Flexicalymene meeki scale in cm CLASS - Trilobita ORDER - Phacopid FAMILY - Calymenidae GENUS/SPECIES - Flexicalymene meeki ROCK UNIT - Richmond Formation AGE - Late Ordovician (445 million years old) LOCALITY - Mt. Orab, Ohio, USA These trilobites are preserved in a weak shale which wears away easily to expose these beautiful fossils. It's no wonder that the Cincinnati area (where these and thousands of other trilobites have been collected) is one of the most popular areas for fossil collecting in the United States. Take a closer look. PRI 42098