Hi there, I have an old trilobite that I bought 20 years ago as a pre-teen that I have now completely forgotten all details of. I remember it was from a US locality, definitely a cambrian age trilobite. It's pretty small, measuring about 7 - 8 mm.
Looking at it now I think it's a Zacanothoides or Olenellus but I cant be sure. It has a long genal spine and what looks to be an impression of another spine at the tip of its pygidium.
As a bonus, if anyone recognizes the locality from the look of the matrix that would be awesome. I was thinking Pioche Formation in Nevada but could be wrong.