| The black, oval to elongated structures embedded in the limestone matrix are fossil algae nodules, called Girvanella, from the Lower Cambrian section of the Lower to Middle Cambrian Carrara Formation, Echo Canyon, Death Valley National Park. |
| The black, oval to elongated structures embedded in the limestone matrix are fossil algae nodules, called Girvanella, from the Lower Cambrian section of the Lower to Middle Cambrian Carrara Formation, Echo Canyon, Death Valley National Park. |