Jurassic marine world fossils unearthed in farmer’s field
Image credit: Neville Hollingworth
The discovery of an exceptional prehistoric site containing the remains of animals that once lived in a tropical sea has been made in a farmer’s field in Gloucestershire.
Discovered beneath a field grazed by an ancient breed of English Longhorn cattle, the roughly 183-million-year-old fossils are stunningly well preserved, as if they were frozen in time.
Contained within three-dimensionally preserved limestone concretions, the remains of fish, ancient marine reptiles, squids, rare insects and more have been revealed for the first time by a team of palaeontologists.
The fossils come from an inland rock layer that was last exposed in the UK more than 100 years ago and represented a unique opportunity to collect fossils from a time when this part of the country was deep underwater. The newly found site is at Court Farm, Kings Stanley near Stroud, Gloucestershire, and was discovered by Sally and Neville Hollingworth, avid fossil collectors who recently uncovered the remains of mammoths in the nearby Cotswold Water Park.
The Hollingworths explained: “These fossils come from the Early Jurassic, specifically a time called the Toarcian. The clay layers exposed at this site near Stroud have yielded a significant number of well-preserved marine vertebrate fossils that are comparable to the famous and exquisitely preserved similar fauna of the Strawberry Bank Lagerstätte from Ilminster, Somerset – a prehistoric site of exceptional fossil preservation. Excavations at Kings Stanley over the last week have revealed a rich source of fossil material, particularly from a rare layer of rock that has not been exposed since the late 19th century.”
The team of eight scientists spent four days with a digger clearing an 80m stretch of grassy bank, digging out several hundred limestone nodules and splitting them by hand, then logging any fossils contained therein on a database, prior to their preparation and conservation. Around 200kg of clay from the concretions was also collected and sieved in a state-of-the-art sediment-processing machine to extract microvertebrate fossils – e.g. small teeth and bones.
Among the best finds were several fossil fish with excellent details of their scales, fins and even their eyeballs. One of the most impressive discoveries was a three-dimensionally preserved fish head, belonging to a type of Jurassic fish called Pachycormus (pictured).
Dr Dean Lomax, a palaeontologist and a visiting scientist at The University of Manchester, who recently led the excavation of the Rutland ichthyosaur that also dates to the Toarcian geological age, was part of the Stroud team and said: “The site is quite remarkable, with numerous beautifully preserved fossils of ancient animals that once lived in a Jurassic sea that covered this part of the UK during the Jurassic. Inland locations with fossils like this are rare in the UK. The fossils we have collected will surely form the basis of research projects for years to come.”
Nigel Larkin, specialist palaeontological conservator and visiting research fellow at Reading University, who was also part of the team, said: “Give a person a fish and you feed them for a day. Give a palaeontologist a fossil fish and they will tell you the species, the age of the rock, the climate of the time when the fish was alive, plus the water depth and salinity and plenty of other information. This site is one big outdoor classroom and the lessons now include geology, palaeontology, evolution and climate change.”
Field observations and preparation of the fauna found so far indicate that the Court Farm fossils were rapidly buried, as suggested by the absence of any encrusting animals or burrows in the sediment. The layered concretions around the skeletons formed relatively early before the sediments were compacted, as the original sediment layering is preserved. These concretions prevented further compaction and compression from the overlying sediments during burial and thus preserved the fossils in three-dimensional time capsules.
Neville Hollingworth added: “Using the latest fossil preparation and imaging techniques to understand this unique fauna in more detail will create a rich repository. Also, we will leave a permanent reference section after excavations have concluded. Given the location, and enthusiasm from the landowner and local community to be involved, it is hoped to plan and develop a local STEM enrichment programme as there will be opportunities for community groups and local schools to be involved in the research, particularly from the Stroud area, with a focus of targeting audiences in areas of low STEM capital.”
The landowner, Adam Knight, said: “I’m delighted that after the initial work that Sally and Nev did over three years ago we now have a full-scale dig on the farm involving a range of fossil experts from The Natural History Museum, University of Manchester, University of Reading and The Open University. It has been a real pleasure to host the dig and I’m excited to see the results of what has been found.”
The key significance of the Stroud site is that it is the only current exposure in the UK of the same horizon that was famous for the fossils it produced in the 19th century. The excavation team believe that the Stroud site has the potential to produce further spectacular fossil material.
The team will continue to analyse the specimens discovered so far, with a view to publishing their research. Many of the specimens collected will be donated to the local Museum in the Park, Stroud, where they will form a significant part of the museum’s palaeontology collections, with some of the fossils planned for public display both at the Museum and at the Boho Bakery Café at Court Farm.
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