View source for Blancan

{{Short description|North American faunal stage according to the North American Land Mammal Ages chronology}}
The '''Blancan 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 4,750,000 to 1,806,000 years [[Before Present|BP]], a period of {{Mya|4.75-1.806|million years}}.<ref name="GeoWhen">[http://www.stratigraphy.org/upload/bak/geowhen/stages/Blancan.html  Blancan North American Stage]. GeoWhen Database. Version 1.1.0. Retrieved 2017-June-26.</ref>  It is usually considered to start in the early-mid [[Pliocene]] Epoch and end by the early [[Pleistocene]].<ref name = lundeliusetal1987 />  The Blancan is preceded by the [[Hemphillian]] and followed by the [[Irvingtonian]] NALMA stages.

As usually defined, it corresponds to the mid-[[Zanclean]] through [[Piacenzian]] and [[Gelasian]] stages in Europe and Asia. In California, the Blancan roughly corresponds to the mid-[[Delmontian]] through [[Repettian]] and [[Venturian]] to the very early [[Wheelerian]]. The Australian contemporary stages are the mid-[[Cheltenhamian]] through [[Kalimnan]] and [[Yatalan]]. In New Zealand, the [[Opoitian]] starts at roughly the same time and the Blancan is further [[:wikt:coeval|coeval]] with the [[Waipipian]] and [[Mangapanian]] stages to the early [[Nukumaruan]]. Finally, in Japan the Blancan starts coeval with the late [[Yuian]], runs alongside the [[Totomian]] and [[Suchian (faunal age)|Suchian]] and ends soon after the start of the [[Kechienjian]].

==Dating issues==
The start date of the Blancan has not been fully established. There is general agreement that it is between 4.9<ref name=Lindsay/> and 4.3 mya (million years ago).<ref name=Cassiliano/> The often-cited GeoWhen database places it at 4.75 mya.<ref name="GeoWhen"/>

There is even stronger disagreement about the end of the Blancan. Some [[Stratigraphy|stratigraphers]] argue for the 1.808 mya date that corresponds better with the end of the [[Pliocene]] and the start of the [[Pleistocene]] (1.808 mya).  This conforms with the extinction of ''[[Borophagus]]'', ''[[Hypolagus]]'', ''[[Paenemarmota]]'', ''[[Plesippus]]'', ''[[Nannippus]]'', and ''[[Rhynchotherium]]'' faunal assemblage between 2.2 and 1.8 mya.<ref name = lundeliusetal1987/> Other [[Paleontology|paleontologists]] find continuity of the [[faunal assemblage]]s well into the Pleistocene, and argue for an end date of 1.2 mya.  This corresponds with the extinction of [[stegomastodon]]s and related species and the appearance of [[mammoth]]s in southern North America.<ref name=Tedford/>

==Fauna==
The middle of the Blancan, about 2.7 mya, is when the [[land bridge]] connection between North and South America was reestablished and [[taxa]] like [[sloth]]s and [[Glyptodont|glyptodonts]] appeared in North America at the height of the [[Great American Interchange]].<ref name=Woodburne/>

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===Notable mammals===
'''[[Artiodactyla]]''' – even-toed ungulates
* ''[[Platygonus]]'', peccaries
'''[[Carnivora]]''' – carnivores
*''[[Arctodus]]'', short-faced bear
*''[[Hesperocyoninae]]'', dog-like carnivores
* ''[[Borophagus]]'', bone-crushing dogs
*''[[Canis]]'', wolves
* ''[[Chasmaporthetes]]'', hyenas
*''[[Smilodon]]'', saber-toothed cat
*''[[Homotherium]]'', saber-toothed cat
*''[[Xenosmilus]]'', saber-toothed cat
'''[[Lagomorpha]]''' – lagomorphs
* ''[[Hypolagus]]'', rabbits
'''[[Perissodactyla]]''' – odd-toed ungulates
* ''[[Nannippus]]'', horses
* ''[[Plesippus]]'', horses – may belong into ''[[Equus (genus)|Equus]]''
* ''[[Equus giganteus]]
'''[[Proboscidea]]'''
* ''[[Rhynchotherium]]'', gomphotheres
* ''[[Stegomastodon]]'', gomphotheres
'''[[Rodent]]ia''' – rodents
* ''[[Paenemarmota]]'', giant marmots
'''[[Xenarthra]]'''
* ''[[Glyptotherium]]'', giant armadillo{{col-2-of-2}}

===Notable birds===
'''[[Cathartidae]]''' – New World vultures
* ''[[Sarcoramphus kernense]]'', Kern Vulture
'''[[Charadriiformes]]'''
* unknown [[Scolopacidae|scolopacid]] (archaic [[calidrid]] or [[turnstone]]?)<ref name = wetmore1937/>
'''[[Falconiformes]]''' – diurnal raptors
* ''[[Falco (bird)|Falco]]'' sp., a falcon<ref name=Feduccia/>
'''[[Passeriformes]]'''
* unknown [[Corvidae|corvid]] (archaic [[magpie]]?)<ref name = wetmore1937 />
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== See also ==
* [[Mount Blanco]]

