ɹˈiːsənt ɹᵻsˈɜːtʃ pˈɑːzɪts ðæt dᵻspˈaɪt ðɛɹ səksˈɛsfəl ˌædæptˈeɪʃən tʊ ɐ pɛlˈædʒɪk lˈaɪfstaɪl, bˈeɪsəl mˈɛtɹɪɹhˌɪntʃɪdz wɜː juːnˈiːkli dˌɪsɐdvˈæntɪdʒd ɐmˌʌŋ əkwˈæɾɪk tˈɛtɹɐpˌɑːdz ɪn ɪvˈɑːlvɪŋ ˌɪntʊ səstˈeɪnd swˈɪmɚz dˈuː tə lˈɪɾəl tə nˈoʊ pˈoʊstɚɹˌoʊdɚsəl ɹᵻtɹˈækʃən ʌvðɪ ɛkstˈɜːnəl nˈɛɹz ʌnlˈaɪk ˈʌðɚ ɹɛptˈɪliən ɡɹˈuːps sˈʌtʃ ɐz mˈɛsəsˌɔːɹz, fˈaɪɾəsˌɔːɹz, θˌælɐɾəsˈɔːɹiənz, sˈɔːɹəsfˌɑːɹdʒɪdz, ˌɪkθɪəsˈɔːɹɪfˌɔːɹmz, sˈɔːɹəptɚɹˌɪdʒənz, plˌɜːɹəsˈɔːɹɪdz ɔːɹ mˈɑːsɐsˌɔːɹɔɪdz, æz wˈɛl æz mæmˈeɪliən sɪtˈeɪʃənz ɔːɹ sˈaɪɚniənz.
Recent research posits that despite their successful adaptation to a pelagic lifestyle, basal metriorhynchids were uniquely disadvantaged among aquatic tetrapods in evolving into sustained swimmers due to little to no posterodorsal retraction of the external nares (unlike other reptilian groups such as mesosaurs, phytosaurs, thalattosaurians, saurosphargids, ichthyosauriforms, sauropterygians, pleurosaurids or mosasauroids, as well as mammalian cetaceans or sirenians).