For decades, museums and textbooks confidently asserted that mud rocks—such as limestone, siltstone, mudstone, and shale—were formed over vast eons as super-fine sediments slowly settled to the bottom of shallow lakes or seas.

In 1980, a theory was proposed that an asteroid or comet impact was primarily responsible for the mass dinosaur extinctions that were observed in the fossil record. But while the impact tale has become widely accepted in popular culture, critical questions remain unanswered.

Around 150 years ago, Charles Darwin asserted that “no organism wholly soft can be preserved.”¹ He concluded this based on the assumption that fossilization required long periods of time.

Ninety percent of marine and 70 percent of terrestrial creatures perished suddenly in an event variously called the Permian extinction, the Permian–Triassic (P-Tr) extinction, or the Great Dying. The calamity’s cause, referred to as the K-T event, remains unknown, even though asteroid impact has been in vogue.