 In the Carnian stage of the Late Triassic ( 228 @.@ 0 - 216 @.@ 5 Mya ) , capitosauroids were joined by the superficially very similar Metoposauridae . Metoposaurids are distinguished from capitosauroids by the positioning of their eye sockets near the front of their skulls . Another group of stereospondyls , the plagiosaurs , had wide heads with external gills , and adapted to life at the bottom of lakes and rivers . By this time , temnospondyls had become a common and widespread component of semiaquatic ecosystems . Some temnospondyls , such as Cryobatrachus and Kryostega , even inhabited Antarctica , which was covered in temperate forests at the time . 
 In the Carnian stage of the Late Triassic ( 228 @.@ 0 - 216 @.@ 5 Mya ) , capitosauroids <a href='uninflect' title='1'><mark>were</mark></a> joined by the superficially very similar Metoposauridae . Metoposaurids are distinguished from capitosauroids by the positioning of their eye sockets near the front of their skulls . Another group of stereospondyls , the plagiosaurs , had wide heads with external gills , and adapted to life at the bottom of lakes and rivers . By this time , temnospondyls <a href='been_done' title='2'><mark>had</mark></a> become a common and widespread component of semiaquatic ecosystems . Some temnospondyls , such as Cryobatrachus and Kryostega , even inhabited Antarctica , which was covered in temperate forests at the time . 
In da Carnian stage of tdaLate Triassic ( 228 @.@ 0 - 216 @.@ 5 Mya ) , capitosauroids was joined by the superficially very similar Metoposauridae . Metoposaurids are distinguished from capitosauroids by the positioning of their eye sockets near the front of their skulls . Another group of stereospondyls , thdalagiosaurs , had wide heads with external gills , and adapted to life at the bottom of lakes and rivers . By this time , temnospondyls done become a common and widespread component of semiaquatic ecosystems . Some temnospondyls , such as Cryobatrachus and Kryostega , even inhabited Antarctica , which was covered in temperate forests at the time .