Analyzing trends in tropical Devonian brachiopod communities during environmental change in the Waterways Formation of northern Alberta

Mendonca, Steven E.; Barclay, Kristina M.; Schneider, Chris L.; Molinaro, Darrin J.; Webb, Amelinda E.; Forcino, Frank L.; Leighton, Lindsey R.

doi:10.1016/j.palaeo.2018.06.020

Cited by 5 publications

(4 citation statements)

References 33 publications

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“…As an ordination, NMDS arranges and then projects multidimensional data onto axes that can explain the relative amount of similarity/dissimilarity between data sets. Unlike other multivariate techniques (e.g., principal component analysis), NMDS does not assume linear relationships or normal distributions between data sets, and it is less sensitive to outliers and zero values (Bush & Brame, 2010; Dexter et al., 2018; Mendonca et al., 2018). Instead, NMDS uses an iterative method for creating ordination results, such that it does not make any assumptions about a linear relationship between data sets, and it can be performed using a variety of specialized distance/dissimilarity measures (e.g., Bray‐Curtis, Euclidean, and Jaccard) designed for specific types of data sets (e.g., Legendre & Legendre, 2012; Moreno et al., 2018).…”

Section: Methodsmentioning

confidence: 99%

“…Including more dimensions in our analysis did not significantly change the groupings, but did decrease the stress value (Figures S1-S3 in Supporting Information S1). Choosing a greater number of dimensions, however, can decrease the amount of ecological variation captured on each axis (e.g., Mendonca et al, 2018). We thus report the NMDS analysis with two dimensions to optimally reflect the environmental relationships in our data set.…”

Section: General Groupings Observed From Nmdsmentioning

confidence: 99%

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Magnetofossils and Benthic Foraminifera Record Changes in Food Supply and Deoxygenation of the Coastal Marine Seafloor During the Paleocene‐Eocene Thermal Maximum

Wagner

Stassen

Thomas

et al. 2022

Paleoceanog and Paleoclimatol

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Continental shelf sediments along the northeast continental margin of North America contain a magnetofossil‐rich interval deposited during the Paleocene‐Eocene Thermal Maximum (PETM), an abrupt global warming event that occurred ∼56 Ma. These magnetofossils were produced by magnetotactic bacteria and unidentified, iron‐biomineralizing organisms. Previous work shows three distinct magnetofossil endmembers identified from principal component analysis of first‐order reversal curves (FORC‐PCA). The relative proportions of these magnetofossil endmembers varied over time during the PETM. Benthic foraminiferal species associations from the same sediments also vary during the PETM. Here, we compare the variability in magnetofossils and benthic foraminifera and statistically test, for the first time, whether they are significantly correlated. We find that changes in the type of magnetofossils present within the sediment correspond to changes in benthic foraminiferal assemblages, thus reflecting syndepositional conditions such as changes in oxygen, nutrients, and organic carbon concentrations, rather than diagenetic processes. We also find that magnetofossil‐producing organisms may respond to specific environmental pressures differently than benthic foraminifera, and in some cases, may better record these environmental signals. Therefore, FORC‐PCA on magnetofossil‐rich sediments can be used to understand discrete changes in ocean and/or early sediment chemistry over episodes of climate change. These environmental responses are inferred from non‐destructive, reproducible magnetic measurements, adding an independent environmental proxy to more commonly studied microfossil and geochemical proxies. Notably, these measurements only require small bulk sediment samples and do not need to contain calcium carbonate, making this approach ideal where sample material is limited and the record is affected by ocean acidification.

