A Roman picked up a ‘sea dragon’ bone 1,600 years before palaeontologists did

This artefact has now been found in Colchester — not in a rock or on the shore, but in a 2nd-century CE archaeological pit, amongst artefacts from the Roman period in Britain. Researchers believe this is the earliest known example of an ichthyosaur fossil that was deliberately collected.

Details

The fossil was discovered in 2024 at the site of the former Essex County Hospital in Colchester. In Roman times, this town was one of Britain’s most important centres and the first provincial capital following Rome’s conquest of the island.

The vertebra was found in a Roman-era pit — that is, an archaeological feature dating from around the 2nd century AD. Alongside it lay fragments of pottery, a horse’s tooth, possible remains of a cat, and a ligula – a small Roman tool resembling a spoon. Such objects may have been used for hygiene, cosmetics or medical procedures.

It is the context that makes the find exceptional. On its own, an ichthyosaur vertebra on the English coast would not be a sensation: the sea could have washed such bones out of ancient rock formations. But in an archaeological pit, amongst artefacts from the Roman period, it raises the question of how people in antiquity perceived fossils.

What was this ‘dragon bone’?

In reality, of course, it is not a dragon. Nor is it a dinosaur. Ichthyosaurs were ancient marine reptiles that bore some resemblance to dolphins: a streamlined body, fins, a life spent in the water and hunting in the ancient seas.

The Colchester find is a fossilised vertebra. Its geological age exceeds 100 million years, but it entered human history much later – around 1,800 years ago, when someone picked it up and took it to Roman Colchester.

For people of that time, such an object must have been difficult to explain. A stone that looks like a bone. A bone that clearly does not belong to an ordinary animal. Modern geology and palaeontology were still centuries away, so such finds were often explained through myths — as the remains of giants, heroes, monsters or unusual creatures.

Where could it have come from?

Researchers have tried to work out exactly where a person might have found this fossil. Traces of greenish sandstone remain on the vertebra. Based on these features, the authors suggested that the likely source was the east coast of Kent, in the area between Folkestone and Hythe.

This is no coincidence. During the Roman period, building stone was quarried and transported from that area. In Colchester, green sandstone was an important building material. Therefore, the person who picked up the vertebra may have come across it whilst the stone was being quarried, transported or worked.

But this remains a hypothesis. One thing is certain: the fossil was found far from its usual geological context. Someone spotted it, took it and moved it to a place where it later ended up in an archaeological layer.

A relic, an amulet or simply a curiosity?

The main question is why it was kept at all. The vertebra was weathered and not particularly impressive by modern museum standards. But to an ancient person, it might have looked strange and valuable precisely because it was unlike an ordinary stone.

The authors propose two main theories. The first is mythological. In the Greco-Roman world, large bones and fossils were sometimes regarded as material traces of heroes, giants or monsters. In that case, the ichthyosaur vertebra might have been kept as a relic or an object of special significance.

The second theory is simpler: curiosity. A person might have picked up this unusual object simply because it stood out from the ordinary stones. In this sense, the find serves as a reminder that the desire to collect ‘something strange’ is far older than museums, scientific collections and modern palaeontology.

Why the archaeological pit is important

The pit itself does not provide a clear-cut answer. The collection of objects inside looks unusual: a fossil, pottery, animal remains and a small Roman tool. Researchers therefore suggest that this may not have been ordinary rubbish, but a so-called structured deposit — that is, the objects may have been placed there deliberately, possibly with symbolic or ritual significance.

The conclusion is this: someone in Roman Britain deliberately removed a fossil from its natural environment. As for why – whether as a relic, an amulet, a curiosity or simply an unusual ‘stone-bone’ – we do not yet know.

Why this is important

This discovery shows that interest in fossils emerged long before the science of extinct animals. People noticed strange bones within stone, removed them, kept them and, in all likelihood, explained them through mythology or personal curiosity.

For the history of palaeontology, this is a rare early example of such behaviour. Ichthyosaurs are usually associated with the 19th century and Mary Anning – the famous fossil hunter whose discoveries on the south coast of England transformed our understanding of prehistoric life.

The Colchester vertebra does not overturn this narrative. But it shows that the fossils themselves attracted people’s attention many centuries before scientists learnt to explain their origins correctly.

Background

Ichthyosaurs lived in the seas of the Mesozoic Era. They were not dinosaurs, although they existed during the same vast era of ancient reptiles. Their bodies were adapted to life in water: fins, an elongated shape, and a fast-paced, predatory lifestyle.

Fossils of marine reptiles have long been known in Britain. The southern coast of England is particularly famous; there, in the 19th century, Mary Anning’s discoveries helped scientists realise that the Earth preserved traces of long-vanished worlds.

But the find from Colchester is interesting for another reason. It is not simply the bone of an ancient animal. It is a bone that was noticed by a person living in Roman times. A single artefact connects two eras of the past at once: the world of the Mesozoic seas and everyday life in Roman Britain.

Source

Study: Patrick S. Spencer et al., “The Earliest Known Purposefully Collected Ichthyosaurian Fossil: A Vertebral Centrum from a Second-Century A.D. Roman Pit in Colchester, Essex”, Britannia, 2026.