# Pierre Shale

The Pierre Shale is a geologic formation or series in the Upper Cretaceous which occurs east of the Rocky Mountains in the Great Plains, from Pembina Valley in Canada to New Mexico.
The Pierre Shale was described by Meek and Hayden in 1862 in the Proceedings of the Academy of Sciences (Philadelphia). They described it as a dark-gray shale, fossiliferous, with veins and seams of gypsum, and concretions of iron oxide. The Pierre Shale is about 3,138 feet (956m) thick at the type locality. It overlies the Niobrara division and underlies the Fox Hills beds. It was named for an occurrence near Fort Pierre on the Missouri River in South Dakota.
The Pierre Shale is of marine origin and was deposited in the Western Interior Seaway. It is correlative with other marine shales that occur farther west, such as the Bearpaw Shale, Mancos Shale and the Lewis Shale. It correlates with the Lea Park Formation in central Alberta. The Pierre is overlain by marginal marine deposits of the Fox Hills Formation.
Most of the formation was deposited in the Campanian Age of the late Cretaceous. However, the discovery of fossils of Baculites baculus in the uppermost beds of the Pierre Shale in the Raton, New Mexico area show that deposition continued here into the early Maastrichtian.

## Mineral resources

The Pierre Shale is the host formation for commercial petroleum deposits in the Florence and Canon City fields in Fremont County, Colorado, and the Boulder Oil Field in Boulder County, Colorado. More recently, natural gas has been extracted in the Raton Basin in southern Colorado. The shale formation is usually too impermeable for hydrocarbon extraction, but produces in areas where it is naturally fractured or fractured by artificial means.

## Paleofauna

| Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon | Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited. |

### Reptiles
#### Dinosaurs

Birds reported from the Pierre Shale Formation :
| Genus | Species | Location | Stratigraphic position | Material | Notes |
| Brodavis | B. varneri | South Dakota | Sharon Springs Member. | | A hesperornithiform. |
| Brodavis | B. sp. | Manitoba | Pembina Member. | | A hesperornithiform. |
| Hesperornis | H. bairdi | South Dakota | Sharon Springs Member. | | A hesperornithid. |
| Hesperornis | H. chowi | Manitoba & South Dakota | Pembina, Millwood, & Sharon Springs Members. | | A hesperornithid. |
| Hesperornis | H. lumgairi | Manitoba | Pembina Member. | | A hesperornithid. |
| Hesperornis | H. macdonaldi | Manitoba & South Dakota. | Gammon, Pembina, Millwood(?), & Sharon Springs Members. | | A hesperornithid. |
| Hesperornis | H. mengeli | Manitoba & South Dakota. | Pembina & Sharon Springs Members. | | A hesperornithid. |
| Hesperornis | H. regalis | Manitoba, South Dakota, & Kansas | Gammon, Pembina, & Sharon Springs Members. | | A hesperornithid. |
| Hesperornis | H. sp. | Manitoba. | Pembina Member. | | Probably referrable to H. regalis, but indistinguishable from H. crassipes. |
| Hesperornithidae | Gen. et. sp. indeterminate | Manitoba. | Pembina Member. | Multiple isolated synascra. | A hesperornithid. |
| Hesperornithiformes | Fam., gen. et sp. indet. | Manitoba. | Pembina Member. | Multiple vertebrae, phalanges, tibiotarsal fragments and a fibula. | |
| Ichthyornis | I. sp. | Manitoba. | Pembina Member. | "MDM B77.03.07 (vertebral centrum), B80.05.14 (femur)". | An ichthyornithe. |
Ornithischians reported from the Pierre Shale Formation :
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
| Claosaurus | C. affinis | South Dakota. | | "Pedal phalanx (lost)." | Currently considered dubious. | |

