The tribal arrangement was originally based on analyses of morphology and ecology. mtDNA cytochrome b sequence and allozyme studies confirm these findings except that the Synthliboramphus murrelets should be split into a distinct tribe, as they appear more closely related to the Alcini – in any case, assumption of a closer relationship between the former and the true guillemots was only weakly supported by earlier studies. وعلى أية حال، لم توجد علاقة وثيقة بين السابق والغلموت سوى افتراض تدعمه الدراسات السابقة بشكل ضعيف.