Late Devonian extinction

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Extinction intensity.svgCambrianOrdovicianSilurianDevonianCarboniferousPermianTriassicJurassicCretaceousPaleogeneNeogene
Marine extinction intensity during the Phanerozoic
%
Millions of years ago
Extinction intensity.svgCambrianOrdovicianSilurianDevonianCarboniferousPermianTriassicJurassicCretaceousPaleogeneNeogene
Comparison of the three episodes of extinction in the Late Devonian (Late D) to other mass extinction events in Earth's history. Plotted is the extinction intensity, calculated from marine genera.

The Late Devonian extinction consisted of several extinction events in the Late Devonian Epoch, which collectively represent one of the five largest mass extinction events in the history of life on Earth. The term primarily refers to a major extinction, the Kellwasser event, also known as the Frasnian-Famennian extinction,[1] which occurred around 372 million years ago, at the boundary between the Frasnian stage and the Famennian stage, the last stage in the Devonian Period.[2][3] Overall, 19% of all families and 50% of all genera became extinct.[4] A second mass extinction called the Hangenberg event, also known as the end-Devonian extinction,[5] occurred 359 million years ago, bringing an end to the Famennian and Devonian, as the world transitioned into the Carboniferous Period.[6]

Although it is well established that there was a massive loss of biodiversity in the Late Devonian, the timespan of this event is uncertain, with estimates ranging from 500,000 to 25 million years, extending from the mid-Givetian to the end-Famennian.[7] Some consider the extinction to be as many as seven distinct events, spread over about 25 million years, with notable extinctions at the ends of the Givetian, Frasnian, and Famennian stages.[8]

By the Late Devonian, the land had been colonized by plants and insects. In the oceans, massive reefs were built by corals and stromatoporoids. Euramerica and Gondwana were beginning to converge into what would become Pangaea. The extinction seems to have only affected marine life. Hard-hit groups include brachiopods, trilobites, and reef-building organisms; the latter almost completely disappeared. The causes of these extinctions are unclear. Leading hypotheses include changes in sea level and ocean anoxia, possibly triggered by global cooling or oceanic volcanism. The impact of a comet or another extraterrestrial body has also been suggested,[9] such as the Siljan Ring event in Sweden. Some statistical analysis suggests that the decrease in diversity was caused more by a decrease in speciation than by an increase in extinctions.[10][11] This might have been caused by invasions of cosmopolitan species, rather than by any single event.[11] Placoderms were hit hard by the Kellwasser event and completely died out in the Hangenberg event, but most other jawed vertebrates were less strongly impacted. Agnathans (jawless fish) were in decline long before the end of the Frasnian and were nearly wiped out by the extinctions.[12]

The extinction event was accompanied by widespread oceanic anoxia; that is, a lack of oxygen, prohibiting decay and allowing the preservation of organic matter.[13][14] This, combined with the ability of porous reef rocks to hold oil, has led to Devonian rocks being an important source of oil, especially in Canada and the United States.[15][16][17]

Late Devonian world[edit]

During the Late Devonian, the continents were arranged differently from today, with a supercontinent, Gondwana, covering much of the Southern Hemisphere. The continent of Siberia occupied the Northern Hemisphere, while an equatorial continent, Laurussia (formed by the collision of Baltica and Laurentia), was drifting towards Gondwana, closing the Rheic Ocean. The Caledonian mountains were also growing across what is now the Scottish Highlands and Scandinavia, while the Appalachians rose over America.[22]

The biota was also very different. Plants, which had been on land in forms similar to mosses and liverworts since the Ordovician, had just developed roots, seeds, and water transport systems that allowed them to survive away from places that were constantly wet—and so grew huge forests on the highlands. Several clades had developed a shrubby or tree-like habitat by the Late Givetian, including the cladoxylalean ferns, lepidosigillarioid lycopsids, and aneurophyte and archaeopterid progymnosperms.[23] Fish were also undergoing a huge radiation, and tetrapodomorphs, such as the Frasnian-age Tiktaalik, were beginning to evolve leg-like structures.[24][25]

Extinction patterns[edit]

The Kellwasser event and most other Later Devonian pulses primarily affected the marine community, and had a greater effect on shallow warm-water organisms than on cool-water organisms. The Kellwasser event's effects were also stronger at low latitudes than high ones.[26]

Reef destruction[edit]

Side view of a stromatoporoid showing laminae and pillars; Columbus Limestone (Devonian) of Ohio

The most hard-hit biological category affected by the Kellwasser event were the calcite-based reef-builders of the great Devonian reef-systems, including the stromatoporoid sponges and the rugose and tabulate corals.[23][27] It left communities of Beloceratids and Manticoceratids devastated[28]. Following the Kellwasser event, reefs of the Famennian were primarily dominated by siliceous sponges and calcifying bacteria, producing structures such as oncolites and stromatolites,[29] although there is evidence this shift in reef composition began prior to the Frasnian-Famennian boundary.[30] The collapse of the reef system was so stark that it would take until the Mesozoic for reefs to recover their Middle Devonian extent. Mesozoic and modern reefs are based on scleractinian ("stony") corals, which would not evolve until the Triassic period. Devonian reef-builders are entirely extinct in the modern day: Stromatoporoids died out in the end-Devonian Hangenberg event, while rugose and tabulate corals went extinct at the Permian-Triassic extinction.

Marine invertebrates[edit]

Further taxa to be starkly affected include the brachiopods, trilobites, ammonites, conodonts, acritarch and graptolites. Cystoids disappeared during this event. The surviving taxa show morphological trends through the event. Trilobites evolved smaller eyes in the run-up to the Kellwasser event, with eye size increasing again afterwards. This suggests vision was less important around the event, perhaps due to increasing water depth or turbidity. The brims of trilobites (i.e. the rims of their heads) also expanded across this period. The brims are thought to have served a respiratory purpose, and the increasing anoxia of waters led to an increase in their brim area in response. The shape of conodonts' feeding apparatus varied with the oxygen isotope ratio, and thus with the sea water temperature; this may relate to their occupying different trophic levels as nutrient input changed.[31] As with most extinction events, specialist taxa occupying small niches were harder hit than generalists.[3]

Vertebrates[edit]

Tiktaalik, an early air-breathing elpistostegalian. They were among the vertebrates which died out due to the Kellwasser event

Vertebrates were not strongly-affected by the Kellwasser event, but still experienced some diversity loss. Around half of placoderm families died out, primarily species-poor bottom-feeding groups. More diverse placoderm families survived the event only to succumb in the Hangenberg event at the end of the Devonian. Most lingering agnathan (jawless fish) groups, such as osteostracans, galeaspids, and heterostracans, also went extinct by the end of the Frasnian. The jawless thelodonts only barely survived, succumbing early in the Famennian.[32] Among freshwater and shallow marine tetrapodomorph fish, the tetrapod-like elpistostegalians (such as Tiktaalik) disappeared at the Frasnian-Famennian boundary. True tetrapods (defined as four-limbed vertebrates with digits) survived and experienced an evolutionary radiation following the Kellwasser extinction,[1] though their fossils are rare until the mid-to-late Famennian.

