| An ammonite--genus Nevadaphylites sp.--from the oldest limestone layers of the lower Jurassic Sunrise Formation, Ammonite Canyon, Nevada--from the earliest parts of Hettangian Stage of the Jurassic Period, roughly 198 million years ago. |
| An ammonite--genus Nevadaphylites sp.--from the oldest limestone layers of the lower Jurassic Sunrise Formation, Ammonite Canyon, Nevada--from the earliest parts of Hettangian Stage of the Jurassic Period, roughly 198 million years ago. |