scholarly journals Accelerated mass extinction in an isolated biota during Late Devonian climate changes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jaleigh Q. Pier ◽  
Sarah K. Brisson ◽  
J. Andrew Beard ◽  
Michael T. Hren ◽  
Andrew M. Bush

AbstractThe fossil record can illuminate factors that contribute to extinction risk during times of global environmental disturbance; for example, inferred thermal tolerance was an important predictor of extinction during several mass extinctions that corresponded with climate change. Additionally, members of geographically isolated biotas may face higher risk because they have less opportunity to migrate to suitable climate refugia during environmental disturbances. Here, we investigate how different types of risk intersect in the well-preserved brachiopod fauna of the Appalachian Foreland Basin during the two pulses of the Frasnian–Famennian mass extinction (Late Devonian, ~ 372 Ma). The selectivity of extinction is consistent with climate change (cooling) as a primary kill mechanism in this fauna. Overall, the extinction was mild relative to other regions, despite the many endemic species. However, vulnerable taxa went extinct more rapidly, during the first extinction pulse, such that the second pulse was insignificant. These results suggest that vulnerable taxa in geographically isolated biotas face heightened extinction risk at the initiation of environmental stress, but that taxa in other regions may eventually see elevated extinction risk if environmental stress repeats or intensifies.

2021 ◽  
Author(s):  
Jaleigh Q. Pier ◽  
Sarah K. Brisson ◽  
J. Andrew Beard ◽  
Michael T Hren ◽  
Andrew M Bush

Abstract The fossil record can illuminate factors that contribute to extinction risk during times of global environmental disturbance; for example, inferred thermal tolerance is an important predictor of extinction during several mass extinctions that corresponded with climate change1,2. Additionally, members of geographically isolated biotas may face higher risk because they have less opportunity to migrate to suitable climate refugia during environmental disturbances. Here, we investigate how these two types of risk intersect in the well-preserved brachiopod fauna of the Appalachian Foreland Basin during the two pulses of the Frasnian-Famennian mass extinction (Late Devonian, ~372 Ma3,4). The selectivity of extinction supports climate change (cooling) as the primary kill mechanism in this fauna, with warm-adapted taxa going extinct preferentially. Overall, the extinction was mild relative to other regions, despite the many endemic species. However, taxa that were vulnerable to climate change went extinct more rapidly, during the first extinction pulse, such that the second pulse was insignificant. These results suggest that vulnerable taxa in geographically isolated biotas face heightened extinction risk at the initiation of environmental stress, but that other regions may “catch up” if environmental stress repeats or intensifies.


2016 ◽  
Vol 113 (30) ◽  
pp. 8380-8385 ◽  
Author(s):  
H. David Sheets ◽  
Charles E. Mitchell ◽  
Michael J. Melchin ◽  
Jason Loxton ◽  
Petr Štorch ◽  
...  

Mass extinctions disrupt ecological communities. Although climate changes produce stress in ecological communities, few paleobiological studies have systematically addressed the impact of global climate changes on the fine details of community structure with a view to understanding how changes in community structure presage, or even cause, biodiversity decline during mass extinctions. Based on a novel Bayesian approach to biotope assessment, we present a study of changes in species abundance distribution patterns of macroplanktonic graptolite faunas (∼447–444 Ma) leading into the Late Ordovician mass extinction. Communities at two contrasting sites exhibit significant decreases in complexity and evenness as a consequence of the preferential decline in abundance of dysaerobic zone specialist species. The observed changes in community complexity and evenness commenced well before the dramatic population depletions that mark the tipping point of the extinction event. Initially, community changes tracked changes in the oceanic water masses, but these relations broke down during the onset of mass extinction. Environmental isotope and biomarker data suggest that sea surface temperature and nutrient cycling in the paleotropical oceans changed sharply during the latest Katian time, with consequent changes in the extent of the oxygen minimum zone and phytoplankton community composition. Although many impacted species persisted in ephemeral populations, increased extinction risk selectively depleted the diversity of paleotropical graptolite species during the latest Katian and early Hirnantian. The effects of long-term climate change on habitats can thus degrade populations in ways that cascade through communities, with effects that culminate in mass extinction.


Paleobiology ◽  
2012 ◽  
Vol 38 (4) ◽  
pp. 627-643 ◽  
Author(s):  
Brianna L. Rego ◽  
Steve C. Wang ◽  
Demir Altiner ◽  
Jonathan L. Payne

