They are a paraphyletic group encompassing all tetrapods excluding the amniotes (tetrapods with an amniotic membrane, such as modern reptiles, birds, and mammals).
ðeɪ ɑːɹ ɐ pˌæɹəfaɪlˈɛɾɪk ɡɹˈuːp ɛŋkˈʌmpəsɪŋ ˈɔːl tˈɛtɹɐpˌɑːdz ɛksklˈuːdɪŋ ðɪ ˈæmnɪˌoʊts tˈɛtɹɐpˌɑːdz wɪð ɐn ˌæmnɪˈɑːɾɪk mˈɛmbɹeɪn, sˈʌtʃ ɐz mˈɑːdɚn ɹˈɛptaɪlz, bˈɜːdz, ænd mˈæməlz.