PanderichthysElginerpetonObruchevichthysIchthyostegaVentastegaMetaxygnathusAcanthostegaWhatcheeriaTulerpetonCrassigyrinusGreerepetonMegalocephalusPhopliderpetonCochleosaurusPhonerpetonEoherpetonProteogyrinusGephyrpstegusBalanerpetonPlatyrhinopsMicrobrachisDiscosauriscusEocaptorhinusDiploceraspisSauropleuraOphiacodonOsteologyMaximum ParsimonyBased on reanalysis of the original matrix.Ahlberg_et_Clack_1998a