Unlike the present species of Agnatha, closest to them, the hagfishes and the lampreys, they were organisms with an alimentation based on the filtering of the debris, because they had no jaws, and this is why they were not active predators.
Diversamente dalle specie attuali di Agnatha, ad essi più affini, le missine e le lamprede, erano organismi a nutrizione detrivora-filtratoria, perché privi di mascelle, per cui non erano attivi predatori.