Postscript - Conserving the fossil fish

We have been quiet over the last 18 months since the discovery of nearly 150 Early Jurassic fossils at Court Farm, but that’s not to say that we haven’t been busy behind the scenes. We’re delighted to announce that the specimens found at this site have been conserved with thanks to generous assistance from the AIM Pilgrim Trust Remedial Conservation grant and the Curry Fund of the Geologists’ Association (www.geologistsassociation.org.uk).

Specialist conservator Nigel Larkin – a member of the original dig team - has been hard at work with expert fossil hunters Sally and Nev Hollingworth, removing mud from the specimens and painstakingly conserving and preparing them for further study and display.

Of the 147 specimens found, all required cleaning. Some specimens required conservation (not least because some of the fossils were found by splitting nodules) and many of the fossils required some mechanical preparation to remove enclosing matrix and reveal more of the specimen to aid in their identification.

Here are a few examples of the type of work undertaken – with thanks to Nigel for sharing his photographs and descriptions of the treatment.

Some specimens were broken during splitting so repairs have been undertaken with an acrylic resin called Paraloid B72 which is often used in museum conservation as any treatment is reversible.

a fossil fish skeleton that required repair

This fish skeleton had a bivalve mollusc preserved with it. This slab containing the specimens was in two pieces so was adhered together.

Some of the fossils were preserved in slabs of matrix that were much larger than necessary so some of the excess rock has been trimmed from such specimens for easier storage and handling. In some cases, the fossils themselves were partially obscured by matrix. These specimens have been mechanically prepared under magnification using pneumatic preparation pens with reciprocating needles and/or with a pneumatic airbrasive unit.

Examples of specimens being prepared (removing matrix to expose more of the fossil) – before and after

the whole surface of this large nodule was prepared away to reveal the ammonite.

at the other end of the scale this tiny fish skull (less than 20mm long) was also prepared

And here are a few more interesting examples of specimens which have been cleaned and prepared.

Prepared small fish skeleton

Some specimens which were split in the field have provided a part and counterpart. This fish below has been exquisitely preserved, even down to what appears to be its stomach contents – thereby providing further evidence of the food chain of this ecosystem.

Example of one of the fish fossils preserved as part and counterpart.

Above is a coprolite (fossilised dropping) in a nodule. It has not been glued together as that would reduce the ability to study the contents of the specimen.

Now that the specimens have been conserved, labelled, packed in archival card trays and safely returned to the Museum, our next step will be to catalogue them. Further academic study will be undertaken to identify the fossils and better understand this rare example of an Early Jurassic marine ecosystem.

We are also still awaiting the insect specimens which are being independently studied by Emily Swaby of the Open University and we’re looking forward to learning more about these – the very presence of them in a marine environment suggests that land must have been nearby.

Lastly, we are planning to put a selection of the finds on display at the Museum in the Park soon. Watch this space and we will let you know when dates are confirmed.

Blog by Zoë Wilcox, Documentation and Collections Officer

Day 4 - Saturday

A slightly different start today, as we assemble at the Boho Bakery first thing to meet with Pennie, the café owner, to discuss holding a public event to share our findings further down the line. Pennie is full of enthusiasm for the dig, and for the possibilities for events, and even perhaps school engagement in the future, and we all come away from the meeting with a spring in our step – whilst we’ve not found exactly what we might have been hoping for in the finds so far, the enthusiasm from Pennie on seeing our discoveries has given us all a boost and reminded us that we do have some really nice finds and that other people will enjoy seeing them too.

Back on site we extend the excavation to the 80m mark, uncovering more nodules and lumps of stone for splitting. Dean makes today’s star find – another exquisitely preserved fish. Later in the day we are joined by Steven Dey – an expert in imaging and 3 modelling. He photographs the Pachycormus found by Nev and Sally prior to this excavation in order to create a 3d scan of it from which models can be made, and uses a drone to record film and still photographs of the site from above – watching him work and seeing the site from the air is a good reminder of just how much we’ve accomplished in the last few days.

Fossil fish - Part & Counterpart (c) Dean Lomax

We begin packing up the finds and all the equipment from the site, and looking back through the finds catalogue I can see that I have recorded 147 items in total. Some of these will be used to make a display in the café, some will be retained for use with schools/children and some will be stabilised, prepared, researched and published before making their way into the museum’s collections. Whilst we didn’t find a whole ichthyosaur (or Adam’s T Rex!) we do have material with a lot of potential for expanding the stories the museum can tell of life in the Stroud District in the Jurassic era.