One of the best-recognized patterns in the evolution of organismal size is the tendency for mean and maximum size within a clade to decrease following a major extinction event and to increase during the subsequent recovery interval. Because larger organisms are typically thought to be at higher extinction risk than their smaller relatives, it has commonly been assumed that size reduction mostly reflects the selective extinction of larger species. However, to our knowledge the relative importance of within- and among-lineage processes in driving overall trends in body size has never been compared quantitatively. In this study, we use a global, specimen-level database of foraminifera to study size evolution from the Late Permian through Late Triassic. We explicitly decompose size evolution into within- and among-genus components. We find that size reduction following the end-Permian mass extinction was driven more by size reduction within surviving species and genera than by the selective extinction of larger taxa. Similarly, we find that increase in mean size across taxa during Early Triassic biotic recovery was a product primarily of size increase within survivors and the extinction of unusually small taxa, rather than the origination of new, larger taxa. During background intervals we find no strong or consistent tendency for extinction, origination, or within-lineage change to move the overall size distribution toward larger or smaller sizes. Thus, size stasis during background intervals appears to result from small and inconsistent effects of within- and among-lineage processes rather than from large but offsetting effects of within- and among-taxon components. These observations are compatible with existing data for other taxa and extinction events, implying that mass extinctions do not influence size evolution by simply selecting against larger organisms. Instead, they appear to create conditions favorable to smaller organisms.


Author(s):  
Paul B. Wignall

What is a mass extinction? Mass extinction events are geologically short intervals of time (always under a million years), marked by dramatic increases of extinction rates in a broad range of environments around the world. In essence they are global catastrophes that left no environment unaffected and that have fundamentally changed the trajectory of life. ‘The great catastrophes’ describes the big five mass extinctions—the end-Ordovician 445 million years ago, the Late Devonian 374 million years ago, the Permo-Triassic 252 million years ago, the end-Triassic 201 million years ago, and Cretaceous-Paleogene sixty-six million years ago—and thoughts on their likely causes, along with other important extinction events identified at the start of the Cambrian and in the Early Jurassic.


Life ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 281
Author(s):  
Dmitry A. Ruban

Recent eustatic reconstructions allow for reconsidering the relationships between the fifteen Paleozoic–Mesozoic mass extinctions (mid-Cambrian, end-Ordovician, Llandovery/Wenlock, Late Devonian, Devonian/Carboniferous, mid-Carboniferous, end-Guadalupian, end-Permian, two mid-Triassic, end-Triassic, Early Jurassic, Jurassic/Cretaceous, Late Cretaceous, and end-Cretaceous extinctions) and global sea-level changes. The relationships between eustatic rises/falls and period-long eustatic trends are examined. Many eustatic events at the mass extinction intervals were not anomalous. Nonetheless, the majority of the considered mass extinctions coincided with either interruptions or changes in the ongoing eustatic trends. It cannot be excluded that such interruptions and changes could have facilitated or even triggered biodiversity losses in the marine realm.


Paleobiology ◽  
2008 ◽  
Vol 34 (1) ◽  
pp. 65-79 ◽  
Author(s):  
Lindsey R. Leighton ◽  
Chris L. Schneider

Examination of organismal characteristics which promote survivorship through both background and mass extinctions may reveal general ecological principles potentially critical to modern conservation efforts. This study explores survivorship of brachiopods, a highly diverse and abundant Paleozoic clade, through the mid-Permian to mid-Triassic interval, which includes the greatest mass extinction in the history of metazoan life. This interval of time separates two of the major Phanerozoic evolutionary faunas. In this regard, survivorship across any one extinction during the interval would not have been relevant if the survivor went extinct shortly after the extinction event; surviving background extinction is as important as surviving a mass extinction. Similarly, taxa that survived but failed to rediversify also were not major elements of the Mesozoic evolutionary fauna. Thus, the analysis aims to analyze survivorship not just across a single extinction but across the entire mid-Permian to mid-Triassic; only survivors through the entire interval can be the ancestors of the Mesozoic clades.Fewer brachiopod genera survived the interval than did brachiopod clades, suggesting that pseudoextinction or insufficient sampling could be a problem in analyzing these extinctions; thus, survivorship analysis should be conducted at the clade level. Nine characteristics were examined for generic representatives of 20 North American brachiopod clades, five of which survived both Permian extinctions and the subsequent earliest Triassic transitional interval. Characteristics include both those that operate on global scales and those that operate on the higher-resolution scales of individuals and populations.Survivors were significantly smaller and occurred less frequently than victims. Mean diversity of communities in which survivors were present was significantly greater. The finding that rare taxa belonging to high-diversity communities were more likely to survive runs counter to traditional predictions. However, these results are consistent with recent studies suggesting that higher diversity within a trophic level may create a buffer, as surviving taxa quickly occupy the vacant niche space of the victims. As size, abundance, and community diversity are all statistically related, the small size of survivors may be an artifact of reduced biovolume per taxon in a diverse community.No significant relationship exists between global-scale processes and survivorship of brachiopods through the mid-Permian to mid-Triassic. The results suggest that ecological processes can strongly influence global extinction patterns.


2021 ◽  
Author(s):  
Hui Zhen Tan ◽  
Justin J.F.J. Jansen ◽  
Gary A. Allport ◽  
Kritika M Garg ◽  
Balaji Chattopadhyay ◽  
...  

