The briefness of this period, and the swiftness with which radiation took place, would help account for the relative scarcity of primitive amphibian fossils.
ðə bɹˈiːfnəs ʌv ðɪs pˈiəɹɪəd, ænd ðə swˈɪftnəs wɪð wˌɪtʃ ɹˌeɪdɪˈeɪʃən tˈʊk plˈeɪs, wʊd hˈɛlp ɐkˈaʊnt fɚðə ɹˈɛlətˌɪv skˈɛɹsᵻɾi ʌv pɹˈɪmᵻtˌɪv æmfˈɪbiən fˈɑːsəlz.