PERMIAN PERIOD 63 



(Inostransevia). As they were probably good swimmers, 

 and not indifferent pedestrians, the vegetarian reptiles 

 must at times have had their locomotive powers severely 

 taxed. 



Some of the tusked reptiles, living in South Africa, 

 resembled lions in the shape of the skull {Dicynodon). 

 Apparently of the same race were certain tuskless and 

 toothless forms (Oudenodon). These, it is thought, belonged 

 to the gentler sex. 



Other " beast-shaped " reptiles were remarkable for crests, (pelyco- 

 supported by spines rising vertically from the backbone saurians) 

 (Pelycosaurians). The crest was probably susceptible of 

 being raised or depressed ; and was only at its highest 

 elevation in times of excitement. In some cases the spines 

 were branched, and the raised crest must have had a broad 

 and hood-hke aspect (Edaphosaurus). 



The animals varied greatly in dimension, some (Edapho- 

 saurus) being the size of sheep, whilst others (Theropleura) 

 were as long as full-grown tigers. They all possessed strong 

 and well-clawed limbs ; and could, no doubt, keep the body 

 clear of the ground when walking. Their haunts, it is sup- 

 posed, were along the banks of rivers and estuaries. Occa- 

 sionally they may have taken to the water ; but they were 

 not well adapted to aquatic life. 



The broad-crested forms, to judge by their teeth, subsisted 

 chiefly on molluscs and vegetables. Most of the other forms 

 were of fierce carnivorous habits (Dimetrodon, etc.) ; and, 

 no doubt, waylaid small amphibians and reptiles incautiously 

 coming to land. At times they certainly became engaged in 

 serious hostiUties ; for many spine-supports have been found 

 marked with ugly wounds. 



Some members of the crested group Uved in Europe ; but 

 the animals were in far greater force and variety on North 

 American scenes. Even there, however, their career was of 

 no great length ; and at the close of the Period they seem 

 to have become extinct on both continents. 



In late Permian times several forms of " beast-shaped " (therio- 

 reptiles — sub-classed as Theriodonts or " beast-toothed "— donts) 

 exhibited marked resemblances to mammals in tooth and 



