The Rise and Fall of Rudist Reefs

Abstract

From the mountains of Europe to the deserts of Mexico, o e finds geo logic formations that contain ancient marine fossils so peculiar in shape that local folk once imagined them to be horns shed by sheep or goats. Some farmers built impressive walls and fences with these odd stones. Many decades ago, they realized that their building materials were in fact the shells of extinct marine organisms. But few of those people could have grasped just how apropos it was to be arrang ing those particular fossils into impos ing barriers. After all, without some training in geology, who would know the ancient animal's true notoriety in the annals of the former world: that of