An article published in the journal “Nature Communications” reports a study of fossils of organisms belonging to the group of cloudinids that show the oldest traces of a digestive tract. A team of researchers led by the paleobiologist James Schiffbauer of the University of Missouri subjected fossils discovered in Nevada dating back to about 550 million years ago to a micro-CT scan that allowed to recreate a 3D image thanks to which it was possible to examine their internal parts. Among the anatomical structures there’s also a primitive digestive tract, a discovery that helps to understand something more about the relationships between the large groups of today’s animals.