Description: This unusual specimen has trilobitomorph features, and has as yet not been described in the literature. It is thought to have affinities with the Burgess Shale genus Emeraldella, but has a broader aspect than examples I have posted (see my other offerings). Notice that the pointed tail spine is present, a feature not always preserved with either the Trilobitomorphs or the Aglaspidids of the region. The most unusual component is the presence of much of the segmented antennae, a feature I have never seen on any of the specimens I have had to date. Any collector of Cambrian fossils from Utah would be pleased to add such an exceptional example.

Briggs D.E.G., and R.A. Robison. 1984. Exceptionally preserved non trilobite arthropods and Anomalocaris from the Middle Cambrian of Utah. University of Kansas Paleontological Contributions, Paper 111:1-24.