Toward an understanding of cosmopolitanism in deep time: a case study of ammonoids from the middle Permian to the Middle Triassic

Paleobiology ◽  
2020 ◽  
Vol 46 (4) ◽  
pp. 533-549
Author(s):  
Xu Dai ◽  
Haijun Song
Keyword(s):  
Mass Extinction ◽  
Middle Triassic ◽  
Theoretical Models ◽  
Geographic Range ◽  
Middle Permian ◽  
Time Interval ◽  
Mass Extinctions ◽  
Deep Time ◽  
Underlying Mechanisms ◽  
Selective Extinction

AbstractCosmopolitanism occurred recurrently during the geologic past, especially after mass extinctions, but the underlying mechanisms remain poorly known. Three theoretical models, not mutually exclusive, can lead to cosmopolitanism: (1) selective extinction in endemic taxa, (2) endemic taxa becoming cosmopolitan after the extinction and (3) an increase in the number of newly originated cosmopolitan taxa after extinction. We analyzed an updated occurrence dataset including 831 middle Permian to Middle Triassic ammonoid genera and used two network methods to distinguish major episodes of ammonoid cosmopolitanism during this time interval. Then, we tested the three proposed models in these case studies. Our results confirm that at least two remarkable cosmopolitanism events occurred after the Permian–Triassic and late Smithian (Early Triassic) extinctions, respectively. Partitioned analyses of survivors and newcomers revealed that the immediate cosmopolitanism event (Griesbachian) after the Permian–Triassic event can be attributed to endemic genera becoming cosmopolitan (model 2) and an increase in the number of newly originated cosmopolitan genera after the extinction (model 3). Late Smithian cosmopolitanism is caused by selective extinction in endemic taxa (model 1) and an increase in the number of newly originated cosmopolitan genera (model 3). We found that the survivors of the Permian–Triassic mass extinction did not show a wider geographic range, suggesting that this mass extinction is nonselective among the biogeographic ranges, while late Smithian survivors exhibit a wide geographic range, indicating selective survivorship among cosmopolitan genera. These successive cosmopolitanism events during severe extinctions are associated with marked environmental upheavals such as rapid climate changes and oceanic anoxic events, suggesting that environmental fluctuations play a significant role in cosmopolitanism.

scholarly journals Flat latitudinal diversity gradient caused by the Permian–Triassic mass extinction

2020 ◽  
Vol 117 (30) ◽  
pp. 17578-17583 ◽  
Author(s):  
Haijun Song ◽  
Shan Huang ◽  
Enhao Jia ◽  
Xu Dai ◽  
Paul B. Wignall ◽  
...  
Keyword(s):  
Mass Extinction ◽  
Middle Triassic ◽  
Early Triassic ◽  
Deep Time ◽  
Latitudinal Diversity Gradient ◽  
Diversity Gradient ◽  
Environmental Extremes ◽  
Low Latitudes ◽  
Marine Fossils ◽  
Selective Extinction

The latitudinal diversity gradient (LDG) is recognized as one of the most pervasive, global patterns of present-day biodiversity. However, the controlling mechanisms have proved difficult to identify because many potential drivers covary in space. The geological record presents a unique opportunity for understanding the mechanisms which drive the LDG by providing a direct window to deep-time biogeographic dynamics. Here we used a comprehensive database containing 52,318 occurrences of marine fossils to show that the shape of the LDG changed greatly during the Permian–Triassic mass extinction from showing a significant tropical peak to a flattened LDG. The flat LDG lasted for the entire Early Triassic (∼5 My) before reverting to a modern-like shape in the Middle Triassic. The environmental extremes that prevailed globally, especially the dramatic warming, likely induced selective extinction in low latitudes and accumulation of diversity in high latitudes through origination and poleward migration, which combined together account for the flat LDG of the Early Triassic.

Selective extinction of late Neogene bivalves on the temperate Pacific coast of South America

Paleobiology ◽  
2007 ◽  
Vol 33 (3) ◽  
pp. 455-468 ◽  
Author(s):  
Marcelo M. Rivadeneira ◽  
Pablo A. Marquet
Keyword(s):  
Body Size ◽  
South America ◽  
Mass Extinction ◽  
Pacific Coast ◽  
Geographic Range ◽  
Life Habit ◽  
Late Neogene ◽  
Probability Of Extinction ◽  
Phylogenetic Effects ◽  
Selective Extinction

