scholarly journals Ecological continuity and transformation after the Permo-Triassic mass extinction in northeastern Panthalassa

2019 ◽  
Vol 15 (3) ◽  
pp. 20180902 ◽  
Author(s):  
Ashley A. Dineen ◽  
Peter D. Roopnarine ◽  
Margaret L. Fraiser
Keyword(s):  
Functional Diversity ◽  
Mass Extinction ◽  
Marine Ecosystems ◽  
Early Triassic ◽  
Intrinsic Structure ◽  
Functional Roles ◽  
Organizational Effects ◽  
Western Us ◽  
Ecological Continuity ◽  
Exact Timing

The Permo-Triassic mass extinction (PTME) is often implicated in the transition from the Paleozoic evolutionary fauna (PEF) to the modern evolutionary fauna (MEF). However, the exact timing and details of this progression are unknown, especially regarding the vacating and filling of functional ecological space after the PTME. Here, we quantify the functional diversity of middle Permian and Early Triassic marine paleocommunities in the western US to determine functional re-organization in the aftermath of the PTME. Results indicate that while the PTME was selective in nature, many new Triassic taxa either re-filled functional roles of extinct Permian taxa or performed the same functional roles as Permian survivors. Despite this functional overlap, Permian survivors and new Triassic taxa differed significantly in their relative abundances within those overlapping functions. This shift in numerical emphasis, driven by an increase in abundance towards more MEF-style traits, may represent a first step in the transition between the PEF and MEF. We therefore suggest that the extreme impact of the PTME had significant and permanent re-organizational effects on the intrinsic structure of marine ecosystems. Early Triassic ecosystems likely bridged the gap between the Paleozoic and modern evolutionary faunas, as newly originated Triassic taxa shared ecospace with Permian survivors, but shifted functional emphasis.

scholarly journals Impact of the Late Triassic mass extinction on functional diversity and composition of marine ecosystems

Palaeontology ◽  
2017 ◽  
Vol 61 (1) ◽  
pp. 133-148 ◽  
Author(s):  
Alexander M. Dunhill ◽  
William J. Foster ◽  
James Sciberras ◽  
Richard J. Twitchett
Keyword(s):  
Functional Diversity ◽  
Mass Extinction ◽  
Marine Ecosystems ◽  
Late Triassic

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 ◽  
2011 ◽  
Vol 37 (3) ◽  
pp. 409-425 ◽  
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.

scholarly journals Decoupled taxonomic and ecological recoveries from the Permo-Triassic extinction

2018 ◽  
Vol 4 (10) ◽  
pp. eaat5091 ◽  
Author(s):  
Haijun Song ◽  
Paul B. Wignall ◽  
Alexander M. Dunhill
Keyword(s):  
Time Scales ◽  
Carrying Capacity ◽  
Mass Extinction ◽  
Marine Species ◽  
Taxonomic Diversity ◽  
Marine Ecosystems ◽  
Trophic Levels ◽  
Ecosystem Structure ◽  
Top Down ◽  
Structure Building

The Permian-Triassic mass extinction was the worst crisis faced by life; it killed >90% of marine species in less than 0.1 million years (Ma). However, knowledge of its macroecological impact over prolonged time scales is limited. We show that marine ecosystems dominated by non-motile animals shifted to ones dominated by nektonic groups after the extinction. In Triassic oceans, animals at high trophic levels recovered faster than those at lower levels. The top-down rebuilding of marine ecosystems was still underway in the latest Triassic, ~50 Ma after the extinction, and contrasts with the ~5-Ma recovery required for taxonomic diversity. The decoupling between taxonomic and ecological recoveries suggests that a process of vacant niche filling before reaching the maximum environmental carrying capacity is independent of ecosystem structure building.

When bivalves took over the world

Paleobiology ◽  
2007 ◽  
Vol 33 (3) ◽  
pp. 397-413 ◽  
Author(s):  
Margaret L. Fraiser ◽  
David J. Bottjer
Keyword(s):  
Mass Extinction ◽  
Arms Race ◽  
Steady Increase ◽  
Early Triassic ◽  
Environmental Distribution ◽  
Biodiversity Crisis ◽  
Marine Communities ◽  
The World ◽  
Mesozoic Marine Revolution ◽  
Permian Mass Extinction

AbstractThe end-Permian mass extinction is commonly portrayed not only as a massive biodiversity crisis but also as the time when marine benthic faunas changed from the Paleozoic Fauna, dominated by rhynchonelliform brachiopod taxa, to the Modern Fauna, dominated by gastropod and bivalve taxa. After the end-Permian mass extinction, scenarios involving the Mesozoic Marine Revolution portray a steady increase in numerical dominance by these benthic molluscs as largely due to the evolutionary effects of an “arms race.” We report here a new global paleoecological database from study of shell beds that shows a dramatic geologically sudden earliest Triassic takeover by bivalves as numerical dominants in level-bottom benthic marine communities, which continued through the Early Triassic. Three bivalve genera were responsible for this switch, none of which has any particular morphological features to distinguish it from many typical Paleozoic bivalve genera. The numerical success of these Early Triassic bivalves cannot be attributed to any of the well-known morphological evolutionary innovations of post-Paleozoic bivalves that characterize the Mesozoic Marine Revolution. Rather, their ability to mount this takeover most likely was due to the large extinction of rhynchonelliform brachiopods during the end-Permian mass extinction and aided by their environmental distribution and physiological characteristics that enabled them to thrive during periods of oceanic and atmospheric stress during the Permian/Triassic transition.

A new faunistic component of the Lower Triassic Panchet Formation of India increases the continental non-archosauromorph neodiapsid record in the aftermath of the end-Permian mass extinction

2021 ◽  
pp. 1-11
Author(s):  
Martín D. Ezcurra ◽  
Saswati Bandyopadhyay ◽  
Kasturi Sen
Keyword(s):  
Mass Extinction ◽  
Lower Triassic ◽  
Maximum Height ◽  
Dorsal Margin ◽  
Early Triassic ◽  
Anterior Portion ◽  
Continental Deposits ◽  
Biotic Recovery ◽  
Patterns And Processes ◽  
Permian Mass Extinction

Abstract The fossil record of Early Triassic diapsids is very important to understand how the end-Permian mass extinction affected ecosystems and the patterns and processes involved in the subsequent biotic recovery. Vertebrate fossil assemblages of continental deposits in current-day South Africa, China, and Russia are the best source of information of this clade during the aftermath of the extinction event. Although considerably less sampled, the Induan continental rocks of the Panchet Formation of the Damodar Basin (eastern India) have also yielded a relatively diverse vertebrate assemblage composed of fishes, temnospondyls, synapsids, and a single proterosuchid taxon. Here, we report on a small isolated diapsid partial ilium (ISIR 1132) from the upper Panchet Formation. This specimen has a distinct morphology compared to other tetrapods that we know, including a shallow emargination on the dorsal margin of the anterior portion of the iliac blade, and ratio between height of iliac blade versus maximum height of iliac acetabulum at level of the dorsalmost extension of supraacetabular crest ≤0.45. Comparisons and a quantitative phylogenetic analysis found ISIR 1132 as a non-archosauromorph neodiapsid. This new specimen expands the reptile diversity in the Panchet Formation as well as for the rest of Gondwana, where Early Triassic non-archosauromorph neodiapsid species are extremely scarce.

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