This is a fabulous Bumastus ioxus from the Rochester Shale of New York. This trilobite is very 3-dimensional, extremely prone, and nicely articulated - both free cheeks are even intact. The dark trilobite contrasts beautifully with the grey matrix. The bug is very well showcased on the plate of dense shale. And at almost one and a half inches long, it is large for a Bumastus from this site. This is a top quality example of this classic Silurian trilobite.