List of prehistoric medusozoan genera

The 8th plate from Ernst Haeckel's Kunstformen der Natur (1904), depicting Discomedusae.

This list of prehistoric medusozoan genera is an attempt to create a comprehensive listing of all genera that have ever been included in the subphylum Medusozoa, excluding purely vernacular terms. The list includes all commonly accepted genera, but also genera that are now considered invalid, doubtful ( nomina dubia ), or were not formally published ( nomina nuda ), as well as junior synonyms of more established names, and genera that are no longer considered medusozoans.

This is a dynamic list and may never be able to satisfy particular standards for completeness. You can help by adding missing items with reliable sources.

Naming conventions and terminology

Naming conventions and terminology follow the International Code of Zoological Nomenclature. Technical terms used include:

• Junior synonym : A name which describes the same taxon as a previously published name. If two or more genera are formally designated and the type specimens are later assigned to the same genus, the first to be published (in chronological order) is the senior synonym, and all other instances are junior synonyms. Senior synonyms are generally used, except by special decision of the ICZN, but junior synonyms cannot be used again, even if deprecated. Junior synonymy is often subjective, unless the genera described were both based on the same type specimen.
• Nomen nudum (Latin for "naked name"): A name that has appeared in print but has not yet been formally published by the standards of the ICZN. Nomina nuda (the plural form) are invalid, and are therefore not italicized as a proper generic name would be. If the name is later formally published, that name is no longer a nomen nudum and will be italicized on this list. Often, the formally published name will differ from any nomina nuda that describe the same specimen.
• Nomen oblitum (Latin for "forgotten name"): A name that has not been used in the scientific community for more than fifty years after its original proposal.
• Preoccupied name: A name that is formally published, but which has already been used for another taxon. This second use is invalid (as are all subsequent uses) and the name must be replaced. As preoccupied names are not valid generic names, they will also go unitalicized on this list.
• Nomen dubium (Latin for "dubious name"): A name describing a fossil with no unique diagnostic features. As this can be an extremely subjective and controversial designation, this term is not used on this list.

The list

Genus	Class	Status	Age	Location	Description	Images
† Allopora	Hydrozoa.	Valid.				Some Karakorum stones (Stoliczkaria and Syringosphaera), relatives of Heterastridium . Fish surrounding a modern Millepora species. Fish near a modern Millepora species. Modern Millepora near Fiji.
† Anthracomedusa	Cubozoa.	Valid.
† Archaeoantennularia	Hydrozoa.	Valid.
† Archaeocryptolaria	Hydrozoa.	Valid.
† Archaeolafoea	Hydrozoa.	Valid.
† Archaeonectris	Hydrozoa.	Valid.
† Astya	Hydrozoa.	Valid.
† Axopora	Hydrozoa.	Valid.
† Axoporella	Hydrozoa.	Valid.
† Cályxhydra	Hydrozoa.	Valid.
† Cannostomites	Scyphozoa.	Valid.
† Congregopora	Hydrozoa.	Valid.
† Conopora	Hydrozoa.	Valid.
† Crucimedusina	Hydrozoa.	Valid.
† Diamantopora	Hydrozoa.	Valid.
† Discophyllum	Hydrozoa.	Valid.
† Distichopora	Hydrozoa.	Valid.
† Drevoôella	Hydrozoa.	Valid.
† Eisenackiella	Hydrozoa.	Valid.
† Epiphyllina	Scyphozoa.	Valid.
† Essexella	Scyphozoa.	Valid.
† Errina	Hydrozoa.	Valid.
† Flexihydra	Hydrozoa.	Valid.
† Gelenoptron	Hydrozoa.	Valid.
† Germanicum	Scyphozoa.	Valid.
† Haootia	incertae sedis	Valid.
† Heterastridium	Hydrozoa.	Valid.
† Hydractinia	Hydrozoa.	Valid.
† Hydrallmania	Hydrozoa.	Valid.
† Inocaulis	Hydrozoa.	Valid.
† Kristinella	Hydrozoa.	Valid.
† Kullingia	Hydrozoa.	Valid.
† Lorenzinia	Scyphozoa.	Valid.
† Mazohydra	Hydrozoa.	Valid.
† Mesokylix	Hydrozoa.	Valid.
† Milleaster	Hydrozoa.	Valid.
Millepora	Hydrozoa.	Valid.
† Octomedusa	Scyphozoa.	Valid.
† Palaeacmea	Hydrozoa.	Valid.
† Palaelophacmaea	Hydrozoa.	Valid.
† Palaeokylix	Hydrozoa.	Valid.
† Palaeomillepora	Hydrozoa.	Valid.
† Palaeonectris	Hydrozoa.	Valid.
† Palaeotuba	Hydrozoa.	Valid.
† Parleria	Hydrozoa.	Valid.
† Philippinactinia	Hydrozoa.	Valid.
† Plectodiscus	Hydrozoa.	Valid.
† Pliobothrus	Hydrozoa.	Valid.
† Protohalecium	Hydrozoa.	Valid.
† Protolyella	Hydrozoa.	Valid.
† Protulophila	Hydrozoa.	Valid.
† Psammactinia	Hydrozoa.	Valid.
† Quadrimedusina	Cubozoa.	Valid.
† Rhabdohydra	Hydrozoa.	Valid.
† Sphenoecium	Hydrozoa.	Valid.
† Sporadopora	Hydrozoa.	Valid.
† Stylaster	Hydrozoa.	Valid.
† Subaxopora	Hydrozoa.	Valid.

See also

• List of prehistoric hexacorals
• List of prehistoric octocorals