Insights from big data into the fossilization potential of marine communities

2021 ◽  
Author(s):  
Jack Shaw ◽  
Derek Briggs ◽  
Pincelli Hull
Keyword(s):  
Fossil Record ◽  
Global Assessment ◽  
High Energy ◽  
Information Loss ◽  
Faunal Composition ◽  
Mean Values ◽  
Marine Communities ◽  
Occurrence Data ◽  
Rock Record ◽  
Approach Zero

<p>Only a small percentage of all life that ever existed is preserved in the rock record. Some animals and environments are particularly unlikely to fossilize—e.g., soft-bodied organisms and high-energy habitats—biasing fossil deposit faunal composition and resultant inferences about macroevolution and macroecology. To estimate the extent of information loss caused by non-preservation we compared diversity data in over 20,000 modern marine assemblages (Ocean Biogeographic Information System; OBIS) with fossil occurrence data (Paleobiology Database; PBDB) to yield a global assessment of assemblage-level fossilization potential as it varies across depth, habitats, and environments. We used two different metrics, taxon fossilization potential and within-environment fossilization potential, to assess the proportion of taxa in a modern community with PBDB occurrences or with PBDB occurrences in the same environment, respectively. Averaged across all 20,000+ marine assemblages, mean taxon fossilization potential is 38% and mean values vary between environments: from 34% in shallow and deep water, 44% in coral reefs, 51% on seamounts, to 15% in pelagic assemblages. Mean within-environment fossilization potential, in contrast, does not exceed 32% (in shallow water), a lower value than that obtained in other studies, and may approach zero (on seamounts and pelagic environments). Differences between these two metrics indicate the large control of environment on fossilization potential. Our results provide a means to include and compare palaeoecological dynamics across a broader range of settings in the fossil record, while accounting for differences in fossilization potential among environments.</p>

Fossilization potential of marine assemblages and environments

Geology ◽  
2020 ◽  
Author(s):  
Jack O. Shaw ◽  
Derek E.G. Briggs ◽  
Pincelli M. Hull
Keyword(s):  
Information System ◽  
Coral Reefs ◽  
Shallow Water ◽  
Deep Water ◽  
Fossil Record ◽  
Global Assessment ◽  
System Database ◽  
Occurrence Data ◽  
Rock Record ◽  
History Of

The fossil record provides the only direct record of the history of life, but it is an incomplete one. Discriminating between what is absent and what is simply not preserved is critical to macroevolutionary and macroecological inferences. A comparison of diversity data in over 20,000 modern marine assemblages from the Ocean Biogeographic Information System database (OBIS) with fossil occurrence data from the Paleobiology Database (PBDB) yielded a global assessment of assemblage-level fossilization potential. We used two different metrics, taxon fossilization potential and within-environment fossilization potential, to assess the proportion of taxa in a modern community with PBDB occurrences or with PBDB occurrences in the same environment, respectively. Taxon fossilization potential of marine genera varies between environments, from 34% in shallow and deep water to 44% in coral reefs, 51% on seamounts, and 15% in pelagic assemblages. Within-environment fossilization potential, in contrast, does not exceed 32% (in shallow water), a lower value than that obtained in other studies, and it may be zero (on seamounts and pelagic environments). These differences are mainly a product of representation in the rock record and sampling biases rather than taxon duration.

scholarly journals Procesos tafonómicos en una encrinita regional pensilvánica (Atokano), Sonora, México

2017 ◽  
Vol 65 (1-1) ◽  
pp. 147
Author(s):  
Catalina Gómez-Espinosa ◽  
Blanca Estela Buitrón-Sánchez
Keyword(s):  
North America ◽  
Debris Flow ◽  
Fossil Record ◽  
High Energy ◽  
Marine Communities ◽  
Storm Wave ◽  
Energy Environment ◽  
Taphonomic Processes

Taphonomic processes in a Pennsylvanian regional encrinite (Atokano), Sonora, Mexico. Crinoids have an extensive fossil record and were a major component in Paleozoic marine communities; encrinites are common crinoid accumulations where specimens are totally disarticulated from the Ordovician to the Jurassic. In Sonora, Mexico, the crinoid skeleton was altered during diagenesis and replaced by silica. The corrasion was high; the incrustation low and there is evidence of dissolution and compaction. This is a sedimentological type accumulation in a high energy environment of allochthonous organism transported in a debris flow, deposited below the storm wave base in an outer ramp. Our results can be correlated with regional encrinites prevalent in the Pennsylvanian cyclothems of North America. Rev. Biol. Trop. 65(Suppl. 1): S147-S159. Epub 2017 November 01. 

