Species: ischyros WIELAND, 1896
Etymology:
= Protostega ischyros (WIELAND, 1896)

Holotype: YPM 1783

Locality: South Fork of Cheyenne River, about 5 miles west of the mouth of Rapid Creek, Custer County, South Dakota.

Horizon: Pierre Formation.

Biostratigraphy:

Age: Late Cretaceous.

Material: Fragmentary shell and fragmentary skeleton.

Referred material:

WIELAND, 1896

Number: Not given: Skull and most of the skeleton.

 

WIELAND

Locality: East bank of the Cheyenne River, in the Pine Ridge Indian Reservations, Shannon County, South Dakota.

Horizon: Pierre Formation.

Biostratigraphy:

Age: Late Cretaceous.

Material:

Number: Not given: Fragmentary skeleton.

 

ZANGERL, 1963

Locality: 8 miles east of Trinidae, Los Guimas County, Colorado.

Horizon: Pierre Formation.

Biostratigraphy:

Age: Late Cretaceous.

Material:

USNM 13439: Centra, girdle elements and ribs.

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Species: marshii WIELAND, 1900
Etymology:
= Protostega marshii (WIELAND, 1900)

Holotype:

Locality: 100 fort Pierre, east side of the south Fork of the Cheyenne River, Stanley County, South Dakota.

Horizon: Pierre Formation.

Biostratigraphy:

Age: Late Cretaceous.

Material: Fragmentary skeleton.