Cruziana sp.
Cruziana are the trials made by a Trilobite walking along the sea bed. It consists of numerous paired scratch marks or grooves left by the walking appendages. Text book example from the most famous Welsh locality for these trace fossils.
Ordovician, Arenig Series. Granianog Sandstone.
Cwm Granianog west side of Nant Ffrancon, Gwynedd, North Wales.
Cruziana : 12.8 cm long.