Earth:Tonian
The Tonian (from Ancient Greek: τόνος, romanized: tónos, meaning "stretch") is the first geologic period of the Neoproterozoic Era. It lasted from 1000 to 720 Mya (million years ago). Instead of being based on stratigraphy, these dates are defined by the ICS based on radiometric chronometry. The Tonian is preceded by the Stenian Period of the Mesoproterozoic Era and followed by the Cryogenian.
History
The Tonian was defined in 1990 by the New Precambrian time scale as being from 1000 to 850 Mya.[1] The name Tonian comes from Ancient Greek: τόνος, romanized: tónos, which means the word "stretch", referring to the rifting that broke up Rodinia during this period.[2] The upper definition was then redefined to 720 Mya in 2014 after discoveries that the original 850 Mya for the lower Cryogenian and the first glaciations at 717 Mya did not match. This is temporary until the basal Cryogenian GSSP is chosen.[3][2]
Geology
Both the Supercontinent Rodinia and the Mirovian superocean remained stable throughout the early Tonian from 1000 to at least 900 Mya. The appearance of sedimentary rocks in multiple places in 850 to 800 Mya has been postulated as an initial breakup of Rodinia. However, there has been little evidence for the breakup of Rodinia during the mid-Tonian, with most agreeing that Rodinia began breaking up at the end of the Tonian, around 750 Mya.[2][4]
The first half of the Tonian has mildly fluctulating carbon isotope values, being transitional from the lower Mesoproterozoic levels to the higher Tonian levels. The later half of the Tonian has high carbon isotope values, with deep excursions happening at least once after 740 Mya, immediately before the Sturtian glaciation in the Cryogenian.[2]
Biology
The first putative metazoan (animal) fossils are dated to the middle to late Tonian (c. 890-800 Mya). The fossils of Otavia antiqua, which has been described as a primitive sponge by its discoverers and numerous other scholars, date back to about 800 mya. Even earlier sponge-like fossils have been reported in reefs dating back to 890 million years before the present, but their identity is highly debated.[5] This dating is consistent with molecular data recovered through genetic studies on modern metazoan species; more recent studies have concluded that the base of the animal phylogenetic tree is in the Tonian.[6][2]
Tonian rocks preserve some of the earliest fossils of macroalgae,[7] such as the benthic macroalgae from the Longfengshan biota of the Luotuoling Formation[8] or the green algae from the Dolores Creek Formation.[9] Arctacellularia tetragonala, a algae found in this period, has chlorophyll derivatives preserved in it.[10] Sinosabellidites huainanensis, an algae from the Huainan biota that was confused for an animal at first glace, was found in this period.[11]
The first large evolutionary radiation of acritarchs occurred during the Tonian. Vase-shaped microfossils abound in late Tonian sediments and represent the earliest testate amoebozoans.[12] Stromatolites begin to swiftly decrease during this period.[13]
Fungi are visibly preserved in this period in 810 to 715 mya shale in the Mbuji-Mayi Supergroup with mycelium-like filaments.[14]
See also
- Earth:Boring Billion – Earth history, 1.8 to 0.8 billion years ago
- Neoproterozoic oxygenation event
- Huainan biota
References
- ↑ Plumb, K. A. (1991-06-01). "New Precambrian time scale" (in en). Episodes Journal of International Geoscience 14 (2): 139–140. doi:10.18814/epiiugs/1991/v14i2/005. https://www.episodes.org/journal/view.html?doi=10.18814/epiiugs/1991/v14i2/005.
- ↑ 2.0 2.1 2.2 2.3 2.4 Gradstein, Felix M.; Ogg, James G.; Schmitz, Mark D.; Ogg, Gabi M. (January 2020) (in En). Geologic Time Scale 2020 - The Tonian and Cryogenian Periods. Candice Janco. pp. 495–519. ISBN 978-0-12-824362-6. https://www.researchgate.net/publication/347686342_The_Tonian_and_Cryogenian_Periods.
- ↑ Shields, Graham A.; Halverson, Galen P.; Porter, Susannah M. (2018-12-01). "Descent into the Cryogenian". Precambrian Research. Descent into the Cryogenian 319: 1–5. doi:10.1016/j.precamres.2018.08.015. ISSN 0301-9268. https://www.sciencedirect.com/science/article/pii/S0301926818304054.
- ↑ Li, Z. X.; Bogdanova, S. V.; Collins, A. S.; Davidson, A.; De Waele, B.; Ernst, R. E.; Fitzsimons, I. C. W.; Fuck, R. A. et al. (2008-01-05). "Assembly, configuration, and break-up history of Rodinia: A synthesis". Precambrian Research. Testing the Rodinia Hypothesis: Records in its Building Blocks 160 (1): 179–210. doi:10.1016/j.precamres.2007.04.021. ISSN 0301-9268. https://web.viu.ca/earle/geol305/labs/Lietal_IGCP440_map_2008.pdf.
- ↑ Turner, Elizabeth C. (28 July 2021). "Possible poriferan body fossils in early Neoproterozoic microbial reefs". Nature 596 (7870): 87–91. doi:10.1038/s41586-021-03773-z. PMID 34321662. Bibcode: 2021Natur.596...87T.
