Episode 162: Cerney Wick

Published on July 23rd, 2024 | by David Marshall

In 2017, the femur of a mammoth was discovered by Sally and Neville Hollingworth in a commercial gravel quarry close to the village of Cerney Wick, on the Gloucestershire/Wiltshire border in England. Subsequent exploration of this site yielded further remains of Pleistocene megafauna including horses, bison, hyena and elk, as well as Neanderthal hand tools.

In the following years, the excavations at Cerney Wick expanded in scope into what is now the largest palaeontological dig in the UK. The potential for public interest in the site and its finds was quickly realised and the documentary ‘Attenborough and the Mammoth Graveyard‘ was produced by Windfall Films for the BBC in 2021. Now, as additional fossils are recovered and a deeper understanding of their depositional environment is gained, we are able to paint a progressively more detailed picture of this exciting locality.

For 2024, Palaeocast was granted special access to the dig, allowing us to record media from within the field. In the tabs below, you’ll find hours of multimedia captured at different stages throughout the field season. We begin with a podcast that introduces Cerney Wick and details the plans for the upcoming dig, this is followed by several days of recording at the site itself and finally a record of the legacy of this year’s fieldwork.

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We were joined by both Sally and Nev as they discuss their mammoth discovery and introduce us to Cerney Wick. We examine the complex geology of the site, with its interplay of Jurassic and Pleistocene sediments, and look ahead to the 2024 field season. Finally, we reflect upon how the dig relies upon cooperation from the quarry’s commercial owners and the numerous volunteers required for the work.

Cerney Wick is the name of a commercial gravel quarry operated by Hills Quarry Products and located in Gloucestershire, England. It is situated within the Cotswolds Water Park, a series of lakes formed as a result of similar quarrying activity throughout the 20^th Century.

Like the other former gravel pits in the surrounding area, the site spends most of its time underwater. These pits act as silt traps, allowing sediments to settle out from quarrying wastewater. These lakes are now a haven for wildlife. Image: Kieran Mason.

Before any excavation, the water has to be drained away. This is a lengthy process and even once empty, the pit will begin to fill up again because the water table in the area is so high. Image: Sally Hollingworth.

This means that the digging work at Cerney Wick is extremely muddy and great care has to be taken to control how water flows into the pit and to continuously maintain water levels. Image: Issy Walker @palaeoissy.

Geologically, the rocks of Cerney Wick are from the Middle Jurassic (Callovian) Kellaways Formation. These rocks are absolutely stuffed with fossils, ammonites in particular, and were the reason why Sally and Nev were fossil hunting here in the first place. These ammonites can be used in stratigraphy to provide very precise dates for rocks. Given the number of them in the Kellaways Formation, the age of this rock is incredibly well constrained. Image: Laura Hobbs.

Cutting through the Kellaways Formation is an ancient channel of the River Thames. In the Pleistocene, this river would have been running over the same Jurassic rocks as are exposed today. Image: Laura Hobbs (modified).

The Thames eventually filled this particular channel with loosely-consolidated sand, clay and gravel. It is in this material that the Pleistocene remains are found. Image: Kieran Mason.

Much of the highly fossiliferous Kellaways Formation has been reworked into the Pleistocene gravel from upstream, meaning that it’s common to find ammonites (such as this *Sigaloceras calloviense*) and other Jurassic taxa alongside the bones of mammoths. Image: Michael Jackson.

Whilst mammoths remains are the headline-grabbing finds, other large and scientifically significant taxa such a this potential rhinoceros are also commonly found. Image: Casey Rich.

Rhino? Bone In-situ by ThinkSee3D on Sketchfab Credit: Steven Dey, ThinkSee3D Ltd.

Molar from a steppe mammoth (specimen CW0038) as it was found *in situ*. Image: Sally Hollingworth.

Sally, Nev and mammoth expert Steven Zhang with the extracted molar. Image: Sally Hollingworth.

Sally and Andy cleaning and preparing the molar in the camp’s conservation tent. Here, a team of volunteers work to stabilise and catalogue the most important finds using a variety of tools and techniques. This protects the fossils from the effects of drying out and allows their safe transfer to a museum where they can be properly stored. Image: Sally Hollingworth.

