| An archaeocyathid (early, extinct calcareous sponge) from the Lower Cambrian Poleta Formation, Waucoba Spring, Death Valley National Park. Note distinctive hollow body chamber exposed along right side of the limestone chunk. |
| An archaeocyathid (early, extinct calcareous sponge) from the Lower Cambrian Poleta Formation, Waucoba Spring, Death Valley National Park. Note distinctive hollow body chamber exposed along right side of the limestone chunk. |