High Quality Content by WIKIPEDIA articles! Hyperoartia or Petromyzontida is a group of jawless fish that includes the modern lampreys and their fossil relatives, the jawless fish of the class Anaspida. Examples of hyperoartians from early in their fossil record are Endeiolepis and Euphanerops, fishes with hypocercal tails that lived during the Late Devonian Period. Some paleontologists still classify these forms among the jawless armored fishes.