Late Paleozoic World, Life & Extinctions Norman MacLeod School of Earth Sciences & Engineering, Nanjing University Late Paleozoic World, Life & Extinctions

Objectives

Understand the structure of the Late Paleozoic (Carbon- iferous - Permian world in terms of timescales, geo- graphy, environments, and organisms.

Understand the structure of Late Paleozoic extinction events.

Understand the major Late Paleozoic extinction drivers.

Understand the degree to which these putative drivers correlate with Late Paleozoic extinction events. Late Paleozoic World, Life & Extinctions

Presentation Topics

Stratigraphy - chronostrati- graphy & geochronology Geography - tectonics & distribution Climate - circulation, temp- erature, weather Biota - protists, inverte- brates, vertebrates, plants Evolution - evolutionary faunas, adaptive radiations, major innovations Significant Events - sea-level changes, volcanic eruptions, marine anoxia events, bolide impacts, extinctions Carboniferous Carboniferous Paleozoic System Durations

75

60

45

30 Duration(myr)

15

0 Camb. Ord. Sil. Dev. Carbon. Perm.

Data from ICS (2020) Carboniferous Timescale

System/ Numerical Period Series/Epoch Stage/Age Age (Ma) 289.9 ± 0.15 Gzhelian Upper 303.7 ± 0.1 Kasimovian 307.0 ± 0.1 Middle Moscovian 315.2 ± 0.2 Pennsylvanian Lower Bashkirian 315.2 ± 0.2 Upper Serpukhovian 323.2 ± 0.4

Carboniferous Middle Visean 346.7 ± 0.4 Tournasian

Mississippian Lower 358.9 ± 0.4

ICS International Chronostrat. Chart 2020/03 Carboniferous Tectonic Configuration

Pangea becomes unified and occupies southern polar region with Euramerica (= Laurentia + Avalonia + Baltica) & Siberia forming satellite continents separated from (former) Gondwana by a broad seaway in the Early Carboniferous the former joined to Gondwana (to form Pangea by the Late Carboniferous.

Northern seaway referred to as Iapetus Ocean Southern seaway referred to as the Rheic Ocean Both Iapetus and Rhetic Oceans close during the Interval … … leaving the Paleo- Tethys, Panthalassic Ocean (= Proto-Pacific).

Map from Scotese PaleoMap Project (2001) Carboniferous Tectonic Configuration

Pangea becomes unified and occupies southern polar region with Euramerica (= Laurentia + Avalonia + Baltica) & Siberia forming satellite continents separated from (former) Gondwana by a broad seaway in the Early Carboniferous the former joined to Gondwana (to form Pangea by the Late Carboniferous.

Northern seaway referred to as Iapetus Ocean Southern seaway referred to as the Rheic Ocean Both Iapetus and Rhetic Oceans close during the Interval … … leaving the Paleo- Tethys, Panthalassic Ocean (= Proto-Pacific).

Map from Scotese PaleoMap Project (2001) Carboniferous Marine Circulation

Simplified, but hemispherically heterogeneous circulation patterns.

Strong circum-Arctic cold current Disrupted circum-equatorial current Northern & southern Paleo- Tethys gyres Broken circum-Antarctic cold current Upwelling zone off western Euamerica & northern Gondwana

Map from Scotese PaleoMap Project (2001) Carboniferous Paleoenvironment

Atmospheric O Atmospheric CO 2 2 35 5000

28 4000

21 3000

14 2000 PercentbyVol. 7 PerMillionParts 1000

0 0 Camb. Ord. Sil. Dev. Carbon. Perm. Camb. Ord. Sil. Dev. Carbon. Perm.

Mean Surface Temperature Sea Level 25 250

20 200

15 150

10 Present 100 Meters Above Meters

DegreesCelsius 5 50

0 0 Camb. Ord. Sil. Dev. Carbon. Perm. Camb. Ord. Sil. Dev. Carbon. Perm. Carboniferous Climate Zones

Comparative Criteria Silurian

O2 Content of 32.3% vol. % Atmosphere (+162%)

CO2 Content of 800 ppm Atmosphere (x3)

Mean Surface 14°C Temperature (0°C)

Sea Level +120m - 0m - +20m

Characterized by high sea-levels and a marked greenhouse effect resulting from high atmospheric CO2 concentrations Greatly expanded tropical, arid & temperate belts Clear southern ice cap early, melting as interval proceeds Falling sea levels through Moscovian, then rising sea levels Draining, the refolding of continental platforms Map from Scotese PaleoMap Project (2000) Carboniferous Cambrian Evolutionary Fauna

