The Arikareean North American Stage on the
geologic timescale
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 geochronol ...
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 ...
according to the
North American Land Mammal Ages
The North American land mammal ages (NALMA) establishes a geologic timescale for North American fauna beginning during the Late Cretaceous and continuing through to the present. These periods are referred to as ages or intervals (or stages when ref ...
chronology (NALMA), typically set from 30,600,000 to 20,800,000 years
BP, a period of . It is usually considered to overlap the
Oligocene
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...
and
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...
epochs. The Arikareean is preceded by the
Whitneyan
The Whitneyan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 33,300,000 to 30,800,000 years BP, a period of . It is usual ...
and followed by the
Hemingfordian
The Hemingfordian on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 20,600,000 to 16,300,000 years BP. It is usually considered to overlap the lates ...
NALMA stages.
The Arikareean can be further divided into the substages of:
*late Late Arikareean: Lower boundary source, base of
Geringian
The Geringian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 30,800,000 to 26,300,000 years BP, a period of . It is usual ...
(approximate)
Paleobiology Database Late Arikareean
/ref>
*early Late Arikareean: base of Geringian (approximate). Upper boundary source: base of Hemingfordian (approximate).
*late Early Arikareean: Lower boundary source of base of Geringian (approximate). Upper boundary source of base of Hemingfordian (approximate).
*early Early Arikareean (shares lower boundary): Upper boundary source of base of Hemingfordian (approximate).
References
Miocene geochronology
Oligocene geochronology
Miocene life
Oligocene life
Miocene animals of North America
Oligocene animals of North America
Miocene Series of North America
Oligocene Series of North America
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