Harpidella misera, Silurian trilobite fossil. Trilobites were arthropods that fed as they crawled on the seabed. They lived between 500 and 300 million years ago and are now extinct. This specimen dates from the Upper Silurian, and was found in the Ludlovian Series, in the Kopanina Formation, in Kosov Quarry, near Beroun, Czech Republic, Czech Republic. The two forms of the fossil seen here are the positive and negative impressions obtained from the fossil site. This specimen is 1 centimetre long.