Function and hydrostatics in the telson of the Burgess Shale arthropod
            Burgessia

Burgessia bella is a characteristic Burgess Shale arthropod (508 Ma), but the unusual preservation of its telson in both straight and bent modes leads to contradictory interpretations of its function. A reinvestigation of the fossil material, including burial attitudes, combined with a comparison with the decay sequence and mechanics of the telson in living Limulus , demonstrates that the telson of Burgessia was flexible in its relaxed state but could be stiffened in life. Evidence of fluid within the telson indicates that this manoeuvrability was achieved by changes in hydrostatic pressure and muscular control. The dual mode in the Burgessia telson is, to my knowledge, the first documented among fossil arthropods. It indicates that the requirement for a rigid telson, which is resolved by a thick sclerotized cuticle in most arthropods, may first have been achieved by hydrostatic means.

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Arthropods from North Greenland: exceptional data in the ‘Cambrian explosion’ debate

The Paleontological Society Special Publications ◽

10.1017/s2475262200006043 ◽

1992 ◽

Vol 6 ◽

pp. 44-44

Author(s):

Graham E. Budd

Keyword(s):

Morphological Changes ◽

Three Dimensional ◽

Cambrian Explosion ◽

Burgess Shale ◽

Phylogenetic Methods ◽

Fossil Material ◽

Body Patterning ◽

Bare Bones ◽

Early Metazoan ◽

North Greenland

'Sirius Passet’ fauna arthropods from the Lower Cambrian Buen Formation of North Greenland form the major component of this exceptionally preserved biota. Early mineralisation of body cavities led to internal anatomy being preserved more readily than external structures such as limbs. Musculature and gut are known in three dimensional form. Many of the taxa present are more easily compared to extant arthropods than to flattened fossil material such as from the Burgess Shale.The most common arthropod is represented by some 1600 specimens. Although widely differing in preservational style, these specimens may be reconciled to provide a coherent model of the three-dimensional anatomy of the arthropod. The affinities of this arthropod lie with the ‘Cheliceromorph’ rather than the Crustacean biramous-limbed arthropods, and may represent a fairly advanced lineage within the clade.Recent discussions of the patterns produced by the early metazoan radiations have concentrated on data available from the Burgess Shale. The continuing discovery and description of other Cambrian lagerstätten such as from North Greenland and Chengjiang has highlighted the degree to which the Burgess Shale fauna should be considered to be an aliquot taken from the foment of the ‘Cambrian Explosion’. The discovery of more taxa is tending to flesh out the bare bones of the Burgess fauna. Conclusions about phylogentic patterns drawn from the Burgess Shale alone may thus be premature.Body patterning in the arthropods, and the validity of the ‘Bauplan’ concept may be investigated by consideration of the actual mechanisms available for profound morphological change. One promising route is provided by the ‘homeotic’ and other hierarchically arranged developmental genes. When the mode of action of these genes is considered in conjunction with phylogenetic methods, it may prove possible to assess evolutionary pathways in terms of the feasibility of the morphological changes required by them rather than relying on what seems inherently reasonable or on marginal advantages in parsimony. Exceptionally preserved biotas also contain the evidence for the evolution of the developmental mechanisms themselves.

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A new hurdiid radiodont from the Burgess Shale evinces the exploitation of Cambrian infaunal food sources

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2019.1079 ◽

2019 ◽

Vol 286 (1908) ◽

pp. 20191079 ◽

Cited By ~ 8

Author(s):

J. Moysiuk ◽

J.-B. Caron

Keyword(s):

British Columbia ◽

Feeding Ecology ◽

Food Sources ◽

Cambrian Explosion ◽

Feeding Apparatus ◽

Burgess Shale ◽

Apex Predators ◽

Oral Cone ◽

Fossil Material ◽

Spinous Processes

Radiodonts, a clade of Cambro-Devonian stem group euarthropods, have classically been regarded as nektonic apex predators. However, many aspects of radiodont morphology and ecology have remained unclear because of the typically fragmentary nature of fossil material. Here, we describe a new hurdiid radiodont based on abundant and exceptionally well-preserved fossils from the Burgess Shale (Marble Canyon area, British Columbia, Canada). Cambroraster falcatus gen. et sp. nov . is characterized by an extra-large horseshoe-shaped head carapace, bearing conspicuous posterolateral spinous processes, and partially covering a short trunk with eight pairs of lateral flaps. Each of the pair of frontal appendages possess five mesially curving rake-like endites equipped with a series of anteriorly directed hooked spines, altogether surrounding the oral cone. This feeding apparatus suggests a micro to macrophagous sediment-sifting feeding ecology. Cambroraster illuminates the evolution of Hurdiidae and evinces the exploitation of the diversifying infauna by these large and specialized nektobenthic carnivores in the aftermath of the Cambrian explosion.

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Banffia constricta, a putative vetulicolid from the Middle Cambrian Burgess Shale

Transactions of the Royal Society of Edinburgh Earth Sciences ◽

10.1017/s0263593305000052 ◽

2005 ◽

Vol 96 (02) ◽

pp. 95 ◽

Cited By ~ 1

Keyword(s):

Burgess Shale ◽

Middle Cambrian

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Anti-Diabetic Activity of a Mineraloid Isolate, in vitro and in Genetically Diabetic Mice

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000048 ◽

2011 ◽

Vol 81 (1) ◽

pp. 34-42 ◽

Cited By ~ 1

Author(s):

Joel Deneau ◽

Taufeeq Ahmed ◽

Roger Blotsky ◽

Krzysztof Bojanowski

Keyword(s):

Dna Microarrays ◽

Human Fibroblasts ◽

Diabetic Animal ◽

In Vitro Tests ◽

Diabetic Mice ◽

Fossil Material ◽

Expression Of Genes ◽

Enhanced Expression ◽

Genetically Diabetic Mice

Type II diabetes is a metabolic disease mediated through multiple molecular pathways. Here, we report anti-diabetic effect of a standardized isolate from a fossil material - a mineraloid leonardite - in in vitro tests and in genetically diabetic mice. The mineraloid isolate stimulated mitochondrial metabolism in human fibroblasts and this stimulation correlated with enhanced expression of genes coding for mitochondrial proteins such as ATP synthases and ribosomal protein precursors, as measured by DNA microarrays. In the diabetic animal model, consumption of the Totala isolate resulted in decreased weight gain, blood glucose, and glycated hemoglobin. To our best knowledge, this is the first description ever of a fossil material having anti-diabetic activity in pre-clinical models.

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