Not Loganellia (an online specimen with no museum number) Note the dorsal narial/oral opening and lack of fins. Compare to Laxaspis below.

Not Loganellia (GLAHM V8304, Early Silurian) is identified here as a primitive galeaspid based on the dorsal oral opening and other traits, including dorsal, lateral and caudal fins.

Tujiaaspis vividus (IVPP V26668, Gai et al. 2024, Early Silurian) is a derived galeaspid that also preserves post-crania.

Laxaspis qujingensis. Liu 1975. is a galeaspid from the Devonian in China nesting closer to Drepanaspis than to Dunyu. The oral opening is dorsal, but not a narrow slit.

Dunyu longiforus (Zhu et al. 2012; Late Silurian, 425mya; IVPP V 17681) is a galeaspid without cranial horns. It nests with Drepanaspis. The oral cavity is the long slit between the nasals, extending to the frontals here. The frontals include the pineal opening. The underside does not include the mouth or gill openings, only a gular sac that expands and contracts to draw in nutrient- and oxygen-rich sea water while Dunyu is otherwise buried in the sea floor sediments. The skull shape is otherwise convergent with the osteostracan, Hemicyclaspis.