Paleoecological and Stratigraphic Controls on Eurypterid Lagerstätten: A Model for Preservation in the Mid-Paleozoic

Vrazo, Matthew B.; Brett, Carlton E.; Ciurca, Samuel J.

doi:10.1130/abs/2016am-283005

Cited by 4 publications

(13 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…hypo‐ to slightly hypersaline) (Vrazo et al . , , ). In both formations exoskeletons (rather than carcasses) of Eurypterus , one of the presumed eurypteroid tracemakers, are much more abundant than all other eurypterid taxa, occur in a wide range of sizes, and are sometimes found in aggregated moult ensembles (Tetlie et al .…”

Section: Discussionmentioning

confidence: 99%

“…This study, together with a later stratigraphical and palaeoecological analysis of this region (Vrazo et al . ), support eurypterid inhabitation of the Williamsville Formation, and consequently remove Ciurca's () environmental constraint on a eurypterid tracemaker in this unit. New trace fossil evidence from a contemporaneous upper Silurian eurypterid Lagerstätte in the Tonoloway Formation of Pennsylvania (Vrazo et al .…”

mentioning

confidence: 83%

“…These microbialites are typically interpreted as lying on, or just above, the flooding surfaces of small‐scale shallowing‐up cycles (Vrazo et al . ). This close eurypterid–microbialite association, in conjunction with a significant increase in faunal diversity in the eurypterid‐bearing beds, has been taken as evidence that eurypterids and other fauna preferentially occupied the shallow subtidal zones of the Williamsville Formation and other Bertie Group units during minor transgressive freshening events (i.e.…”

Section: Geological Settingmentioning

confidence: 97%

“…when salinity levels were nearly euhaline; Vrazo et al . ). Although OʼConnell's () early deltaic interpretation has since been widely contested, the presence of terrestrial plants ( Cooksonia ; Edwards et al .…”

Section: Geological Settingmentioning

confidence: 97%

“…Eurypterids have been observed with or above thrombolites and other microbialites in the A Member and in a number of other upper Silurian units, including the Tonoloway Formation, in the central and northern Appalachian Basin (Ciurca ; Vrazo et al . , ). These microbialites are typically interpreted as lying on, or just above, the flooding surfaces of small‐scale shallowing‐up cycles (Vrazo et al .…”

Section: Geological Settingmentioning

confidence: 99%

See 4 more Smart Citations

New trace fossil evidence for eurypterid swimming behaviour

Vrazo

Ciurca²

2017

Palaeontology

Self Cite

View full text Add to dashboard Cite

We describe a recently discovered trace fossil from a eurypterid Konservat‐Lagerstätte in the upper Silurian Tonoloway Formation of Pennsylvania, and formally describe contemporaneous traces from the Williamsville Formation Lagerstätte of Ontario. The traces from both localities are assigned here to Arcuites bertiensis igen. et isp. nov. Based on comparisons with previously described eurypterid trackways, neoichnological experiments, and the co‐occurrence with eurypterid remains, Arcuites is interpreted as having been made by the swimming leg (sixth prosomal appendage) of swimming juvenile to adult eurypteroid eurypterids, and represents the first unambiguous trace fossil evidence for eurypterid swimming behaviour. The morphology of Arcuites indicates that eurypteroid eurypterids swam using drag‐based rowing, whereby the animal propelled itself forward by moving its oar blade‐like swimming paddles in an in‐phase backstroke. Arcuites morphology also indicates that the eurypteroid swimming appendage had a greater degree of movement than was previously suggested, and a revised rowing model is proposed. Differences in the abundance of A. bertiensis in the Tonoloway and Williamsville formations suggest a bathymetric control on eurypterid swimming behaviour and trace production. The association of Arcuites with eurypterid body fossils in both units indicates that these Lagerstätten were autochthonous assemblages and provides additional evidence for eurypterid inhabitation of shallow subtidal marine environments in the late Silurian.