Finds catalogue

On a personal level I have also had the opportunity to learn a huge amount from real experts in their respective fields, and take part in a palaeontological excavation which is something I’ve never done before. It was a privilege to be invited to be a part of the team and whilst I’m tired enough to want to sleep for a week, I wouldn’t have it any other way.

And, this was all really only the start of the journey. Now the finds have to be cleaned, prepared, written up and then some of them will come to the museum for display. Before that though, we’re planning a fossil fishing family fun day at the farm in October – meet the experts, have fossils you’ve found identified, and maybe even have a go at fossil hunting on this very special site. Keep an eye on our What’s On calendar for more information.

With thanks to the Geologists Association Curry Fund for financing part of the excavations, to Adam for giving us access to his land and being so accommodating, and to Pennie & Dave and their team at Boho Bakery for keeping us caffeinated and hydrated, and for their enthusiasm and interest in the whole process and its outcomes.

Blog by Alexia Clark, Documentation & Collections Officer

Day 3 - Friday

Today we are joined on site by Owen – a palaeontologist and primary school teacher – who is keen to help with splitting the rocks, and crucially also has the knowledge and experience to know whether the rocks he splits contain anything of interest.

We also have another Emily with us today – this Emily is still at school, but has been involved in digs with Nev for over a decade and is interested in pursuing a career in palaeontology in the future. In order to give her the broadest possible experience she is put to work on all areas of the dig – picking nodules from the mechanical excavation, field walking, scrubbing and splitting rocks, documentation and David also takes the time to explain his extraordinary sieving and washing machine to her. He believes he will have processed around 200kg of sediment by the time we leave site.

We find more bits of ammonite and several bivalves, more blocks of ‘fish debris’, and a few more small fossil fish today – interestingly we’re finding more heads than bodies which leads to speculation about whether we’re seeing the remains of a larger creature’s lunch! Then, just after our lunch break, a cheer goes up from those splitting rocks up on the bank. Nev has split a rock containing an absolutely beautiful fossilised fish. The level of preservation is astonishing – scales, bones, fins and even the eyeball is visible – and there is a suggestion that under a microscope it is possible there will even be some evidence of the creature’s stomach contents when it died. The stone splitters continue their work with a noticeable upturn in enthusiasm and energy – everyone is hoping there are more fish to come.

NEv’s Fossil fish (C) Dean Lomax

By the end of the day we’re about 65 metres along the bank, but no more star finds have been made – still, tomorrow is another day and we’re all holding out hope for more substantial remains.

Blog by Alexia Clark, Documentation & Collections Officer

Day 2 - Thursday

Arriving on site and seeing the huge pile of nodules waiting to be cleaned, split and recorded is a little daunting, though this is tempered by the excitement of waiting to see what we might find. We crack on immediately (if you’ll forgive the pun) – hauling stone nodules off the site and piling them up to be cleaned and split whilst other members of the team supervise the digger and pile up yet more freshly excavated nodules and lumps of stone to be dealt with.

Rock Splitting

Fossiliferous Limestone

Emily has brought a professor from the Open University with her today – an expert in sedimentology and stratigraphy and they spend much of the day recording information about the different layers in the excavated exposure. Emily also records the first insect finds from the site – a tiny beetle, sadly it’s missing its head so we’re unable to establish if it’s John, Paul, George or Ringo!

We discover today that in addition to the nodules there are flatter lumps of laminated stone which split much more easily and seem more likely to contain what we’re now calling ‘miscellaneous fish debris’ – tiny accumulations of material which will be better understood when we can see it under a lens!

Todays finds include more ammonite impressions, some coprolites and excitingly, the first piece of something which could be ichthyosaur – Dean thinks it could be a piece of rostrum (jaw), though it’ll need closer examination to be sure. We also have the first find of a fish – a tiny little fish which for right now we’re affectionately calling a sardine!

Adam, the landowner, pops down a couple of times today to see what we’ve found and utters the quote which is sure to make the press release: ‘Sod the sardines, where’s my T-Rex!’

Sardine

Blog by Alexia Clark, Documentation & Collections Officer

Day 1 - Wednesday

We meet at the Boho Bakery – a café near to our excavation site at 9am for introductions and a safety briefing.

