| This is a rather robust undescribed ptychopariid trilobite cephalon/head shield from the Lower Cambrian Harkless Formation, Esmeralda County, Nevada; reddish-brown staining of specimen is by naturally occurring iron oxides. |
| This is a rather robust undescribed ptychopariid trilobite cephalon/head shield from the Lower Cambrian Harkless Formation, Esmeralda County, Nevada; reddish-brown staining of specimen is by naturally occurring iron oxides. |