†Posidonia Bronn 1828 (clam)
Bivalvia - Ostreida - Posidoniidae
Parent taxon: Posidoniidae according to H. E. Vokes 1980
Sister taxa: Amonotis, Aulacomyella, Bositra, Didymotis, Magnolobia, Posidonotis, Pterohalobia
Subtaxa: Posidonia aranea, Posidonia blatchleyi, Posidonia circularis, Posidonia daytonensis, Posidonia dianensis, Posidonia jacksoni, Posidonia limbata, Posidonia madisonensis, Posidonia olenekensis, Posidonia ostenfeldii, Posidonia semiundata, Posidonia somaliensis, Posidonia wengensis
Ecology: stationary epifaunal suspension feeder