How do you work out if a creature that's only preserved as rock sank or swam? You create a complex 3D model of its stricture using X-rays is how.
This image shows a 3D model of an ammonite—a kind of creature that lived in the sea up to 65 million years ago—created using a series of those X-ray scans by René Hoffmann from Ruhr University in BochumGermany. From these, he calculated the likely weight and volume of the creature, comparing the measurements to other animals that still grace our planet. His findings suggest that young ammonites, with 11 chambers, could float—though he's yet to confirm what became of the adults. [New Scientist]
Image by Damian Gorczany