2.5" Oligocene Fossil Crab (Branchioplax) - Washington State

This is a partial example of the Oligocene aged fossil crab Branchioplax washingtoniensis. These crabs are found within hard concretions or nodules that weather out of the Hoko River Formation in Clallam County, Washington. Preparing these concretions is a time consuming and skilled task due to the hardness of the stone.

The majority of the concretion has been prepped away from this crab. The legs were missing but both claws remained intact.

Below is an example of a Pulalius vulgaris crab in its concretion after having been broken open with a sledge hammer, prior to preparation.