This is an Exceptional example of a Pyritized Double Triarthrus Eatoni Trilobite from Lewis County, New York.
Pyritized Trilobites are rare and in most cases exhibit soft tissue preservation as pyrite replacement.
This is a Natural Double Triarthrus Eatoni trilobite block, the second trilobite is in the picture at the 26mm mark on the ruler. Because soft tissue preservation is so rare, these trilobites are highly sought after. These trilobites are generally very small. In this block there is one small trilobite and one large size for the species. These trilobites come form the rich layers originally worked and described by Beecher. Because of his work we now know more about these trilobites and their soft tissue replacement.
The Double Triarthrus Eatoni were found in Whetstone Gulf Formation of Lewis County, New York.
Because of the deposits they are found in, they appear to have lived on the deep sea floor and these environments with little oxygen was perfect for fossilization. But in one of these places in the Frankfort Formation, called Beecher’s Trilobite Bed, Pyrite has delicately preserved Triarthus to the point of soft tissue preservation.
The large one is 1 inch long with antennae and the smaller one is just over 1/4 inch. They sit on a dark gray rock roughly triangular 2 1/2 inches by 6 inches. The attached photograph is of the larger trilobite.