This trilobite is a rare Archaeaspis macropleuron from the Lower Cambrian of Nevada. This species was also known informally as Eofallotaspis and as the "oldest trilobite". How ever Archaeaspis is certainly one of the oldest trilobites in the USA.
And the genus Archaeaspis in particular shows some characteristics of the Redlichiidae and the Olenellidae. In general, the Fallotaspididae represent a very primal trilobite family. In addition to the Redlichiidae and Olenellidae, the Corynexochidae, Ellipsocephaloidea and Yunnanocephalidae are likely to have emerged from them. This specimen is a decorative and rare example of this extremely interesting trilobite.
Esmeralda County, Nevada, USA
about 15 mm long
Lower Cambrian , Montenegro Member, Campito Formation , Fallotaspis Zone