Hyperoartia is a group of jawless fishes that includes the modern lampreys and their fossil relatives. Example of hyperoartian from early in their fossil record are Endeiolepis and Euphanerops, fish with hypocercal tails that lived during the Late Devonian Period. Some paleontologists still classify these forms among the jawless armored fish.
The only hyperoartians surviving today are lampreys, classified in the Petromyzontiformes. The discovery of the fossil Priscomyzon, pushed back the oldest known occurence of true lampreys to the Late Devonian. The evidence of phylogeny, however, suggests that the lamprey lineage diverged much earlier from other vertebrates, rather than arising from ostracoderm fishes. The origin of Hyperoartia may therefore extend back to the early Paleozoic, if not earlier.
o Hyperoartii Müller, 1844 sensu Janvier, 1997 and Shu et al., 1999 [Hyperoartia] (lampreys; nahkiaiskalat) |?- †Haikouichthys ercaicunensis Luo, Hu & Shu, 1999 sensu Shu et al., 1999 `--o “Pteromyxontimorpha” |-- †Legendrelepis parenti `--o Petromyzontiformes sensu lato |-- †Hardistiella montanensis Janvier & Lund, 1983 [paraphyletic Mayomyzoninae] `--+-- †Mayomyzon pieckoensis Bardack & Zangerl, 1962 [paraphyletic Mayomyzoninae] `--+-- †Pipiscius zangerli Bardack & Richardson, 1977 [paraphyletic Mayomyzoninae] `-- Petromyzontidae [Petromyzontiformes sensu stricto] (modern lampreys;nykynahkiaiset)