early Early Hemphillian subage - late Early Hemphillian subage
9.4 - 4.7 Ma
| International Chronostratigraphic Timescale | North American Mammal Subages/Zones | |||
|---|---|---|---|---|
| 1.4 | ||||
| Neogene | Pliocene | Piacenzian | Senecan/Rexroadian | 2.58 |
| Zanclean | 3.6 | |||
| Late Hemphillian/late Early Hemphillian/early Early Hemphillian | 4.7 | |||
| Miocene | Messinian | 5.333 | ||
| Tortonian | 7.246 | |||
| Late Clarendonian/Early Clarendonian | 9.4 | |||
| Serravallian | 11.63 | |||
| late Late Barstovian/early Late Barstovian/Early Barstovian | 12.5 | |||
| Langhian | 13.82 | |||
| Burdigalian | 15.98 | |||
| Late Hemingfordian/Early Hemingfordian | 16.3 | |||
| late Late Arikareean/early Late Arikareean/late Early Arikareean/early Early Arikareean/Harrisonian | 18.5 | |||
| Aquitanian | 20.44 | |||
| 23.03 * | ||||
| 23.1 | ||||
| 29.5 | ||||