TheHemingfordian on thegeologic timescale is the North Americanfaunal stage according to theNorth American Land Mammal Ages chronology (NALMA), typically set from 20,600,000 to 16,300,000 yearsBP.^[1] It is usually considered to overlap the latestAquitanian andBurdigalian of theEarly Miocene. The Hemingfordian is preceded by theArikareean and followed by theBarstovian NALMA stages.

The Hemingfordian can be further divided into the substages of:

• Late/Upper Hemingfordian: Lower boundary source: base ofBurdigalian (approximate).
• Early/Lower Hemingfordian (shares lower boundary)