210 Shark and Compaiiy 



adaptation. During the Jurassic, the sharks began to flourish, forming 

 many families, including variants we now call the skates and rays. And, 

 by the close of the Miocene Period (26 to 12 milHon years ago), sharks 

 were among the most abundant creatures in the sea. Every now extant 

 family of shark was there, from the ancestor of the common dogfish to 

 the colossal forebears of the modern Great White shark. 



Relics of these ancient sharks still exist. They lie in the ooze of 

 seabeds and they are buried in the bottoms of ancient seas where, today, 

 man grows crops and builds his cities. Hundreds of shark teeth have 

 been found on the plains of central Kansas; in Wyoming, Idaho, New 

 Mexico; in New Jersey, South Carolina, New York, and Maryland. In 

 Alabama cotton fields, shark teeth have been unearthed amid the fossil- 

 ized bones of the Zeuglodon, a prehistoric whale which grew to 70 feet 

 and may have been a prey of sharks. 



In the soil of a farm in Parke County, Indiana, is a tableau, formed 

 of fossils, that tells a tale of the primeval epoch when Indiana was awash 

 with sea. The story, pieced together by paleontologists of the Chicago 

 Natural History Museum, began when an uncommonly high tide ap- 

 parently carried several large sharks across a sand bar and into a shallow 

 sahne basin. When the water receded, the sharks were trapped. They 

 were too large to get over the bar. Smaller fish could enter and leave 

 the basin at will, and these became the sharks' prey. 



But the sharks were not all of the same species. At least one was 

 large and voracious, with rapacious teeth and a jaw I6V2 inches long. 

 So long as fish were plentiful, the big shark apparently was content 

 to let its smaller brethren, with their crushing, pavement-like teeth, 

 munch on crustaceans and mollusks. The day came, however, when the 

 big shark hunted down the smaller ones. It ate them, sometimes so 

 gluttonously that it merely bit off a mouthful and let the rest of its vic- 

 tim sink to the bottom, uneaten. 



The whole story is there to see in a fossil lode rich in detached skulls 

 and tail fins. Ordinarily, scavengers or bacteria would soon have con- 

 sumed these tidbits, and the evidence that tells the tale of the trapped 

 sharks would have been erased from the fossil record. But, luckily for 

 paleontologists, there were no scavengers. Mud, perhaps hurled by 

 some convulsion of the earth, shrouded anything that fell to the bot- 

 tom, protecting it for millions of years from bacterial destruction. 



Another drama that lay unseen for millions of years was unveiled in 

 1853 when a geologist with the Pacific Railroad Survey found several 

 shark teeth on a parched California hill more than a hundred miles from 

 the sea. Since that day, thousands of shark teeth have been found in that 

 hill and the cluster of hills around it. The area, about 7 miles northeast 

 of Bakersfield, California, is called Sharktooth Hill. 



