Cleaning up a weird scientist's messy study is a chore four kids decide to make short work of on a Saturday morning! The kids file animals into drawers according to their species, 'til they discover a replica of a dinosaur. They hesitate to dispense with the oldest creature on earth by filing it in the "EXTINCT" drawer! However, they soon find many surprises in store, including disagreement as to what creature actually is the oldest on earth, from four wisecracking and argumentative cockroaches eavesdropping from a shelf!