Hyperoartia or
Petromyzontida is a disputed group of
vertebrates that includes the modern
lampreys and their
fossil relatives. Examples of hyperoartians from early in their fossil record are
Endeiolepis and
Euphanerops, fish-like animals with hypocercal tails that lived during the Late
Devonian Period. Some
paleontologists still place these forms among the "
ostracoderms" (jawless armored fishes) of the
class Anaspida, but this is increasingly considered an artificial arrangement based on
ancestral traits.