ðɪs wʊdhɐv bˌɪn ɪmpˈɜːməbəl ænd ðˈʌs fˈoːɹst ðə dɪvˈɛləpmənt ʌv mˈoːɹ səfˈɪstᵻkˌeɪɾᵻd ɹˈɛspɹətˌoːɹi ˌæpɚɹˈæɾəs ɪnðə fˈɔːɹm ʌv ɡˈɪlz.
This would have been impermeable and thus forced the development of more sophisticated respiratory apparatus in the form of gills.