Uncertainty and Underdetermination in Precambrian Paleobiology — Extinct

There may be one last item to say. A number of of the opposite preservational morphs of Aspidella have names that ought to now be acquainted. These embody Ediacaria (Sprigg’s unique “jellyfish”) and Spriggia, which Glaessner interpreted as a medusoid. Certainly, as Gehling et al. write, “As soon as the Aspidella morphs have been retrodeformed [restored to their original forms], they can’t be distinguished from different Ediacaran discoidal taxa, and can be recognized variously as Ediacaria, Cyclomedusa, Spriggia, Tirasiana, Irridinitus, or Planomedusites if present in different Ediacaran websites across the globe” (442). The conclusion, once more, is that these names select totally different areas of a morphological continuum, through which a spread of fossil buildings are produced by variations in physique dimension and sedimentary circumstances.

That is how the “Age of Jellyfish” ends. Not with a bang however a whimper.


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For a treasure trove of knowledge on Aspidella, see:

And for a pleasant write-up on the Charnia saga, see:

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