414 



THE NATIONAL GEOGRAPHIC MAGAZINE 



high up on the Pace: op A STEEP CPIPP WE pound a partial, skeleton op the 



• WONDERFUL, ARMORED DINOSAUR ANKYEOSAURUS (SEE PAGE 413) 



The skull lies just above the pick. The skeleton was disarticulated, but all bones were 

 found on the same level as deposited millions of years ago. To secure the specimen, the 

 whole face of the hillside was blasted off, making a cut 30 feet long, 40 feet high, and 20 feet 

 back into the hill, before all of the bones of this specimen were secured. 



dividual bones are scattered all through 

 the strata. 



WHEN SOUTHERN CANADA HAD A PEORIDA 

 CEIMATE 



At that time southern Canada and the 

 northern part of the United States en- 

 joyed a climate similar to that of Florida, 

 for fig fruits and palm leaves are often 

 found in these same rocks. Numerous 

 coal veins and petrified wood bespeak 

 the tropical abundance of the vegetation. 



Above the Edmonton beds, flanking the 

 mountains, there are several hundred feet 

 of sandstones and clays called the Paska- 

 poo beds, which were deposited after the 

 dinosaurs became extinct (see page 412). 



These strata mark the beginning of the 

 Age of Mammals. The giant reptiles 

 had disappeared ; their remains are never 

 found in this formation ; but in places 

 the beds contain mammal teeth, small 

 bones, leaves, and fresh-water shells. 



It is probable that when this formation 

 was deposited the country had been suffi- 

 ciently elevated to drain ofT the marshes, 

 and that the drainage of the waters was 

 the chief cause of extinction of the dino- 

 saurs. They were creatures that did not 

 migrate any great distance to more fa- 

 vorable conditions, as do mammals, and 

 it is quite possible that the particular 

 food of the herbivorous forms became 

 scarce. The known plant remains are 