scholarly journals Sauropterygian remains from the Middle Triassic of Villány, Hungary—new information on the aquatic reptile fauna of Tisza Megaunit (Triassic southern Eurasian shelf region)

2021 ◽  
Author(s):  
Martin Segesdi ◽  
Attila Ősi
Keyword(s):  
Fossil Record ◽  
Middle Triassic ◽  
Faunal Composition ◽  
Shallow Marine ◽  
Germanic Basin ◽  
Marine Communities ◽  
New Information ◽  
History Of ◽  
The One ◽  
Shelf Region

AbstractSauropterygia was a diverse clade of secondary aquatic reptiles, which represented one of the most important vertebrate groups in the shallow marine communities during the Triassic. However, despite the long history of collection and examination of sauropterygian remains, previous studies have indicated that the fossil record of this group is incomplete, making the understanding of their palaeobiogeographic relations difficult. Here we describe new sauropterygian remains from the Middle Triassic (Ladinian) Templomhegy Dolomite Member (Villány, southern Hungary), which were unearthed during systematic fieldwork of previous years. Among several non-diagnostic sauropterygian remains, this material contains isolated bones belonging to Nothosaurus sp., Simosauridae indet. and a small-sized nothosaurid. The known faunal composition from Villány is similar to what was described from the Middle Triassic of the Germanic Basin and Bihor Mountains (northwestern Romania). Besides isolated elements, a probably associated skeleton of a small-sized eosauropterygian specimen of unknown affinities is also reported here. This locality widens our knowledge on Triassic sauropterygian distribution and provides new information about the previously not well-known Middle Triassic vertebrate fauna of the one-time southern Eurasian shelf region.

scholarly journals AB0100 EVALUATION OF PGA LEVEL FOR CLINICAL REMISSION WITH BOOLEAN CRITERIA, 10MM OR 20MM?

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1078.1-1079
Author(s):  
I. Yoshii
Keyword(s):  
Disease Activity ◽  
Patient Group ◽  
Clinical Remission ◽  
Global Assessment ◽  
Activity Index ◽  
T Test ◽  
Mean Values ◽  
Significant Difference ◽  
Remission Criteria ◽  
The Mean

Background:Patient’s global assessment (PGA) is one important component of Boolean composite criteria for remission in treat with rheumatoid arthritis (RA). However, PGA no more than 10mm is sometimes obstacle to attain clinical remission. In recent few years, one opinion that PGA no more than 20mm may be comparable as no more than 10mm.Objectives:The aim of this study is to analyze how difference of these PGA level affect disease activity and daily activities in living, and evaluate which is optimal for the remission with Boolean remission criteria from real world setting.Methods:RA patients who were followed up for more than three years in the institute were picked up in the study. Each patient was monitored with tenderness joint count (TJC), swollen joint count (SJC), PGA, evaluator’s global assessment (EGA), serum C-reactive protein level (CRP), calculated disease activity score with simplified disease activity index(SDAI), Health Assessment Questionnaire Disability Index (HAQ-DI), and pain score using visual analog scale (PS-VAS) every consulted time from the first encounter (Baseline). Patients were classified according to achievement of Boolean remission criteria. Group 1: a patient group who attained Boolean remission wih TJC≦1, SJC≦1, CRP≦1mg/dl, and PGA≦1 (G-1), Group 2: a patient group who could not attained the Boolean remission used in the G-1 evaluation, but could attained another Boolean remission with TJC≦1, SJC≦1, CRP≦1mg/dl, and PGA≦2 (G-2), and Group 3: a patient group who could not attain Boolean remission for neither criterion.Mean values of measured parameters at Baseline and after the Baseline were compared statistically with Student T-test. Mean values of the same parameters in the G-1 and G-2 at the time of attain Boolean remission for each criteria, mean values of each of these parameters thereafter, and changes of these parameters were compared statistically with Student T-test.Results:A total of 438 patients 385 in the G-1 group, 16 in the G-2 group, and 37 in the G-3 group, were recruited. In parameters at Baseline, level of TJC, SJC, PGA, EGA, SDAI, and HAQ-DI in the G-1 was significantly lower than in the G-3, whereas no significant differences in any parameters demonstrated between in the G-2 and G-3. Level of HAQ-DI, and PS-VAS after Baseline in the G-1 was lower than in the G-3, whereas no significant difference of these parameters after Baseline demonstrated between in the G-2 and G-3. TJC, SJC, PGA, and EGA demonstrated significant less level in the G-1 than in the other two groups. The mean SDAI score at the time of first achievement of Boolean remission in the G-1 and G-2 were 1.08 and 2.57, respectively. The mean value of SDAI score after remission in the G-1 and G-2 were 3.35 and 6.44, respectively. These values and PS-VAS including change of the SDAI score demonstrated significant difference between the two groups (p<0.01), whereas HAQ-DI in the two groups demonstrated no significant difference.Conclusion:These results suggested that setting PGA as no more than 10mm should be reasonable for the evaluation of clinical remission with the Boolean criteria.Disclosure of Interests:None declared

