X-rays reveal fossil secrets

A sophisticated imaging technique has allowed scientists to virtually peer inside a 10-million-year-old sea urchin, uncovering a treasure trove of hidden fossils.

3-D reconstruction showing the fossil sea urchin and the boring bivalves inside it 
[Credit: Dr Imran Rahman/University of Bristol]

The international team of researchers from the United Kingdom, Spain and Germany, including Dr Imran Rahman from the University of Bristol, studied the exceptional specimen with the aid of state-of-the-art X-ray computed tomography (CT).

Their results show that the sea urchin fossil was riddled with borings made by shelled invertebrates called bivalves. These fossilized boring bivalves were preserved inside the sea urchin in very large numbers, proving that the bivalves were using the sea urchin as an 'island' habitat on the seafloor, as occurs in modern oceans.

The new information provided by the CT scan allowed the scientists to assign the bivalves to the genus Rocellaria, members of which are known to bore into rocks and shells today.