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A reconstruction of the ancient inhabitants of the Castle Bank Quarry in Wales.
Credit: Yang Dinghua
Creationists frauds like to make much of the so-called 'Cambrian Explosion' some 542–485 million years ago, when, so they claim the fossil record shows that a whole range of multicellular species with different body plans, suddenly appeared without ancestry, as if by magic.
Of course it was nothing of the sort and lasted some 6-10 million years during which multicellular organisms evolved out of the Ediacaran biota and arms races between predators and prey, made possible by the evolution of mobility (the Ediacarans had probably been sedentary filter-feeders, fixed to rocks and the sea bed) led to the evolution of different forms of mobility, senses such as sight and touch which require a nervous system, defensive armour like shells, spines and scales, burrowing and of course advanced digestive and excretory systems to process the new food supplies.
With little competition for natural niches, it is hardly surprising that diversification was rapid, but the impression of sudden appearance in the fossil record is due to the fact that most of the biota were soft-bodied (bones, teeth and shells not yet having evolved) and so the conditions in which they were preserved was rare. Previously, almost all out knowledge of the Cambrian biota came from the Burgess Shales from Canada, so all we have is a snapshot of the state of play at a moment in time with nothing on which to base a claim of sudden appearance or unnaturally rapid diversification.
But now though, thanks to a chance discovery made during the Covid-19 pandemic lockdown, we have another collection of soft-bodied fossils from Wales from the Ordovician Period, some 462 million years ago, the geological period immediately following the Cambrian. This collection of fossils shows the state of play some 20 million years after the Cambrian. Not surprisingly, these reveal a clear ancestry in the Cambrian with some of the species bearing a striking resemblance to Cambrian species such as the iconic Opabinia, Yohoia and Wiwaxia.
The discovery is the subject of a paper in Nature Ecology & Evolution by scientists from Cambridge University, UK, which is sadly behind an expensive paywall, together with several astonishing pictures of the fossils and artist's reconstructions, however, the abstract is available here. The work is also described in a brief news release from Cambridge University:
Newly discovered soft-bodied fossil site found in WalesMore technical detail is given in the abstract to their paper with photographs and charts available in the extended data:
In an unexpected outcome of the Covid lockdowns, a new fossil site has been discovered in Wales. It is one of the very rare sites where soft tissues and complete organisms are preserved in abundance, rather than just hard parts like shells and bones. These exceptional deposits tell us much of what we know about the evolution of life. Among the best of them are the famous Burgess Shale-type faunas, named after the location in Canada. There are many of these fossils in Cambrian rocks (when recognizable animal fossils first appear, some 542–485 million years ago) but almost none after that time. As a result, palaeontologists know a lot about Cambrian marine life, but far less about how it evolved in the periods immediately afterwards. The newly discovered site in Wales is from the middle of the succeeding Ordovician Period, some 462 million years ago, and rivals the best of the Cambrian deposits in terms of the diversity of fossils and extraordinary levels of preservation. One of the striking features of this deposit is that it contains relatives of some Cambrian ‘weird wonders’, alongside more modern-looking forms such as horseshoe crabs and starfish. So far, well over 150 species have been recovered, almost all of them being new and many very small, at only 1–3 mm long. This remarkable new assemblage, known as Castle Bank, was discovered during the 2020 lockdown by Dr Joe Botting and Dr Lucy Muir, near to their home in Llandrindod, central Wales. Dr Stephen Pates, a Herchel Smith Postdoctoral Fellow in the Department of Zoology, started collaborating with Dr Botting and Dr Muir by studying fossils together on Zoom during 2020, and was able to visit the site in 2021 when restrictions started to ease. A paper describing the new fauna has been published in Nature Ecology and Evolution, but this is only the first stage. The purpose is to announce the discovery of this fossil assemblage, and what it can potentially tell us, but later work will start to describe all the fossils in detail, revealing a hitherto unseen marine community from 462 million years ago.
Extended Data Fig. 3: Additional new sponge taxa from the Castle Bank fauna.
Extended Data Fig. 4: Deuterostomes from the Castle Bank fauna.
Extended Data Fig. 6: Biomineralized fossils of the Castle Bank fauna.
a, small, complex hexactinellid sponge (level uncertain) with euplectellid-like skeletal strands (NMW.2021.3 G.35); b, tall cylindrical hexactinellid with hypodermal pentactins and rossellid-like architecture (NIGP175889); c, complex conico-cylindrical hexactinellid (NMW.2021.3 G.36); d, stalked ascosponge (new genus) from level A8 with small soft-tissue region (top) supported by long basalia (NMW.2021.3 G.37); e, Teganiella sp. from level A6, the first record from outside the Americas (NMW.2021.3 G.38); f, the most abundant sponge species at the site, a small conical ascosponge from level A9 (NMW.2021.3 G.39i); g, complex hexactinellid (NMW.2021.3 G.40); h, relatively large rossellid-like sponge with abundant prostalia (NMW.2021.3 G.39ii). Scale bars 1 mm.