Magnitude of diversity loss[edit]

The late Devonian crash in biodiversity was more drastic than the familiar extinction event that closed the Cretaceous. A recent survey (McGhee 1996) estimates that 22% of all the 'families' of marine animals (largely invertebrates) were eliminated. The family is a great unit, and to lose so many signifies a deep loss of ecosystem diversity. On a smaller scale, 57% of genera and at least 75% of species did not survive into the Carboniferous. These latter estimates[a] need to be treated with a degree of caution, as the estimates of species loss depend on surveys of Devonian marine taxa that are perhaps not well enough known to assess their true rate of losses, so it is difficult to estimate the effects of differential preservation and sampling biases during the Devonian.

Duration and timing[edit]

Extinction rates appear to have been higher than the background rate, for an extended interval covering the last 20–25 million years of the Devonian. During this time, about eight to ten distinct events can be seen, of which two, the Kellwasser and the Hangenberg events, stand out as particularly severe.[33] The Kellwasser event was preceded by a longer period of prolonged biodiversity loss.[34]

The Kellwasser event, named for its type locality, the Kellwassertal in Lower Saxony, Germany, is the term given to the extinction pulse that occurred near the Frasnian–Famennian boundary (372.2 ± 1.6 Ma). Most references to the "Late Devonian extinction" are in fact referring to the Kellwasser, which was the first event to be detected based on marine invertebrate record and was the most severe of the extinction crises of the Late Devonian.[35] There may in fact have been two closely spaced events here, as shown by the presence of two distinct anoxic shale layers.[36][37][38]

Potential causes[edit]

Since the Kellwasser-related extinctions occurred over such a long time, it is difficult to assign a single cause, and indeed to separate cause from effect. From the end of the Middle Devonian (382.7 ± 1.6 Ma), into the Late Devonian (382.7 ± 1.6-358.9 ± 0.4 Ma), several environmental changes can be detected from the sedimentary record, which directly affected organisms and caused extinction. What caused these changes is somewhat more open to debate. Possible triggers for the Kellwasser event are as follows:

Weathering and anoxia[edit]

During the Late Silurian and Devonian, land plants, assisted by fungi,[39][40] underwent a hugely significant phase of evolution known as the Silurian-Devonian Terrestrial Revolution.[41][42] Their maximum height went from 30 cm at the start of the Devonian, to 30 m archaeopterids,[43] at the end of the period. This increase in height was made possible by the evolution of advanced vascular systems, which permitted the growth of complex branching and rooting systems,[23] facilitating their ability to colonise drier areas previously off limits to them.[44] In conjunction with this, the evolution of seeds permitted reproduction and dispersal in areas which were not waterlogged, allowing plants to colonise previously inhospitable inland and upland areas.[23] The two factors combined to greatly magnify the role of plants on the global scale. In particular, Archaeopteris forests expanded rapidly during the closing stages of the Devonian.[45] These tall trees required deep rooting systems to acquire water and nutrients, and provide anchorage. These systems broke up the upper layers of bedrock and stabilized a deep layer of soil, which would have been of the order of metres thick. In contrast, early Devonian plants bore only rhizoids and rhizomes that could penetrate no more than a few centimeters. The mobilization of a large portion of soil had a huge effect: soil promotes weathering, the chemical breakdown of rocks, releasing ions which are nutrients for plants and algae.[23]

The relatively sudden input of nutrients into river water as rooted plants expanded into upland regions may have caused eutrophication and subsequent anoxia.[31] For example, during an algal bloom, organic material formed at the surface can sink at such a rate that decomposing organisms use up all available oxygen by decaying them, creating anoxic conditions and suffocating bottom-dwelling fish. The fossil reefs of the Frasnian were dominated by stromatoporoids and (to a lesser degree) corals—organisms which only thrive in low-nutrient conditions. Therefore, the postulated influx of high levels of nutrients may have caused an extinction.[23][46] Anoxic conditions correlate better with biotic crises than phases of cooling, suggesting anoxia may have played the dominant role in extinction.[47] Evidence exists of a rapid increase in the rate of organic carbon burial and for widespread anoxia in oceanic bottom waters.[48][23] Signs of anoxia in shallow waters have also been described from a variety of localities.[49][50][51] Good evidence has been found for high-frequency sea-level changes around the Frasnian–Famennian Kellwasser event, with one sea-level rise associated with the onset of anoxic deposits.[52]

The timing, magnitude, and causes of Kellwasser anoxia remain poorly understood.[14] Anoxia was not omnipresent across the globe; in some regions, such as South China, the Frasnian-Famennian boundary instead shows evidence of increased oxygenation of the seafloor.[53] Trace metal proxies in black shales from New York state point to anoxic conditions only occurring intermittently, being interrupted by oxic intervals, further indicating that anoxia was not globally synchronous,[54] a finding also supported by the prevalence of cyanobacterial mats in the Holy Cross Mountains in horizons encompassing the Kellwasser event.[55] Evidence from various European sections reveals that Kellwasser anoxia was relegated to epicontinental seas and developed as a result of upwelling of poorly oxygenated waters within ocean basins into shallow waters rather than a global oceanic anoxic event that intruded into epicontinental seas.[56]

Global cooling[edit]

A positive oxygen isotope excursion in phosphates is known from the Frasnian-Famennian boundary, corresponding to a removal of atmospheric carbon dioxide and a global cooling event. This oxygen isotope excursion is known from time-equivalent strata in South China and in the western Palaeotethys, suggesting it was a globally synchronous climatic change. The concomitance of the drop in global temperatures and the swift decline of metazoan reefs indicates the blameworthiness of global cooling in precipitating the extinction event.[57]

