Caenoidea
{{Short description|Superfamily of mayflies}}
{{Automatic taxobox
| image = Caenis.horaria.jpg
| image_upright = 0.7
| image_caption = Caenis horaria
| taxon = Caenoidea
}}
Caenoidea is a superfamily of mayflies in the suborder Pannota. Members of this superfamily can be distinguished from those of Ephemerelloidea by the fact that the gills of the nymphs are filamentous.{{cite journal |author1=Dias, Lucimar G. |author2=Salles, Frederico F. |author3=Francischetti, Cesar N. |author4=Ferreira, Paulo Sérgio F. |year=2006 |title=Key to the genera of Ephemerelloidea (Insecta: Ephemeroptera) from Brazil |journal=Biota Neotropica |volume=6 |issue=1 |doi=10.1590/S1676-06032006000100015 |doi-access=free }}
The following families are recognised:{{cite web |url=http://tolweb.org/tree?group=Ephemeroptera&contgroup=Pterygota |title=Ephemoptera: Mayflies |year=2002 |work=The Tree of Life Web Project |access-date=2015-06-01}}