Why do we find large "pools" of fossil plants and animals but none of recent origin? Actuallysuch concentrations are found today when natural disasters occur, but our minds remain on the disasters and forget the numerous dead. The volcanic eruption of Vesuvius in 79 AD killed manypeople in the ancient Roman cities of Herculaneum and Pompeii where we may still see some of their remains. Every flood kills and buries thousands of animals; a sudden flood entering a saltwater cove, or sheltered inlet, will bury and kill literally millions of seashore living things, perhaps not to be seen again until dug up as fossil during some distant millennium. What may seem like a common occurrence in the fossil-filled rocks exposed to our eyes, is a seriesof scattered events from a past millions upon millions of years long.
adj. 为数众多的,许多