CW0038 cleaned, prepared and conserved. Image: Sally Hollingworth.

CW0038 Steppe Mammoth Tooth by ThinkSee3D on Sketchfab Credit: Steven Dey, ThinkSee3D Ltd.

Other mammoth finds have been pretty significant, like this tusk. Image: Kieran Mason.

Reconstruction of Cerney Wick in the Pleistocene with steppe mammoths and Neanderthals. Image: Mark O’Dell.

We arranged to get an exclusive tour of the site a few days before digging was due to begin, but why is this important?

Normally, the public only get to see the results of an excavation. Sometimes, they might even get to see part of the excavation itself. Rarely, however, does anyone get to see a site before ground is even broken!

In this video, we visit the site immediately after the water had been drained away. What does it look like? How much rock is visible? Which fossils can already be found? Dave even makes a significant discovery that becomes the first specimen of the 2024 dig!

This video is a Patreon exclusive. As an additional benefit to becoming a Patreon backer (Ordovician level and above), you will have the opportunity to actually win one of the ammonites you see being collected here!

We returned to Cerney Wick on day eight of the dig. Camp had been set up, volunteers were on site and ground had been broken. Spectacular fossils had already been found by this point and it didn’t take long for new finds to start coming up right before our eyes!

We managed to record a huge amount of multimedia as we tried to capture as full a picture of the dig as possible. How did it all operate? Which activities/processes were happening on site? Which roles did the volunteers take on?

Of course, we did manage to see some pretty spectacular fossils being uncovered as well!

Note: Since this is a live dig, all the identifications made in the field should be taken as preliminary. As specimens are excavated, cleaned and analysed, more information becomes available and it is not uncommon for the interpretation of a fossil to change throughout this process. This is all part of the scientific process, something that is not often shown.

Ice Age finds

The Pleistocene mammoth remains are probably the most iconic things to come out of Cerney Wick, they’re not the whole story; a rich fauna including bison, horse, hyaena, wolves and even rhinos have also been recovered from the site. Whilst there were enough finds that we could have spent our entire time filming the excavation of this material, we instead wanted to focus on giving you the experience of being at the dig yourself.

All that said, there is still plenty of opportunity to see many of these fossils throughout the content we’ve produced. Many of the fossils shown in this section reappear in the conservation tent later in the day.

Jurassic finds

Though the fossils of the Kellaways formation might not attract the attention of the TV cameras, they are still highly significant in their own right and were no less a part of this dig than the Pleistocene material. There are still a lot of unanswered questions about the Kellaways formation and new discoveries, such as those below, just keep adding to our understanding of these Jurassic seas.

An extended version of this video (00:09:40) is available on Patreon.

Volunteer roles

Volunteering at a excavation of this scale is not just limited to digging; there are a huge number of diverse roles from operating a drone or a digger, to recording finds with GPS or photogrammetry. Each volunteer brings with them their own skills and so there is always something to learn from someone else. The learning isn’t just confined to the digging either, in the evenings the volunteers would give each other lectures about their specialist areas and included everything from plesiosaurs to flint knapping.

Conservation

The discovery and extraction of a fossil is only just the start of its journey. If you want a fossil to remain intact, then it is probably going to need some kind of conservation. This is definitely the case for the bones discovered at Cerney Wick which start drying out as soon as they are exposed to the air. This material needs immediate treatment and it’s for that reason that there is a conservation team on site working to rapidly clean and stabilise material as it comes out of the ground.

In this section we follow some of the prep process for the Pleistocene material, taking bones from the dig site through the conservation tent and seeing what new details emerge as we clean up the specimens.

We’re given a guided tour of the conservation tent where we’re shown what the team is currently working on and we reunite with some of the bones we saw being excavated a little earlier.

We are then introduced to Paraloid B72: the reversible glue that’s routinely used in fossil preparation.

An extended version of this video (00:04:00) is available on Patreon.

Stone tools

Some of the most significant finds from the site have been those that demonstrate that humans and Pleistocene megafauna were inhabiting this area at the same time. Stone tools such as Neanderthal hand axes have been found on site and this year’s dig got off to a flying start with the discovery of another specimen on the very first day!

