| Here is a inexpensive trilobite of the species Gravicalymene arcuata from the upper Ordovician of Wales. | |||
| Location: | Cynwyd / Corwen , N. Wales | ||
| Size trilobite: | about 17 mm wide | ||
| Age: | Ordovician, Ashgill, Katian, Rawtheyan, Dolhir Beds (about. 449 Mill. Years) | ||