Species: repandus COPE, 1869
Etymology:
= Osteopygis repandus (COPE, 1869)
= Propleura repanda (COPE, 1869)

Holotype: AMNH 2353

Locality: Barnsboro, Gloucester County, New Jersey.

Horizon: Hornerstown Formation, Rancocas Group.

Biostratigraphy:

Age: Late Maastrichtian Stage, uppermost Senonian subepoch, Gulf Epoch, Late Cretaceous.

Material: 3 peripherals and a part of the fourth of the right side, the first of the left side, and for other peripherals, one nearly complete costal and parts of others and a portion of a femur.
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Species: ponderosa COPE, 1871
Etymology:
= Osteopygis ponderosa (COPE, 1871)

Holotype: AMNH 1475

Locality: Hornerstown, Monmouth County, New Jersey.

Horizon: Hornerstown Formation, Rancocas Group.

Biostratigraphy:

Age: Late Maastrichtian Stage, uppermost Senonian subepoch, Gulf Epoch, Late Cretaceous.

Material: Portions of the 11th peripheral and the pygal, portions of about 6 costals, a part of a supposed hypoplastron, a scapular arch, a considerable part of a humerus, a part of a femur and part of a lower jaw.
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Species: arkansaw SCHMIDT, 1944
Etymology: In reference to Arksansas, where the specimen was found.

Holotype: FM P27045

Locality: Gather Brothers farm, 1 mile northeast of Okolona, NE 1/4, sec. 29, T 73S, R 20W, Clark County, Arkansas.

Horizon: Marlbrook Marl, Gulf Series.

Biostratigraphy:

Age: Late Cretaceous.

Material: A nearly complete carapace and plastron.