The "greening" of the continents during the Silurian-Devonian Terrestrial Revolution that led to them being covered with massive photosynthesizing land plants in the first forests reduced CO2 levels in the atmosphere.[58] Since CO2 is a greenhouse gas, reduced levels might have helped produce a chillier climate, in contrast to the warm climate of the Middle Devonian.[23] The biological sequestration of carbon dioxide may have ultimately led to the beginning of the Late Palaeozoic Ice Age during the Famennian, which has been suggested as a cause of the Hangenberg event.[59]

The weathering of silicate rocks also draws down CO2 from the atmosphere, and CO2 sequestration by mountain building has been suggested as a cause of the decline in greenhouse gases during the Frasnian-Famennian transition. This mountain-building may have also enhanced biological sequestration through an increase in nutrient runoff.[60] The combination of silicate weathering and the burial of organic matter to decreased atmospheric CO2 concentrations from about 15 to three times present levels. Carbon in the form of plant matter would be produced on prodigious scales, and given the right conditions, could be stored and buried, eventually producing vast coal measures (e.g. in China) which locked the carbon out of the atmosphere and into the lithosphere.[61] This reduction in atmospheric CO2 would have caused global cooling and resulted in at least one period of late Devonian glaciation (and subsequent sea level fall),[23] probably fluctuating in intensity alongside the 40ka Milankovic cycle. The continued drawdown of organic carbon eventually pulled the Earth out of its greenhouse state during the Famennian into the icehouse that continued throughout the Carboniferous and Permian.[62][63]

Volcanism[edit]

Magmatism was suggested as a cause of the Late Devonian extinction in 2002.[64] The end of the Devonian Period had extremely widespread trap magmatism and rifting in the Russian and Siberian platforms, which were situated above the hot mantle plumes and suggested as a cause of the Frasnian / Famennian and end-Devonian extinctions.[65] The Viluy Large igneous province, located in the Vilyuysk region on the Siberian Craton, covers most of the present day north-eastern margin of the Siberian Platform. The triple-junction rift system was formed during the Devonian Period; the Viluy rift is the western remaining branch of the system and two other branches form the modern margin of the Siberian Platform. Volcanic rocks are covered with post Late Devonian–Early Carboniferous sediments.[66] Volcanic rocks, dyke belts, and sills that cover more than 320,000 km2, and a gigantic amount of magmatic material (more than 1 million km3) formed in the Viluy branch.[66] The Viluy and Pripyat-Dnieper-Donets large igneous provinces were suggested to correlate with the Frasnian / Famennian extinction,[67] with the Kola and Timan-Pechora magmatic provinces being suggested to be related to the Hangenberg event at the Devonian-Carboniferous boundary.[65] Viluy magmatism may have injected enough CO2 and SO2 into the atmosphere to have generated a destabilised greenhouse and ecosystem, causing rapid global cooling, sea-level falls and marine anoxia occur during Kellwasser black shale deposition.[67][68][69]

Coronene and mercury enrichment has been found in deposits dating back to the Kellwasser event, with similar enrichments found in deposits coeval with the Frasnes event at the Givetian-Frasnian boundary and in ones coeval with the Hangenberg event. Because coronene enrichment is only known in association with large igneous province emissions and extraterrestrial impacts and the fact that there is no confirmed evidence of the latter occurring in association with the Kellwasser event, this enrichment strongly suggests a causal relationship between volcanism and the Kellwasser extinction event.[70]

Recent studies have confirmed a correlation between Viluy traps in the Vilyuysk region on the Siberian Craton and the Kellwasser extinction by 40Ar/39Ar dating.[71][72] Ages show[clarification needed] that the two volcanic phase hypotheses are well supported and the weighted mean ages of each volcanic phase are 376.7±3.4 and 364.4±3.4 Ma, or 373.4±2.1 and 363.2±2.0 Ma, which the first volcanic phase is in agreement with the age of 372.2±3.2 Ma proposed for the Kellwasser event. However, the second volcanic phase is slightly older than Hangenberg event, which is dated to around 358.9±1.2 Ma.[clarification needed][72]

Another overlooked contributor to the Kellwasser mass extinction could be the now extinct Cerberean Caldera which was active in the Late Devonian period and thought to have undergone a supereruption approximately 374 million years ago.[b][74] Remains of this caldera can be found in the modern day state of Victoria, Australia. Eovariscan volcanic activity in present-day Europe may have also played a role in conjunction with the Viluy Traps.[75][76]

Impact event[edit]

Bolide impacts can be dramatic triggers of mass extinctions. An asteroid impact was proposed as the prime cause of this faunal turnover.[3][77] The impact that created the Siljan Ring either was just before the Kellwasser event or coincided with it.[78][79] Most impact craters, such as the Kellwasser-aged Alamo, cannot generally be dated with sufficient precision to link them to the event; others dated precisely are not contemporaneous with the extinction.[2] Although some evidence of meteoric impact have been observed in places, including iridium anomalies[80] and microspherules,[81][82][83] these were probably caused by other factors.[47][84][85]

Supernova[edit]

A more recent explanation suggests that a nearby supernova explosion was the cause for the specific Hangenberg event, which marks the boundary between the Devonian and Carboniferous periods. This could offer a possible explanation for the dramatic drop in atmospheric ozone during the Hangenberg event that could have permitted massive ultraviolet damage to the genetic material of lifeforms, triggering a mass extinction. Recent research offers evidence of ultraviolet damage to pollen and spores over many thousands of years during this event as observed in the fossil record and that, in turn, points to a possible long-term destruction of the ozone layer. A supernova explosion is an alternative explanation to global temperature rise, that could account for the drop in atmospheric ozone. Because very high mass stars, required to produce a supernova, tend to form in dense star-forming regions of space and have short lifespans lasting only at most tens of millions of years, it is likely that if a supernova did occur, multiple others also did within a few million years of it. Thus, supernovae have also been speculated to have been responsible for the Kellwasser event, as well as the entire sequence of environmental crises covering several millions of years towards the end of the Devonian period. Detecting either of the long-lived, extra-terrestrial radioisotopes 146Sm or 244Pu in one or more end-Devonian extinction strata would confirm a supernova origin. However, there is currently no direct evidence for this hypothesis.[86]

