Oogenus: Plagioolithus IMAI & AZUMA, 2014
Etymology: Greek, plagi, 'oblique', in reference to obliquely standing calcite crystal columns in the external layer, and Greek, oolithus, 'egg stone'.

Oospecies: fukuiensis IMAI & AZUMA, 2014
Etymology: The specific name refers to Fukui where FPDM-V-0009175 was collected.

Holotype: FPDM-V-0009175

Locality: Katsuyama City, Fukui Prefecture, Honshu Island, Japan.

Horizon: Kitadani Formation.

Biostratigraphy:

Age: Barremian Stage, Lower Gallic Subepoch, Middle Early Cretaceous Epoch, Early Cretaceous.

Material: 3 eggshell fragments.