The origin of modern amphibians belonging to Lissamphibia, which first appeared during the Early Triassic, around 250 million years ago, has long been contentious.
ðɪ ˈɔːɹɪdʒˌɪn ʌv mˈɑːdɚn æmfˈɪbiənz bᵻlˈɔŋɪŋ tə lˌɪsɐmfˈɪbiə, wˌɪtʃ fˈɜːst ɐpˈɪɹd dˈʊɹɹɪŋ ðɪ ˈɜːli tɹaɪˈæsɪk, ɚɹˈaʊnd tˈuːhˈʌndɹɪd fˈɪfti mˈɪliən jˈɪɹz ɐɡˈoʊ, hɐz lˈɔŋ bˌɪn kəntˈɛnʃəs.