The greatest hits of all time: the histories of dominant genera in the fossil record

Paleobiology ◽  
2018 ◽  
Vol 44 (3) ◽  
pp. 368-384 ◽  
Author(s):  
Roy E. Plotnick ◽  
Peter Wagner
Keyword(s):  
Simple Model ◽  
Fossil Record ◽  
Target Groups ◽  
Higher Taxa ◽  
Occurrence Data

AbstractCertain taxa are noticeably common within collections, widely distributed, and frequently long-lived. We have examined these dominant genera as compared with rarer genera, with a focus on their temporal histories. Using occurrence data from the Paleobiology Database, we determined which genera belonging to six target groups ranked among the most common within each of 49 temporal bins based on occurrences. The turnover among these dominant taxa from bin to bin was then determined for each of these groups, and all six groups when pooled. Although dominant genera are only a small fraction of all genera, the patterns of turnover mimic those seen in much larger compilations of total biodiversity. We also found that differences in patterns of turnover at the top ranks among the higher taxa reflect previously documented comparison of overall turnover among these classes. Both dominant and nondominant genera exhibit, on average, symmetrical patterns of rise and fall between first and last appearances. Dominant genera rarely begin at high ranks, but nevertheless tend to be more common when they first appear than nondominant genera. Moreover, dominant genera rarely are in the top 20 when they last appear, but still typically occupy more localities than nondominant genera occupy in their last interval. The mechanism(s) that produce dominant genera remain unclear. Nearly half of dominant genera are the type genus of a family or subfamily. This is consistent with a simple model of morphological and phylogenetic diversification and sampling.

scholarly journals Pyrite Textures, Trace Elements and Sulfur Isotope Chemistry of Bijaigarh Shales, Vindhyan Basin, India and Their Implications

Minerals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 588
Author(s):  
Indrani Mukherjee ◽  
Mihir Deb ◽  
Ross R. Large ◽  
Jacqueline Halpin ◽  
Sebastien Meffre ◽  
...  
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Sulfur Isotope ◽  
Volcanic Rocks ◽  
Central India ◽  
High Energy ◽  
Vindhyan Basin ◽  
Mean Values ◽  
Fine Grained ◽  
Sedimentary Pyrite

The Vindhyan Basin in central India preserves a thick (~5 km) sequence of sedimentary and lesser volcanic rocks that provide a valuable archive of a part of the Proterozoic (~1800–900 Ma) in India. Here, we present an analysis of key sedimentary pyrite textures and their trace element and sulfur isotope compositions in the Bijaigarh Shale (1210 ± 52 Ma) in the Vindhyan Supergroup, using reflected light microscopy, LA-ICP-MS and SHRIMP-SI, respectively. A variety of sedimentary pyrite textures (fine-grained disseminated to aggregates, framboids, lags, and possibly microbial pyrite textures) are observed reflecting quiet and strongly anoxic water column conditions punctuated by occasional high-energy events (storm incursions). Key redox sensitive or sensitive to oxidative weathering trace elements (Co, Ni, Zn, Mo, Se) and ratios of (Se/Co, Mo/Co, Zn/Co) measured in sedimentary pyrites from the Bijaigarh Shale are used to infer atmospheric redox conditions during its deposition. Most trace elements are depleted relative to Proterozoic mean values. Sulfur isotope compositions of pyrite, measured using SHRIMP-SI, show an increase in δ34S as we move up stratigraphy with positive δ34S values ranging from 5.9‰ (lower) to 26.08‰ (upper). We propose limited sulphate supply caused the pyrites to incorporate the heavier isotope. Overall, we interpret these low trace element signatures and heavy sulfur isotope compositions to indicate relatively suppressed oxidative weathering on land during the deposition of the Bijaigarh Shale.

