A continent the width of the U.S. has been missing for 155 million years. Scientists have long puzzled whether this chunk of northwest Australia has been either floating somewhere unseen, resting on the ocean floor, or slowly fusing to the underbelly of a larger landmass. Modern mapping largely ruled out the first two theories, but let’s say a 3,000-mile slab of terra firma did get lodged beneath another continent. Experts believe they would have at least been able to find some trace of it. Really, how could something so large…
