Oogenus: Preprismatoolithus ZELENITSKY & HILLS, 1996
Etymology: Latin, meaning before, in reference to the occurrence of Preprismatoolithus in the late Jurassic, prior to the late Cretaceous oogenus Prismatoolithus.

Oospecies: coloradensis (HIRSCH, 1994) ZELENITSKY & HILLS, 1996

Holotype: MWC 122.3.1/HEC 457

Locality: Young Locality, Delta County, Colorado.

Horizon: Upper Salt Water Wash Member, Morrison Formation.

Biostratigraphy: Zone 2.

Age: Comobluffian age, Kimmeridgian Stage, uppermost Malm Epoch, Late Jurassic.

Referred material:

MWC 122.2/HEC 418-R2, 532-4: Pathological eggshells.