#### Mosasaurs

Mosasaurs reported from the Pierre Shale Formation :
| Genus | Species | Location | Stratigraphic position | Material | Notes |
| Clidastes | C. propython | Manitoba. | Pembina Member. | MDM M74.10.06 (skull, mandible, vertebral column). | A mosasaurine also known from the Mooreville Chalk. |
| Clidastes | | Western Kansas. | | Vertebrae associated with 'Plesiosaurus' gulo currently lost. | Likely represents the stomach contents of 'Plesiosaurus' gulo. |
| Globidens | G. dakotensis | South Dakota. | Sharon Springs Member. | FMNH PR 846. | A globidensin. |
| Globidens | G. schurmanni | At the Big Bend of the Missouri River, Buffalo County, South Dakota. | Uppermost DeGrey Formation. | "SDSM 74764, partial anterior skeleton, including cranium, jaws, cervical and trunk vertebrae partially articulated, pectoral girdles, partial anterior paddle, isolated humerus and ulna, and isolated caudal vertebrae". | |
| Globidens | G. sp. | Northwestern Logan County, Kansas. | Upper level of the Sharon Springs Member. | A nearly complete right dentary (FHSM VP–13828). | A globidensin. |
| Hainosaurus | H. pembinensis | Near Morden, Manitoba. | Pembina Member. | | Reassigned to the genus Tylosaurus. |
| Jormungandr | J. walhallaensis | Cavalier County, North Dakota. | Pembina Member. | Partial skull & skeleton. | A mosasaurine. |
| Latoplatecarpus | L. nichollsae | "19 km northwest of Morden, Manitoba". | Pembina Member. | A skeleton (CMN 52261). | A plioplatecarpine. |
| Mosasauridae | Subfam., gen. et. sp. indeterminate | Manitoba. | Pembina Member. | Fragmentary specimens consisting "mostly of vertebral scraps, ribs and flipper elements". | |
| Platecarpus | P. coryphaeus | | Pembina Member. | | Now deemed synonymous with P. tympaniticus. |
| Platecarpus | P. ictericus | | Pembina Member. | | Now deemed synonymous with P. tympaniticus. |
| Platecarpus | P. somenensis | | Pembina Member. | | Found to nest within Latoplatecarpus nichollsae. |
| Platecarpus | P. tympaniticus | | Pembina Member. | Abundant specimens. | A pliopatecarpine and the most abundant mosasaur of the Pierre Shale. |
| Platecarpus | P. sp. | Manitoba. | Pembina Member. | "Isolated skull elements, humeri and pectoral girdles". | Probably referrable to P. tympaniticus based on size, but size alone is deemed insufficient for species identification. |
| Plioplatecarpinae | Gen. et. sp. indeterminate | Manitoba. | Pembina Member. | Poorly preserved and unprepared remains. | |
| Plioplatecarpus | P. nichollsae | "19 km northwest of Morden, Manitoba". | Pembina Member. | A skeleton (CMN 52261). | Reassigned to the genus Latoplatecarpus. |
| Prognathodon | P. overtoni | South Dakota. | Virgin Creek Member. | KUVP 950 (the holotype for the species) and SDSM 3339. | A mosasaurine also found in the Bearpaw Shale. |
| Tylosaurinae | Gen. et. sp. indet. | Manitoba. | Pembina Member. | Isolated limb and girdle elements (MDM M74.28.05, M75.20.06, M82.13.17, M84.09.18). | |
| Tylosaurus | T. pembinensis | Near Morden, Manitoba. | Pembina Member. | | A tylosaurine. |
| Tylosaurus | T. proriger | Manitoba. | Pembina Member. | MDM M77.17.07 quadrate, FMNH PR 591 quadrate, pubis, vertebrae. | A tylosaurine. |

