Didymograptus murchisoni are popular graptolite fossils, mainly because these particular specimens are so easily visible within their shale matrix when compared to other species, even when viewed with the naked eye. Graptolites were small colonial marine animals, believed to have been filter feeders, their name is derived from the Greek words, 'Graptos' meaning written, and 'Lithos' meaning rock, an allusion to the fact that upon first glance, these fossils will actually look like they have been drawn on to the rock. This particular species is of didymograptus murchisoni and is well known because of its tuning fork shape due to its double stipe. They are of Ordovician age, specifically the Llanvirn series making them between 478 to 471 million years, found in their name sake series, the Murchisoni zone, they come from Abereiddy Bay, Wales, UK. The specimens vary slightly in size, but on average are 60 x 50 mm with the matrix, with the actual fauna varying in size on the shale, the pieces will come supplied in a card tray with an information label.