| Trilobites from the Lower Cambrian Harkless Formation, Esmeralda County, Nevada. Assigned to the genus-species Perrisopyge triangulata. Photograph courtesy a specific scientific publication. |
| Trilobites from the Lower Cambrian Harkless Formation, Esmeralda County, Nevada. Assigned to the genus-species Perrisopyge triangulata. Photograph courtesy a specific scientific publication. |