#### Plesiosaurs

Plesiosaurs reported from the Pierre Shale Formation :
| Genus | Species | Location | Stratigraphic position | Material | Notes |
| Alzadasaurus | A. pembertonii | South Dakota. | Sharon Springs Member. | Complete specimen (SDSM 451). | Synonymized with Styxosaurus snowii. |
| Alzadasaurus | cf. A. pembertonii | Manitoba. | Pembina Member. | A specimen consisting of two femora, one humerus, two epipodials, fragments of the pelvic girdle and 14 vertebrae (MDM P83.02. 18). | Synonymized with Styxosaurus snowii. |
| Elasmosauridae | Gen. et. sp. indeterminate | Manitoba. | Pembina Member. | | Remains undiagnostic at the generic level. |
| Elasmosauridae | | Logan County, Kansas. | Upper Sharon Springs Member. | KUVP 129744, a specimen associated with 47 gastroliths. | An elasmosaurid too fragmentary to identify below the family level. |
| Elasmosaurus | E. platyurus | Kansas. | Sharon Springs member. | Multiple specimens, including the holotype. | An elasmosaurid. |
| Elasmosaurus | ?E. sp. | Manitoba. | Pembina Member. | "An incomplete specimen (TMP P84.162.4), consisting of pelvic girdle, distal end of a propodial, an epipodial and 21 vertebrae". | |
| Martinectes | M. bonneri | Wyoming & South Dakota. | Sharon Springs Member and Pembina Member. | 2 specimens: an adult (UNSM 50133) and a juvenile (UNSM 55810), and several others. | A polycotylid. |
| Plesiosauria | Fam., gen. et. sp. indeterminate | | Pembina Member. | "Specimens consisting mostly of ribs, caudal vertebrae, broken girdle plates and phalanges". | "Further identification is not possible due to poor preservation and the incomplete nature of the material". |
| 'Plesiosaurus' | 'P.' gulo | Western Kansas. | | KUVP 1329 (the original specimen consisted of "eleven cervical, thirteen dorsal, and seven or eight other vertebrae" but now only 3 vertebrae remain). | An elasmosaurid associated with the remains of a mosasaur (likely Clidastes), representing the stomach contents of the plesiosaur. |
| Polycotylidae | Gen. et. sp. indeterminate | Morden area, Manitoba. | Pembina Member. | Many isolated vertebrae and partial skull remains. | A polycotylid. |
| Serpentisuchops | S. pfisterae | Wyoming. | Upper half of the upper member. | "Specimen GPM5001". | A polycotylid. |
| Styxosaurus | S. snowii | South Dakota. | Sharon Springs Member. | Complete specimen (SDSM 451). | An elasmosaurid originally reported as Alzadasaurus pembertoni. |
| Styxosaurus | cf. S. snowii | Manitoba. | Pembina Member. | A specimen consisting of two femora, one humerus, two epipodials, fragments of the pelvic girdle and 14 vertebrae (MDM P83.02. 18). | An elasmosaurid originally reported as cf. Alzadasaurus pembertoni. |
| Styxosaurus | | Kansas. | Sharon Springs Member. | NJSM 15435. | An elasmosaurid tentatively assigned to the genus Styxosaurus. |
| Trinacromerum | T. bonneri | Wyoming & South Dakota. | Sharon Springs Member and Pembina Member. | 2 specimens: an adult (UNSM 50133) and a juvenile (UNSM 55810), and several others. | Now moved to the genus Martinectes. |
| Trinacromerum | T. cf. T. kirki | Manitoba. | Pembina Member. | TMP P84.162.3. | A polycotylid. |
| Trinacromerum | T. sp. | Manitoba. | Pembina Member. | Many poorly preserved specimens. | A polycotylid. |

#### Pterosaurs

Pterosaurs reported from the Pierre Shale Formation :
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
| Pteranodon | P. longiceps | Kansas, Wyoming & South Dakota. | Sharon Springs Member. | A skull and multiple postcranial elements. | A pteranodontid. | |

#### Turtles

Turtles reported from the Pierre Shale Formation :
| Genus | Species | Location | Stratigraphic position | Material | Notes |
| Archelon | A. ischyros | Along the Cheyenne River in Custer County, South Dakota. | | | A protostegid. |
| Archelon | A. sp. | Colfax County, New Mexico. | | 3 carapace fragments (NMMNHP-16079 and P-16104). | A protostegid. |
| Protostega | P. sp. | Manitoba. | Pembina Member. | MDM T75.01.06. | A protostegid. |
| Testudines | Fam., gen. et sp. indet. | Manitoba. | Pembina Member. | | Remains only identifiable as "small turtles", probably referrable to Toxochelys latiremis. |
| Toxochelys | T. latiremis | Kansas & Manitoba. | Pembina Member. | | |

