Using a method called synchrotron X-ray microtomography, the researchers created a virtual 3D version of a fossilized cockroach preserved in a piece of amber in Lebanon dating from the Lower Cretaceous (about 120 million years ago). The unfortunate roach expired in the act of relieving itself, leaving a partially extruded piece of fossilized poop, known as a coprolite, that contained bits of wood.
The wood particles had smooth edges, suggesting the roach didn't chew them. And the insect's digestive system wasn't capable of decomposing the wood. The most likely explanation, the researchers concluded, was that the roach ate some poop from an herbivorous dinosaur.
Other fossilized species of cockroaches have been found with undigested carbon-based debris in their guts, but only the bowel of the Blattulidae specimen contained wood. Members of the Blattulidae family represented about 1 percent of all insects and more than 30 percent of cockroaches alive during the Mesozoic, and probably co-existed with a dominant vertebrate group such as sauropod dinosaurs, the researchers said.