Cluster Agnostid "Trilobites" (Peronopsis) - Wheeler Shale, Utah

Agnostids were small, blind arthropods that thrived during the Middle Cambrian period. They've typically been classified as an order of trilobites, though there is ongoing debate about whether they truly belong as trilobites, or a separate stem group. This is a cluster of about a dozen of them from the Wheeler Shale in Utah which has been cleaned with air abrasives. There is a negative impression of a large, Elrathia kingii trilobite on the back of the piece.