Irvingtonian
TheIrvingtonian North American Land Mammal Ageon thegeologic timescaleis the North Americanfaunal stageaccording to theNorth American Land Mammal Ageschronology (NALMA), spanning from 1.8 million – 250,000 yearsBP.[1][2]Named after an assemblage of fossils from theIrvington DistrictofFremont, California,[3]the Irvingtonian is usually considered to overlap theLower PleistoceneandMiddle Pleistoceneepochs. The Irvingtonian is preceded by theBlancanand followed by theRancholabreanNALMAstages.
The Irvingtonian can be further divided into substages:
- Irvingtonian I - approximately 1.9 MA TO 0.85 MA
- Irvingtonian II - approximately 0.85 MA TO 0.4 MA
- Irvingtonian III - approximately 0.4 MA TO 0.25 MA[1]
The beginning of the Irvingtonian is defined by the first appearance ofMammuthussouth of 55° N in North America, and the beginning of the succeeding Rancholabrean is defined by the first appearance ofBison.[4]
In South America, it chronologically overlaps with theUquian(partial),Ensenadan,andLujanianinSouth American Land Mammal Ages.
Fauna
[edit]
Notable mammals[edit]Artiodactyla- even-toed ungulates
Carnivora- carnivores
Lagomorpha- lagomorphs
Perissodactyla- odd-toed ungulates Proboscidea- elephants
Rodentia- rodents
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Notable birds[edit]
Falconiformes- diurnal raptors
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References
[edit]- ^abThe _Blancan, Irvingtonian and Rancholabrean Mammal Agesby Christopher J. Bell and Ernest L. Lundelius Jr., Anthony D. Barnosky, Russell W. Graham, Everett H. Lindsay, Dennis R. Ruez Jr., Holmes A. Semken Jr., S. David Webb, and Richard J. Zakrzewski. January 2004 in the book: Late Cretaceous and Cenozoic Mammals of North America: Biostratigraphy and Geochronology. Chapter: 7. Publisher: Columbia University Press; Editors: Michael O. Woodburne. pp274-276
- ^Smith, Gregory James; DeSantis, Larisa R. G. (February 2020)."Extinction of North American Cuvieronius (Mammalia: Proboscidea: Gomphotheriidae) driven by dietary resource competition with sympatric mammoths and mastodons".Paleobiology.46(1): 41–57.doi:10.1017/pab.2020.7.ISSN0094-8373.
- ^Savage, D.E.(1951) Late Cenozoic vertebrates of the San Francisco Bay region,University of California Publications, Bulletin of the Department of Geological Sciences28:215-314
- ^"Irvingtonian North American Land Mammal Age".Florida Museum.2017-03-28.Retrieved2020-04-24.
- ^abWetmore (1937)
- ^Feduccia (1970)