Zanthopsis vulgaris   scale in cms CLASS - Malacostraca ORDER - Decapoda FAMILY - Xanthidae GENUS/SPECIES - Hepatus epheliticus ROCK UNIT - Keasey Formation AGE - Oligocene Epoch (40 million years old) LOCALITY - Vernonia, Oregon, USA Fossil crabs are rare in the fossil record, but many are preserved in the small concretions of the Keasey Formation. These concretions erode from the sea cliffs of the northern Oregon coast and are ready for inspection by cracking them open. PRI 42152