Some fish had developed primitive lungs that help them breathe air when the stagnant pools of the Devonian swamps were low in oxygen.
sˌʌm fˈɪʃ hæd dɪvˈɛləpt pɹˈɪmᵻtˌɪv lˈʌŋz ðæt hˈɛlp ðˌɛm bɹˈiːð ˈɛɹ wɛn ðə stˈæɡnənt pˈuːlz ʌvðə dɛvˈoʊniən swˈɑːmps wɜː lˈoʊ ɪn ˈɑːksɪdʒən.