| Phylum: Mollusca Class: Bivalvia (Pelecypoda) High Resolution Image Location: Tucson Mountains Age: Pennsylvanian Formation: Horquilla Limestone |  |
| Phylum: Brachiopoda Class: Articulata Order: Spiriferidea Spiriferid Valve with hinge Age: Pennsylvanian Formation: Horquilla Limestone High Resosution Image |  |
| Phylum: Brachiopoda Class: Articulata Order: Spiriferidea Spiriferid Brachiopod Age: Pennsylvanian Formation: Horquilla Limestone High Resosution Image |  |
| Phylum: Brachiopoda Brachiopod Age: Pennsylvanian Formation: Horquilla Limestone High Resosution Image |  |
| Phylum: Brachiopoda Brachiopods Age: Pennsylvanian Formation: Horquilla Limestone High Resosution Image |  |
| Phylum: Assorted Assorted Pennsylvanian Fossils Location: Tucson Mountains. Age: Pennsylvanian Formation: Horquilla Limestone High Resolution Image |  |
| Phylum: Assorted Assorted Pennsylvanian Fossils Location: Tucson Mountains. Age: Pennsylvanian Formation: Horquilla Limestone High Resolution Image |  |
| Phylum: Assorted Assorted Pennsylvanian Fossils Location: Tucson Mountains. Age: Pennsylvanian Formation: Horquilla Limestone High Resolution Image |  |