Trilobite Graptolite

Inarticulata Monoplacophora Hyolith Carboniferous Paleozoic Evolutionary Fauna

Articulata Crinoid

Tabulate Coral Bryozoan Ammonite Ruose Coral Carboniferous Modern Evolutionary Fauna

Bivalve Gastropod Echinoid Bony Fish Carboniferous Reefs

Carboniferous Reef

Widespread reef formation in epicontinental seas, becoming progressively more restricted geographically as the tropical Iapetus and Rhetic seas close. Laurentia / Euamerica Baltica Siberia Northern Gondwana Map from Scotese PaleoMap Project (2000) Carboniferous Reefs

Carboniferous deep-water reefs were typically characterized as mud mounds.

Core of reef-forming organisms (e.g., bryozoans, crinoids) created topological reef by baffling lime mud around themselves Carboniferous mud reefs had no apparent framework Began in deeper water, but could grow into shallower depths Microbial reef organisms important elements of reef composition/construction Reef structure attracted a host of marine benthos & nekton

Diagram from Wood (1998) Carboniferous Fish

Platystomus Rhizodus

Latimeria Acrolepis Carboniferous Fish Carboniferous Elasmobranchs

Akmonistion Diploselache

Hybodontid

Damocles serrates Carboniferous Elasmobranchs Carboniferous Terrestrial Environment

Adjacent to the low and mid-latitude shallow seas were dense tropical forests that form the basis for thick and laterally extensive coal deposits. Temperate forests and steppes were present at higher latitudes

Plants Arthropods (incl. insects) Amphibians The first reptiles

Carboniferous Terrestrial Scene Carboniferous Terrestrial Environment

Equisetales Sphenophyllales Lycopodiales Lepidodendrales Filicales (Horse Tails) (Scramblers) (Club Mosses) (Scale Trees) (Ferns)

Cordaitales Cycadophyta (Early Conifers) (Cycads) Carboniferous Terrestrial Environment

Carboniferous Forest Carboniferous Terrestrial Arthropods

Terrestrial arthropods were able to grow to such enormous sizes because of the high concentration of O2 in the Carboniferous atmosphere (32.3% vol. %, or +162% present day concentrations)

Arthropleura (Largest known land arthropod: Length 2.5 m)

Pulmonoscorpius Carboniferous Terrestrial Insects

Dictyoptera (Cockroach Ancestor) Meganeura Protorthoptera (Largest known insects: wingspan c. 75 cm) (Earliest known Winged Insect)

Palaeodictyoptera (Superorder: 50% of all known insects) Carboniferous Quadrupeds (Amphibians)

Eyrops Pederpes (Labyrinthodont: Temnospondyl) (Labyrinthodont)

Hyloplesion (Lepospondyl: Microsauria)

Dioplocaulus (Lepospondyl: Lissamphibian) Ophiderpeton (Lepospondyl: Aïstopod) Carboniferous Quadrupeds (Amphibians)

Chart from Roelants et al. (2005) Carboniferous Amphibian - Reptile Transition

Reptiles appear in the fossil record in the Late Carboniferous

Reptile Characteristics

Strong skeletal Advanced lung & leg Development of hard- structure designs shelled eggs (and Protective coating for Loss of gills possibly paternal egg- incubation behaviors) skin (scales) Dominantly carnivorous Increased brain size Carboniferous Reptile Cranium Types

Anapsid

Synapsid Parapsid

Euryapsid Diapsid Carboniferous Quadrupeds (Reptiles)

Protoclepsydrops Gephyrostegus

Hylonomus (Earliest Reptile) Petrolacosaurus (Early Diapsid)

Archaeothyris (Early Synapsid) Carboniferous Biodiversity

800

600 Carboniferous Extinction

400

Modern Fauna

200 Paleozoic Fauna NumberFamiliesof

Cambrian Fauna 0 Cambrian Ordovician Sil. Devonian Carbon. Permian Tri. Jurassic Cretaceous Tertiary 500 400 300 200 100 0 Geological Time Data from Sepkoski (1981) Carboniferous Biodiversity

Figure from Fan et al. (2020) Carboniferous Extinctions End-Ordovician End-Devonian End-Permian End-Triassic End-Cretaceous 80 Palaeozoic Mesozoic Cenozoic Carbonif. 60