AbstractWe assessed selective extinction patterns in bivalves during a late Neogene mass extinction event observed along the temperate Pacific coast of South America. The analysis of 99 late Neogene and Quaternary fossil sites (recorded from 7°S to 55°S), yielding ∼2800 occurrences and 118 species, revealed an abrupt decline in Lyellian percentages during the late Neogene–Pleistocene, suggesting the existence of a mass extinction that decimated ∼66% of the original assemblage. Using the late Neogene data set (n = 59 species, 1346 occurrences), we tested whether the extinction was nonrandom according to taxonomic structure, life habit, geographic range, and body size. Our results showed that the number of higher taxa that went extinct was not different than expected by random. At first sight, extinction was selective only according to life habit and geographic range. Nevertheless, when phylogenetic effects were accounted for, body size also showed significant selectivity. In general, epifaunal, small-sized (after phylogenetic correction), and short-ranged species tended to have increased probability of extinction. This is verified by strong interactions between the variables herein analyzed, suggesting the existence of nonlinear effects on extinction chances. In the heavily decimated epifaunal forms, survival was not enhanced by widespread ranges or larger body sizes. Conversely, the widespread and large-sized infaunal forms tended to have lower probability of extinction. Overall, the ultimate extinction of late Neogene bivalve species along the Pacific coast of South America seems to have been determined by a complex interplay of ecological and historical (phylogenetic) effects.

Within- and among-genus components of size evolution during mass extinction, recovery, and background intervals: a case study of Late Permian through Late Triassic foraminifera

Paleobiology ◽  
2012 ◽  
Vol 38 (4) ◽  
pp. 627-643 ◽  
Author(s):  
Brianna L. Rego ◽  
Steve C. Wang ◽  
Demir Altiner ◽  
Jonathan L. Payne
Keyword(s):  
Mass Extinction ◽  
Extinction Risk ◽  
Maximum Size ◽  
Size Reduction ◽  
Late Triassic ◽  
Mass Extinctions ◽  
Late Permian ◽  
Biotic Recovery ◽  
Size Evolution ◽  
Selective Extinction

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.

scholarly journals Tooth morphology elucidates shark evolution across the end-Cretaceous mass extinction

PLoS Biology ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. e3001108
Author(s):  
Mohamad Bazzi ◽  
Nicolás E. Campione ◽  
Per E. Ahlberg ◽  
Henning Blom ◽  
Benjamin P. Kear
Keyword(s):  
Mass Extinction ◽  
Mass Extinctions ◽  
Morphological Response ◽  
Geometric Morphometric ◽  
Deep Time ◽  
Predator Species ◽  
Geologic Time ◽  
Marine Predators ◽  
Time Diversity ◽  
Early Paleogene

Sharks (Selachimorpha) are iconic marine predators that have survived multiple mass extinctions over geologic time. Their prolific fossil record is represented mainly by isolated shed teeth, which provide the basis for reconstructing deep time diversity changes affecting different selachimorph clades. By contrast, corresponding shifts in shark ecology, as measured through morphological disparity, have received comparatively limited analytical attention. Here, we use a geometric morphometric approach to comprehensively examine tooth morphologies in multiple shark lineages traversing the catastrophic end-Cretaceous mass extinction—this event terminated the Mesozoic Era 66 million years ago. Our results show that selachimorphs maintained virtually static levels of dental disparity in most of their constituent clades across the Cretaceous–Paleogene interval. Nevertheless, selective extinctions did impact apex predator species characterized by triangular blade-like teeth. This is particularly evident among lamniforms, which included the dominant Cretaceous anacoracids. Conversely, other groups, such as carcharhiniforms and orectolobiforms, experienced disparity modifications, while heterodontiforms, hexanchiforms, squaliforms, squatiniforms, and †synechodontiforms were not overtly affected. Finally, while some lamniform lineages disappeared, others underwent postextinction disparity increases, especially odontaspidids, which are typified by narrow-cusped teeth adapted for feeding on fishes. Notably, this increase coincides with the early Paleogene radiation of teleosts as a possible prey source, and the geographic relocation of disparity sampling “hotspots,” perhaps indicating a regionally disjunct extinction recovery. Ultimately, our study reveals a complex morphological response to the end-Cretaceous mass extinction and highlights an event that influenced the evolution of modern sharks.