### Fish
#### Bony fish

Bony fish reported from the Pierre Shale Formation :
| Genus | Species | Presence | Stratigraphic position | Material | Notes |
| Apsopelix | A. sp. cf. A. anglicus | Hughes County, South Dakota. | Upper DeGrey Formation. | SDSM 77482. | A crossognathid. |
| Bananogmius | B. evolutus | Manitoba. | Pembina Member. | An articulated skull (MDM F75.05.06). | Reassigned to the genus Pentanogmius. |
| Bananogmius | B. sp. | Near Thornhill, Manitoba. | Pembina Member. | Skull and vertebral column (MMMN V82). | Specimen originally identified as Ananogmius sp. |
| Cimolichthys | C. nepaholica | Manitoba. | Pembina Member. | | An aulopiform. |
| Cylindracanthus | | Hyde County, South Dakota. | Verendrye Formation. | A rostral spine (SDSM 30638). | |
| Enchodus | E. gladiolus | | Sharon Springs Member. | | An aulopiform. |
| Enchodus | E. petrosus | Manitoba. | Pembina Member and Sharon Springs Member. | | An aulopiform. |
| Enchodus | E. cf. saevus | Manitoba. | Pembina Member. | FMNH PF 5391 (a dentary, maxilla and palatine). | Now a junior synonym of E. petrosus. |
| Enchodus | E. sp. | Manitoba. | Pembina Member. | 2 isolated vertebrae and isolated palatal fangs. | An aulopiform. |
| Ichthyodectes | I. ctenodon | Manitoba. | Pembina Member. | Multiple mandibles and some skull and vertebral material. | An ichthyodectid. |
| Ichthyodectidae | Gen. et. sp. indet. | Manitoba. | Pembina Member. | Vertebrae and partial caudal fins. | An ichthyodectid not referrable to Xiphactinus but indistinguishable from other ichthyodectid genera. |
| Pachyrhizodus | P. caninus | Manitoba. | Pembina Member. | A skull and anterior portions of the body (MDM F74.04.06), and a right dentary (FMNH PF 5397). | A pachyrhizodontid. |
| Pachyrhizodus | P. minimus | Manitoba. | Pembina Member. | FMNH PF 5402. | A pachyrhizodontid. |
| Pachyrhizodus | P. sp. | Manitoba. | Pembina Member. | 2 isolated vertebral centra (MMMN V73 ). | A pachyrhizodontid. |
| Pachyrhizodus | P. sp. indet. | Hughes County, South Dakota. | DeGrey Formation. | SDSM 77481. | A pachyrhizodontid. |
| Pentanogmius | P. evolutus | Manitoba. | Pembina Member. | An articulated skull (MDM F75.05.06). | A plethodid, originally reported as Bananogmius evolutus. |
| Protosphyraena | P. gladius | Hyde County, South Dakota. | DeGrey Formation. | SDSM 66288 (major portion of pectoral fin). | A pachycormid. |
| Protosphyraena | P. sp. | Manitoba. | Pembina Member. | A left premaxilla (FMNH PF 5400). | Probably represents P. gladius. |
| Stratodus | S. apicalis | Manitoba. | Pembina Member. | | An aulopiform. |
| Teleostei | Order, fam., gen. et. sp. indet. | Manitoba. | Pembina Member. | Mostly vertebrae, but also caudal fins and skulls in some specimens. | |
| Xiphactinus | X. audax | Manitoba and Lyman County, South Dakota. | Pembina Member and middle part of the Sharon Springs Member. | | An ichthyodectid. |