== References ==
{{reflist|refs=
<ref name= Cassiliano >{{cite journal|author=Cassiliano, Michael L.|year=1999|title= Biostratigraphy of Blancan and Irvingtonian mammals in the Fish Creek–Vallecito Creek section, southern California, and a review of the Blancan-Irvingtonian boundary|journal=[[Society of Vertebrate Paleontology|J. Vertebr. Paleontol.]]|volume=19|issue=1|pages= 169–186|doi=10.1080/02724634.1999.10011131}}</ref>

<ref name=Feduccia>{{cite journal|author=Feduccia, J. Alan|year=1970|title= Some birds of prey from the Upper Pliocene of Kansas|journal=[[Auk (journal)|Auk]]|volume=87|issue=4|pages= 795–797|url=http://sora.unm.edu/sites/default/files/journals/auk/v087n04/p0795-p0797.pdf|doi=10.2307/4083714|last2=Ford|first2=Norman L.|jstor=4083714 }}</ref>

<ref name= Lindsay>{{cite journal|author=Lindsay, Everett|year=2002|title= Recognition of the Hemphillian/Blancan boundary in Nevada|journal=[[Society of Vertebrate Paleontology|J. Vertebr. Paleontol.]]|volume=22|issue=2|pages= 429–442|doi=10.1671/0272-4634(2002)022[0429:ROTHBB]2.0.CO;2|s2cid=129779648 |url=http://www.bioone.org/perlserv/?request=get-abstract&doi=10.1671%2F0272-4634(2002)022%5B0429%3AROTHBB%5D2.0.CO%3B2|display-authors=etal|url-access=subscription}}</ref>

<ref name = lundeliusetal1987>Lundelius, E.L. Jr. ''et al.'' (1987): The North American Quaternary Sequence. ''In:'' Woodburne, Michael O. (ed.): ''Cenozoic mammals of North America: geochronology and biostratigraphy'': 211–235. University of California Press, Berkeley. {{ISBN|0-520-05392-3}}</ref>

<ref name= Tedford >{{cite journal|author=Tedford, Richard H.|year=1981|title= Mammalian biochronology of the late Cenozoic basins of New Mexico|journal=Geological Society of America Bulletin|volume=92|issue=12|pages= 1008–1022|doi=10.1130/0016-7606(1981)92<1008:MBOTLC>2.0.CO;2|bibcode=1981GSAB...92.1008T }}</ref>

<ref name = wetmore1937>{{cite journal|author=Wetmore, Alexander|year=1937|title= The Eared Grebe and other Birds from the Pliocene of Kansas|journal=[[Condor (journal)|Condor]]|volume=39|issue=1|pages= 40|url=http://sora.unm.edu/sites/default/files/journals/condor/v039n01/p0040-p0040.pdf | doi = 10.2307/1363487 |jstor=1363487 }}</ref>

<ref name=Woodburne>Woodburne, Michael O. & Swisher, C.C. III (1995): Land mammal high-resolution geochronology, intercontinental overland dispersals, sea level, climate, and vicariance. ''Society for Economic Paleontology and Mineralogy Special Publications'' '''54''': 335–364. {{ISBN|1-56576-024-7}}</ref> 
}}

==Further reading==
*Lourens, L. ''et al.'' (2004): The Neogene Period. ''In:'' Gradstein, F.; Ogg, J. & Smith, A.G. (eds.): ''A Geologic Time Scale 2004''. Cambridge University Press. {{ISBN|0-521-78142-6}}
*{{cite journal|author1=Morgan, Gary S.  |author2=Lucas, Spencer G. |name-list-style=amp |year=2003|title= Mammalian Biochronology of Blancan and Irvingtonian (Pliocene and Early Pleistocene) Faunas from New Mexico|journal=Bulletin of the American Museum of Natural History|volume=279|pages=269–320|url=http://digitallibrary.amnh.org/dspace/bitstream/2246/447/15/B279a12.pdf|doi=10.1206/0003-0090(2003)279<0269:C>2.0.CO;2 |s2cid=87984338 }}


{{Neogene Footer}}
{{Quaternary Footer}}

[[Category:Blancan| ]]
[[Category:Pleistocene life]]
[[Category:Pliocene life]]
[[Category:Zanclean]]
[[Category:Piacenzian]]
[[Category:Calabrian (stage)]]
[[Category:Pliocene animals of North America]]
[[Category:Pleistocene animals of North America]]
[[Category:Cenozoic Texas]]
[[Category:Pliocene United States]]
[[Category:Pleistocene United States]]