Chibanian Explained

Chibanian
Color:	Chibanian
Time Start:	0.774
Time End:	0.129
Timeline:	Quaternary
Name Formality:	Formal
Name Accept Date:	January 2020
Synonym1:	Middle Pleistocene
Synonym2:	Ionian
Celestial Body:	earth
Usage:	Global (ICS)
Timescales Used:	ICS Time Scale
Chrono Unit:	Age
Strat Unit:	Stage
Timespan Formality:	Formal
Lower Boundary Def:	1.1 m below the directional midpoint of the Brunhes-Matuyama magnetic reversal
Lower Gssp Location:	Chiba, Japan
Lower Gssp Accept Date:	January 2020^[1]
Upper Boundary Def:	Not formally defined
Upper Def Candidates:	Marine Isotope Substage 5e
Upper Gssp Candidates:	None

The Chibanian, more widely known as Middle Pleistocene (its previous informal name), 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.^[2] The Chibanian name was officially ratified in January 2020. It is currently estimated to span the time between 0.770 Ma (770,000 years ago) and 0.129 Ma (129,000 years ago), also expressed as 770–126 ka. It includes the transition in palaeoanthropology from the Lower to the Middle Paleolithic over 300 ka.

The Chibanian is preceded by the Calabrian and succeeded by the proposed Tarantian.^[3] The beginning of the Chibanian is the Brunhes–Matuyama reversal, when the Earth's magnetic field last underwent reversal.^[4] Its end roughly coincides with the termination of the Penultimate Glacial Period and the onset of the Last Interglacial period (corresponding to the beginning of Marine Isotope Stage 5).^[5]

The term Middle Pleistocene was in use as a provisional or "quasi-formal" designation by the International Union of Geological Sciences (IUGS). While the three lowest ages of the Pleistocene, the Gelasian, Calabrian and Chibanian have been officially defined, the Late Pleistocene has yet to be formally defined.^[6]

Definition process

The International Union of Geological Sciences (IUGS) had previously proposed replacement of the Middle Pleistocene by an Ionian Age based on strata found in Italy. In November 2017, however, the Chibanian (based on strata at a site in Chiba Prefecture, Japan) replaced the Ionian as the Subcommission on Quaternary Stratigraphy's preferred GSSP proposal for the age that should replace the Middle Pleistocene sub-epoch.^[7] The "Chibanian" name was ratified by the IUGS in January 2020.^[2]

Climate

By early Middle Pleistocene, the Mid-Pleistocene Transition had changed the glacial cycles from an average 41,000 year periodicity present during most of the Early Pleistocene to a 100,000 year periodicity,^[8] with the glacial cycles becoming asymmetric, having long glacial periods punctuated by short warm interglacial periods.^[9] Millennial-scale climatic variability continued to be highly sensitive to precession and obliquity cycles.^[10]

The late Middle Pleistocene was a time of regional aridification in the Levant, with a shallow lake covering what is now the Shishan Marsh drying and developing into a marsh.^[11]

Eastern Africa's hydroclimate was governed primarily by orbital precession, although modulated significantly by the 100 kyr eccentricity cycle.^[12]

Along the northwestern Australian coast, the intensification of the Leeuwin Current resulted in an expansion of reefs coincident with the Great Barrier Reef's formation.^[13]

Events

The Early-Middle Pleistocene boundary saw the migration of true horses out of North America and into Eurasia.^[14] Also around this time, the European mammoth species Mammuthus meridionalis became extinct and was replaced by the Asian species Mammuthus trogontherii (the steppe mammoth). This was coincident with the migration of the elephant genus Palaeoloxodon out of Africa and into Eurasia, including the first appearance of species like the European straight-tusked elephant (Palaeoloxodon antiquus). With the extinction of Sinomastodon in East Asia at the Early-Middle Pleistocene boundary, gomphotheres became completely extinct in Afro-Eurasia,^{[15] [16]} but continued to persist in the Americas into the Late Pleistocene. There was a major extinction of carnivorous mammals in Europe around the Early-Middle Pleistocene transition, including the giant hyena Pachycrocuta.^[17] The mid-late Middle Pleistocene saw the emergence of the woolly mammoth (Mammuthus primigenius), and its replacement of Mammuthus trogontherii, with the replacement of M. trogontherii in Europe by woolly mammoths being complete by around 200,000 years ago.^[18] The last member of the notoungulate family Mesotheriidae, Mesotherium, has its last records around 220,000 years ago, leaving Toxodontidae as the sole family of notoungulates to persist into the Late Pleistocene.^[19] During the late Middle Pleistocene, around 195,000-135,000 years ago, the steppe bison (the ancestor of the modern American bison) migrated across the Bering land bridge into North America, marking the beginning of the Rancholabrean faunal stage.^[20] Around 500,000 years ago, the last members of the largely European aquatic frog genus Palaeobatrachus and by extension the family Palaeobatrachidae became extinct.^[21]

