| Fossil freshwater pelecypods, genus Pisidium sp. from the Upper Pleistocene Sehoo Formation, Nevada; specimens are roughly 20,000 years old. Size of specimens, left to right: 13mm, 15mm, 12mm. |
| Fossil freshwater pelecypods, genus Pisidium sp. from the Upper Pleistocene Sehoo Formation, Nevada; specimens are roughly 20,000 years old. Size of specimens, left to right: 13mm, 15mm, 12mm. |