basin, Western Australia. One new genus and four species in two genera are described from zones 11, 13a and 13b of the middle and late Frasnian: Trimerocephaloides sinevisus gen. nov. and sp. nov., T. ? linguiformis sp. nov., Acuticryphops acuticeps (Kayser, 1889) and A. klapperi sp. nov. Late Frasnian phacopines are either blind, as shown for the first time in Trimerocephaloides sinevisus, or show trends to decreasing eye size up to the Frasnian–Famennian ‘Kellwasser’ mass extinction event. This evolutionary trend in Acuticryphops is demonstrated to have been global at this time. One new genus and six species of early Famennian phacopids are described, from the Upper triangularis, crepida and rhomboidea zones: Houseops gen. nov. with the new taxa H. canningensis sp. nov., H. beckeri sp. nov. and H. sp. A, Babinops planiventer Feist & Becker, 1997, B. minor sp. nov., Trimerocephalus tardispinosus Feist & Becker, 1997 and T. mimbi sp. nov. In contrast to European sections where exclusively blind phacopids are known in earliest Famennian sites, initial recovery following the mass extinction event in Canning peri-reefal environments is characterized by oculated forms. These trilobites must have evolved from conservative ancestors with normal eyes that had succeeded in surviving the Kellwasser biocrises in reef-related shallow water niches. Thus the origin of post-event phacopids from shallow water environments is demonstrated for the first time. Descendant lineages show increasing eye size, increased cephalic vaulting and effacement during the early Famennian.

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3. The origin of mammals

Mammals: A Very Short Introduction ◽

10.1093/actrade/9780198766940.003.0003 ◽

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.

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Rapid macrobenthic diversification and stabilization after the end-Cretaceous mass extinction event

Geology ◽

10.1130/g47589.1 ◽

2020 ◽

Vol 48 (11) ◽

pp. 1048-1052

Author(s):

Francisco J. Rodríguez-Tovar ◽

Christopher M. Lowery ◽

Timothy J. Bralower ◽

Sean P.S. Gulick ◽

Heather L. Jones

Keyword(s):

Mass Extinction ◽

Rapid Recovery ◽

Community Recovery ◽

Scientific Drilling ◽

Extinction Event ◽

Chicxulub Impact Crater ◽

Mass Extinction Event ◽

International Ocean Discovery Program ◽

Extinction Events ◽

The Impact

Abstract Previous ichnological analysis at the Chicxulub impact crater, Yucatán Peninsula, México (International Ocean Discovery Program [IODP]/International Continental Scientific Drilling Program [ICDP] Site M0077), showed a surprisingly rapid initial tracemaker community recovery after the end-Cretaceous (Cretaceous-Paleogene [K-Pg]) mass extinction event. Here, we found that full recovery was also rapid, with the establishment of a well-developed tiered community within ∼700 k.y. Several stages of recovery were observed, with distinct phases of stabilization and diversification, ending in the development of a trace fossil assemblage mainly consisting of abundant Zoophycos, Chondrites, and Planolites, assigned to the Zoophycos ichnofacies. The increase in diversity is associated with higher abundance, larger forms, and a deeper and more complex tiering structure. Such rapid recovery suggests that favorable paleoenvironmental conditions were quickly reestablished within the impact basin, enabling colonization of the substrate. Comparison with the end-Permian extinction reveals similarities during recovery, yet postextinction recovery was significantly faster after the K-Pg event. The rapid recovery has significant implications for the evolution of macrobenthic biota after the K-Pg event. Our results have relevance in understanding how communities recovered after the K-Pg impact and how this event differed from other mass extinction events.

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Differential human impact on the survival of genetically distinct avian lineages

Bird Conservation International ◽

10.1017/s0959270900002264 ◽

1999 ◽

Vol 9 (2) ◽

pp. 147-154 ◽

Cited By ~ 12

Author(s):

Austin L. Hughes

Keyword(s):

Human Impact ◽

Physical Environment ◽

Mass Extinction ◽

The Earth ◽

Biotic Diversity ◽

Extinction Event ◽

Mass Extinction Event ◽

Extinction Events ◽

The Impact ◽

Mass Extinction Events

SummaryAt the present time the earth is facing an anthropogenic (human-caused) mass extinction event that may eventually rival previous mass extinction events caused by drastic changes i n the physical environment; however, the impact of this event on the earth's biotic diversity remains difficult to predict. Patterns of extinction and endangerment in birds, one of the best known taxonomically among major groups of organisms, showed that the distribution of human impact has been non-uniform relative to phylogenetic relationships. Fifteen major avian lineages differed over 35-fold with respect to the frequency of historical extinction and over threefold with respect to frequency of current threat; and overall rates of both extinction and threat were significantly higher in non-passerine orders than in passerines. Moreover, among both passerines and non-passerines, the rate of historic extinction has been significantly higher for species in monotypic genera than for other species; and in passerines, the rate of current threat is significantly higher for species in monotypic genera than for other species. Thus, the anthropogenic extinction and threat to avian species has specifically targeted species that are phylogenetically and thus, presumably genetically, unique.

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