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 83%

Section: Geological Settingmentioning

confidence: 97%

Section: Geological Settingmentioning

confidence: 97%

Section: Geological Settingmentioning

confidence: 99%

See 3 more Smart Citations

New trace fossil evidence for eurypterid swimming behaviour

Vrazo

Ciurca²

2017

Palaeontology

Self Cite

View full text Add to dashboard Cite

show abstract

Redescription, paleogeography, and experimental paleoecology of the Silurian phyllocaridGonatocaris

Collette¹,

Plotnick²

2020

J. Paleontol.

View full text Add to dashboard Cite

Gonatocaris decora (Clarke, 1901) is an unusual, highly ornamented Silurian phyllocarid from the Pittsford Shale Member of the Vernon Formation, Salina Group of New York, that has been allied with Emmelezoe in the past due to the possession of an ‘optic tubercle.’ The systematic positions of Gonatocaris and Emmelezoe have been difficult to assess due to the lack of complete remains, attributions based on spurious characters, and missing and unfigured specimens. Relatively recent collections of Gonatocaris decora, along with a relocation of the original type material of Emmelezoe, have allowed a reexamination of all relevant genera and a more robust systematic placement for G. decora. Characters of generic importance for Gonatocaris include a greatly elongated abdomen; an acute angle of the ventral carapace margin separating distinct anteroventral and posteroventral margins from each other; and distinctive, multiscale horizontal ridge-like ornament of the carapace valves. Growth was found to be isometric. Experimental work done using a model of the scale-like ornament and multiple grain sizes of substrate indicates that cuticle ornament may have served to increase friction between the animal and a fine sand substrate, although resistance to predation is the currently favored hypothesis. Because Gonatocaris species are currently known only from the eastern margin of Laurentia and northern South China, it is likely that this genus was nektonic. Accumulations of similarly sized carapaces and other disarticulated sclerites in shallow-water settings may indicate spawning events following molting en masse.

show abstract

Stranger than a scorpion: a reassessment of Parioscorpio venator, a problematic arthropod from the Llandoverian Waukesha Lagerstätte

et al. 2021

View full text Add to dashboard Cite

A relatively uncommon arthropod of the Waukesha lagerstätte, Parioscorpio venator, is redescribed as an arthropod bearing a combination of characters that defy ready classification. Diagnostic features include sub‐chelate ‘great appendages’, a lack of antennae, multiramous anterior trunk appendages, filamentous fan‐like rear trunk appendages, and apparently thin and poorly preserved pleural fields. Phylogenetic analysis resolves this organism as basal to crown‐group Mandibulata and Chelicerata, but its exact placement is inconclusive. Thus, we compare its morphology to several stem groups of arthropods in a discussion of its plausible taxonomic affinities. The examined specimens are probably carcasses and preserve a variety of soft‐tissue details, including muscle blocks in the head, eyes and eye facets, likely ventral nerve cords, a central gut tract and trunk legs with multiple filamentous elements organized into stiff bundles. The preservation habits of P. venator are characterized and compared to previous assessments of Waukesha lagerstätte taxa. Four preservation habits are observed: a phosphatized habit showing flattened to partly three‐dimensional mineralization in francolite; a mouldic habit largely left behind by removed francolite that shows no carbon enrichment despite a darkened colour; sheet‐like or speckled carbonaceous compressions; and scattered pyrite crystals. This redescription highlights both the palaeobiological value of ‘small’ lagerstätten typical of the middle Palaeozoic and the caution that must be taken when interpreting their more enigmatic constituents.

show abstract

Paleoecological and Stratigraphic Controls on Eurypterid Lagerstätten: A Model for Preservation in the Mid-Paleozoic

Cited by 4 publications

References 0 publications

New trace fossil evidence for eurypterid swimming behaviour

New trace fossil evidence for eurypterid swimming behaviour

Redescription, paleogeography, and experimental paleoecology of the Silurian phyllocaridGonatocaris

Stranger than a scorpion: a reassessment of Parioscorpio venator, a problematic arthropod from the Llandoverian Waukesha Lagerstätte

Contact Info

Product

Resources

About