Palaeoanthropology

The Chibanian includes the transition in palaeoanthropology from the Lower to the Middle Paleolithic: i.e., the emergence of Homo sapiens sapiens between 300 ka and 400 ka.^[22] The oldest known human DNA dates to the Middle Pleistocene, around 430,000 years ago. This is the oldest found, .^[23]

After analyzing 2,496 remains of Castor fiber (Eurasian beaver) and Trogontherium cuvieri found at Bilzingsleben in Germany, a team of scientists concluded that, around 400 ka, hominids in the area hunted and exploited beavers. They may have been targeted for their meat (based on cut marks on the bones) and skin.^[24]

Chronology

Age	paleoclimate	glaciation	palaeoanthropology
790–761 ka	MIS 19		Peking Man (Homo erectus)
761–712 ka	MIS 18
712–676 ka	MIS 17
676–621 ka	MIS 16
621–563 ka	MIS 15	Gunz-Haslach interglacial	Heidelberg Man (Homo heidelbergensis), Bodo cranium
563–524 ka	MIS 14
524–474 ka	MIS 13		Boxgrove Man (Homo heidelbergensis)
474–424 ka	MIS 12	Anglian Stage in Britain; Haslach glaciation	Tautavel Man (Homo erectus)
424–374 ka		Hoxnian (Britain), Yarmouthian (North America)	Swanscombe Man (Homo heidelbergensis)
374–337 ka	MIS 10	Mindel glaciation, Elster glaciation, Riss glaciation
337–300 ka		Purfleet Interglacial in Britain	Mousterian
300–243 ka	MIS 8		Irhoud 1 (Homo sapiens); Middle Paleolithic; Haplogroup A (Y-DNA)
243–191 ka	MIS 7	Aveley Interglacial in Britain	Galilee Man Haua Fteah
191–130 ka	MIS 6		Herto Man (Homo sapiens); Macro-haplogroup L (mtDNA); Mousterian
130 - 123 ka	MIS 5e	peak of Eemian interglacial sub-stage, or Ipswichian in Britain	Klasies River Caves Sangoan