Other hypotheses[edit]

Other mechanisms put forward to explain the extinctions include tectonic-driven climate change, sea-level change, and oceanic overturning.[87] These have all been discounted because they are unable to explain the duration, selectivity, and periodicity of the extinctions.[88][47]

See also[edit]

Notes[edit]

  1. ^ The species estimate is the toughest to assess and most likely to be adjusted.
  2. ^ Though a super eruption on its own would have devastating effects in both short term and long term, the Late Devonian extinction was caused by a series of events which contributed to the extinction.[73]

References[edit]

  1. ^ a b Clack, Jennifer A. (13 August 2007). "Devonian climate change, breathing, and the origin of the tetrapod stem group". Integrative and Comparative Biology. 47 (4): 510–523. doi:10.1093/icb/icm055. Retrieved 15 January 2023.
  2. ^ a b Racki, 2005
  3. ^ a b c McGhee, George R. Jr, 1996. The Late Devonian Mass Extinction: the Frasnian/Famennian Crisis (Columbia University Press) ISBN 0-231-07504-9
  4. ^ "John Baez, Extinction, April 8, 2006".
  5. ^ Sallan, L.; Galimberti, A. K. (2015-11-13). "Body-size reduction in vertebrates following the end-Devonian mass extinction". Science. 350 (6262): 812–815. doi:10.1126/science.aac7373. PMID 26564854. S2CID 206640186.
  6. ^ Caplan, Mark L; Bustin, R.Mark (May 1999). "Devonian–Carboniferous Hangenberg mass extinction event, widespread organic-rich mudrock and anoxia: causes and consequences". Palaeogeography, Palaeoclimatology, Palaeoecology. 148 (4): 187–207. Bibcode:1999PPP...148..187C. doi:10.1016/S0031-0182(98)00218-1.
  7. ^ Stigall, Alycia (2011). "GSA Today - Speciation collapse and invasive species dynamics during the Late Devonian "Mass Extinction"". www.geosociety.org. Retrieved 2021-03-30.
  8. ^ Sole, R. V., and Newman, M., 2002. "Extinctions and Biodiversity in the Fossil Record - Volume Two, The earth system: biological and ecological dimensions of global environment change" pp. 297-391, Encyclopedia of Global Environmental Change John Wiley & Sons.
  9. ^ Sole, R. V., and Newman, M. Patterns of extinction and biodiversity in the fossil record Archived 2012-03-14 at the Wayback Machine
  10. ^ Bambach, R.K.; Knoll, A.H.; Wang, S.C. (December 2004). "Origination, extinction, and mass depletions of marine diversity". Paleobiology. 30 (4): 522–542. doi:10.1666/0094-8373(2004)030<0522:OEAMDO>2.0.CO;2. S2CID 17279135.
  11. ^ a b Stigall, 2011
  12. ^ Sallan, L. C.; Coates, M. I. (June 2010). "End-Devonian extinction and a bottleneck in the early evolution of modern jawed vertebrates". Proceedings of the National Academy of Sciences. 107 (22): 10131–10135. Bibcode:2010PNAS..10710131S. doi:10.1073/pnas.0914000107. PMC 2890420. PMID 20479258.
  13. ^ Girard, Catherine; Renaud, Sabrina (25 June 2007). "Quantitative conodont-based approaches for correlation of the Late Devonian Kellwasser anoxic events". Palaeogeography, Palaeoclimatology, Palaeoecology. 250 (1–4): 114–125. doi:10.1016/j.palaeo.2007.03.007. Retrieved 15 January 2023.
  14. ^ a b Carmichael, Sarah K.; Waters, Johnny A.; Königshof, Peter; Suttner, Thomas J.; Kido, Erika (December 2019). "Paleogeography and paleoenvironments of the Late Devonian Kellwasser event: A review of its sedimentological and geochemical expression". Global and Planetary Change. 183: 102984. doi:10.1016/j.gloplacha.2019.102984. S2CID 198415606. Retrieved 23 December 2022.
  15. ^ Wang, Pengwei; Chen, Zhuoheng; Jin, Zhijun; Jiang, Chunqing; Sun, Mingliang; Guo, Yingchun; Chen, Xiao; Jia, Zekai (February 2018). "Shale oil and gas resources in organic pores of the Devonian Duvernay Shale, Western Canada Sedimentary Basin based on petroleum system modeling". Journal of Natural Gas Science and Engineering. 50: 33–42. doi:10.1016/j.jngse.2017.10.027. Retrieved 15 January 2023.
  16. ^ Dong, Tian; Harris, Nicholas B.; McMillan, Julia M.; Twemlow, Cory E.; Nassichuk, Brent R.; Bish, David L. (15 May 2019). "A model for porosity evolution in shale reservoirs: An example from the Upper Devonian Duvernay Formation, Western Canada Sedimentary Basin". AAPG Bulletin. 103 (5): 1017–1044. doi:10.1306/10261817272. Retrieved 15 January 2023.
  17. ^ Smith, Mark G.; Bustin, R. Marc (1 July 2000). "Late Devonian and Early Mississippian Bakken and Exshaw Black Shale Source Rocks, Western Canada Sedimentary Basin: A Sequence Stratigraphic Interpretation". AAPG Bulletin. 84 (7): 940–960. doi:10.1306/A9673B76-1738-11D7-8645000102C1865D. Retrieved 15 January 2023.
  18. ^ Parry, S. F.; Noble, S. R.; Crowley, Q. G.; Wellman, C. H. (2011). "A high-precision U–Pb age constraint on the Rhynie Chert Konservat-Lagerstätte: time scale and other implications". Journal of the Geological Society. London: Geological Society. 168 (4): 863–872. doi:10.1144/0016-76492010-043.
  19. ^ Kaufmann, B.; Trapp, E.; Mezger, K. (2004). "The numerical age of the Upper Frasnian (Upper Devonian) Kellwasser horizons: A new U-Pb zircon date from Steinbruch Schmidt(Kellerwald, Germany)". The Journal of Geology. 112 (4): 495–501. Bibcode:2004JG....112..495K. doi:10.1086/421077.