40 PercentExtinction 20

0 Cambrian Ord. Sil. Dev. Carb. Perm. Trias. Jurassic Cretaceous Paleoc. Neo. Paleozoic Mesozoic Cenozoic

Data from Sepkoski (1998) Carboniferous Extinctions

System/ Numerical Period Series/Epoch Stage/Age Age (Ma) 289.9 Gzhelian Upper 303.7 Kasimovian Mid-Carboniferous 307.0 Extinction event Middle Moscovian Ammonites

Pennsylvanian 315.2 Conodonts Lower Bashkirian 315.2 Crinoids Upper Serpukhovian Brachiopods 323.2 Middle Visean Carboniferous 346.7

Mississippian Lower Tournasian 358.9 0 900 1800 No. Of Genera

ICS International Chronostrat. Chart 2020/03 Carboniferous Sea-Level Changes

System/ Numerical Period Series/Epoch Stage/Age Age (Ma) 289.9 Gzhelian Upper 303.7 Kasimovian 307.0 Middle Moscovian

Pennsylvanian 315.2 Lower Bashkirian 315.2 Upper Serpukhovian 323.2 Middle Visean Carboniferous 346.7

Mississippian Lower Tournasian 358.9 0 900 1800 0.5 0.0 200 100 0 No. Of Genera Onlap Sea Level

ICS International Chronostrat. Chart 2020/03 Carboniferous Ocean Anoxia Events

System/ Numerical Period Series/Epoch Stage/Age Age (Ma) 289.9 Gzhelian Upper 303.7 Kasimovian 307.0 Middle Moscovian

Pennsylvanian 315.2 Lower Bashkirian 315.2 Upper Serpukhovian 323.2 Middle Visean Carboniferous 346.7

Mississippian Lower Tournasian 358.9 0 900 1800 No. Of Genera

ICS International Chronostrat. Chart 2020/03 Carboniferous LIP Eruptions

System/ Numerical Period Series/Epoch Stage/Age Age (Ma) 289.9 Skagerrak (150 Kkm2) Gzhelian Upper 303.7 Kasimovian 307.0 Middle Moscovian

Pennsylvanian 315.2 Lower Bashkirian 315.2 Kennedy-Conors- Upper Serpukhovian Auburn (500 Kkm2) 323.2 Tianshan (250 Kkm2) Middle Visean Carboniferous 346.7

Mississippian Lower Tournasian 358.9 0 900 1800 No. Of Genera

ICS International Chronostrat. Chart 2020/03 Carboniferous LIP Eruptions Kennedy-Conors-Auburn Large Igneous Province

This eruption differs from typical LIPs in the silicic composition of the extrusive and its intraplate location. Thus it is recognized as a silica LIP, also known as a failed rift. Despite its extended duration this is a small LIP and no known extinctions have been definitely tied to its eruption.

Age: c. 320 - 280 Mya Extent: 500 Kkm2 Duration: ??? Location: Eastern Australia

Map from Bryan (2005) Carboniferous LIP Eruptions Tarim - Tianshan Large Igneous Province

This extended eruption appears to have taken place in three pulses, each of which had its own mineralogy signature. Physiologic expression includes floe basalt extrusive and intrusive dike swarms. This is a small LIP and no known extinctions have been definitely tied to its eruption.

Age: c. 300 - 280 Mya Extent: 250 Kkm2 Duration: 20 Myr Location: Northwestern China

Map from Xu et al. (2014) Carboniferous LIP Eruptions Skagerrak Large Igneous Province

This eruption appears to mark the location of a stable mantle plume, which was part of the African Large Low Shear Velocity Province. This is a small LIP and no known extinctions have been definitely tied to its eruption.

Age: c. 300 Mya Extent: 500 Kkm2 Duration: 4 Myr Location: Sweden, Norway, Scotland

Map from Torsvik et al. (2008) Carboniferous Bolide Impacts

System/ Numerical Period Series/Epoch Stage/Age Age (Ma) Mishina Gora (4 km), 289.9 Serra da Cangalha (12 km), Gzhelian Middlesboro (6 km), Upper 303.7 Ile Rouleau (4 km), Kasimovian Decaturville (6 km) 307.0 Middle Moscovian

Pennsylvanian 315.2 Crooked Creek (7 km), Lower Bashkirian Serpent Mound (8 km) 315.2 Upper Serpukhovian Charlevoix (54 km) 323.2 Gweni-Fada (14 km), Middle Visean Aorounga (12.6 km) Carboniferous 346.7 West Hawk (2.4 km) Mississippian Lower Tournasian 358.9 0 900 1800 No. Of Genera

