Christopher Ehret has proposed that Proto-Afroasiatic originally had as many as thirty-seven separate verbal extensions, many of which then became fossilized as third consonants.
kɹˈɪstəfɚɹ ˈeɪɹɪt hɐz pɹəpˈoʊzd ðæt pɹˈoʊɾoʊˌæfɹoʊˌeɪsɪˈæɾɪk ɚɹˈɪdʒɪnəli hæd æz mˈɛni æz θˈɜːɾisˈɛvən sˈɛpɹət vˈɜːbəl ɛkstˈɛnʃənz, mˈɛnɪəv wˌɪtʃ ðˈɛn bɪkˌeɪm fˈɑːsəlˌaɪzd æz θˈɜːd kˈɑːnsənənts.