Implications for the study of fossil Asteroidea (Echinodermata) of new genera and species from the Eocene of Florida

2009 ◽  
Vol 83 (4) ◽  
pp. 562-574 ◽  
Author(s):  
Daniel B. Blake ◽  
Roger W. Portell
Keyword(s):  
Family History ◽  
New Taxa ◽  
Middle Jurassic ◽  
Fossil Record ◽  
New Genera ◽  
Crown Group ◽  
Marine Communities ◽  
The Family ◽  
Ocala Limestone

Oyenaster oblidus, Ocalaster timucum, and Ocalaster seloyi are new genera and species of the family Goniasteridae (Asteroidea) described from the Eocene Ocala Limestone of Florida. Although the fossil record of asteroids is sketchy, goniasterids appear to have been important contributors to marine communities since at least the Middle Jurassic. Similarities between living goniasterids and their fossil precursors indicate that plesiomorphy and convergence have been important in family history, and as a result, taxonomic interpretation is challenging. Even partial fossil goniasterids are rare, forcing systematists to rely heavily on isolated marginal ossicles, although some authors have expressed the need for caution. Building around three new taxa, we suggest that broader approaches can aid systematic interpretation of all crown-group asteroids. We also suggest that the inevitably idiosyncratic interpretations of marginal-based systematics can be partially tested using blind evaluations.

scholarly journals Discrete Source Synthesis of the X-Ray Background

1980 ◽  
Vol 92 ◽  
pp. 233-233 ◽  
Author(s):  
A. Cavaliere ◽  
L. Danese ◽  
G. De Zotti ◽  
A. Franceschini
Keyword(s):  
Power Law ◽  
Energy Content ◽  
High Energy ◽  
Discrete Source ◽  
Distribution Functions ◽  
Mean Values ◽  
X Ray ◽  
X Ray Background ◽  
Luminosity Evolution

The recent deep X-ray surveys suggest that discrete sources comprise most, if not all, of the energy content of the background (cf. Giacconi, this volume). We have shown that, if sources have flat power law spectra and relatively sharp high-energy cutoffs, their combined emission can also mimic very accurately its extended (2 - 400 keV) spectral shape. A broad distribution of cutoff energies Ec is required, in this case, to model the high-energy (E ≳ 20 - 40 keV) part: a power law envelope of distribution functions of various types of sources can be envisaged; alternatively, the well-known fact that most of the 2 − 10 keV background should be produced by low flux, low Ec sources can suggest that Ec ∝ (1 + z)−η. The quality of the fit turns out to be not very sensitive to the amount of number/luminosity evolution assumed, though the minimum χ2 test slightly favours strongly evolving sources. In the case of differential luminosity ∝ E−γ and evolution ∝ (1 + z)α with 0 ≤ α ≤ 6, the best fits to pre HEAO-1 data are obtained for mean values of the spectral index γ ≈ 0.5 − 0.9 and for dispersions Δγ ≃ 0.5 - 0.7. Rather wide ranges of values of γ and Δγ are, however, still allowed; e.g., for α = 6, the allowed intervals are 0.2 ≤ γ ≤ 1.3, 0 ≤ Δγ ≤ 0.7.

scholarly journals A fresh look at the fossil evidence for early Archaean cellular life

2006 ◽  
Vol 361 (1470) ◽  
pp. 887-902 ◽  
Author(s):  
Martin Brasier ◽  
Nicola McLoughlin ◽  
Owen Green ◽  
David Wacey
Keyword(s):  
Critical Analysis ◽  
Fossil Record ◽  
Volcanic Glass ◽  
New Approach ◽  
Microbial Origin ◽  
Cellular Life ◽  
Fossil Evidence ◽  
Rock Record ◽  
Inclusion Trails ◽  
Self Organizing

The rock record provides us with unique evidence for testing models as to when and where cellular life first appeared on Earth. Its study, however, requires caution. The biogenicity of stromatolites and ‘microfossils’ older than 3.0 Gyr should not be accepted without critical analysis of morphospace and context, using multiple modern techniques, plus rejection of alternative non-biological (null) hypotheses. The previous view that the co-occurrence of biology-like morphology and carbonaceous chemistry in ancient, microfossil-like objects is a presumptive indicator of biogenicity is not enough. As with the famous Martian microfossils, we need to ask not ‘what do these structures remind us of?’, but ‘what are these structures?’ Earth's oldest putative ‘microfossil’ assemblages within 3.4–3.5 Gyr carbonaceous cherts, such as the Apex Chert, are likewise self-organizing structures that do not pass tests for biogenicity. There is a preservational paradox in the fossil record prior to ca 2.7 Gyr: suitable rocks (e.g. isotopically light carbonaceous cherts) are widely present, but signals of life are enigmatic and hard to decipher. One new approach includes detailed mapping of well-preserved sandstone grains in the ca 3.4 Gyr Strelley Pool Chert. These can contain endolithic microtubes showing syngenicity, grain selectivity and several levels of geochemical processing. Preliminary studies invite comparison with a class of ambient inclusion trails of putative microbial origin and with the activities of modern anaerobic proteobacteria and volcanic glass euendoliths.

Sign in / Sign up

Export Citation Format

Share Document