Infaunal response during the end-Permian mass extinction

Abstract The end-Permian mass extinction (EPME) profoundly shaped shallow marine ecosystems. Although much has been learned about this event based on the body-fossil record, the global infaunal response to the EPME, as represented by ichnofossils, is much less understood. Here we analyze secular changes in ichnodiversity and ichnodisparity from the late Permian to the Middle Triassic based on a global trace-fossil data set. Results show that, in contrast to the body-fossil record, late Permian global ichnodiversity and ichnodisparity maintained their level until the Griesbachian, followed by a sharp loss in the Dienerian. Notably, the Griesbachian shows an unusual dominance of shallower tiers. The discrepancy between the body- and trace-fossil record is interpreted to be the result of the resurgence of widespread microbial matgrounds in the Griesbachian that aided the preservation of surface, semi-infaunal, and shallow-tier ichnofossils. Our study shows that the EPME strongly affected the sediment mixed layer, allowing the preservation of shallower tier trace fossils. The disappearance of the mixed layer in the earliest Triassic may have enhanced pyrite burial in sediments and inhibited its further re-oxidation, therefore impacting sea water sulfate concentrations.

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Ecological innovations in the Cambrian and the origins of the crown group phyla

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2015.0287 ◽

2016 ◽

Vol 371 (1685) ◽

pp. 20150287 ◽

Cited By ~ 31

Author(s):

Graham E. Budd ◽

Illiam S. C. Jackson

Keyword(s):

Fossil Record ◽

Early Period ◽

Trace Fossils ◽

The Body ◽

Trace Fossil ◽

Simulation Studies ◽

Crown Group ◽

Relative Lack ◽

Rapid Diversification ◽

Body Fossil

Simulation studies of the early origins of the modern phyla in the fossil record, and the rapid diversification that led to them, show that these are inevitable outcomes of rapid and long-lasting radiations. Recent advances in Cambrian stratigraphy have revealed a more precise picture of the early bilaterian radiation taking place during the earliest Terreneuvian Series, although several ambiguities remain. The early period is dominated by various tubes and a moderately diverse trace fossil record, with the classical ‘Tommotian’ small shelly biota beginning to appear some millions of years after the base of the Cambrian at ca 541 Ma. The body fossil record of the earliest period contains a few representatives of known groups, but most of the record is of uncertain affinity. Early trace fossils can be assigned to ecdysozoans, but deuterostome and even spiralian trace and body fossils are less clearly represented. One way of explaining the relative lack of clear spiralian fossils until about 536 Ma is to assign the various lowest Cambrian tubes to various stem-group lophotrochozoans, with the implication that the groundplan of the lophotrochozoans included a U-shaped gut and a sessile habit. The implication of this view would be that the vagrant lifestyle of annelids, nemerteans and molluscs would be independently derived from such a sessile ancestor, with potentially important implications for the homology of their sensory and nervous systems.

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Early and Middle Triassic trends in diversity, evenness, and size of foraminifers on a carbonate platform in south China: implications for tempo and mode of biotic recovery from the end-Permian mass extinction

Paleobiology ◽

10.1666/08082.1 ◽

2011 ◽

Vol 37 (3) ◽

pp. 409-425 ◽

Cited By ~ 57

Author(s):

Jonathan L. Payne ◽

Mindi Summers ◽

Brianna L. Rego ◽

Demir Altiner ◽

Jiayong Wei ◽

...

Keyword(s):

South China ◽

Mass Extinction ◽

Evolutionary Dynamics ◽

Middle Triassic ◽

Carbonate Platform ◽

Early Triassic ◽

Data Set ◽

Recovery Pattern ◽

Biotic Recovery ◽

Permian Mass Extinction

Delayed biotic recovery from the end-Permian mass extinction has long been interpreted to result from environmental inhibition. Recently, evidence of more rapid recovery has begun to emerge, suggesting the role of environmental inhibition was previously overestimated. However, there have been few high-resolution taxonomic and ecological studies spanning the full Early and Middle Triassic recovery interval, leaving the precise pattern of recovery and underlying mechanisms poorly constrained. In this study, we document Early and Middle Triassic trends in taxonomic diversity, assemblage evenness, and size distribution of benthic foraminifers on an exceptionally exposed carbonate platform in south China. We observe gradual increases in all metrics through Early Triassic and earliest Middle Triassic time, with stable values reached early in the Anisian. There is little support in our data set for a substantial Early Triassic lag interval during the recovery of foraminifers or for a stepwise recovery pattern. The recovery pattern of foraminifers on the GBG corresponds well with available global data for this taxon and appears to parallel that of many benthic invertebrate clades. Early Triassic diversity increase in foraminifers was more gradual than in ammonoids and conodonts. However, foraminifers continued to increase in diversity, size, and evenness into Middle Triassic time, whereas diversity of ammonoids and conodonts declined. These contrasts suggest decoupling of recovery between benthic and pelagic environments; it is unclear whether these discrepancies reflect inherent contrasts in their evolutionary dynamics or the differential impact of Early Triassic ocean anoxia or associated environmental parameters on benthic ecosystems.