The team consists of:

·         Sally & Nev Hollingworth who discovered the site, but are best known for discovering the mammoth site at Cerney Wick last year

·         Dean Lomax from the University of Manchester. Famed for his work on the Rutland Ichthyosaur, Dean is a renowned palaeontologist and writer, and is familiar with the Museum having looked at our collections for his book ‘Dinosaurs of the British Isles’ published in 2014

·         Nigel Larkin, geological curator, conservator, preparator and all-round expert in all things Natural Science. I have worked with Nigel before on reports concerning the Museum’s collections, so he too is a familiar face

·         David & Alison Ward – experts in fossil sharks, from the Natural History Museum

·         Emily Swaby a PhD student from the open university who is studying fossil insects from the Toarcian stage of the early Jurassic

Throughout our time on site we will be joined by other people, but this is the core team.

Blog by Alexia Clark, Documentation & Collections Officer

The team

Having seen the amazing fossils Sally & Nev have already discovered at the site we’re all excited to get going so we make our way down to the site and meet Pat – the digger driver. Nev outlines his plan for the week, and we begin by field-walking the area to be excavated picking up bits of belemnite and ammonite, as well as marking the length of the bank out into 10m sections.

Pachycormus - Found by Sally and nev in advance of the dig

I set up a documentation station ready to record the finds as they’re made – we’ll be recording the location the find was made, the type of fossil and any other pertinent information we can see, as well as allocating each find a unique number.

David and Alison are assembling a very complicated system of tanks, hoses and buckets – I think the intention is to gather samples of earth or clay and then to wash and sieve it in order to search for tiny fossils and other material which could be missed by the excavation techniques employed elsewhere on site.

The digger starts scraping back the soil and almost immediately round nodules of limestone are being exposed. The first of these to be split reveals a beautiful section of fossilised wood, and anticipation is high for what we might find next.

Fossil Wood from the first nodule to be split

The nodules are placed in buckets and taken down to a base camp under the eaves of the barn for cleaning, splitting and recording. I get involved in scrubbing the clay off the nodules, but I’m not quite brave enough (and also much too clumsy) to be trusted with a lump hammer and chisel, so I don my safety glasses and watch the experts split the rocks from a safe distance.

As the only non-palaeontologist on site I am very much the novice and there’s lots to learn. However, when small fragments of pottery, glass and clay pipe are found I am suddenly the expert! Sadly none of these finds are worthy of recording in my site catalogue.

As the day progresses we find lots of nodules with the impression or mould of an ammonite on the top, but save for blocks with many tiny pieces of fish scale and bone, actual fossils are few and far between and we’ve certainly not seen anything like the finds Sally and Nev showed us earlier. We’re also finding that the stone is much harder than we expected – unlike most of the limestone around here which is soft and easy to cut, these nodules have a hard grey centre, and the splitters really have their work cut out for them. By late afternoon, the area by the barn resembles the work site of a chain-gang!

Ammonite Impression

We call it quits at around 5pm having excavated about 25 metres along the bank and created an enormous pile of stone nodules for processing. We agree arrangements to be back on site at 8.30 tomorrow with renewed vigour and excitement for what we’ll find as we continue to excavate.

Introduction

In April 2022 I received a very interesting email letting me know about a site of Palaeontological interest recently discovered in the Stroud District. The initial contact was just to let me know about the existence of the site, but things developed quickly from there and before I knew it I was informed that there was going to be an excavation, and asked firstly if the museum would be able to house any finds and secondly if I’d like to take part. Wow! I’ve never been involved in this sort of thing before, but I was sent a couple of pictures of fossils already found at the site and I was hooked (if you’ll forgive the pun!).

Jump forward to late July and I had secured for a pot of funding to support the cost of a JCB and cover the expenses for some of Britain’s foremost palaeontologists to take part, purchased a pair of safety goggles, and been very cryptic with a very small number of colleagues about what was about to take place.

This project wouldn’t have been possible without the assistance of the Geologists’ Association Curry Fund who helped to finance the excavation phase. All members of the excavation team are also indebted to Adam, the farmer, for allowing us access to his land, and to Pennie and Dave at the Boho Bakery for keeping us caffeinated and hydrated throughout the dig!

Photo shows the excavation site (c) Steven Dey

Blog by Alexia Clark, Documentation & Collections Officer