Arandaspis prionotolepis (Ritchie and Gilbert-Tomlinson 1977; Ordovician, 465mya; 15 cmlong) is a member of the Arandaspididae that looked like a large, armored tadpole, or a large armored Metaspriggina. This jawless, finless filter feeder was basal to similar placoderms, including Phyllolepis,

Poraspis brevis (Kiaer 1930; Klaer and Heintz 1935; Late Silurian to Early Devonian, 410mya; 10.5cm) is traditionally considered a member of the Heterostraci. Here Poraspis nests basal to Qilinyu, a basal member of the Placodermi. Both share spike-like fins at the genesis of fins for this clade.