DINOSAURS. Ill 



remains from several localities. The most striking feature — from 

 which the Stegosaur takes its name — was the presence of huge 

 bony plates belonging to its skin, as well as large and small 

 spines. Some of the plates were from two to three feet in diameter, 

 and they were of various shapes. Of the spines, some were of 

 great size and power, one pair being each over two feet long ! 

 The skull was remarkably small, and more like that of a lizard 

 than we find in most Dinosaurs ; the jaws were short and 

 massive. Little was known at first of the brain, but fortunately 

 a later discovery showed the brain-case well preserved. Later 

 still, more than twenty other specimens of this Dinosaur were 

 obtained, so that nearly every portion of the skeleton is now 

 known. The skulls indicate that the creature possessed large eyes 

 and a considerable power of smell. The jaws contain but a 

 single row of teeth in actual use ; but as these wore out, they 

 were replaced by others lodged in a cavity below. Teeth, how- 

 ever, were not its strong point ; they indicate a diet of soft 

 succulent vegetation. The vertebrae have the faces of their 

 centra more or less bi-concave. Many curious features in the 

 skeleton can only be explained with reference to the heavy 

 armour of plates and spines with which the Stegosaur was 

 provided. Thus the vertebrae have their " neural spines " 

 expanded at the summit to aid in supporting part of the armour. 

 (See Fig. 26.) The fore limbs were short and massive, but pro- 

 vided with five fingers ; the hind limbs were very much larger and 

 more powerful. These and the powerful tail show that the monster 

 could support itself on them as on a tripod, in an upright posi- 

 tion, and this position must have been easily assumed in conse- 

 quence of the massive hind quarters. As in Iguanodon, there 

 were three toes to the hind feet, and these were probably covered 

 by strong hoofs. The fore limbs could move freely in various 

 directions like a human arm, and were probably used in self- 

 defence. (See Fig. 27.) But for this purpose the tail with its 

 four pairs of huge spines would be very effective, and one could 



