The Hemphillian North American Stage on the geologic timescale is the North American faunal stage

Faunal stage

In chronostratigraphy, a stage is a succession of rock strata laid down in a single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by convention have the same name, and the same boundaries.Rock...

 according to the North American Land Mammal Ages

North American Land Mammal Ages

The North American Mammal Ages establishes a geologic timescale for prehistoric North American fauna beginning 66.5 Ma during the Paleocene and continuing through to the Late Pleistocene...

 chronology (NALMA), typically set from 10,300,000 to 4,900,000 years BP

Before Present

Before Present years is a time scale used in archaeology, geology, and other scientific disciplines to specify when events in the past occurred. Because the "present" time changes, standard practice is to use AD 1950 as the origin of the age scale, reflecting the fact that radiocarbon...

, a period of . It is usually considered to overlap the Tortonian

Tortonian

The Tortonian is in the geologic timescale an age or stage of the late Miocene that spans the time between 11.608 ± 0.005 Ma and 7.246 ± 0.005 Ma . It follows the Serravallian and is followed by the Messinian....

 epoch of the Late Miocene

Late Miocene

The Late Miocene is a sub-epoch of the Miocene Epoch made up of two stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch....

 and Zanclean

Zanclean

The Zanclean is the lowest stage or earliest age on the geologic time scale of the Pliocene. It spans the time between 5.332 and 3.6 Ma ± 0.005 Ma . It is preceded by the Messinian age of the Miocene epoch, and followed by the Piacenzian age....

 epoch of the Early Pliocene. The Hemphillian is preceded by the Clarendonian

Clarendonian

The Clarendonian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology , typically set from 13,600,000 to 10,300,000 years BP, a period of . It is usually considered to overlap the Serravallian of the Middle...

 and followed by the Blancan

Blancan

The Blancan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology , typically set from 4,750,000 to 1,808,000 years BP, a period of .. It is usually considered to start in the early-mid Pliocene epoch and end...

NALMA stages.

The Hemphillian can be further divided into the substages of:

• Late/Upper Hemphillian: Lower boundary source of the base of the Hemphillian (approximate).
• late Early Hemphillian: Lower boundary source of the base of the Hemphillian (approximate). Upper boundary source: base of Blancan (approximate).
• early Early Hemphillian: Upper boundary source: base of Blancan (approximate).