The next time you hear the crinkling of a potato chip bag in the middle of the night and see an army of cockroaches scurry off the kitchen counter, consider this before you reach for the roach spray: Cockroaches have been around forever, or at least longer than dinosaurs. In fact, more than a decade ago, a geology student at Ohio State University found the largest-ever fossil of a complete cockroach. It was 3.5 inches (9 centimeters) long and 300 million years old. Scientists could see the veins in its wings, along with its legs and antennae [sources: CBC News, Ohio State University].
Cockroaches were around long before the Cretaceous Period began and survived long after it ended (as we're all too aware). During the Cretaceous Period, the insects feasted on dino poop, or so some scientists think. Researchers at the Slovak Academy of Sciences accidently made the discovery as they researched the diet of the ancient bugs. Using a sophisticated imaging method called synchrotron X-ray microtomography, researchers built a 3-D version of a fossilized cockroach that they found encased in amber. The bug was about 120 million years old, which puts it in the Lower Cretaceous Period. As they examined the roach's gut, they found bits of wood that they believe came from dinosaur excrement [source: Lewis].