 Originally , temnospondyls were classified according to the structure of their vertebrae . Early forms , with complex vertebrae consisting of a number of separate elements , were placed in the suborder Rachitomi , and large Triassic aquatic forms with simpler vertebrae were placed in the suborder Stereospondyli . With the recent growth of phylogenetics , this classification is no longer viable . The basic rhachitomous condition is found in many primitive tetrapods , and is not unique to one group of temnospondyls . Moreover , the distinction between rhachitomous and stereospondylous vertebrae is not entirely clear . Some temnospondyls have rhachitomous , semirhachitomous , and sterospondylous vertebrae at different points in the same vertebral column . Other taxa have intermediate morphologies that do not fit into any category . Rachitomi is no longer recognized as a group , but Stereospondyli is still considered valid . Below is a simplified taxonomy of temnospondyls showing currently recognized groups : 
 Originally , temnospondyls <a href='uninflect' title='1'><mark>were</mark></a> classified according to the structure of their vertebrae . Early forms , with complex vertebrae consisting of a number of separate elements , <a href='uninflect' title='2'><mark>were</mark></a> placed in the suborder Rachitomi , and large Triassic aquatic forms with simpler vertebrae <a href='uninflect' title='3'><mark>were</mark></a> placed in the suborder Stereospondyli . With the recent growth of phylogenetics , this classification <a href='drop_aux' title='4'><mark>is</mark></a>no longer viable . The basic rhachitomous condition is found in many primitive tetrapods , and <a href='negative_concord' title='5'><mark>is</mark></a> <a href='negative_concord' title='6'><mark>not</mark></a>unique to one group of temnospondyls . Moreover , the distinction between rhachitomous and stereospondylous vertebrae <a href='negative_concord' title='7'><mark>is</mark></a> <a href='negative_concord' title='8'><mark>not</mark></a>entirely clear . Some temnospondyls <a href='got' title='9'><mark>have</mark></a> rhachitomous , semirhachitomous , and sterospondylous vertebrae at different points in the same vertebral column . Other taxa <a href='got' title='10'><mark>have</mark></a> intermediate morphologies <a href='null_relcl' title='11'><mark>that</mark></a>do not fit into <a href='None' title='12'><mark>any</mark></a><a href='negative_concord' title='13'><mark>category</mark></a> . Rachitomi is no longer recognized as a group , but Stereospondyli is still considered valid . Below <a href='drop_aux' title='14'><mark>is</mark></a>a simplified taxonomy of temnospondyls showing currently recognized groups : 
Originally , temnospondyls was classified according to the structure of their vertebrae . Early forms , with complex vertebrae consisting of a number of separate elements , was placed in the suborder Rachitomi , and large Triassic aquatic forms with simpler vertebrae was placed in the suborder Stereospondyli . wit da recent growth of phylogenetics , this classification no longer viable . Tdabasic rhachitomous condition is found in many primitive tetrapods , and ain't unique to one group of temnospondyls . Moreover , thdaistinction between rhachitomous and stereospondylous vertebrae ain't entirely clear . sum temnospondyls got rhachitomous , semirhachitomous , and sterospondylous vertebrae at different points in thedame vertebral column . Other taxa got intermediate morphologies do not fit into no category . Rachitomi ain't no longer recognized as a group , but Stereospondyli is still considered valid . Below a simplified taxonomy of temnospondyls showin currently recognized groups :