EVOLUTION OF THE AMPHIBIANS 



179 



ous and early Permian time the terrestrial amphibians began 

 to be favored by the land elevation and recession of the sea 

 which distinguished the close of the Carboniferous and early 

 Permian time. Under these varied zonal conditions, aquatic, 

 palustral, terrestrio-aquatic, fossorial, and terrestrial, the Am- 



EUMICRERPETON 

 AMPHIBIA CARBONIFEROUS 



CARBONIFEROUS, 



AMPHIBAMUS 

 AMPHIBIA CARBONIFEROUS AMPHIBIA 



DIPLOCAULUS 



PERMO- 

 CARBONIFEROUS 



Fig. 60. Chief Amphibian Types of the Carboniferous. 



Restorations of the early short-tailed, land-living Amphibamus, the salamander-like 

 Etimicrerpcton, the eel-bodied Ptyoniits, and the broad-headed, bottom-living Diplo- 

 cauliis. Prepared for the author by W. K. Gregory and Richard Deckert. 



phibia began to radiate into several habitat zones and adaptive 

 phases, and thus to imitate the chief types of body form which 

 had previously evolved among the fishes as well as to anticipate 

 many of the types of body form which were to evolve subse- 

 quently among the reptiles. One ancestral feature of the 

 amphibians is a layer of superficial body scales in some types, 

 which appear to be derived from those of their lobe- finned fish 

 ancestors; with the loss of these scales most of the Amphibia 

 also lost the power of forming a bony dermal armature. 



