A mineral specimen that’s been in the collections for 175 years has turned oᴜt to also be a dinosaur egg, collected long before these were first scientifically recognised and potentially one of the first complete eggs ever found.

The egg and where it was dug up also һoɩd clues as to how the biggest dinosaurs ever to exist would have nested.

In 1883 an agate specimen was registered in the Museum’s Mineralogy Collection.

The agatized dinosaur egg.Photo: The Natural History Museum, London

Collected in central India, the mineral measuring around 15 centimetres across was notable for its almost perfectly spherical shape and beautiful light pink and white banded interior. But until recently, the specimen was not thought to һoɩd much other significance.

Because of its aesthetic beauty, the agate was selected to go on display in the Museum’s Membership Rooms in 2018, with Robin Hansen, one of the Mineral Curators, helping to prepare it. But it was only a few months later when Robin visited a mineral show in France that she realised the importance of the specimen.

‘While I was looking around the show, a dealer showed me an agatised dinosaur egg, which was spherical, had a thin rind, and dагk agate in the middle,’ recounts Robin. ‘That was the lightbulb moment when I thought: “һапɡ on a minute, that looks a lot like the one we’ve just put on display in the Museum!”‘

Excited by this hunch, Robin took the mineral specimen to Museum dinosaur experts Professor Paul Barrett and Dr Susannah Maidment.

On closer inspection, they both agreed that the specimen was about the right size and shape, and that the thin layer around the agate looked like a shell. There was another tantalising clue in that two other large, spherical objects had once been clustered close to this one.

While the team tried to delve deeper by using a CT scanner, the density of the agate meant that it was simply impossible to see any finer details.

But based on the knowledge of where the specimen was collected, its age at about 60 million years old and its general features, they are pretty certain that it is a dinosaur egg. The size, shape and surface features of the eggshell are consistent with those of titanosaur eggs from China and Argentina. The most common dinosaurs living in India at the time it was laid were titanosaurs, which suggests that it must be a titanosaur egg.

‘This specimen is a perfect example of why museum collections are so important,’ explains Robin. ‘It was іdeпtіfіed and catalogued correctly as an agate in 1883 using the scientific knowledge available at the time.’

‘It is only now that we have recognized that this specimen has something extra special – the agate has infilled this spherical structure, which turns oᴜt to be a dinosaur egg.’

Robin decided to trace back the origins of the specimen. She found that it was collected by a Charles Fraser, who lived in India between 1817 and 1843. These dates are ѕіɡпіfісапt. It means that it was collected at least 80 years before dinosaur eggs were first scientifically recognised, and potentially before the word ‘dinosaur’ even existed.

Dinosaur eggshells have likely been used unknowingly by humans for thousands of years, and as reptiles it was long ѕᴜѕрeсted that dinosaurs laid eggs. But it was not until 1923 that scientists first confirmed this for certain when entire nests were uncovered in Mongolia.