†Cayeuxia Frollo 1938 (green alga)
Bryopsidophyceae - Caulerpales - Halimedaceae
Parent taxon: Udoteaceae according to J. -C. Fischer 1969
Sister taxa: Alpinocodium, Boueina, Brandneria, Calabricodium, Collarecodium, Egericodium, Eugonophyllum, Felixporidium, Halimeda, Hydracara, Madonicodium, Nipponophycus, Trelonella, Saccamminopsis, Palaeoporella
Subtaxa: Cayeuxia moldavica
Ecology: stationary epifaunal "photoautotroph"