If you were not there then you missed one of your Society’s great evenings.  For a start there was Adrian Wyatt giving a memorable ‘Rock of the Month’ on a local term used to describe solids found in the Mercian mudstones—Skerry.  Nothing to do with Old Norse or rocky islands this is a local term and it took Adrian a bit of Sherlock to discover its meaning.  Well done Adrian.

Professor David Siveter, Emeritus Professor of Palaeontology, Leicester University

David came to speak to us about fossils discovered recently (1996) in volcanic (bentonite) deposits in the Coalbrookdale Formation of the Wenlock Series (Silurian), in Herefordshire.  He is one of the team investigating this unique find.  The locality of the deposit is a closely guarded secret, and one suspects that this secrecy extends too, to some of the terms they use.  For example, the nodules housing the fossils from around 425 million years ago have the code name….’potatoes’.  Some of the other words that David used seemed like code to most of us, too – lagerstatte—uhh—OK German for ‘storage-place’, to palaeontologists a storage of fossils preserved with exceptional detail including soft body parts.  Offacolus kingi, Colymbosathon eplecticos (a creature that the Sun newspaper memorably headlined as having a 425 million year old ‘todger’—Sun readers amongst you will no doubt recall it), Kenostrychus clementsi, and many others being names given to the new species discovered.

We felt at home immediately with David, a ‘Black Country boy’ from Dudley, easily able to describe his work in terms that we could all understand and answer our questions with clarity and humour.  We were, I think the expression is ‘blown away’, by the beautiful slides of delicate creatures from all those years ago, most completely new to science.  The importance of the HL is that it opens a window into the very detail of shallow sea life from the Silurian, one of the few examples worldwide and the one providing the most detail.  David said that this places the deposit in the top 20 in the world, alongside much better known locations such as the Burgess Shales (Cambrian) in Canada.  Does Herefordshire realize its fame?

Back to the fossils.  Forget dinos and horsehair ferns, these guys are tiny, tiny, housed inside ‘potato’ sized limestone nodules, visible only when cracked in two—thereby exposing, but in two dimensions only, creatures from less than 1mm to around 20mm in size.  How they were actually captured by a rare fossilization process remains a mystery, subject of much debate.  Examination by current non-destructive techniques such as CT scans and X Rays gave poor results (although there is hope for the future) so the team had to resort to a destructive method coupled with digital photography and computers to reveal innermost details. Briefly, a very small amount is ground off the face of the kernel holding the fossil, and the face photographed.  Carried out repeatedly, thin section by thin section, a comprehensive digital dataset is saved to computer. 

Clever software puts it all together and allows the scientist to add false colour, rotate the view in three dimensions and reveal startling new information about the evolution of life itself. The detail is truly remarkable, very fine cilia are seen and in cases the whole internal structure and organs show up.  I hope that the few photographs reproduced here from the team’s work, illustrate this clearly, but you really needed to see David’s animated slides rotating the creatures—amazing.

Following his talk and stopover in Martley, I was able to show him Martley Rock site, Scar Cottage and the Chantry geology garden.  He was most amused and could not understand how there was such an active society yet none of the committee are geologists.  He loved what we are doing and Janet has booked him to appear again at our AGM in November 2014 to talk Chinese fossils—may I suggest you start learning Mandarin right away?

For a readable article with much more information, also here