Bivalvia - Cardiida - Ungulinidae
Alternative spelling: Zemysina
Parent taxon: Diplodonta according to E. J. Moore 1988
See also Marwick 1960, Sepkoski 2002 and Zinsmeister 1983
Sister taxa: Diplodonta (Diplodonta), Diplodonta (Microstagon), Diplodonta (Phlyctiderma), Diplodonta (Sphaerella), Diplodonta (Timothynus), Diplodonta acclinis, Diplodonta aleutica, Diplodonta astartea, Diplodonta balcombensis, Diplodonta confusa, Diplodonta corbiscula, Diplodonta cornea, Diplodonta davisi, Diplodonta dilatata, Diplodonta dissona, Diplodonta ferruginata, Diplodonta globosa, Diplodonta hopkinsiensis, Diplodonta incerta, Diplodonta inconspicua, Diplodonta infrequens, Diplodonta lupinus, Diplodonta mediamericana, Diplodonta nucleiformis, Diplodonta orbella, Diplodonta paralta, Diplodonta parilis, Diplodonta problematica, Diplodonta punctata, Diplodonta shilohensis, Diplodonta soror, Diplodonta subquadrata, Diplodonta subrotunda, Diplodonta subrotundata, Diplodonta subvexa, Diplodonta torelli, Diplodonta transversaria, Diplodonta vaticani, Diplodonta villardeboeana, Diplodonta zelandica, Taras (Diplodonta) alta, Felaniella insula, Felaniella palmerae, Diplodonta (Felaniella) sericata, Felaniella (Felaniella), Felaniella confusa, Felaniella senegalensis, Taras (Taras), Taras goodspeedi, Taras griesensis, Felaniella (Zemysia) elliptica
Subtaxa: Diplodonta (Zemysina) densiscalpta Diplodonta (Zemysina) globus Diplodonta (Zemysina) lamberti Diplodonta (Zemysina) pacifica
Type: Zemysina globus
Ecology: facultatively mobile infaunal suspension feeder
Distribution:
• Pliocene of Belgium (6 collections), New Zealand (1)
• Eocene of Belgium (1), New Zealand (1)
• Paleocene of the Russian Federation (1), United States (1: California)
Total: 11 collections each including a single occurrence