47° 



DISTRIBUTION IN SPACE AND TIME 



presents some points of resemblance to birds, probably due to 

 their having been adapted to the same kind of locomotion on 



Fig. 1328. — Stcgosaurus (much reduced) 



the ground. These limbs were relatively very long, and they 

 were also digitigrade, ?.c. the animals possessing them walked on 

 tiptoe. The best - known member of the group lylgnanodon, 



fig. 1329) inhabited England, 

 Belgium, and Germany during 

 the second half of the Meso- 

 zoic epoch, and the larger of 

 the two known species was 

 nearly 30 feet in length. The 

 Horned Dinosaurs [Ceratop- 

 sia), which were among the 

 later forms of the epoch, in- 

 cluded a remarkable herbiv- 

 orous creature ( Triccratops) 

 over 20 feet in length, with 

 three horns on the head, and 

 a curious bony shield covering 

 the neck. 



Flying Reptiles [Piero- 

 sauria). — The organs of flight of these extraordinary animals 

 have elsewhere been described (see vol. iii, p. 308). Some 

 were of small size, and of these the Pterodactyles i^Ptcrodactyhis, 



Fig. 1329.— Igii.inodon (much reduced). sc, Scapula 

 CO, coracojd; i and v (in fore-limb , thumb and little fing-er 

 p, pubis produced back into post-pubi> (//'); is, ischium 

 i-TV [in hind-limb), ist to 4th toes. 