#### Cartilaginous fish

Cartilaginous fish reported from the Pierre Shale Formation :
| Genus | Species | Presence | Stratigraphic position | Material | Notes |
| Archaeolamna | A. kopingensis | Western Kansas. | Sharon Springs Member. | A partial skeleton with articulated teeth. | An archaeolamnid. |
| Cretalamna | C. appendiculata | Manitoba. | Pembina Member. | Vertebral centra. | A megatoothed shark. |
| Euselachii | Fam., gen. et sp. indet. | Near Thornhill, Manitoba. | Pembina Member. | "Three vertebral centra, 15 mm in diameter". | Probably represents Squalicorax, but also indistinguishable from juvenile specimens of Cretalamna. |
| Squalicorax | S. sp. aff. S. kaupi | Manitoba. | Pembina Member. | "MDM S80.01.14 (2 teeth), FMNH PF 5399 (1 tooth)". | An anacoracid. |

### Marine vertebrates

* Gillicus
* Pseudocorax
* Carcharias

### Invertebrates
#### Annelids

Annelids reported from the Pierre Shale Formation :
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
| Diploconcha | D. sp. | Wyoming. | | | | |

#### Arthropods

Arthropods reported from the Pierre Shale Formation :
| Genus | Species | Location | Stratigraphic position | Material | Notes |
| Dioratiopus | D. hearttailensis | Butte County, South Dakota. | Gammon Ferruginous Member. | | A longodromitid crab. |
| Dromiopsis | D. kimberlyae | Butte County, South Dakota. | Lower Pierre Shale. | 2 specimens. | A dynomenid crab. |
| Heus | H. foersteri | Tepee Buttes, South Dakota. | | | A raninid crab. |
| Hoplitocarcinus? | H.? punctatus | Tepee Buttes, Colorado. | | | A crab. |
| Hoploparia | H. mickelsoni | Butte County, South Dakota. | Gammon Ferruginous Member. | | A lobster. |
| Limulus | L. coffini | Fort Collins, Colorado. | Rocky Ridge Sandstone Member. | Thoracetron. | A horseshoe crab. |
| Necrocarcinus | N. davisi | Butte County, South Dakota. | Gammon Ferruginous Member. | | A necrocarcinid crab. |
| Plagiophthalmus | P. bjorki | Tepee Buttes, South Dakota. | | | A prosopid crab. |
| Protocallianassa | P. russelli | Butte County, South Dakota. | Gammon Ferruginous Member. | | A mud shrimp. |
| Raninella | R. manningi | Tepee Buttes, South Dakota. | | | A raninid crab. |
| Raninella | R. oaheensis | Butte County, South Dakota. | Gammon Ferruginous Member. | | A raninid crab. |
| Rugafarius | R. fredrichi | Butte County, South Dakota. | Gammon Ferruginous Member. | | A spiny lobster. |
| Xanthosia | X. elegans occidentalis | Butte County, South Dakota. | Gammon Ferruginous Member. | | A xanthid crab. |
| Zygastrocarcinus | Z. cardsmithi | Carter County, Montana. | Groat Sandstone Bed, Gammon Ferruginous Member. | | A homolid crab. |