  20. ^ Algeo, T. J. (1998). "Terrestrial-marine teleconnections in the Devonian: links between the evolution of land plants, weathering processes, and marine anoxic events". Philosophical Transactions of the Royal Society B: Biological Sciences. 353 (1365): 113–130. doi:10.1098/rstb.1998.0195.
  21. ^ "Chart/Time Scale". www.stratigraphy.org. International Commission on Stratigraphy.
  22. ^ McKerrow, W.S.; Mac Niocaill, C.; Dewey, J.F. (2000). "The Caledonian Orogeny redefined". Journal of the Geological Society. 157 (6): 1149–1154. Bibcode:2000JGSoc.157.1149M. doi:10.1144/jgs.157.6.1149. S2CID 53608809.
  23. ^ a b c d e f g h i Algeo, T.J.; Scheckler, S. E. (1998). "Terrestrial-marine teleconnections in the Devonian: links between the evolution of land plants, weathering processes, and marine anoxic events". Philosophical Transactions of the Royal Society B: Biological Sciences. 353 (1365): 113–130. doi:10.1098/rstb.1998.0195. PMC 1692181.
  24. ^ Dalton, Rex (2006). "The fish that crawled out of the water". Nature: news060403–7. doi:10.1038/news060403-7. S2CID 129031187. Archived from the original on 2006-04-11. Retrieved 2006-04-06.
  25. ^ Neil H. Shubin, Edward B. Daeschler and Farish A. Jenkins Jr (6 April 2006). "The pectoral fin of Tiktaalik roseae and the origin of the tetrapod limb". Nature. 440 (7085): 764–771. Bibcode:2006Natur.440..764S. doi:10.1038/nature04637. PMID 16598250. S2CID 4412895.
  26. ^ Ma, Kunyuan; Hinnov, Linda; Zhang, Xinsong; Gong, Yiming (August 2022). "Astronomical climate changes trigger Late Devonian bio- and environmental events in South China". Global and Planetary Change. 215: 103874. doi:10.1016/j.gloplacha.2022.103874. Retrieved 22 November 2022.
  27. ^ Zapalski, Mikołaj K.; Berkowski, Błażej; Wrzołek, Tomasz (23 March 2016). "Tabulate Corals after the Frasnian/Famennian Crisis: A Unique Fauna from the Holy Cross Mountains, Poland". PLOS ONE. 11 (3). doi:10.1371/journal.pone.0149767. Retrieved 26 January 2023.
  28. ^ "Kellwasser Event | paleontology | Britannica". www.britannica.com. Retrieved 2023-01-31.
  29. ^ Copper, Paul (2002-06-20). "Reef development at the Frasnian/Famennian mass extinction boundary". Palaeogeography, Palaeoclimatology, Palaeoecology. 181 (1): 27–65. doi:10.1016/S0031-0182(01)00472-2. ISSN 0031-0182.
  30. ^ Shen, Jianwei; Webb, Gregory E.; Qing, Hairuo (16 November 2010). "Microbial mounds prior to the Frasnian-Famennian mass extinctions, Hantang, Guilin, South China". Sedimentology. 57 (7): 1615–1639. doi:10.1111/j.1365-3091.2010.01158.x. Retrieved 26 January 2023.
  31. ^ a b Balter, Vincent; Renaud, Sabrina; Girard, Catherine; Joachimski, Michael M. (November 2008). "Record of climate-driven morphological changes in 376 Ma Devonian fossils". Geology. 36 (11): 907. Bibcode:2008Geo....36..907B. doi:10.1130/G24989A.1.
  32. ^ Friedman, Matt; Sallan, Lauren Cole (2012). "Five hundred million years of extinction and recovery: a phanerozoic survey of large-scale diversity patterns in fishes: EXTINCTION AND RECOVERY IN FISHES". Palaeontology. 55 (4): 707–742. doi:10.1111/j.1475-4983.2012.01165.x. S2CID 59423401.
  33. ^ Algeo, T.J., S.E. Scheckler and J. B. Maynard (2001). "Effects of the Middle to Late Devonian spread of vascular land plants on weathering regimes, marine biota, and global climate". In P.G. Gensel; D. Edwards (eds.). Plants Invade the Land: Evolutionary and Environmental Approaches. Columbia Univ. Press: New York. pp. 13–236.{{cite book}}: CS1 maint: multiple names: authors list (link)
  34. ^ Streel, M.; Caputo, M.V.; Loboziak, S.; Melo, J.H.G. (2000). "Late Frasnian--Famennian climates based on palynomorph analyses and the question of the Late Devonian glaciations". Earth-Science Reviews. 52 (1–3): 121–173. Bibcode:2000ESRv...52..121S. doi:10.1016/S0012-8252(00)00026-X. hdl:2268/156563.
  35. ^ Percival, L. M. E.; Davies, J. H. F. L.; Schaltegger, Urs; De Vleeschouwer, D.; Da Silva, A.-C.; Föllmi, K. B. (22 June 2018). "Precisely dating the Frasnian–Famennian boundary: implications for the cause of the Late Devonian mass extinction". Scientific Reports. 8. doi:10.1038/s41598-018-27847-7. PMID 29934550. Retrieved 26 January 2023.
  36. ^ Riquier, Laurent; Tribovillard, Nicolas; Averbuch, Olivier; Devleeschuwer, Xavier; Riboulleau, Armelle (30 September 2006). "The Late Frasnian Kellwasser horizons of the Harz Mountains (Germany): Two oxygen-deficient periods resulting from different mechanisms". Chemical Geology. 233 (1–2): 137–155. doi:10.1016/j.chemgeo.2006.02.021. Retrieved 15 January 2023.
  37. ^ Joachimski, Michael M.; Buggisch, Werner (1 August 1993). "Anoxic events in the late Frasnian—Causes of the Frasnian-Famennian faunal crisis?". Geology. 21 (8): 675–678. doi:10.1130/0091-7613(1993)021<0675:AEITLF>2.3.CO;2. Retrieved 15 January 2023.
  38. ^ Renaud, Sabrina; Girard, Catherine (15 February 1999). "Strategies of survival during extreme environmental perturbations: evolution of conodonts in response to the Kellwasser crisis (Upper Devonian)". Palaeogeography, Palaeoclimatology, Palaeoecology. 146 (1–4): 19–32. doi:10.1016/S0031-0182(98)00138-2. Retrieved 15 January 2023.
