WGCG Spring 2021 Newsletter - Flipbook - Page 11
WGCG
Spring 2021 Newsletter
The Castle Bank Biota and Microscopes for
Amateur Science
Joe Botting & Lucy Muir
Receiving a £2000 Holloway Bursary was a great boon for a major new research project in central Wales. We
are extremely grateful for the support, and would like to introduce the project, and the purpose to which
the funds have been directed.
The Castle Bank Biota
In marine sedimentary rocks, fossils are nearly ubiquitous. Most of them, however, represent only a tiny
fraction of the living community: the hard, resistant components that have a reasonable chance of being
fossilised. These can include mineralised shells, bones, and wood, but only a small proportion of those
'fossilizable' components ever make it into the fossil record. We can accumulate and analyse these remains,
and have done for centuries, but they're a bit of a blunt instrument: they give us a very murky view of a few
of the major patterns in life's history.
Palaeontology depends in many ways on the exceptions: the rare places where conditions were able to turn
delicate and even soft-bodied animals into fossils. These sites are called Konservat-Lagerstätten and are
rightly celebrated; they include such iconic deposits as the Sölnhofen Plattenkalk (Germany) and the Burgess
Shale (Canada). The extraordinary Burgess Shale is one of a suite of similar deposits in Cambrian rocks
worldwide (the 'Burgess Shale-type faunas') that preserve exquisite detail of soft-bodied organisms that
were buried in marine mudstones and siltstones. Some, like China's Chengjiang Biota, are even richer than
the Burgess itself. However, the environmental peculiarities that opened this window were apparently
restricted only to the Cambrian and Early Ordovician periods; they have given us an unprecedented
understanding of marine communities at this time, but this view does not extend into younger rocks. There
are Konservat-Lagerstätten later in the Ordovician, including some in Wales, but they are all relatively
limited; they represent odd environments or limited communities, with only some soft tissues.
The discovery of a new Burgess Shale type fauna in Powys promises to be a revelation. Discovered during
lockdown, only three miles from our home, it has already yielded truly remarkable preservation of an
extremely diverse range of organisms. The preservation is exquisite, showing even microscopic cilia on
millimetre-long tentacles of tiny filter-feeders, and the gut of soft-bodied worms. Although still in the very
early stages of exploration, it is clear that the Castle Bank assemblage is the closest Ordovician equivalent
we have to the best Cambrian faunas, in both diversity and preservation. No papers have yet been published,
so there are limits to what we can write here... but there is already a rich fauna, including diverse sponges,
several phyla of worms, a wide range of soft-bodied arthropods, and even the minute, fantastically delicate
zooids of graptolites. Despite that, we've barely started.
The assemblage includes surviving Cambrian taxa from the Burgess Shale-type faunas, and much
more modern, derived organisms that are more familiar from the modern world . It is difficult to predict the
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