dˈʊɹɹɪŋ ðə tɹaɪˈæsɪk pˈiəɹɪəd tˈuːhˈʌndɹɪd fˈɪfti tˈuː tə tˈuːhˈʌndɹɪd wˈʌn mˈɪliən jˈɪɹz ɐɡˈoʊ, ðə ɹˈɛptaɪlz kəntˈɪnjuːd tʊ ˈaʊtkəmpˈiːt ðɪ æmfˈɪbiənz, lˈiːdɪŋ tʊ ɐ ɹᵻdˈʌkʃən ɪn bˈoʊθ ðɪ æmfˈɪbiənz sˈaɪz ænd ðɛɹ ɪmpˈoːɹtəns ɪnðə bˌaɪoʊsfˈɪɹ.
During the Triassic Period (252 to 201 million years ago), the reptiles continued to out-compete the amphibians, leading to a reduction in both the amphibians' size and their importance in the biosphere.