SCANNING THE CLIFFS FOR SLEEPING MONSTERS 



In a single quarry along these cliffs bones representing several hundred individuals have been 



washed out of the bank. 



On land there were hoofed quadru- 

 pedal herbivorous kinds, some, like Mo- 

 noclonius (see page 426), having an im- 

 mense skull, six feet in length, with three 

 horns, a short one over each eye and a 

 longer one above the nose. The jaws ter- 

 minated in a sharp clipping beak, like that 

 of a turtle, and further back in the mouth 

 there were rows of double-rooted teeth. 

 The back of the skull was developed into 

 a broad shield, with scalloped border, 

 extending over the neck. It was ances- 

 tral to the later Triceratops. 



A CREATURE FULLY ENCASED IN ARMOR, 



INCLUDING VISORS TO SAFEGUARD 



HIS EVES 



Strangest of all was the herbivorous 

 Ankylosaurus, a stocky, short-legged, big- 

 bodied creature, completely encased in 

 armor. Dermal plates covered the skull, 

 followed by rings of plates over the neck 

 and rows of flat plates over the back and 

 hips. Its tail terminated in a huge club, 

 and the belly was covered by a pliable 



mosaic of small, close-set plates. It was 

 further protected by a movable plate that 

 could be dropped down like a shutter over 

 each eye, thus completing its protection 

 from insects and formidable foes. 



Preying on the various herbivorous 

 kinds were powerful flesh-eaters, Alberto- 

 saurus, resembling those shown on page 

 429 — an active animal 30 feet long and 

 about 15 feet high. Armed with large, 

 serrate dagger teeth and sharp, bird-like 

 claws, it was capable of destroying any 

 of its herb-eating relatives. It walked 

 habitually on its hind legs, balanced by a 

 long tail, while the short, reduced front 

 legs could have been used only in grasp- 

 ing its prey. 



That great numbers of these creatures 

 lived in the ancient marshes is evident 

 from the numerous remains found in the 

 rocks. In a single quarry, of which there 

 are many on the Red Deer River, bones 

 representing several hundred individuals 

 have been washed out of the bank, and 

 more or less complete skeletons and in- 



4i3 



