Gravicalymene arcuata trilobite fossil collected within the Dolhir Formation, near Corwen, North Wales. This trilobite is of upper Ordovician age - more specifically within the Ashgill series of the Ordovician period - 443 to 449 million years ago. This particular example has been slightly distorted however the main features are still well preserved. The specimen is 0.8 x 0.6 cm in dimension and is held within a pale siltstone matrix is. It is provided in a small plastic bag with an information label.