The Rancholabrean North American Land Mammal Age on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), [1] Named after the famed Rancho La Brea fossil site (more commonly known as the La Brea tar pits) in Los Angeles, California,[2] the Rancholabrean is characterized by the presence of the genus Bison, which appeared in northwestern North America during the Illinoian (globally known as the Penultimate Glacial Period or Marine Isotope Stage 6) around 190-130,000 years ago, before becoming established across North America during the Sangamonian (globally known as the Last Interglacial) around 130-115,000 years ago.[3] The age of the Rancho is usually considered to overlap the late Middle Pleistocene and Late Pleistocene epochs. The Rancholabrean is preceded by the Irvingtonian NALMA stage, and it is succeeded by the Santarosean age.[4] The Rancholabrean ended around 14-12,000 years ago at the end of the Pleistocene.
The Rancholabrean can be further divided into the substages of the Sheridanian: Upper boundary source of the base of the Holocene (approximate)[5]
On other continents, the Rancholabrean shares this time period with the Oldenburgian of European Land Mammal Ages, and the latter Lujanian of the South American Land Mammal Ages.
References
edit- ^ 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
- ^ 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
- ^ Froese, Duane; Stiller, Mathias; Heintzman, Peter D.; Reyes, Alberto V.; Zazula, Grant D.; Soares, André E. R.; Meyer, Matthias; Hall, Elizabeth; Jensen, Britta J. L.; Arnold, Lee J.; MacPhee, Ross D. E.; Shapiro, Beth (2017-03-28). "Fossil and genomic evidence constrains the timing of bison arrival in North America". Proceedings of the National Academy of Sciences. 114 (13): 3457–3462. Bibcode:2017PNAS..114.3457F. doi:10.1073/pnas.1620754114. ISSN 0027-8424. PMC 5380047. PMID 28289222.
- ^ Barnosky, Anthony D; Holmes, Michael; Kirchholtes, Renske; Lindsey, Emily; Maguire, Kaitlin C; Poust, Ashley W; Stegner, M Allison; Sunseri, Jun; Swartz, Brian; Swift, Jillian; Villavicencio, Natalia A (2014-12-01). "Prelude to the Anthropocene: Two new North American Land Mammal Ages (NALMAs)". The Anthropocene Review. 1 (3): 225–242. Bibcode:2014AntRv...1..225B. doi:10.1177/2053019614547433. ISSN 2053-0196.
- ^ Paleobiology Database, Sheridanian substage