The Rancholabrean North American Land Mammal Age 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 geochr ...

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 chronology (NALMA), typically set from less than 240,000 years to 11,000 years BP, a period of .Sanders, A.E., R.E. Weems, and L.B. Albright III (2009) Formalization of the mid-Pleistocene "Ten Mile Hill beds" in South Carolina with evidence for placement of the Irvingtonian–Rancholabrean boundary, ''Museum of Northern Arizona Bulletin'' 64:369-375 Named after the famed

Rancho La Brea Rancho La Brea was a Mexican land grant in present-day Los Angeles County, California, given in 1828 to Antonio Jose Rocha and Nemisio Dominguez by José Antonio Carrillo, the alcalde of Los Angeles. Rancho La Brea consisted of one square le ...

fossil site (more commonly known as the La Brea tar pits) in Los Angeles, California,Savage, D.E. (1951) Late Cenozoic vertebrates of the San Francisco Bay region, ''University of California Publications, Bulletin of the Department of Geological Sciences'' 28:215-314 the Rancholabrean is characterized by the presence of the genus '' Bison'' in a Pleistocene context, often in association with other extinct Pleistocene forms such as ''

Mammuthus A mammoth is any species of the extinct elephantid genus ''Mammuthus'', one of the many genera that make up the order of trunked mammals called proboscideans. The various species of mammoth were commonly equipped with long, curved tusks and, i ...

''. The age is usually considered to overlap the late

Middle Pleistocene The Chibanian, widely known by its previous designation of Middle Pleistocene, is an age in the international geologic timescale or a stage in chronostratigraphy, being a division of the Pleistocene Epoch within the ongoing Quaternary Period. The ...

and

Late Pleistocene The Late Pleistocene is an unofficial Age (geology), age in the international geologic timescale in chronostratigraphy, also known as Upper Pleistocene from a Stratigraphy, stratigraphic perspective. It is intended to be the fourth division of ...

epochs. The Rancholabrean is preceded by the Irvingtonian NALMA stage, and it is succeeded by the Santarosean age. The Rancholabrean can be further divided into the substages of the Sheridanian: Upper boundary source of the base of the

Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togethe ...

(approximate) By another terminology, it can be split into two sub-intervals, ''Ra1'' from 250,000 to 115,000 years ago, and ''Ra2'' from 115,000 to 12,000 years ago. On other continents, the Rancholabrean shares this time period with the Oldenburgian of

European Land Mammal Ages The European Land Mammal Mega Zones (abbreviation: ELMMZ, more commonly known as European land mammal ages or ELMA) are zones in rock layers that have a specific assemblage of fossils (biozones) based on occurrences of fossil assemblages of Europe ...

, and the latter

Lujanian The Lujanian age is a South American land mammal age within the Pleistocene and Holocene epochs of the Neogene, from 0.8–0.011 Ma or 800–11 tya. It follows the Ensenadan. The age is usually divided into the middle Pleistocene Bonaerian stag ...

of the

South American Land Mammal Ages The South American land mammal ages (SALMA) establish a geologic timescale for prehistoric South American fauna beginning 64.5 Ma during the Paleocene and continuing through to the Late Pleistocene (0.011 Ma). These periods are referred to as age ...

References

{{Quaternary Footer Pleistocene life Middle Pleistocene Late Pleistocene Pleistocene animals of North America Pleistocene California Geology of Los Angeles County, California