| Identification: Cycadeoidea sp. |
| Common Name: Petrified stem of extinct tree |
| Kingdom: Plantae (Green Plants) |
| Phylum: Tracheophyta (Vascular Plants) |
| Class: Cycadopsida |
| Family: Cycadeoidaceae |
| Location: United States |
| Rock Unit/Stratigraphy: |
| Geologic Time Frame: Cretaceous Period |
| Estimated age: Approximately 125 million years before present |
| Significance: Cycadeoid fossils have no known living descendant, but evidence suggests they might be closely related to flowering plants. |
| Other notable fact: Cycadeoids were the predominant fossil in currently the only national monument that has ever been decommissioned, Fossil Cycad National Monument in South Dakota. It was decommissioned due to absence of fossils due to overcollecting. |
