Our Blog
Roman Colchester discovery is the earliest known deliberately collected ichthyosaur fossil
Sep
Colchester Archaeological Trust archaeologist Charlie Hodges with the ichthyosaur fossil, which they identified during post-excavation finds processing.
A fossil recovered from a Roman pit in Colchester has been identified as the earliest known example of an ichthyosaur fossil deliberately collected by people.
The approximately 100-million-year-old fossil is part of an ichthyosaur vertebra. Although the animal lived millions of years before humans, the fossil was found in a pit dating to the third quarter of the second century AD, demonstrating that it had been collected and retained during the Roman period.
The discovery predates the pioneering nineteenth-century fossil discoveries of Mary Anning at Lyme Regis by around 1,600 years.
Ichthyosaur centrum obtained from a late 2nd century Roman pit in Colchester (Find no. 4022) in anterior articular (A), posterior (B), left lateral (C), dorsal (D), and ventral (E) views.
The vertebra was recovered by Colchester Archaeological Trust during excavations undertaken in 2024 at the former Essex County Hospital site on Lexden Road. The archaeological work was carried out in advance of the redevelopment of the site by Essex Housing Development LLP.
Although isolated and weathered ichthyosaur vertebrae can be relatively unremarkable coastal finds, the Roman context in which this example was discovered makes it exceptional.
Patrick Spencer, an archaeologist at Colchester Archaeological Trust and lead author of the published study, said: “On several parts of the English coastline, an isolated and heavily wave-worn ichthyosaur vertebra washed out from the base of a cliff may often be a commonplace find and usually of little significance.
“In this case, however, its discovery in a securely dated Roman pit made it entirely exceptional. It appears that somebody acquired the fossil, transported it to Colchester and retained it before it was eventually deposited in the pit.”
Green sandy rock adhering to the fossil, together with its weathered condition, suggests that it most probably originated on the east Kent coast between Folkestone and Hythe.
Greensand building stone was quarried along this coastline during the Roman period and transported elsewhere in south-east Britain. Greensand was used as a building material in Roman Colchester, providing a possible connection between the fossil’s place of origin and the town in which it was eventually deposited.
The fossil was found alongside a small Roman toilet or cosmetic spoon known as a ligula, a horse tooth, pottery, and an unusual group of animal remains that may include the bones of a cat.
The precise reason why someone in Roman Britain collected and preserved the fossil cannot be established. It may have been retained simply because it was an unusual and intriguing natural object.
Another possibility is that it was given significance through Greco-Roman traditions in which large fossils and ancient bones could be interpreted as the physical remains of legendary creatures, heroes or other beings from the distant past.
Adam Wightman, Director of Archaeology at Colchester Archaeological Trust talking to Charlotte Knappet, of Fisher Jones Greenwood at the launch of the Lexden Lady exhibtion in May 2026.
The character of the other material placed in the pit also raises the possibility that the fossil’s eventual deposition was deliberate or structured, although the researchers emphasise that its meaning remains uncertain.
Adam Wightman, Director of Archaeology at Colchester Archaeological Trust and co-author of the study, said: “This is a wonderful example of how an apparently modest object can completely change in significance once its archaeological context is understood.
“The fossil does not just tell us about an animal that lived approximately 100 million years ago. It also offers an extraordinarily rare glimpse of somebody living in Roman Britain encountering evidence of a world far older than their own.
“We cannot know exactly what that person believed the object to be, but we can say that they noticed it, selected it and preserved it. That moment of human curiosity connects us very directly with someone who lived in Colchester nearly 1,900 years ago.”
Robert Masefield of Teta Tech Consulting added that: “It is always fascinating to see examples in the archaeological record of the collection and curation of significantly older objects in later prehistoric and historic contexts. In many cases this probably does represent more than the simple reburial of curiosities retained as heirlooms. The potential implications of burial of the ichthyosaur vertebrae in this Roman pit as a signifier of mythological beliefs have been suitably recognised by CAT.”
Councillor Russell Quirk, Deputy Leader at Essex County Council, said: “This remarkable discovery shows that development and heritage can go hand in hand. Thanks to the work carried out ahead of Essex Housing’s redevelopment of the Former Essex County Hospital site, we’ve uncovered a fascinating piece of history that links Roman Colchester with a creature that swam the oceans millions of years ago. It is another reminder of the extraordinary stories still waiting to be discovered beneath our feet in Essex.”
For further information:
Alexander Smith
Colchester Archaeological Trust
01206 501785
as@catuk.org
The research
The paper, “The Earliest Known Purposefully Collected Ichthyosaurian Fossil: A Vertebral Centrum from a Second-century A.D. Roman Pit in Colchester, Essex”, was written by Patrick S. Spencer, Adam N. Wightman and Laura E.A. Pooley.
It was published online by Cambridge University Press in the journal Britannia on 28 May 2026.
View of the archaeological excavation at the former Essex County Hospital site on Lexden Road, Colchester.
The excavation
The fossil was recovered during archaeological excavations at the former Essex County Hospital site on Lexden Road, Colchester.
The excavation was undertaken by Colchester Archaeological Trust in advance of a 120-home redevelopment by Essex Housing Development LLP. Archaeological investigation was required because the site lies within the extensive Roman emetery and settlement area to the west of the walled Roman town.
The Lexden Lady exhibition at Roman Circus Visitor Centre, where the exhibition will run until May 2027.
Other discoveries
Other discoveries from the excavation include the high-status late-Roman burial of a woman who died in her late twenties or thirties.
She was buried in a decorated lead coffin with grave goods including jet hairpins and rare glass vessels. Scientific analysis has also identified traces of frankincense and gypsum associated with the burial.
Read more about this discovery here.