#### Bivalves

Bivalves reported from the Pierre Shale Formation :
| Genus | Species | Location | Stratigraphic position | Material | Notes |
| Cataceramus? | C.? barabini | Northeastern New Mexico. | | | An inoceramid. |
| Cataceramus? | C.? cf. C. barabini | Northeastern New Mexico. | | | An inoceramid. |
| Chlamys | C. (Chlamys) nebrascensis | Bowman County, North Dakota. | Probably from the Baculites reesidei Zone. | | A pectinid. |
| Cuspidaria | C. sp. | Bowman County, North Dakota. | | 6 poorly-preserved, broken, decorticated specimens. | A cuspidariid. |
| Cymbophora | C. cf. C. gracilis | Bowman County, North Dakota. | | 9 complete specimens. | A mactrid. |
| Eriphylopsis | E. gregaria | Bowman County, North Dakota. | Probably from the Baculites reesidei Zone. | 40 complete and incomplete specimens. | An astartid. |
| Gervillia | G. sp. | Bowman County, North Dakota. | | One badly decorticated incomplete specimen. | |
| Inoceramus | I. (Endocostea) barabini | Bowman County, North Dakota. | Probably from the Baculites reesidei Zone. | About 25 specimens. | An inoceramid. |
| Inoceramus | I. (Endocostea) fribrosa | Bowman County, North Dakota. | | 4 small incomplete specimens. | An inoceramid. |
| Inoceramus | I. oblongus | West of Cimarron. | | | An inoceramid. |
| Inoceramus | I. sagensis | Bowman County, North Dakota. | | | An inoceramid. |
| Inoceramus | I. (Cremnoceramus) sp. | Bowman County, North Dakota. | | One decorticated incomplete specimen. | An inoceramid. |
| Inoceramus | I. sp. A | Bowman County, North Dakota. | | One specimen that is badly decorticated. | An inoceramid. |
| Inoceramus | I. sp. B | Bowman County, North Dakota. | | One slightly crushed specimen. | An inoceramid. |
| Limopsis | L. parvula | Bowman County, North Dakota. | Probably from the Baculites reesidei Zone. | About 40 specimens. | A limopsid. |
| Lucina | L. (Lucina) occidentalis | Bowman County, North Dakota. | | 14 specimens. | A lucinid. |
| Mactra | M. sp. | Bowman County, North Dakota. | | 4 broken incomplete molds. | A mactrid. |
| Malletia | M. evansi | Bowman County, North Dakota. | Probably from the Baculites reesidei Zone. | "7 badly decorticated incomplete specimens". | A malletiid. |
| Malletia | M. sp. | Bowman County, North Dakota. | Probably from the Baculites reesidei Zone. | 7 small, almost complete specimens. | A malletiid. |
| Modiolus | M. meekii | Bowman County, North Dakota. | Probably from the Baculites reesidei Zone. | 2 small incomplete internal molds. | |
| Nemodon | N. sulcatinus | Bowman County, North Dakota. | Probably from the Baculites reesidei Zone. | One badly weathered internal mold. | A parallelodontid. |
| Nucula | N. sp. | Bowman County, North Dakota. | | "Five badly decorticated incomplete specimens". | A nuculid. |
| Ostrea | O. congesta | Bowman County, North Dakota. | Probably from the Baculites reesidei Zone. | 3 slightly crushed fragments. | An ostreid. |
| Ostrea | O. sp. | Bowman County, North Dakota. | | Numerous fragments. | An ostreid. |
| Protocardia | P. (Leptocardia) rara | Bowman County, North Dakota. | | "10 complete, decorticated specimens". | A cardiid. |
| Pteria | P. linguaeformis | Bowman County, North Dakota. | | About 15 broken specimens. | A pteriid. |
| ?Syncyclonema | ?S. rigida | Bowman County, North Dakota. | | 2 right valves. | An entoliid. |

#### Brachiopods

Brachiopods reported from the Pierre Shale Formation :
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
| Lingula | L. sp. | Wyoming. | Lower unnamed shale member. | | | |

