28 ANIMALS OF THE SEASHORE 



anywhere in present seas. Such species are common 

 along parts of Chesapeake Bay and at certain places 

 along- the coast of North and South Carolina. 



Fossil shells are frequently found on the New 

 Jersey beaches, but they are almost always those of 

 species still living in the ocean. While they cannot 

 always be spotted with certainty, they can often be 

 recognized by their black color and worn character. 

 While most of these fossil shells belong to species 

 still living in the sea, there are a few that are not 

 living in the waters of New Jersey today. Some of 

 these live in warmer seas farther south between Cape 

 Hatteras and Florida. These are thought to have 

 lived perhaps 100,000 years ago during the last inter- 

 glacial stage, just before the last great ice sheets 

 came down from the north. The seas were probably 

 warmer then than at present and it would have been 

 possible for these warm water animals to have lived 

 as far north as New Jersey. The deposit containing 

 these fossils is known as the Cape May formation. 



During interglacial time there was more water 

 in the sea than at present because there was less ice 

 on the earth; the melting of the polar glaciers had 

 poured an extra quantity of water into the sea 

 causing it to submerge parts of the present land. 

 The advance of the ice in (Wisconsin) glacial time 

 caused sea level to fall. 



In a few places along the New Jersey coast 

 fossils from this interglacial sea arc found in gravel, 

 sand or clay above present sea level. However, 

 better fossils are obtained below the surface in well 

 borings or dredgings. 



At certain places along the New Jersey coast, 

 especially on the coastal islands, real estate develop- 

 ments have been created by pumping sand upon the 



