sˌʌm dʒɪˈɑːlədʒˌɪsts ˈɑːɹɡjuː ðætðɪ ˈoʊpənɪŋ ʌvðə nˈɔːɹθ ɐtlˈæntɪk wʌz tɹˈɪɡɚd baɪ ðə sʌbdˈʌkʃən ʌv pˌænθɐlˈæsə ˌʌndɚ ðə wˈɛstɚn mˈɑːɹdʒɪnz ʌvðɪ ɐmˈɛɹɪkəz wˌaɪl ˈʌðɚɹ ˈɑːɹɡjuː ðætðə klˈoʊʒɚɹ ʌvðə pˈeɪlɪˌoʊtˈɛθiz ænd tˈɛθiz ɹɪzˈʌltᵻd ɪnðə bɹˈeɪkˈʌp.
Some geologists argue that the opening of the North Atlantic was triggered by the subduction of Panthalassa under the western margins of the Americas while other argue that the closure of the Paleo-Tethys and Tethys resulted in the break-up.