The Chadronian age within the North American Land Mammal Ages chronology is the North American

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 convent ...

typically set from 38,000,000 to 33,900,000 years BP, a period of .Paleobiology Database, Chadronian
/ref> It is usually considered to fall within the

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

epoch. The Chadronian is preceded by the

Duchesnean The Duchesnean North American Stage on the geologic timescale is a North American Land Mammal Age (NALMA), with an age from 42 to 38 million years BP, representing . It falls within the Eocene epoch. The Duchesnean is preceded by the Uintan and ...

and followed by the

Orellan The Orellan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), 34-32 million years ago. It is usually considered to fall within the Early Oligocene. ...

NALMA stages. The Chadronian can be further divided into the substages of: *Late/Upper Chadronian (shares upper boundary). Lower boundary source of the base of the Priabonian (approximate) *Middle Chadronian. Lower boundary source and base of the Priabonian (approximate). Upper boundary source of the base of the Orellan (approximate). *Early/Lower Chadronian (shares lower boundary). Upper boundary source: base of Orellan (approximate).

Geological time

The Chadronian maintains a period of time within the Priabonian through

Rupelian The Rupelian is, in the geologic timescale, the older of two ages or the lower of two stages of the Oligocene Epoch/ Series. It spans the time between . It is preceded by the Priabonian Stage (part of the Eocene) and is followed by the Chattian ...

of the Late Eocene through Early Oligocene in the

geologic time scale The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochr ...

References

Eocene life Eocene animals of North America {{geochronology-stub