  39. ^ Lutzoni, François; Nowak, Michael D.; Alfaro, Michael E.; Reeb, Valérie; Miadlikowska, Jolanta; Krug, Michael; Arnold, A. Elizabeth; Lewis, Louise A.; Swofford, David L.; Hibbett, David; Hilu, Khidir; James, Timothy Y.; Quandt, Dietmar; Magallón, Susana (21 December 2018). "Contemporaneous radiations of fungi and plants linked to symbiosis". Nature Communications. 9: 1–11. doi:10.1038/s41467-018-07849-9. Retrieved 7 December 2022.
  40. ^ Retallack, Gregory J. (June 2022). "Ordovician-Devonian lichen canopies before evolution of woody trees". Gondwana Research. 106: 211–223. doi:10.1016/j.gr.2022.01.010. Retrieved 22 November 2022.
  41. ^ Capel, Elliot; Cleal, Christopher J.; Xue, Jinzhuang; Monnet, Claude; Servais, Thomas; Cascales-Miñana, Borja (August 2022). "The Silurian–Devonian terrestrial revolution: Diversity patterns and sampling bias of the vascular plant macrofossil record". Earth-Science Reviews. 231. doi:10.1016/j.earscirev.2022.104085. Retrieved 15 January 2023.
  42. ^ Xue, Jinzhuang; Huang, Pu; Wang, Deming; Xiong, Conghui; Liu, Le; Basinger, James F. (May 2018). "Silurian-Devonian terrestrial revolution in South China: Taxonomy, diversity, and character evolution of vascular plants in a paleogeographically isolated, low-latitude region". Earth-Science Reviews. 180: 92–125. doi:10.1016/j.earscirev.2018.03.004. Retrieved 15 January 2023.
  43. ^ Beck, C.B. (April 1962). "Reconstructions of Archaeopteris, and further consideration of its phylogenetic position". American Journal of Botany. 49 (4): 373–382. doi:10.1002/j.1537-2197.1962.tb14953.x. hdl:2027.42/141981.
  44. ^ Gurung, Khushboo; Field, Katie J.; Batterman, Sarah J.; Goddéris, Yves; Donnadieu, Yannick; Porada, Philipp; Taylor, Lyla L.; Mills, Benjamin J. W. (4 August 2022). "Climate windows of opportunity for plant expansion during the Phanerozoic". Nature Communications. 13. doi:10.1038/s41467-022-32077-7. Retrieved 24 December 2022.
  45. ^ Stein, William E.; Berry, Christopher M.; Morris, Jennifer L.; Hernick, Linda VanAller; Mannolini, Frank; Ver Straeten, Charles; Landing, Ed; Marshall, John E. A.; Wellman, Charles H.; Beerling, David J.; Leake, Jonathan R. (3 February 2020). "Mid-Devonian Archaeopteris Roots Signal Revolutionary Change in Earliest Fossil Forests". Current Biology. 30 (3): 321–331. doi:10.1016/j.cub.2019.11.067. Retrieved 15 January 2023.
  46. ^ Smart, Matthew S.; Filippelli, Gabriel; Gilhooly III, William P.; Marshall, John E.A.; Whiteside, Jessica H. (9 November 2022). "Enhanced terrestrial nutrient release during the Devonian emergence and expansion of forests: Evidence from lacustrine phosphorus and geochemical records". GSA Bulletin. doi:10.1130/B36384.1.
  47. ^ a b c Algeo, T.J.; Berner, R.A.; Maynard, J.B.; Scheckler, S.E.; Archives, G.S.A.T. (1995). "Late Devonian Oceanic Anoxic Events and Biotic Crises: "Rooted" in the Evolution of Vascular Land Plants?" (PDF). GSA Today. 5 (3).
  48. ^ Joachimski, Michael M.; Ostertag-Henning, Christian; Pancost, Richard D.; Strauss, Harald; Freeman, Katherine H.; Littke, Ralf; Sinninghe Damsté, Jaap S.; Racki, Grzegorz (1 May 2001). "Water column anoxia, enhanced productivity and concomitant changes in δ13C and δ34S across the Frasnian–Famennian boundary (Kowala — Holy Cross Mountains/Poland)". Chemical Geology. 175 (1–2): 109–131. doi:10.1016/S0009-2541(00)00365-X. Retrieved 26 January 2023.
  49. ^ Bond, David P. G.; Zatoń, Michał; Wignall, Paul B.; Marynowski, Leszek (11 March 2013). "Evidence for shallow-water 'Upper Kellwasser' anoxia in the Frasnian–Famennian reefs of Alberta, Canada". Lethaia. 46 (3): 355–368. doi:10.1111/let.12014. Retrieved 12 January 2023.
  50. ^ Carmichael, Sarah K.; Waters, Johnny A.; Suttner, Thomas J.; Kido, Erika; DeReuil, Aubry A. (1 April 2014). "A new model for the Kellwasser Anoxia Events (Late Devonian): Shallow water anoxia in an open oceanic setting in the Central Asian Orogenic Belt". Palaeogeography, Palaeoclimatology, Palaeoecology. 399: 394–403. doi:10.1016/j.palaeo.2014.02.016. Retrieved 12 January 2023.
  51. ^ Bond, David P. G.; Wignall, Paul B. (2005). "Evidence for Late Devonian (Kellwasser) anoxic events in the Great Basin, Western United States". In Over, D. J.; Morrow, J. R.; Wignall, Paul B. (eds.). Understanding Late Devonian And Permian-Triassic Biotic and Climatic Events: Towards an Integrated Approach. Developments in Palaeontology and Stratigraphy. Vol. 20. Elsevier. pp. 225–262. doi:10.1016/S0920-5446(05)80009-3. ISBN 978-0-444-52127-9.
  52. ^ David P. G. Bond; Paul B. Wignalla (2008). "The role of sea-level change and marine anoxia in the Frasnian-Famennian (Late Devonian) mass extinction" (PDF). Palaeogeography, Palaeoclimatology, Palaeoecology. 263 (3–4): 107–118. Bibcode:2008PPP...263..107B. doi:10.1016/j.palaeo.2008.02.015.
  53. ^ Cui, Yixin; Shen, Bing; Sun, Yuanlin; Ma, Haoran; Chang, Jieqiong; Li, Fangbing; Lang, Xianguo; Peng, Yongbo (July 2021). "A pulse of seafloor oxygenation at the Late Devonian Frasnian-Famennian boundary in South China". Earth-Science Reviews. 218: 1–22. doi:10.1016/j.earscirev.2021.103651. Retrieved 15 January 2023.
