HIERARCHICAL CLASSIFICATION OF THE SUPERCLASS PETROMYZONTOMORPHI+

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SUPERCLASS PETROMYZONTOMORPHI LINKS

Description of Superclass Petromyzontomorphi

The following descriptions come from Benton (2005), Nelson (2006), Janvier and Arsenault (2007) and Janvier (2008a). Eschmeyer and Fong (2011) place the Petromyzontiformes within the Cephalaspidomorphi. Taxa in red are extinct.

SUPERCLASS PETROMYZONTOMORPHI
- CLASS PETROMYZONTIDA
  - The lampreys are similar to the hagfishes, but they have a nostril that opens into a pouch beneath the brain and two semicircular canals in each ear. Like the hagfishes, their bodies are eel-like. Their mouth is firm and funnel-like and is lined with keratin toothlets. Unlike hagfishes, the lampreys have a vertebral column which is associated with the notochord.
  - Mississippian (oldest known) to present
  - ORDER PETROMYZONTIFORMES
    - FAMILY PETROMYZONTIDAE
    - The Northern Lampreys. They are found north of 30o N in marine and freshwater. Parasitic and non-parasitic.
    - Petromyzon, Ichthyomyzon, Caspiomyzon, Tetrapleurodon, Entosphenus, Eudontomyzon, Lampetra, Okkelbergia, Lethenteron.
    - FAMILY GEOTRIIDAE
    - Southern Lampreys. They are found in marine and freshwater in the southern temperate zone. Parasitic.
    - Geotria
    - FAMILY MORACIIDAE
    - Southern topeyed Lampreys. They occur in the southern temperate zone in marine and freshwater. Parasitic and non-parasitic.
    - Mordacia
    - FAMILY MAYOMYZONTIDAE+
    - These lampreys had no teeth.
    - Pennsylvanian Period
    - Mayomyzon
    - FAMILY UNNAMED+
    - They had rays in the anal fin, had a hypocercal tail, and lacked an oral sucker. Their relationship to the other lampreys, especially Mayomyzon, remains unknown.
    - Mississippian Period
    - Hardistiella+
- CLASS EUPHANEROPSIDA+
  - These fishes had strongly-hypocercal tails and fin rays. Devonian
  - ORDER JAYMOTIIFORMES
    - FAMILY ENDEIOLEPIDAE
    - Endeiolepis.
    - FAMILY ACHANARELLIDAE
    - Achanarella
    - FAMILY JAYMOYTIIDAE
    - Jaymoytius
    - FAMILY EUPHAEROPIDAE
    - Cornovichthys, Euphanerops.
    - FAMILY RHYNCHOLEPIDIDAE
    - Rhyncholepis.

LITERATURE CITED

Benton, M. J. 2005. Vertebrate Paleontology. Third Edition. Blackwell Publishing, Malden, MA.

Delarbre, C., C. Gallut, V. Barriel, P. Janvier, and G. Gachelin. 2002. Complete mitochondrial DNA of the hagfish, Eptatretus burgeri: the comparative analysis of mitochondrial DNA sequences strongly supports the cyclostome monophyly. Molecular Phylogenetics and Evolution. 22: 184–192.

Eschmeyer, M. N. and J. D. Fong. 2011. “Pisces”. IN: Zhang, Z-Q., ed. Animal biodiversity: an outline of higher-level classification and survey of taxonomic richness. Zootaxa. 3148: 26-38.

Janvier, P. 2008a. Early jawless vertebrates and cyclostome origins. Zoological Science. 25: 1045-1056.

Janvier, P. and M. Arsenault. 2007. The anatomy of Euphanerops longaevus Woodward, 1900, an anaspid-like jawless vertebrate from the Upper devonian of Miguasha, Quebec, Canada. Geodiversitas. 29(1): 143-216.

Nelson, J. S. 2006. Fishes of the World. 4th edition. John Wiley and Sons, Inc. New York.

By Jack R. Holt. Last revised: 12/30/2013

HIERARCHICAL CLASSIFICATION OF THE SUPERCLASS PETROMYZONTOMORPHI+

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