We are able to resurrect ancient creatures and project them into the 21st Century

Dr Mark Sutton University of Oxford

Scientists have suspected their existence since the early 1990s, but for the past 10 years have been unable to extract them from their grave without destroying them.

"For one reason and another the material physically could not be got out of the rock," says Dr Mark Sutton of the University of Oxford, UK, "so we had to use a different technique to get a feeling of what these creatures looked like."

Dr Sutton and his colleagues were looking at molluscs, crustaceans and worms which lived 425 million years ago in an ancient continental sea that covered Herefordshire in England.

Their fossilised bodies were entombed in the hard volcanic rock that now carpets the area.

Microscopic slices

Now, at last, they can be seen for the very first time. The researchers ground the rock and fossils away in microscopically thin slices. By taking a series of detailed photographs as they went, they were able to produce computerised 3-D images.

These images allowed the scientists to identify the unique creatures. Not only do they include entirely new species, but new genera, families and orders, too.

Around 15 to 20 new creatures were found in all. Details of one of the animals have just been published in the journal Nature and the researchers are still examining the rest.

"Once we have imaged these animals we can start working out what they were, we can look at the way they lived, work out how they interacted perhaps, and eventually, hopefully, reconstruct the entire ecosystem," Dr Sutton told BBC News Online.

Sunken reefs

"Using our new technique, we are finding that we are able to resurrect ancient creatures and project them into the 21st Century.

"These 'virtual fossils' are an amazing combination of the old and the new, and we are looking forward to studying many other organisms and adding more pieces to the evolutionary jigsaw," he added.

During their lifetime, in the Silurian Period, Herefordshire was covered in a deep sea containing sunken reefs and a wide variety marine life.

At some point, volcanic ash rained down on to the sea floor and instead of being squashed flat or decomposing as normal, the engulfed animals were preserved in exceptional entirety.

An extremely rich fossil archive was created, containing the distant ancestors of today's snails, mussels, shrimps and octopi. The images bring the prehistoric organisms to life in unprecedented detail, with intricate plates and spines clearly visible.