Prepare Your Own Fossil Crab Concretion - Washington State

This is a Late Eocene aged nodule/concretion collected after eroding away from the Lincoln Creek Formation in Grays Harbor County, Washington State. It shows an exposed carapace of the species Branchioplax washingtoniensis. The nodule measures 3.2" long and the fossil could either be left as is or further exposed.

Note: Preparing these concretions can be quite time consuming and will typically require the use of an air scribe or air abrasives due to the hardness of the stone.

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