#### Cephalopods

Cephalopods reported from the Pierre Shale Formation :
| Genus | Species | Location | Stratigraphic position | Material | Notes |
| Baculites | B. baculus | New Mexico. | Upper & uppermost Pierre Shale. | | An ammonite. |
| Baculites | B. cf. baculus | Bowman County, North Dakota. | Baculites reesidei Range Zone. | 1 broken specimen. | An ammonite. |
| Baculites | B. compressus | At the Big Bend of the Missouri River, Buffalo County, South Dakota. | Uppermost DeGrey Formation. | | Specimens associated with Globidens schurmanni. |
| Baculites | B. cf. B. eliasi | Northeastern New Mexico. | | | An ammonite. |
| Baculites | B. grandis? | Bowman County, North Dakota. | | One large, crushed, badly weathered specimen. | An ammonite. |
| Baculites | B. reesidei | Bowman County, North Dakota. | Baculites reesidei Zone. | 11 broken specimens. | An ammonite. |
| Baculites | B. sp. | Bowman County, North Dakota. | Upper Baculites reesidei Zone. | 10 broken exfoliated specimens. | An ammonite. |
| Baculites | B. sp. | Northeastern New Mexico. | | | An ammonite. |
| Belemnitella | B. bulbosa | | Upper Pierre Shale. | | A belemnite also found in the Fox Hills Formation. |
| Belemnitella | B.? sp. | Meade County, South Dakota. | Baculites compressus zone. | 1 specimen (BHI-7009). | A belemnite. |
| Didymoceras | D. cochleatum | South Dakota & Wyoming. | Gregory & Red Bird Silty members. | Numerous fragments. | An ammonite. |
| Didymoceras | D. nebrascense | "Northwestern New Mexico through northeastern Montana". | | | An ammonite. |
| Didymoceras | D. sp. | Colfax County, New Mexico. | | | An ammonite. |
| Enchoteuthis | E. cobbani | Meade & Pennington counties, South Dakota. | Baculites cuneatus Zone & possibly the underlying B. compressus Zone. | 2 specimens. | A coleoid, originally described as Tusoteuthis cobbani. |
| Enchoteuthis | E. melanae | Niobrara County, Wyoming. | Baculites obtusus zone, Sharon Springs Member. | Multiple specimens. | A coleoid. |
| Eutrephoceras | E. dekayi | Colorado, Bowman County, North Dakota and Colfax County, New Mexico. | Probably from the Baculites reesidei Zone. | | A nautiloid, one specimen from Colorado showing signs of mosasaur predation. |
| Eutrephoceras | E. montanaensis | Northeastern New Mexico. | | | A nautiloid. |
| Exiteloceras | E. sp. | Bowman County, North Dakota. | | One fragmented body chamber. | A nostoceratid ammonite. |
| Hoploscaphites | H. brevis | Bowman County, North Dakota. | | "Ten almost complete specimens and many fragments of early whorls". | An ammonite. |
| Hoploscaphites | H. crassus | Montana & Wyoming. | | | An ammonite. |
| Hoploscaphites | H. criptonodosus | Montana, Wyoming, Colorado, and possibly South Dakota. | "Upper part of the Baculites baculus Zone and overlying B. grandis Zone". | | An ammonite also found in the Bearpaw Shale. |
| Hoploscaphites | H. macer | Montana, Wyoming & Colorado. | "Upper part of the Baculites baculus Zone and lower part of the overlying B. grandis Zone". | | An ammonite also found in the Bearpaw Shale. |
| Hoploscaphites | H. cf. H. nicolleti | Bowman County, North Dakota. | | 2 specimens. | An ammonite. |
| Hoploscaphites | H. nodosus | Near Raton, New Mexico. | "30-45 m below the top of the Pierre Shale". | | An ammonite. |
| Hoploscaphites | H. peterseni | Montana & Wyoming. | | | An ammonite. |
| Hoploscaphites | H. plenus | Montana, Wyoming & North Dakota. | | | An ammonite. |
| Hoploscaphites | H. quadrangularis | Bowman County, North Dakota. | Probably from the Baculites reesidei Zone. | One broken shaft with aperture. | An ammonite. |
| Hoploscaphites | H. sp. | Bowman County, North Dakota. | | One broken specimen. | An ammonite. |
| Hoploscaphites | H. sp. | Colfax County, New Mexico. | | | An ammonite. |
| Jeletzkytes | J. nodosus | At the Big Bend of the Missouri River, Buffalo County, South Dakota. | Uppermost DeGrey Formation. | | Specimens associated with Globidens schurmanni. |
| Placenticeras | P. intercalere | Bowman County, North Dakota. | | "One decorticated specimen badly fractured by calcite crystal growth". | An ammonite. |
| Placenticeras | P. meeki | Colfax County, New Mexico and Bowman County, North Dakota. | Baculites reesidei Zone. | | An ammonite. |
| Placenticeras | P. newberryi | Colfax County, New Mexico. | | | An ammonite. |
| Ponteixites | P. robustus | Eastern Montana. | | | Now a junior synonym of Rhaeboceras. |
| Rhaeboceras | R. burkholderi | Dawson County, Montana. | Upper part of the Pierre Shale (Baculites eliasi zone). | | An ammonite. |
| Rhaeboceras | R. cedarense | Dawson County, Montana. | Baculites baculus/grandis zone. | | An ammonite. |
| Rhaeboceras | R. robustus | Eastern Montana. | | | An ammonite. |
| Scaphites | S. nodosus | Near Raton. | "About 15 m below the top of the Pierre Shale". | | An ammonite. |
| Solenoceras | S. sp. | Bowman County, North Dakota. | | 3 fragmented specimens. | A nostoceratid ammonite. |
| Tusoteuthis | T. cobbani | Meade & Pennington counties, South Dakota. | Baculites cuneatus Zone & possibly the underlying B. compressus Zone. | 2 specimens. | Moved to the genus Enchoteuthis. |
| Tusoteuthis | T. longa | South Dakota. | Baculites compressus Zone. | | A coleoid. |