  54. ^ Haddad, Emily E.; Boyer, Diana L.; Droser, Mary L.; Lee, Bridget K.; Lyons, Timothy W.; Love, Gordon D. (15 January 2018). "Ichnofabrics and chemostratigraphy argue against persistent anoxia during the Upper Kellwasser Event in New York State". Palaeogeography, Palaeoclimatology, Palaeoecology. 490: 178–190. doi:10.1016/j.palaeo.2017.10.025. Retrieved 15 January 2023.
  55. ^ Kazmierczak, J.; Kremer, B.; Racki, Grzegorz (7 August 2012). "Late Devonian marine anoxia challenged by benthic cyanobacterial mats". Geobiology. 10 (5): 371–383. doi:10.1111/j.1472-4669.2012.00339.x. Retrieved 26 January 2023.
  56. ^ Bond, David P. G.; Wignall, Paul B.; Racki, Grzegorz (1 March 2004). "Extent and duration of marine anoxia during the Frasnian–Famennian (Late Devonian) mass extinction in Poland, Germany, Austria and France". Geological Magazine. 141 (2): 173–193. doi:10.1017/S0016756804008866. Retrieved 15 January 2023.
  57. ^ Huang, Cheng; Joachimski, Michael M.; Gong, Yiming (1 August 2018). "Did climate changes trigger the Late Devonian Kellwasser Crisis? Evidence from a high-resolution conodont record from South China". Earth and Planetary Science Letters. 495: 174–184. doi:10.1016/j.epsl.2018.05.016. Retrieved 15 January 2023.
  58. ^ Le Hir, Guillaume; Donnadieu, Yannick; Goddéris, Yves; Meyer-Berthaud, Brigitte; Ramstein, Gilles; Blakey, Ronald C. (October 2011). "The climate change caused by the land plant invasion in the Devonian". Earth and Planetary Science Letters. 310 (3–4): 203–212. Bibcode:2011E&PSL.310..203L. doi:10.1016/j.epsl.2011.08.042. Retrieved 15 January 2023.
  59. ^ Brezinski, D.K.; Cecil, C.B.; Skema, V.W.; Kertis, C.A. (2009). "Evidence for long-term climate change in Upper Devonian strata of the central Appalachians". Palaeogeography, Palaeoclimatology, Palaeoecology. 284 (3–4): 315–325. Bibcode:2009PPP...284..315B. doi:10.1016/j.palaeo.2009.10.010.
  60. ^ Averbuch, O.; Tribovillard, N.; Devleeschouwer, X.; Riquier, L.; Mistiaen, B.; Van Vliet-Lanoe, B. (2 March 2005). "Mountain building-enhanced continental weathering and organic carbon burial as major causes for climatic cooling at the Frasnian–Famennian boundary (c. 376 Ma)?". Terra Nova. 17 (1): 25–34. doi:10.1111/j.1365-3121.2004.00580.x. S2CID 140189725. Retrieved 23 December 2022.
  61. ^ Carbon locked in Devonian coal, the earliest of Earth's coal deposits, is currently being returned to the atmosphere.
  62. ^ Rosa, Eduardo L. M.; Isbell, John L. (2021). "Late Paleozoic Glaciation". In Alderton, David; Elias, Scott A. (eds.). Encyclopedia of Geology (2nd ed.). Academic Press. pp. 534–545. doi:10.1016/B978-0-08-102908-4.00063-1. ISBN 978-0-08-102909-1. S2CID 226643402.
  63. ^ Qie, Wenkun; Algeo, Thomas J.; Luo, Genming; Herrmann, Achim (1 October 2019). "Global events of the Late Paleozoic (Early Devonian to Middle Permian): A review". Palaeogeography, Palaeoclimatology, Palaeoecology. 531: 109259. doi:10.1016/j.palaeo.2019.109259. S2CID 198423364. Retrieved 23 December 2022.
  64. ^ Kravchinsky, V.A.; K.M. Konstantinov; V. Courtillot; J.-P. Valet; J.I. Savrasov; S.D. Cherniy; S.G. Mishenin; B.S. Parasotka (2002). "Palaeomagnetism of East Siberian traps and kimberlites: two new poles and palaeogeographic reconstructions at about 360 and 250 Ma". Geophysical Journal International. 148 (1): 1–33. Bibcode:2002GeoJI.148....1K. doi:10.1046/j.0956-540x.2001.01548.x.
  65. ^ a b Kravchinsky, V. A. (2012). "Paleozoic large igneous provinces of Northern Eurasia: Correlation with mass extinction events". Global and Planetary Change. 86–87: 31–36. Bibcode:2012GPC....86...31K. doi:10.1016/j.gloplacha.2012.01.007.
  66. ^ a b Kuzmin, M.I.; Yarmolyuk, V.V.; Kravchinsky, V.A. (2010). "Phanerozoic hot spot traces and paleogeographic reconstructions of the Siberian continent based on interaction with the African large low shear velocity province". Earth-Science Reviews. 148 (1–2): 1–33. Bibcode:2010ESRv..102...29K. doi:10.1016/j.earscirev.2010.06.004.
  67. ^ a b Bond, D. P. G.; Wignall, P. B. (2014). "Large igneous provinces and mass extinctions: An update". GSA Special Papers. 505: 29–55. doi:10.1130/2014.2505(02). ISBN 9780813725055. Retrieved 23 December 2022.
  68. ^ Joachimski, M. M.; et al. (2002). "Conodont apatite δ18O signatures indicate climatic cooling as a trigger of the Late Devonian mass extinction". Geology. 30 (8): 711. Bibcode:2002Geo....30..711J. doi:10.1130/0091-7613(2002)030<0711:caosic>2.0.co;2.
  69. ^ Ma, X. P.; et al. (2015). "The Late Devonian Frasnian–Famennian event in South China — Patterns and causes of extinctions, sea level changes, and isotope variations". Palaeogeography, Palaeoclimatology, Palaeoecology. 448: 224–244. doi:10.1016/j.palaeo.2015.10.047.
  70. ^ Kaiho, Kunio; Miura, Mami; Tezuka, Mio; Hayashi, Naohiro; Jones, David S.; Oikawa, Kazuma; Casier, Jean-Georges; Fujibayashi, Megumu; Chen, Zhong-Qiang (April 2021). "Coronene, mercury, and biomarker data support a link between extinction magnitude and volcanic intensity in the Late Devonian". Global and Planetary Change. 199: 103452. doi:10.1016/j.gloplacha.2021.103452. S2CID 234364043. Retrieved 23 December 2022.