See also

• Mid-Pleistocene Transition
• 100,000-year problem
• Pleistocene megafauna

Notes and References

1. Web site: Global Boundary Stratotype Section and Point . International Commission of Stratigraphy . 26 December 2020.
2. Web site: Japan Puts Its Mark on Geologic Time with the Chibanian Age . . Eos – Earth & Space Science News . 30 January 2020 . 31 January 2020 . Hornyak, Tim.
3. Web site: International Chronostratigraphic Chart . International Commission on Stratigraphy . Cohen . K. M. . Finney . S. C. . Gibbard . P. L. . Fan . J.-X. . January 2020 . 23 February 2020.
4. Book: Ogg . James G. . Smith . Alan G. . Gradstein . Felix M. . A Geological Time Scale 2004 . limited . 2004 . Cambridge University Press . Cambridge . 9780521786737 . 28 . 3rd.
5. Eemian interglacial reconstructed from a Greenland folded ice core . Nature . 493 . 7433 . 489–494 . 2013 . D. Dahl-Jensen & others . 2013Natur.493..489N . 10.1038/nature11789 . 23344358. 4420908.
6. The Quaternary System/Period and its major sub-divisions . P. L. Gibbard . Russian Geology and Geophysics . Elsevier BV . Special Issue: Topical Problems of Stratigraphy and Evolution of the Biosphere . 56 . 4 . 686–688 . 17 April 2015 . 10.1016/j.rgg.2015.03.015 . 2015RuGG...56..686G . 13 November 2019.
7. Web site: Japan-based name 'Chibanian' set to represent geologic age of last magnetic shift . The Japan Times . 14 November 2017 . 13 November 2019.
8. Berends . C. J. . Köhler . P. . Lourens . L. J. . van de Wal . R. S. W. . June 2021 . On the Cause of the Mid-Pleistocene Transition . Reviews of Geophysics . en . 59 . 2 . 10.1029/2020RG000727 . 2021RvGeo..5900727B . 1874/412413 . 236386405 . 8755-1209. free .
9. Chalk . Thomas B. . Hain . Mathis P. . Foster . Gavin L. . Rohling . Eelco J. . Sexton . Philip F. . Badger . Marcus P. S. . Cherry . Soraya G. . Hasenfratz . Adam P. . Haug . Gerald H. . Jaccard . Samuel L. . Martínez-García . Alfredo . Pälike . Heiko . Pancost . Richard D. . Wilson . Paul A. . 2017-12-12 . Causes of ice age intensification across the Mid-Pleistocene Transition . Proceedings of the National Academy of Sciences . en . 114 . 50 . 13114–13119 . 10.1073/pnas.1702143114 . free . 0027-8424 . 5740680 . 29180424. 2017PNAS..11413114C .
10. Sun . Youbin . McManus . Jerry F. . Clemens . Steven C. . Zhang . Xu . Vogel . Hendrik . Hodell . David A. . Guo . Fei . Wang . Ting . Liu . Xingxing . An . Zhisheng . 1 November 2021 . Persistent orbital influence on millennial climate variability through the Pleistocene . . en . 14 . 11 . 812–818 . 10.1038/s41561-021-00794-1 . 2021NatGe..14..812S . 240358493 . 1752-0908 . 26 February 2024.
11. Boyd . Kelsey C. . Ames . Christopher J.H. . Cordova . Carlos E. . 1 June 2022 . The Middle to Late Pleistocene transition in the Azraq Oasis, Jordan: A phytolith-based reconstruction of wetland palaeoecology . . en . 595 . 110967 . 10.1016/j.palaeo.2022.110967 . 2022PPP...59510967B . 4 July 2024 . Elsevier Science Direct.
12. Lupien . Rachel L. . Russell . James M. . Pearson . Emma J. . Castañeda . Isla S. . Asrat . Asfawossen . Foerster . Verena . Lamb . Henry F. . Roberts . Helen M. . Schäbitz . Frank . Trauth . Martin H. . Beck . Catherine C. . Feibel . Craig S. . Cohen . Andrew S. . 24 February 2022 . Orbital controls on eastern African hydroclimate in the Pleistocene . . en . 12 . 1 . 3170 . 10.1038/s41598-022-06826-z . 2045-2322 . 28 July 2024. 8873222 .
13. Gallagher . Stephen J. . Wallace . Malcolm W. . Hoiles . Peter W. . Southwood . John M. . November 2014 . Seismic and stratigraphic evidence for reef expansion and onset of aridity on the Northwest Shelf of Australia during the Pleistocene . . en . 57 . 470–481 . 10.1016/j.marpetgeo.2014.06.011 . 2014MarPG..57..470G . 23 June 2024 . Elsevier Science Direct. 11343/52678 . free .