ICS International Chronostrat. Chart 2020/03 Carboniferous Bolide Impacts

Gwen-Fada Crater

Impact origin confirmed via surface expression and the presence of shocked minerals in material surrounding the crater. No substantial extinctions appear to be associated with this impact despite its association with another, similarly sized impact

Age: 345 Mya Diameter: 22 km Location: Chad, Central Africa Carboniferous Bolide Impacts

Aorounga Crater Clearly a multi-ringed impact structure confirmed on the basis of physical expression, satellite imagery and presence of shocked minerals in material surrounding the crater. Satellite imagery reveals to quasi-circular structures close to the crater, which some have interpreted to have been made by associated bolide fragments.

Age: < 345 Mya Diameter: 12.6 km Location: Chad, Central Africa Carboniferous Bolide Impacts

Charlevoix Crater A classic and easily recognized crater on the basis of associated impact features (e.g., cone-in-cone structures, shock metamorphism) and gravity data. However, this crater has little surface expression owing, presumably, to glacial scour. Based on the size of the crater it is estimated that the impact was c. 2 km in diameter and was of stony composition. Despite its size no substantial extinctions are known to be associated with this impact. Age: 342 ± 15 Mya Diameter: 54 km Location: Charlevoix, Quebec, Canada Carboniferous Bolide Impacts

Serra da Cangalha Crater A multi-ringed impact structure confirmed on the basis of physical expression, satellite imagery and presence of impact breccias, shatter cones and shocked minerals in material surrounding the crater. Radial faults extend up to 16 km from the crater center. No substantial extinctions are known to be associated with this impact.

Age: < 299 Mya Diameter: 12.6 km Location: Tocantins - Maranhao border, Brazil Carboniferous Extinctions: Synthesis

Given its long duration it is somewhat surprising that no major extinction event occurs in the Carboniferous. This fact alone suggests that hypotheses involving periodic extinctions are incorrect. Neither bolide impact, not LIP volcanism exhibit a close association with major drops in biodiversity. The fact that there seems little synchronicity between these time series, as well as the small magnitudes of both datasets overall, suggests the synergy between these potential extinction mechanisms was not achieved. The large Charlevoix impact does not appear to have induced any noteworthy extinctions. This suggests that even large impacts do not necessarily perturb the global ecosystem to the extent some have suggested. The minor, mid-Cretaceous drop in biodiversity seems associated with oceanographic changes precipitated by the onset of glaciation. Permian Permian Paleozoic System Durations

75

60

45

30 Duration(myr)

15

0 Camb. Ord. Sil. Dev. Carbon. Perm.

Data from ICS (2020) Permian Timescale

System/ Numerical Period Series/Epoch Stage/Age Age (Ma) 252.902 ± 0.024 Changhsingian Lopingian 254.14 ± 0.07 Wuchiapingian 259.1 ± 0.5 Capitanian 265.1 ± 0.4 Guadalupian Wordian 268.8 ± 0.5 Roadian 272.95 ± 0.11 Kungurian

Permian 283.5 ± 0.6 Artinskian Cisuralian 290.1 ± 0.26 Sakmarian 293.52 ± 0.17 Asselian 298.9 ± 0.15

ICS International Chronostrat. Chart 2020/03 Permian Tectonic Configuration

Final Assembly of Pangea Pangea emerges as the continental shelves Euramerica joins with of the island continents continue to coalesce. Gondwana In addition this whole of Pangea continues to Siberia joins with Northern drift northward and to rotate China counterclockwise. Pangea extends from southern pole almost to the northern pole Circum-equatorial circulation curtailed Continued reduction of Paleo- Tethys Ocean

Map from Scotese PaleoMap Project (2001) Permian Tectonic Configuration

Final Assembly of Pangea Pangea emerges as the continental shelves Euramerica joins with of the island continents continue to coalesce. Gondwana In addition this whole of Pangea continues to Siberia joins with Northern drift northward and to rotate China counterclockwise. Pangea extends from southern pole almost to the northern pole Circum-equatorial circulation curtailed Continued reduction of Paleo- Tethys Ocean

Map from Scotese PaleoMap Project (2001) Permian Marine Circulation

Simple ocean circulation patterns

Strong circum-Arctic cold current (= Arctic gyre) No circum-equatorial current, but strong northern & southern and Panthalassic gyres Northern & southern Paleo- Tethys gyres Strong circum-Antarctic cold current (= Antarctic gyre) Upwelling zone off western Pangean west coast and southern (Australian) peninsula

Map from Scotese PaleoMap Project (2001) Permian Paleoenvironment

Atmospheric O Atmospheric CO 2 2 35 5000

28 4000

21 3000

14 2000 PercentbyVol. 7 PerMillionParts 1000

0 0 Camb. Ord. Sil. Dev. Carbon. Perm. Camb. Ord. Sil. Dev. Carbon. Perm.