The impact of accelerated climate change on extinction risk is not well-characterised despite its increasing relevance. Comparative genomics of extinct versus extant species might be useful in elucidating broad trends in faunal endangerment. We investigated fluctuations in genetic diversity and extinction timing in our genomic dataset of nine species of particularly vulnerable migratory shorebirds (Numenius), including two species widely thought to be extinct. Most species faced generally sharp declines in effective population sizes, a proxy for genetic diversity, soon after the Last Glacial Maximum. During this time, a warming climate supported forest expansions at the expense of open habitats, exacerbated by human-induced mass extinctions of megafauna only a few thousand years prior, resulting in unprecedented reductions in shorebird breeding habitat. Species breeding in temperate regions, where they widely overlap with human populations, have been most strongly affected. Late Quaternary events can exert long-lasting effects on some species' susceptibility to extinction. Genomic inquiry is crucial in informing conservation actions in the fight against ongoing biodiversity loss.


2020 ◽  
Author(s):  
William J. Foster ◽  
Georgy Ayzel ◽  
Terry T. Isson ◽  
Maria Mutti ◽  
Martin Aberhan

AbstractDecision tree algorithms are rarely utilized in paleontological research, and here we show that machine learning algorithms can be used to identify determinants of extinction as well as predict extinction risk. This application of decision tree algorithms is important because the ecological selectivity of mass extinctions can reveal critical information on organismic traits as key determinants of extinction and hence the causes of extinction. To understand which factors led to the mass extinction of life during an extreme global warming event, we quantified the ecological selectivity of marine extinctions in the well-studied South China region during the end-Permian mass extinction using the categorized gradient boosting algorithm. We find that extinction selectivity varies between different groups of organisms and that a synergy of multiple environmental stressors best explains the overall end-Permian extinction selectivity pattern. Extinction risk was greater for genera that were limited to deep-water habitats, had a stationary mode of life, possessed a siliceous skeleton or, less critically, had calcitic skeletons. These selective losses directly link the extinction to the environmental effects of rapid injections of carbon dioxide into the ocean-atmosphere system, specifically the combined effects of expanded oxygen minimum zones, rapid warming, and ocean acidification.


Paleobiology ◽  
2018 ◽  
Vol 45 (1) ◽  
pp. 70-84 ◽  
Author(s):  
Carl J. Reddin ◽  
Ádám T. Kocsis ◽  
Wolfgang Kiessling

AbstractGeologically rapid climate change is anticipated to increase extinction risk nonuniformly across the Earth's surface. Tropical species may be more vulnerable than temperate species to current climate warming because of high tropical climate velocities and reduced seawater oxygen levels. To test whether rapid warming indeed preferentially increased the extinction risk of tropical fossil taxa, we combine a robust statistical assessment of latitudinal extinction selectivity (LES) with the dominant views on climate change occurring at ancient extinction crises. Using a global data set of marine fossil occurrences, we assess extinction rates for tropical and temperate genera, applying log ratios to assess effect size and Akaike weights for model support. Among the classical “big five” mass extinction episodes, the end-Permian mass extinction exhibits temperate preference of extinctions, whereas the Late Devonian and end-Triassic selectively hit tropical genera. Simple links between the inferred direction of climate change and LES are idiosyncratic, both during crisis and background intervals. More complex models, including sampling patterns and changes in the latitudinal distribution of continental shelf area, show tropical LES to be generally associated with raised tropical heat and temperate LES with global cold temperatures. With implications for the future, our paper demonstrates the consistency of high tropical temperatures, habitat loss, and the capacity of both to interact in generating geographic patterns in extinctions.


2020 ◽  
Vol 287 (1933) ◽  
pp. 20200730
Author(s):  
Maria João Fernandes Martins ◽  
Gene Hunt ◽  
Carmi Milagros Thompson ◽  
Rowan Lockwood ◽  
John P. Swaddle ◽  
...  

Sexual selection often favours investment in expensive sexual traits that help individuals compete for mates. In a rapidly changing environment, however, allocation of resources to traits related to reproduction at the expense of those related to survival may elevate extinction risk. Empirical testing of this hypothesis in the fossil record, where extinction can be directly documented, is largely lacking. The rich fossil record of cytheroid ostracods offers a unique study system in this context: the male shell is systematically more elongate than that of females, and thus the sexes can be distinguished, even in fossils. Using mixture models to identify sex clusters from size and shape variables derived from the digitized valve outlines of adult ostracods, we estimated sexual dimorphism in ostracod species before and after the Cretaceous/Palaeogene mass extinction in the United States Coastal Plain. Across this boundary, we document a substantial shift in sexual dimorphism, driven largely by a pronounced decline in the taxa with dimorphism indicating both very high and very low male investment. The shift away from high male investment, which arises largely from evolutionary changes within genera that persist through the extinction, parallels extinction selectivity previously documented during the Late Cretaceous under a background extinction regime. Our results suggest that sexual selection and the allocation of resources towards survival versus reproduction may be an important factor for species extinction during both background and mass extinctions.


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