Fire, Flowers, and Dinosaurs

2018 ◽  
Author(s):  
Andrew C. Scott
Keyword(s):  
Atmospheric Oxygen ◽  
Time Interval ◽  
Mass Extinctions ◽  
Fossil Plants ◽  
Geological Time ◽  
Ecosystem Recovery ◽  
Deep Time ◽  
The World ◽  
The University ◽  
Lateral Thinking

The Mesozoic Era is the geological interval comprising the Triassic, Jurassic, and Cretaceous Periods, and it is best known for the rise and fall of the dinosaurs. The Mesozoic began around 250 million years ago and continued to around 66 million years ago—a not inconsiderable chunk of geological time, and framed by mass extinctions at its beginning and end. Fifty years ago there were very few published papers on fire in deep time, but the most important one, which I’ve touched on before, was ‘Forest fire in the Mesozoic’, by Tom Harris of the University of Reading. Tom was an important scientist, one of the leading palaeobotanists in the world. Energetic and passionate about his fossil plants, he was a scientist with broad interests, and given to experimentation and lateral thinking. The evidence that Tom used in his paper on fires in the Mesozoic was limited to only a couple of charcoal occurrences in these rocks. The Permian Period ended with the biggest known mass extinction in Earth history, when life was almost wiped out. Whole ecosystems collapsed. So what would the world have looked like at the start of the Triassic? Among whole groups of plants that had become extinct were the giant club mosses that had been the major coal-forming plants of the late Paleozoic, and the glossopterids that had dominated southern continental vegetation. In the first few million years after the extinctions, plant diversity appears to have been low, but some new plants became prominent, including the pole-like spore-bearing lycopod called Pleuromeia, and the scrambling seedplant called Dicroidium, which had fern-like foliage. The first 10 million years of the Triassic are thought to have been a time of ecosystem recovery. According to Berner’s model, the Triassic started with very low levels of oxygen in the atmosphere. Researchers had noticed that there were no coals found at the beginning of the Triassic, and this interval was called the ‘coal gap’. The problem, therefore, was that charcoal in coal could not be used as a proxy for atmospheric oxygen for this time interval.

Comparison of oxygen consumption byTerebratalia transversa(Brachiopoda) and two species of pteriomorph bivalve molluscs: implications for surviving mass extinctions

Paleobiology ◽  
2012 ◽  
Vol 38 (4) ◽  
pp. 525-537 ◽  
Author(s):  
Loren A. Ballanti ◽  
Alexa Tullis ◽  
Peter D. Ward
Keyword(s):  
Oxygen Consumption ◽  
Mass Extinction ◽  
Mass Extinctions ◽  
Bivalve Molluscs ◽  
Tissue Mass ◽  
Metabolic Characteristics ◽  
Significant Difference ◽  
Insight Into ◽  
Selective Extinction ◽  
Lower Tolerance

The Permian/Triassic mass extinction marks a permanent phylogenetic shift in the composition of the sessile benthos, from one largely dominated by articulate brachiopods to one dominated by mollusks. Widespread evidence of oceanic hypoxia and anoxia at this time provides a possible selective kill mechanism that could help explain the large taxonomic losses in brachiopods compared to the morphologically and ecologically similar bivalve molluscs. Our study compared the oxygen consumption of an articulate brachiopod,Terebratalia transversa, with that of two pteriomorph bivalves,Glycymeris septentrionalisandMytilus trossulus, under normoxia and hypoxia, as well as their tolerance to anoxia, to gain insight into the relative metabolic characteristics of each group. We found no significant difference in the oxygen consumption of the three species when normalized to the same dry-tissue mass. However, when calculated for animals of the same external linear dimensions, bivalve oxygen consumption was two to three times greater than that of brachiopods. Our results also showed no significant decrease in the oxygen consumption of the three species until measured at a partial pressure of oxygen ∼10% of normoxic values. Finally,T. transversaandM. trossulusshowed no significant difference in their tolerance to complete anoxia, but both showed a much lower tolerance than another bivalve,Acila castrensis. Findings from this study suggest that oxygen limitation is unlikely to account for the observed selective extinction of brachiopods during the Permian/Triassic mass extinction. Results may provide valuable information for assessing hypotheses put forth to explain why articulate brachiopods continue to remain a relatively minor group in marine environments.

scholarly journals The latitudinal diversity gradient of tetrapods across the Permo-Triassic mass extinction and recovery interval

2020 ◽  
Vol 287 (1929) ◽  
pp. 20201125 ◽  
Author(s):  
Bethany J. Allen ◽  
Paul B. Wignall ◽  
Daniel J. Hill ◽  
Erin E. Saupe ◽  
Alexander M. Dunhill
Keyword(s):  
Mass Extinction ◽  
Large Scale ◽  
Middle Triassic ◽  
Global Climate ◽  
Time Interval ◽  
Late Permian ◽  
Biodiversity Patterns ◽  
Latitudinal Diversity Gradient ◽  
Earth History ◽  
Diversity Gradient