- ↑ Kliman, Richard M. (Apr 14, 2016). Encyclopedia of Evolutionary Biology. Academic Press. p. 251. ISBN 978-0-12-800426-5.
- ↑ Del Cortona, Andrea; Jackson, Christopher J.; Bucchini, François; Van Bel, Michiel; D'hondt, Sofie; Škaloud, Pavel; Delwiche, Charles F.; Knoll, Andrew H. et al. (7 January 2020). "Neoproterozoic origin and multiple transitions to macroscopic growth in green seaweeds" (in en). Proceedings of the National Academy of Sciences of the United States of America 117 (5): 2551–2559. doi:10.1073/pnas.1910060117. ISSN 0027-8424. PMID 31911467.
- ↑ Jing, Yinghao; Chen, Zhong-Qiang; Anderson, Ross P.; Wang, Xue; Zheng, Zemin; Feng, Xueqian (November 2022). "Microscopic and geochemical analyses of the Tonian Longfengshan biota from the Luotuoling Formation (Hebei Province, North China) with taphonomic implications" (in en). Precambrian Research 382. doi:10.1016/j.precamres.2022.106899. https://linkinghub.elsevier.com/retrieve/pii/S0301926822003436. Retrieved 19 May 2024.
- ↑ Maloney, Katie M.; Halverson, Galen P.; Schiffbauer, James D.; Xiao, Shuhai; Gibson, Timothy M.; Lechte, Maxwell A.; Cumming, Vivien M.; Millikin, Alexie E.G. et al. (22 March 2021). "New multicellular marine macroalgae from the early Tonian of northwestern Canada" (in en). Geology 49 (6): 743–747. doi:10.1130/G48508.1. ISSN 0091-7613. Bibcode: 2021Geo....49..743M. https://pubs.geoscienceworld.org/gsa/geology/article-abstract/49/6/743/595633/New-multicellular-marine-macroalgae-from-the-early?redirectedFrom=fulltext. Retrieved 19 May 2024.
- ↑ Sforna, Marie Catherine; Loron, Corentin C.; Demoulin, Catherine F.; François, Camille; Cornet, Yohan; Lara, Yannick J.; Grolimund, Daniel; Ferreira Sanchez, Dario et al. (2022-01-10). "Intracellular bound chlorophyll residues identify 1 Gyr-old fossils as eukaryotic algae" (in en). Nature Communications 13 (1): 146. doi:10.1038/s41467-021-27810-7. ISSN 2041-1723. https://www.nature.com/articles/s41467-021-27810-7.
- ↑ Dong, Lin; Xiao, Shuhai; Shen, Bing; Yuan, Xunlai; Yan, Xianqin; Peng, Yongbo (2008-02-18). "Restudy of the worm-like carbonaceous compression fossils Protoarenicola, Pararenicola, and Sinosabellidites from early Neoproterozoic successions in North China". Palaeogeography, Palaeoclimatology, Palaeoecology. The Dawn of Animal Life: Evolutionary and Palaeoecological Patterns in the Neoproterozoic-Cambrian Animal Fossil Record 258 (3): 138–161. doi:10.1016/j.palaeo.2007.05.019. ISSN 0031-0182. https://www.sciencedirect.com/science/article/pii/S0031018207004518.
- ↑ Tingle, Kelly E.; Porter, Susannah M.; Raven, Morgan R.; Czaja, Andrew D.; Webb, Samuel M.; Bloeser, Bonnie (18 January 2023). "Organic preservation of vase-shaped microfossils from the late Tonian Chuar Group, Grand Canyon, Arizona, USA" (in en). Geobiology 21 (3): 290–309. doi:10.1111/gbi.12544. ISSN 1472-4677. PMID 36651474. Bibcode: 2023Gbio...21..290T.
- ↑ Bernhard, Joan M.; Virginia P., Edgcomb; Visscher, Pieter T.; Jeglinski, Marleen (May 28, 2013). "Insights into foraminiferal influences on microfabrics of microbialites at Highborne Cay, Bahamas" (in en). doi:10.1073/pnas.1221721110. https://www.pnas.org/action/cookieAbsent.
- ↑ Bonneville, S.; Delpomdor, F.; Préat, A.; Chevalier, C.; Araki, T.; Kazemian, M.; Steele, A.; Schreiber, A. et al. (2020-01-22). "Molecular identification of fungi microfossils in a Neoproterozoic shale rock". Science Advances 6 (4). doi:10.1126/sciadv.aax7599. PMID 32010783. PMC 6976295. https://www.science.org/doi/10.1126/sciadv.aax7599.
Further reading
- "Tonian Period". GeoWhen Database. http://www.stratigraphy.org/geowhen/stages/Tonian.html.
- Ogg, James G. (2004). "Status on Divisions of the International Geologic Time Scale". Lethaia 37 (2): 183–199. doi:10.1080/00241160410006492. Bibcode: 2004Letha..37..183O.