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Section: Methodsmentioning

confidence: 99%

Section: General Groupings Observed From Nmdsmentioning

confidence: 99%

Magnetofossils and Benthic Foraminifera Record Changes in Food Supply and Deoxygenation of the Coastal Marine Seafloor During the Paleocene‐Eocene Thermal Maximum

Wagner

Stassen

Thomas

et al. 2022

Paleoceanog and Paleoclimatol

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“…The methods employed in paleontological research are ideally determined by the goals of the study [1][2][3][4], but can also be influenced by locality and outcrop availability [5,6], lithology [7], funding or time limitations, or even researchers' specific expertise or traditions within the discipline. Previous work has sought to determine the most appropriate field methods [3,4,8,9], lab methods [2,8], and statistical techniques [4,10] to use in paleoecological research.…”

Section: Introductionmentioning

confidence: 99%

“…To understand ecological conditions of the past, paleontologists often compile faunal presence and abundance of fossil assemblages [1,11,12]. Irrespective of the specific goal of a paleoecological study, the taxonomic identifications and abundance counts used to determine fossil community distributions can be done in the field [e.g., 3,5,[13][14][15] or fossils can be collected and brought back to the lab [e.g., [16][17][18][19][20]. When collecting fossils to bring back to the lab, two different fossil collection methods are typically employed: (1) bulk collection of stratigraphically in-place fossil-containing sediment or rock, and (2) surface collection of loose, individual fossils that have weathered out of an outcrop.…”

Section: Introductionmentioning

confidence: 99%

The influence of collection method on paleoecological datasets: In-place versus surface-collected fossil samples in the Pennsylvanian Finis Shale, Texas, USA

Forcino

Stafford

2020

PLoS ONE

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There are multiple common methods for collecting fossil material in the field for paleoecological analyses, so it is important to determine if and how different methods may affect the similarities and differences among taxonomic samples. Here, we evaluate the influence of two fossil collection field methods (stratigraphically in-place bulk-sediment versus picking up weathered-out fossils from the ground surface) on paleoecological results, using the Pennsylvanian marine invertebrate assemblages of the Finis Shale in Texas. Based on an informal review of recent paleoecology papers, we observed that the lithology of the study material and the nature of the research question correspond to choice of field collection protocols; however, collection protocols are not always clearly explained or justified in the text of the papers. For the present case study, we collected stratigraphically equivalent samples from three outcrops using both the surface pickup and in-place bulk sediment methods. We found a difference in the abundance and composition of paleocommunities between these two collection methods. Evidence to support this includes the significant differences between samples using PERMANOVA (p < 0.001), the clear separation in ordination space of samples clustered by sampling method, the significantly higher richness in the surface samples (p < 0.001), and the considerable variation in relative abundances of various taxa and taxonomic groups. Richness and evenness were higher among the surface-collected samples, possibly due to collector bias, weathering artifacts, or spatial and temporal variability. Paleontologists strive to do the best science possible with the material available. Often, paleoecological research methods are limited by time, funding, or the nature of the material. In such cases, we recommend examining both collection methods, even if for only a fraction of the sampling. If only one method is possible, we recommend the use in-place, bulk-collected samples.

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Early Permian macroinvertebrate assemblages from the Siang and Subansiri districts, Arunachal Pradesh: Implications on the regional stratigraphy, palaeoenvironment, palaeoecology, and palaeobiogeography

et al. 2021

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Analyzing trends in tropical Devonian brachiopod communities during environmental change in the Waterways Formation of northern Alberta

Cited by 5 publications

References 33 publications

Magnetofossils and Benthic Foraminifera Record Changes in Food Supply and Deoxygenation of the Coastal Marine Seafloor During the Paleocene‐Eocene Thermal Maximum

Magnetofossils and Benthic Foraminifera Record Changes in Food Supply and Deoxygenation of the Coastal Marine Seafloor During the Paleocene‐Eocene Thermal Maximum

The influence of collection method on paleoecological datasets: In-place versus surface-collected fossil samples in the Pennsylvanian Finis Shale, Texas, USA

Early Permian macroinvertebrate assemblages from the Siang and Subansiri districts, Arunachal Pradesh: Implications on the regional stratigraphy, palaeoenvironment, palaeoecology, and palaeobiogeography

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