| Clue | Source | Date |
|---|---|---|
| Geologic period between the Ordovician and Devonian periods of the Palaeozoic era (8) | Mirror Quiz | 18 Aug 2025 |
| Fancy urinal is of a certain period | ||
| Period when the first true fish appeared | The Times Concise | 05 Jun 2017 |
| Period in which early invertebrate land animals appeared | ||
| Geological era | ||
| Of a geological period. |