| "Cast of a hook-shaped horizontal burrow preserved on the underside of a siltstone lens." Figure 9B. From the Lower Cambrian Pyramid Shale Member of the Carrara Formation, Titantothere Canyon section, Grapevine Mountains, Death Valley National Park. |
Trace Fossils Figured In United States Geological Survey Professional Paper 1047, Physical Stratigraphy and Trilobite Biostratigraphy of the Carrara Formation (Lower And Middle Cambrian) in the Southern Great Basin by Allison R. Palmer and Robert B. Halley, 1979
| "Cast of a hook-shaped horizontal burrow preserved on the underside of a siltstone lens." Figure 9B. From the Lower Cambrian Pyramid Shale Member of the Carrara Formation, Titantothere Canyon section, Grapevine Mountains, Death Valley National Park. |