14. Vershinina . Alisa O. . Heintzman . Peter D. . Froese . Duane G. . Zazula . Grant . Cassatt-Johnstone . Molly . Dalén . Love . Der Sarkissian . Clio . Dunn . Shelby G. . Ermini . Luca . Gamba . Cristina . Groves . Pamela . Kapp . Joshua D. . Mann . Daniel H. . Seguin-Orlando . Andaine . Southon . John . December 2021 . Ancient horse genomes reveal the timing and extent of dispersals across the Bering Land Bridge . Molecular Ecology . en . 30 . 23 . 6144–6161 . 10.1111/mec.15977 . 33971056 . 2021MolEc..30.6144V . 0962-1083. 10995/118212 . free .
15. Wang . Yuan . Jin . Chang-zhu . Mead . Jim I. . August 2014 . New remains of Sinomastodon yangziensis (Proboscidea, Gomphotheriidae) from Sanhe karst Cave, with discussion on the evolution of Pleistocene Sinomastodon in South China . Quaternary International . en . 339-340 . 90–96 . 2014QuInt.339...90W . 10.1016/j.quaint.2013.03.006.
16. Cantalapiedra . Juan L. . Sanisdro . Oscar L. . Zhang . Hanwen . Alberdi . Mª Teresa . Prado . Jose Luis . Blanco . Fernando . Saarinen . Juha . 1 July 2021 . The rise and fall of proboscidean ecological diversity . Nature Ecology & Evolution . 355 . 9 . 1266–1272 . 10.1038/s41559-021-01498-w . 34211141 . 2021NatEE...5.1266C . 235712060 . Escience.magazine.org . 21 August 2021.
17. Palombo . Maria Rita . Sardella . Raffaele . Novelli . Micaela . March 2008 . Carnivora dispersal in Western Mediterranean during the last 2.6Ma . Quaternary International . en . 179 . 1 . 176–189 . 10.1016/j.quaint.2007.08.029. 2008QuInt.179..176P .
18. Lister . Adrian M. . October 2022 . Mammoth evolution in the late Middle Pleistocene: The Mammuthus trogontherii-primigenius transition in Europe . Quaternary Science Reviews . en . 294 . 107693 . 2022QSRv..29407693L . 10.1016/j.quascirev.2022.107693 . 252264887.
19. Fernández-Monescillo . Marcos . Martínez . Gastón . García López . Daniel . Frechen . Manfred . Romero-Lebrón . Eugenia . Krapovickas . Jerónimo M. . Haro . J. Augusto . Rodríguez . Pablo E. . Rouzaut . Sabrina . Tauber . Adan A. . February 2023 . The last record of the last typotherid (Notoungulata, Mesotheriidae, Mesotherium cristatum) for the middle Pleistocene of the western Pampean region, Córdoba Province, Argentina, and its biostratigraphic implications . Quaternary Science Reviews . en . 301 . 107925 . 10.1016/j.quascirev.2022.107925. 2023QSRv..30107925F . 254913691 .
20. 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. . 2017-03-28 . Fossil and genomic evidence constrains the timing of bison arrival in North America . Proceedings of the National Academy of Sciences . en . 114 . 13 . 3457–3462 . 2017PNAS..114.3457F . 10.1073/pnas.1620754114 . 0027-8424 . 5380047 . 28289222 . free.
21. Wuttke . Michael . Přikryl . Tomáš . Ratnikov . Viacheslav Yu. . Dvořák . Zdeněk . Roček . Zbyněk . September 2012 . Generic diversity and distributional dynamics of the Palaeobatrachidae (Amphibia: Anura) . Palaeobiodiversity and Palaeoenvironments . en . 92 . 3 . 367–395 . 10.1007/s12549-012-0071-y . 2012PdPe...92..367W . 130080167 . 1867-1594.
22. The Age of Hominin Fossils from Jebel Irhoud, Morocco, and the origins of the Middle Stone Age . Nature . 546 . 7657 . 293–296 . 8 June 2017 . D. Richter & others. 10.1038/nature22335 . 28593967 . 2017Natur.546..293R . 205255853. .
23. News: The Oldest Human Genome Ever Has Been Sequenced, And It Could Rewrite Our History . Crew . Bec . ScienceAlert . 15 March 2016 . 5 June 2019.
24. Gaudzinski-Windheuser . Sabine . Kindler . Lutz . Roebroeks . Wil . 2023-11-13 . Beaver exploitation, 400,000 years ago, testifies to prey choice diversity of Middle Pleistocene hominins . Scientific Reports . en . 13 . 1 . 19766 . 10.1038/s41598-023-46956-6 . 2045-2322. free . 37957223 . 10643649 . 2023NatSR..1319766G . 1887/3674398 . free .