Here is a very rare fossil crab. This is a Carinaranina sp. from the Oligocene of Washington. This type of crab has a very long and narrow carapace (similar to a ''Sand Flea''), with a wonderfully punctate texture that is beautifully displayed on this specimen. This unusual crab is well preserved in half a concretion. The extremely tough matrix has been painstakingly removed from the top of the crab to showcase the 3-dimensional specimen. The fossil has excellent color and contrast and is almost perfectly centered in the concretionary matrix. This is a wonderful example of this highly collectible arthropod from the Oligocene.