 <unk> are placed as basal <unk> in phylogenetic analyses , with their exact positioning varying between studies . Depending on the classification of modern amphibians , they are either included in the crown group <unk> or the stem of <unk> . Crown @-@ group <unk> are descendants of the most recent common ancestor of all living <unk> and stem <unk> are forms that are outside the crown group . Modern amphibians have recently been suggested as descendants of <unk> , which would place them within crown <unk> . Below is a cladogram from <unk> et al . ( 2003 ) placing <unk> within crown <unk> : 