  71. ^ Courtillot, V.; et al. (2010). "Preliminary dating of the Viluy traps (Eastern Siberia): Eruption at the time of Late Devonian extinction events?". Earth and Planetary Science Letters. 102 (1–2): 29–59. Bibcode:2010ESRv..102...29K. doi:10.1016/j.earscirev.2010.06.004.
  72. ^ a b Ricci, J.; et al. (2013). "New 40Ar/39Ar and K–Ar ages of the Viluy traps (Eastern Siberia): Further evidence for a relationship with the Frasnian–Famennian mass extinction". Palaeogeography, Palaeoclimatology, Palaeoecology. 386: 531–540. doi:10.1016/j.palaeo.2013.06.020.
  73. ^ "Devonian Mass Extinction: Causes, Facts, Evidence & Animals". Study.com. Retrieved 4 October 2019.
  74. ^ Clemens, J. D.; Birch, W. D. (2012). "Assembly of a zoned volcanic magma chamber from multiple magma batches: The Cerberean Cauldron, Marysville Igneous Complex, Australia". Lithos. 155: 272–288. Bibcode:2012Litho.155..272C. doi:10.1016/j.lithos.2012.09.007.
  75. ^ Racki, Grzegorz; Rakociński, Michał; Marynowski, Leszek; Wignall, Paul B. (26 April 2018). "Mercury enrichments and the Frasnian-Famennian biotic crisis: A volcanic trigger proved?". Geology. 46 (6): 543–546. doi:10.1130/G40233.1. Retrieved 23 December 2022.
  76. ^ Racki, Grezgorz (June 2020). "A volcanic scenario for the Frasnian–Famennian major biotic crisis and other Late Devonian global changes: More answers than questions?". Global and Planetary Change. 189: 103174. doi:10.1016/j.gloplacha.2020.103174. S2CID 216223745. Retrieved 23 December 2022.
  77. ^ Digby McLaren, 1969
  78. ^ Reimold, Wolf U.; Kelley, Simon P.; Sherlock, Sarah C.; Henkel, Herbert; Koeberl, Christian (26 January 2010). "Laser argon dating of melt breccias from the Siljan impact structure, Sweden: Implications for a possible relationship to Late Devonian extinction events". Meteoritics & Planetary Science. 40 (4): 591–607. doi:10.1111/j.1945-5100.2005.tb00965.x. Retrieved 14 January 2023.
  79. ^ J.R. Morrow and C.A. Sandberg. Revised Dating Of Alamo And Some Other Late Devonian Impacts In Relation To Resulting Mass Extinction, 68th Annual Meteoritical Society Meeting (2005)
  80. ^ Becker, R. Thomas; House, Michael R.; Kirchgasser, William T.; Playford, Phillip E. (1991). "Sedimentary and faunal changes across the frasnian/famennian boundary in the canning basin of Western Australia". Historical Biology. 5 (2–4): 183–196. doi:10.1080/10292389109380400. Retrieved 15 January 2023.
  81. ^ Claeys, Philippe; Casier, Jean-Georges (April 1994). "Microtektite-like impact glass associated with the Frasnian-Famennian boundary mass extinction". Earth and Planetary Science Letters. 122 (3–4): 303–315. doi:10.1016/0012-821X(94)90004-3. Retrieved 15 January 2023.
  82. ^ Claeys, Philippe; Casier, Jean-Georges; Margolis, Stanley V. (21 August 1992). "Microtektites and Mass Extinctions: Evidence for a Late Devonian Asteroid Impact". Science. 257 (5073): 1102–1104. doi:10.1126/science.257.5073.1102. Retrieved 15 January 2023.
  83. ^ Claeys, P.; Kyte, F. T.; Herbosch, A.; Casier, J.-G. (1 January 1996). "Geochemistry of the Frasnian-Famennian boundary in Belgium: Mass extinction, anoxic oceans and microtektite layer, but not much iridium?". Special Paper of the Geological Society of America. 307: 491–506. doi:10.1130/0-8137-2307-8.491. Retrieved 26 January 2023.
  84. ^ Wang K, Attrep M, Orth CJ (December 2017). "Global iridium anomaly, mass extinction, and redox change at the Devonian-Carboniferous boundary". Geology. 21 (12): 1071–1074. doi:10.1130/0091-7613(1993)021<1071:giamea>2.3.co;2.
  85. ^ Nicoll, Robert S.; Playford, Phillip E. (September 1993). "Upper Devonian iridium anomalies, conodont zonation and the Frasnian-Famennian boundary in the Canning Basin, Western Australia". Palaeogeography, Palaeoclimatology, Palaeoecology. 104 (1–4): 105–113. doi:10.1016/0031-0182(93)90123-Z. Retrieved 15 January 2023.
  86. ^ Fields, Brian D.; Melott, Adrian L.; Ellis, John; Ertel, Adrienne F.; Fry, Brian J.; Lieberman, Bruce S.; Liu, Zhenghai; Miller, Jesse A.; Thomas, Brian C. (2020-08-18). "Supernova triggers for end-Devonian extinctions". Proceedings of the National Academy of Sciences of the United States of America. 117 (35): 21008–21010. arXiv:2007.01887. Bibcode:2020PNAS..11721008F. doi:10.1073/pnas.2013774117. ISSN 0027-8424. PMC 7474607. PMID 32817482.
  87. ^ Racki, Grzegorz (September 1998). "Frasnian–Famennian biotic crisis: undervalued tectonic control?". Palaeogeography, Palaeoclimatology, Palaeoecology. 141 (3–4): 177–198. doi:10.1016/S0031-0182(98)00059-5. Retrieved 26 January 2023.
  88. ^ Kabanov, P.; Jiang, C. (May 2020). "Photic-zone euxinia and anoxic events in a Middle-Late Devonian shelfal sea of Panthalassan continental margin, NW Canada: Changing paradigm of Devonian ocean and sea level fluctuations". Global and Planetary Change. 188. doi:10.1016/j.gloplacha.2020.103153. Retrieved 26 January 2023.

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