Extended Data Fig. 4: Deuterostomes from the Castle Bank fauna.
a–c, dendroid graptolite Dictyonema sp. with zooids (NMW.2021.3 G.40); a, cross-polarized light to highlight tubarium; b, plane-polarized light, with dark spots being zooids within thecae; c, detail of zooid (boxed in b) with evidence for cephalic shield (cs) and lophophore (loph) (NMW.2021.3 G.41); d, multi-branched benthic graptolite (NMW.2021.3 G.43); e–g, overall view (with interpretative drawing, f) and detail of body region of hemichordate with lophophore (loph) of two main tentacles and short lateral projections, fusellar-banded tube (tub), and reticulate holdfast region (ho) (NMW.2021.3 G.44); h, pair of Dendrocystites-like solutans from uncertain level (NMW.2021.3 G.45); i, undescribed asterozoan (NMW.2021.3 G.67); j, conodont (NMW.2021.3 G.95); k, bedding plane assemblage of conodonts (NMW.2021.3 G.96). Scale bars 1 mm (except c and k: 0.5 mm).
Extended Data Fig. 6: Biomineralized fossils of the Castle Bank fauna.
a, undescribed fenestellid bryozoan from uncertain level, attached to poorly preserved orthocone nautiloid (NMW.2021.3 G.62); b, phosphatic tube of the cnidarian Sphenothallus sp., from uncertain level (NMW.2021.3 G.63); c, brachiopod Monobolina ramsayi from level A0 (NMW.2021.3 G.68); d, unidentified acrotretid brachiopod (NMW.2021.3 G.90); e; encrusting brachiopod Schizocrania multistriata from uncertain level (NMW.2021.3 G.91); f, cnidarian Paraconularia sp. (NMW.2021.3 G.92). Scale bars: a–c, e–f: 1 mm; d: 0.5 mm.
Abstract
Burgess Shale-type faunas are critical to our understanding of animal evolution during the Cambrian, giving an unrivalled view of the morphology of ancient organisms and the ecology of the earliest animal-dominated communities. Rare examples in Lower Ordovician strata such as the Fezouata Biota illustrate the subsequent evolution of ecosystems but only from before the main phase of the Great Ordovician Biodiversification Event. Later Ordovician Konservat-Lagerstätten are not directly comparable with the Burgess Shale-type faunas as they do not represent diverse, open-shelf communities, limiting our ability to track ecological development through the critical Ordovician biodiversification interval. Here we present the Castle Bank fauna: a highly diverse Middle Ordovician Burgess Shale-type fauna from Wales (UK) that is directly comparable with the Burgess Shale and Chengjiang biotas in palaeoenvironment and preservational style. The deposit includes animals with morphologies similar to the iconic Cambrian taxa Opabinia, Yohoia and Wiwaxia, combined with early examples of more derived groups such as barnacles. Many taxa such as kinorhynchs show the small sizes typical of modern faunas, illustrating post-Cambrian miniaturization. Castle Bank provides a new perspective on early animal evolution, revealing the next chapter in ecosystem development following the Chengjiang, Burgess Shale and Fezouata biotas.
Botting, J.P., Muir, L.A., Pates, S. et al.
A Middle Ordovician Burgess Shale-type fauna from Castle Bank, Wales (UK).
Nat Ecol Evol 7, 666–674 (2023). https://doi.org/10.1038/s41559-023-02038-4
© 2023 Springer Nature Ltd.
Reprinted under the terms of s60 of the Copyright, Designs and Patents Act 1988.
Creationists need to pretend to be too stupid to understand that, shown a consecutive series of still from a movie, that the stills represent a continuously changing scene, because there are empty gaps between them.
These are the same people who also have to pretend that they think their grandparents probably magically appeared from no-where, made of nothing, because no-one saw their great grandparents having sex, because Ken Ham has told them that scientific explanations are only valid if you personally witness then happening, so a magical explanation, including a supernatural entity doing magic, is most likely to be the true one.
Normal people however, can readily understand why a series of fossils over time represents a continuous process of change leading from earlier forms to later ones and that nothing ever comes from nothing without ancestors.
But then it's axiomatic that creationists would rather be thought of as stupid than wrong.
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