From Wikipedia - Reading time: 5 minThis article contains a list of fossil-bearing stratigraphic units in the state of Wisconsin, U.S.
| Group or Formation | Period | Notes |
|---|---|---|
| Black River Group/Platteville Formation | Ordovician | |
| Black River Group/Platteville Limestone | Ordovician | |
| Brandon Bridge Formation | Silurian | |
| Byron Formation | Silurian | |
| Decorah Formation | Ordovician | |
| Decorah Shale | Ordovician | |
| Dresbach Formation | Cambrian | |
| Franconia Formation | Cambrian | |
| Galena Formation | Ordovician | |
| Galena Dolomite | Ordovician | |
| Galena Group/Dubuque Formation | Ordovician | |
| Galena Group/Dunleith Formation | Ordovician | |
| Galena Group/Guttenberg Formation | Ordovician | |
| Galena Group/Ion Formation | Ordovician | |
| Galena Group/Spechts Ferry Formation | Ordovician | |
| Galena Group/Wise Lake Formation | Ordovician | |
| Glenwood Formation | Ordovician | |
| Grand Detour Formation | Ordovician | |
| Guttenberg Formation | Ordovician | |
| Ion Formation | Ordovician | |
| Jordan Sandstone | Cambrian | |
| Lake Church Formation | Devonian | |
| Manistique Formation | Silurian | |
| Maquoketa Formation | Ordovician | |
| Maquoketa Group/Brainard Shale Formation | Ordovician | |
| Maquoketa Group/Fort Atkinson Formation | Ordovician | |
| Maquoketa Group/Fort Atkinson Limestone | Ordovician | |
| Maquoketa Group/Neda Formation | Ordovician | |
| Maquoketa Group/Scales Shale Formation | Ordovician | |
| Mayville Formation | Silurian | |
| Mifflin Formation | Ordovician | |
| Milwaukee Formation | Devonian | |
| Nachusa Formation | Ordovician | |
| Oneota Formation | Ordovician | |
| Pecatonica Formation | Ordovician | |
| Platteville Formation | Ordovician | |
| Platteville Group/Grand Detour Formation | Ordovician | |
| Platteville Group/McGregor Formation | Ordovician | |
| Platteville Group/Mifflin Formation | Ordovician | |
| Platteville Group/Pecatonica Formation | Ordovician | |
| Platteville Group/Quimbys Mill Formation | Ordovician | |
| Potsdam Sandstone | Cambrian | |
| Prairie du Chien Group | Ordovician | |
| Quimbys Mill Formation | Ordovician | |
| Racine Formation | Silurian | |
| Racine Dolomite | Silurian | |
| Spechts Ferry Formation | Ordovician | |
| St. Peter Sandstone | Ordovician | |
| Trempealeau Formation | Cambrian | |
| Waukesha Formation | Silurian | |
| Waukesha Dolomite | Silurian |