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Trace fossil evidence for restoration of marine ecosystems following the end-Permian mass extinction in the Lower Yangtze region, South China

Palaeogeography Palaeoclimatology Palaeoecology ◽

10.1016/j.palaeo.2010.11.023 ◽

2011 ◽

Vol 299 (3-4) ◽

pp. 449-474 ◽

Cited By ~ 81

Author(s):

Zhong-Qiang Chen ◽

Jinnan Tong ◽

Margaret L. Fraiser

Keyword(s):

South China ◽

Mass Extinction ◽

Marine Ecosystems ◽

Trace Fossil ◽

Fossil Evidence ◽

Lower Yangtze Region ◽

Lower Yangtze ◽

Permian Mass Extinction

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The Fossil Record of Early Tetrapods: Worker Effort and the End-Permian Mass Extinction

Acta Palaeontologica Polonica ◽

10.4202/app.2009.0025 ◽

2010 ◽

Vol 55 (2) ◽

pp. 229-239 ◽

Cited By ~ 14

Author(s):

Emma L. Bernard ◽

Marcello Ruta ◽

James E. Tarver ◽

Michael J. Benton

Keyword(s):

Mass Extinction ◽

Fossil Record ◽

Early Tetrapods ◽

Permian Mass Extinction

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Ammonoid recovery from the Late Permian mass extinction event

Comptes Rendus Palevol ◽

10.1016/j.crpv.2005.02.004 ◽

2005 ◽

Vol 4 (6-7) ◽

pp. 517-530 ◽

Cited By ~ 23

Author(s):

Alistair J. McGowan

Keyword(s):

Mass Extinction ◽

Late Permian ◽

Extinction Event ◽

Mass Extinction Event ◽

Permian Mass Extinction

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LINGULIDE BRACHIOPODS AND THE TRACE FOSSIL LINGULICHNUS FROM THE TRIASSIC OF WESTERN CANADA: IMPLICATIONS FOR FAUNAL RECOVERY AFTER THE END-PERMIAN MASS EXTINCTION

Palaios ◽

10.2110/palo.2005.p05-103r ◽

2007 ◽

Vol 22 (1) ◽

pp. 74-97 ◽

Cited By ~ 38

Author(s):

J.-P. ZONNEVELD ◽

T. W. BEATTY ◽

S. G. PEMBERTON

Keyword(s):

Mass Extinction ◽

Trace Fossil ◽

Western Canada ◽

Permian Mass Extinction

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Estimating the number of pulses in a mass extinction

Paleobiology ◽

10.1017/pab.2016.30 ◽

2018 ◽

Vol 44 (2) ◽

pp. 199-218 ◽

Cited By ~ 1

Author(s):

Steve C. Wang ◽

Ling Zhong

Keyword(s):

Mass Extinction ◽

Fossil Record ◽

Nearest Neighbor ◽

Hypothesis Test ◽

Information Criterion ◽

Data Set ◽

Recovery Potential ◽

Step Algorithm ◽

Extinction Events ◽

Fossil Preservation

AbstractThe Signor-Lipps effect states that even a sudden mass extinction will invariably appear gradual in the fossil record, due to incomplete fossil preservation. Most previous work on the Signor–Lipps effect has focused on testing whether taxa in a mass extinction went extinct simultaneously or gradually. However, many authors have proposed scenarios in which taxa went extinct in distinct pulses. Little methodology has been developed for quantifying characteristics of such pulsed extinction events. Here we introduce a method for estimating the number of pulses in a mass extinction, based on the positions of fossil occurrences in a stratigraphic section. Rather than using a hypothesis test and assuming simultaneous extinction as the default, we reframe the question by asking what number of pulses best explains the observed fossil record.Using a two-step algorithm, we are able to estimate not just the number of extinction pulses but also a confidence level or posterior probability for each possible number of pulses. In the first step, we find the maximum likelihood estimate for each possible number of pulses. In the second step, we calculate the Akaike information criterion and Bayesian information criterion weights for each possible number of pulses, and then apply ak-nearest neighbor classifier to these weights. This method gives us a vector of confidence levels for the number of extinction pulses—for instance, we might be 80% confident that there was a single extinction pulse, 15% confident that there were two pulses, and 5% confident that there were three pulses. Equivalently, we can state that we are 95% confident that the number of extinction pulses is one or two. Using simulation studies, we show that the method performs well in a variety of situations, although it has difficulty in the case of decreasing fossil recovery potential, and it is most effective for small numbers of pulses unless the sample size is large. We demonstrate the method using a data set of Late Cretaceous ammonites.

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