#### Echinoderms

Echinoderms reported from the Pierre Shale Formation :
| Genus | Species | Location | Stratigraphic position | Material | Notes |
| Betelgeusia | B. brezinai | Pennington County, South Dakota. | Didymoceras cheyennensis Zone. | | A starfish. |
| Brezinacantha | B. tolis | Pennington County, South Dakota. | Didymoceras cheyennensis Zone. | Multiple specimens. | A brittle star. |
| Coulonia | | Southern Colorado. | Top of the Pierre Shale. | | An astropectinid starfish. |
| Eurysalenia | E. minima | Wyoming. | | | A sea urchin. |
| Lakotacrinus | L. brezinai | South Dakota. | | | A crinoid. |
| Pedicellasterinae? | Gen. et. sp. indeterminate | Pennington County, South Dakota | Didymoceras cheyennensis zone. | One small arm fragment (AMNH-FI 111853). | A starfish. |

#### Gastropods

Gastropods :
| Genus | Species | Location | Stratigraphic position | Material | Notes |
| Anchura? | A.? sp. | Bowman County, North Dakota. | Probably from the Baculites reesidei Zone. | "One broken, badly decorticated, medium-sized specimen". | |
| Anisomyon | A. sexsulcatus? | Bowman County, North Dakota. | Probably from the Baculites reesidei Zone. | "One badly decorticated specimen that is essentially an internal mold". | A siphonariid. |
| Anisomyon | | At the Big Bend of the Missouri River, Buffalo County, South Dakota. | Uppermost DeGrey Formation. | | A siphonariid, specimens associated with Globidens schurmanni. |
| Atira | A. nebrascensis | Bowman County, North Dakota. | Probably from the Baculites reesidei Zone. | 3 decorticated specimens. | |
| Cylichna | C. sp. | Bowman County, North Dakota. | "Baculites reesidei Zone". | "One weathered specimen so badly decorticated that it is essentially a mold of the interior". | |
| Cylindrotruncatum | C. cf. C. demursum | Bowman County, North Dakota. | Probably from the Baculites reesidei Zone. | "One, small, broken, badly decorticated specimen". | |
| Cylindrotruncatum | C. sp. | Bowman County, North Dakota. | Probably from the Baculites reesidei Zone. | "Two medium-sized specimens; one in excellent condition and one internal mold". | |
| Drepanochilus | D. sp. | Bowman County, North Dakota. | Probably from the Baculites reesidei Zone. | Approximately 20 specimens. | |
| Euspira | E. obliquata | Bowman County, North Dakota. | Baculites reesidei Zone. | 25 nearly complete specimens. | |
| Euspira | E. rectilabrum | Bowman County, North Dakota. | Probably from the Baculites reesidei Zone. | 4 fairly complete shells. | |
| Pyrifuses | P. sp. | Bowman County, North Dakota. | | 1 weathered external mold. | |
| Striaticostatum? | S.? sp. | Bowman County, North Dakota. | Baculites reesidei Zone. | One specimen. | |
| Turritella | T. macnaryensis? | Bowman County, North Dakota. | Probably from the Baculites reesidei Zone. | 2 specimens. | |

#### Scaphopods

Scaphopods reported from the Pierre Shale Formation :
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
| Dentalium | D. gracile | Bowman County, North Dakota. | "Probably from the Baculites reesidei Zone". | "3 nearly complete specimens & numerous fragments". | | |