This is an exceptional Triarthrus eatoni from the Whetstone Gulf Formation in Lewis County, New York. There are only a few locations in the world where trilobites are preserved with soft body parts and not just an empty shell. It is even rarer to find soft body preservation with pyrite (iron sulphide or fool’s gold). Preservation of pyritized trilobites with their legs, gills and antennae happened under extremely specialized environmental conditions. The trilobites were rapidly buried in mud which was low in organic matter, lacked oxygen but were rich in highly reactive iron.
The mudstone bed where these gorgeous trilobites were collected is only about 4 – 10 centimetres thick! It is very probably that future specimens of pyritized trilobites with soft body preservation will be extremely difficult to find and that the thin layers will soon run out. Don’t miss out on their opportunity to get one of these unique treasures in the fossil world.
Specimen measures 10 millimetres. It is preserved ventrally (from the underside).