The decline in species richness from the equator to the poles is referred to as the latitudinal diversity gradient (LDG). Higher equatorial diversity has been recognized for over 200 years, but the consistency of this pattern in deep time remains uncertain. Examination of spatial biodiversity patterns in the past across different global climate regimes and continental configurations can reveal how LDGs have varied over Earth history and potentially differentiate between suggested causal mechanisms. The Late Permian–Middle Triassic represents an ideal time interval for study, because it is characterized by large-scale volcanic episodes, extreme greenhouse temperatures and the most severe mass extinction event in Earth history. We examined terrestrial and marine tetrapod spatial biodiversity patterns using a database of global tetrapod occurrences. Terrestrial tetrapods exhibit a bimodal richness distribution throughout the Late Permian–Middle Triassic, with peaks in the northern low latitudes and southern mid-latitudes around 20–40° N and 60° S, respectively. Marine reptile fossils are known almost exclusively from the Northern Hemisphere in the Early and Middle Triassic, with highest diversity around 20° N. Reconstructed terrestrial LDGs contrast strongly with the generally unimodal gradients of today, potentially reflecting high global temperatures and prevailing Pangaean super-monsoonal climate system during the Permo-Triassic.

Taxon age and selectivity of extinction

Paleobiology ◽  
1991 ◽  
Vol 17 (1) ◽  
pp. 49-57 ◽  
Author(s):  
George E. Boyajian
Keyword(s):  
Species Richness ◽  
Mass Extinction ◽  
Geometric Mean ◽  
Geographic Range ◽  
Mass Extinctions ◽  
Marine Animals ◽  
Bootstrap Analysis ◽  
The Mean ◽  
Standard Deviations ◽  
Family Survival

Taxon-age distributions were compiled for families of marine animals surviving or becoming extinct in each stage of the Phanerozoic. I demonstrate, through the use of a modified bootstrap analysis, that there is no difference between the longevity of families becoming extinct during times of background extinction and times of mass extinction. In both mass and background extinction intervals the mean age of families that become extinct is 2 standard deviations below the geometric mean taxon age of families available for extinction. Young families are more susceptible to extinction, perhaps as the result of lower species richness or of occupying a smaller geographic range. There is no tendency during mass extinctions toward loss of families with different taxon ages other than those that become extinct during background times. Thus, in terms of family survival, mass extinction appears to be an exaggeration of processes of background extinction.

Selective extinction of late Neogene bivalves on the temperate Pacific coast of South America

Paleobiology ◽  
2007 ◽  
Vol 33 (3) ◽  
pp. 455-468 ◽  
Author(s):  
Marcelo M. Rivadeneira ◽  
Pablo A. Marquet
Keyword(s):  
Body Size ◽  
South America ◽  
Mass Extinction ◽  
Pacific Coast ◽  
Geographic Range ◽  
Life Habit ◽  
Late Neogene ◽  
Probability Of Extinction ◽  
Phylogenetic Effects ◽  
Selective Extinction

AbstractWe assessed selective extinction patterns in bivalves during a late Neogene mass extinction event observed along the temperate Pacific coast of South America. The analysis of 99 late Neogene and Quaternary fossil sites (recorded from 7°S to 55°S), yielding ∼2800 occurrences and 118 species, revealed an abrupt decline in Lyellian percentages during the late Neogene–Pleistocene, suggesting the existence of a mass extinction that decimated ∼66% of the original assemblage. Using the late Neogene data set (n = 59 species, 1346 occurrences), we tested whether the extinction was nonrandom according to taxonomic structure, life habit, geographic range, and body size. Our results showed that the number of higher taxa that went extinct was not different than expected by random. At first sight, extinction was selective only according to life habit and geographic range. Nevertheless, when phylogenetic effects were accounted for, body size also showed significant selectivity. In general, epifaunal, small-sized (after phylogenetic correction), and short-ranged species tended to have increased probability of extinction. This is verified by strong interactions between the variables herein analyzed, suggesting the existence of nonlinear effects on extinction chances. In the heavily decimated epifaunal forms, survival was not enhanced by widespread ranges or larger body sizes. Conversely, the widespread and large-sized infaunal forms tended to have lower probability of extinction. Overall, the ultimate extinction of late Neogene bivalve species along the Pacific coast of South America seems to have been determined by a complex interplay of ecological and historical (phylogenetic) effects.

Iron-mediated deep-time preservation of osteocytes in a Middle Triassic reptile bone

2019 ◽  
pp. 1-8 ◽  
Author(s):  
D. Surmik ◽  
M. Dulski ◽  
B. Kremer ◽  
J. Szade ◽  
R. Pawlicki
Keyword(s):  
Middle Triassic ◽  
Deep Time
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