Rare Pyritized Trilobites
This is an absolutely extraordinary fossil with eight rare Triarthrus eatoni trilobites preserved on a single slab. Finding this many pyritized Triarthrus on a single slab is exceedingly unusual. This special piece comes from the Late Ordovician shale of 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! Likely, 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 the opportunity to get one of these unique treasures of the fossil world.
Largest specimen is preserved dorsally (from above) and measures 1.9 cm (not including antennae - very sizeable for this species).
Next to this beautiful trilobite is one more small dorsal specime and 6 ventral specimens (preserved from the side / underside). Matrix measures 5.9 x 5.5 x 1.1 inches / 15 cm x 14 cm x 2.9.
Learn more about pyritized Triarthrus trilobites, including how they are discovered and prepared. Find out interesting general facts about trilobite fossils here. Follow this link to learn how fossils become pyritized.