EVOLUTION OF THE AMPHIBIANS 



183 



The Age of Amphibians passes its cHmax in Permian time 

 (Fig 63.). In Triassic time there still survive the giant terres- 

 trial forms. 



Evidences of extensive intercontinental connections in the 

 northern hemisphere are also found in the similarity of type 

 between the great terrestrial amphibians of such widely sepa- 

 rated areas as Texas and Wiirtemberg, which develop into simi- 

 lar resemblances between the great labyrinthodont amphibians 

 of Lower Triassic times of Europe, North America, and Africa. 

 Ancestral to these Triassic giants is the large, sluggish, water- 

 and shore-living Eryops of the Texas Permian, with massive 

 head, depending on its short, powerful limbs and broad, spread- 

 ing feet for land propulsion, and in a less degree upon its tail for 

 propulsion in the water. This animal may be regarded as a 

 collateral ancestor of the labyrinthodonts; it belongs to a type 

 which spread all over Europe and North America and persisted 

 into the Mdopias of the Triassic. 



Fig. 64. Skeleton of Eryops from the Permo-Carboniferous of Texas. 

 A type of the stegocephalian Amphibia which were structurally ancestral to the Laby- 

 rinthodonts of the Triassic. Mounted in the Amerjcan Museum of Natural History. 



