KnowraAcanthodiiLinked fromLinked fromThe 4 pages that link to Acanthodii, each with the reason it gives.All 4Related 1Compared with 3OperculumCompared with: Their gill openings provide an evolutionary comparison with opercular coverings.OstracodermCompared with: Acanthodians show another early vertebrate route that already included jaws.DunkleosteusCompared with: Their fin spines and lighter body form contrast with Dunkleosteus’s heavy armor.