Editing Cephalaspidomorphi (section)

== Lampreys ==
Some reference works and databases have regarded Cephalaspidomorphi as a [[Linnean taxonomy|Linnean]] class whose sole living representatives are the [[lamprey]]s.<ref name = "Nelson 1994">
{{cite book
 | author = Nelson, Joseph S.
 | year = 1994
 | title = Fishes of the World
 | edition = Third
 | publisher = John Wiley and Sons
 | isbn = 0-471-54713-1}}</ref> Evidence now suggests that lampreys acquired the characters they share with cephalaspids by [[convergent evolution]].<ref name = "Forey & Janvier">
{{Cite book
  | author = Forey, Peter
  | author2 = Janvier, Philippe
  | name-list-style = amp
  | year = 2012
  | contribution = Agnathans and the origin of jawed vertebrates
  | title = Shaking the tree: readings from Nature in the history of life
  | editor-last = Gee
  | editor-first = Henry
  | editor-link = Henry Gee
  | pages = 251–266
  | place = USA
  | publisher = University of Chicago Press; Nature/Macmillan Magazines
  | isbn = 978-0-226-28497-2
  }}</ref>
<ref name = "Janvier 2008">
{{cite journal
 | author = Janvier, Philippe
 | year = 2008 
 | title = Early Jawless Vertebrates and Cyclostome Origins
 | journal = Zoological Science
 | pmid = 19267641
 | volume = 25
 | issue = 10 | pages = 1045–1056
 | doi = 10.2108/zsj.25.1045
| doi-access = free
 }}</ref>
As such, many newer works about fishes classify lampreys in a separate group called [[Hyperoartia|Petromyzontida or Hyperoartia]].<ref name = "Nelson 2006">
{{cite book
 | author = Nelson, J. S.
 | year = 2006
 | title = Fishes of the World
 | publisher = John Wiley and Sons, Inc.
 | location = New York
 | edition = 4th
 | pages = 601 pp
 | isbn = 0-471-25031-7
}}
</ref>