Neanderthal hand axe (specimen CW001). Image: Jacob Quinn.

CW001 Neanderthal Axe by ThinkSee3D on Sketchfab Credit: Steven Dey, ThinkSee3D Ltd.

We returned to Cerney Wick on the final day of digging. This was the last opportunity to get specimens out of the ground before the site was left to fill up with water for another year (at least). Many difficult decisions had to be made about what to extract, what to leave behind and whether any more new ground should be explored at all!

Again, we saw some amazing specimens come out of the ground and actually got a chance to go into a lot more detail about fossil conservation and preparation. Dave managed to find his own mammoth bone* live on camera and we revealed some of the most beautiful ammonites.

We end our time in the field with a couple of interviews looking back at what’s happened over the last few weeks.

Whilst it was an incredibly busy day for everyone on site, Kieran still took the time to show us how archaeological digs are conducted systematically. Having swapped his hammer for a trowel, Dave made the discovery of a mammoth bone* live on camera.

*Yes, that’s what I’m claiming as a mammoth bone.

Returning to camp, we were given a full run-down of everything that goes on in the conservation tent with Conservation Team Leader Alison Park. We also discuss what to do with some of the ammonites we found when we first visited the site.

We kept the cameras rolling after the last video and had an unplanned look at a very large ammonite with Mark Kemp. Would it be worth taking a hammer to it and risking what was already there?

Yes. The answer was a massive yes.

Mark then helped us prepare some of the ammonites we have collected throughout our time at Cerney Wick. Remember, our Patreon backers have an exceptionally good chance to win one of the ammonites we collected!

Reflections

All too soon the dig was over and whilst everyone was weary after weeks of effort, nobody really wanted things to end. Despite that, there was a sense of celebration and a recognition of a job well done. We felt this was an important time to look back on the successes and challenges of the 2024 field season.

Following the 2024 dig, an exhibition was held at the Corinium Museum (Cirencester, England) in which some of the best material was displayed. Hosting the fossils within a museum so close to Cerney Wick allowed local people better access to the discoveries made on their doorstep.

This exhibition also allows us to look back at some of the most interesting fossils to have been discovered this year, including some of the specimens that we saw be extracted, conserved and prepared.

Jurassic finds

Smaller marine invertebrates from the Jurassic Kellaways Formation. As you can see, the ammonites were quite diverse and very well preserved.

Some of the larger ammonites and blocks with multiple fossils. The *Kosmoceras jasoni* that we revealed in the conservation tent even made it into the exhibition (second specimen down from the corner of the room).

The best preserved specimens were kept behind glass.

Possibly the best find of the dig was the skull of a marine crocodile. The species has yet to be identified and so it might still represent a new taxon.

Jurassic Crocodile Skull by ThinkSee3D on Sketchfab Credit: Steven Dey, ThinkSee3D Ltd.

Pleistocene finds

The proboscidean remains took centre-stage and whilst not everything could be displayed due to the size, there was still a good representation of the kind of material that was being discovered at Cerney Wick. Shown here are a collection of teeth including a molar from a straight-tusked elephant (*Palaeoloxodon antiquus*).

This display cabinet contained a selection of mammoth bones including the rib we saw being extracted and prepared on day eight.

Some of the mammoth tusks and bones found this year.

A collection of Neanderthal stone and bone tools from Cerney Wick and the surrounding area.

Other Outputs

We will try to keep this section up to date with news and outputs from Cerney Wick. What is next for this collection of fossils?

Hopefully we might even be able to return in 2025!

Acknowledgements: We’d like to thank Sally and Neville Hollingworth for their help with putting this series together and for accommodating us in the field. We recognise Hills Quarry Products for making their site so accessible for research and science communication. Thanks to all the volunteers who have contributed to the multimedia in this series and especially to Laura Hobbs who has provided assistance throughout. Finally, thanks to all our backers on Patreon who help make projects like this possible.

Tags: Ammonite, elephantid, Fieldwork, Human, Ice Age, mammoth, neanderthal, proboscidean