ðeɪ flˈɜːɹɪʃt bɹˈiːfli dˈʊɹɹɪŋ ðɪ ˈɜːli tɹaɪˈæsɪk, əkˈɜːɹɪŋ wˈɜːldwaɪd bᵻfˌoːɹ dᵻklˈaɪnɪŋ æt ðə stˈɑːɹt ʌvðə mˈɪdəl tɹaɪˈæsɪk, ɔːlðˈoʊ ðə ɡɹˈuːp kəntˈɪnjuːd ʌntˈɪl ðə lˈeɪt tɹaɪˈæsɪk.
They flourished briefly during the Early Triassic, occurring worldwide before declining at the start of the Middle Triassic, although the group continued until the Late Triassic.