Mean Surface Temperature Sea Level 25 250

20 200

15 150

10 Present 100 Meters Above Meters

DegreesCelsius 5 50

0 0 Camb. Ord. Sil. Dev. Carbon. Perm. Camb. Ord. Sil. Dev. Carbon. Perm. Permian Climate Zones

Expansion of all warm climate zones In any respects the climate resembled that of the modern Earth more closely than at any previous time Tropical zone centered in Paleo-Tethys Reduced polar cold zones w/ consequent effect on atmospheric circulation

Comparative Criteria Silurian

O2 Content of 23.0% vol. % Atmosphere (+115%)

CO2 Content of 900 ppm (x3) Atmosphere

Mean Surface 16°C (+2°C) Temperature

Sea Level +60m - -20 m

Map from Scotese PaleoMap Project (2001) Permian Climate Zones

Expansion of all warm climate zones In any respects the climate resembled that of the modern Earth more closely than at any previous time Tropical zone centered in Paleo-Tethys Reduced polar cold zones w/ consequent effect on atmospheric circulation

Comparative Criteria Silurian

O2 Content of 23.0% vol. % Atmosphere (+115%)

CO2 Content of 900 ppm (x3) Atmosphere

Mean Surface 16°C (+2°C) Temperature

Sea Level +60m - -20 m

Map from Scotese PaleoMap Project (2001) Permian Climate Zones

Permian (250 Mya) Climatic Deterioration The Early Permian was characterized by an icehouse climate, with an ice cap at the southern pole and mountain glaciers The later Permian, however, was one of the most intense hothouse climates the Earth has experienced since its formation. These shifts took place remarkably rapidly – by geological standards – and were caused substantially by the assembly of Pangea Permian Cambrian Evolutionary Fauna

Trilobite Monoplacophoran

Inarticulata Polychaeta Hyolith Permian Paleozoic Evolutionary Fauna

Articulata Crinoid

Ostracode Ammonite Bryozoan Rugose Coral Permian Modern Evolutionary Fauna

Bivalve Gastropod Echinoid Bony Fish Permian Reefs

Widespread reef formation dominantly around the margins of the Paleo-Tethys Reefs extending above and 40° N/S latitude (which is the modern limit of reef formation). Reefs absent from regions inferred to be upwelling sites (except in South China). Reefs built by calcareous sponges, encrusting algae, rudistid bivalves.

Permian Reef

Map from Scotese PaleoMap Project (2000) Permian Marine Vertebrates: Fish

Palaeoniscum Aeduella

Tetrapodomorpha

Dorypterus Roslerichthys Paramblypterus Permian Marine Vertebrates: Elasmobranchs

Orthacanthus Helicoprion

Hybodus

Wodnika Permian Terrestrial Environment

Permian Terrestrial Scene

The Early Permian was characterized In the late Permian the interior of Pangea by a cool-temperate climate, coal (= North America, Greenland, Europe, swamps occupying both the tropical South America, Africa) was a vast dessert areas around the Paleo Tethys ocean, though low-latitude tropical coal swamps but also as high southern latitudes persisted around Paleo Tethys and high- right up to the polar front. latitude temperate forest in the south. Permian Glossopteris Flora (Early Permian)

Glossopteris Equisetales Sphenophyllales Lycopodiales Filicales (Tongue-leafed Tree) (Horse Tails) (Scramblers) (Club Mosses) (Ferns) Permian Glossopteris Flora (Early Permian)

Cordaitales Cycadales Ginkoales Coniferales (Conifer Ancestor) (Cycads) (Ginkos) (Conifers) Permian Dicroidium Flora (Late Permian)

Dicroidium Cycadales Filicales Ginkoales Podocarp Conifer (Forked-leaf Seed Fern) (Cycads) (Ferns) (Ginkos) (Conifers) Permian Terrestrial Environments

Early Permian Forest Permian Terrestrial Environments

Late Permian Landscape Permian Terrestrial Quadrupeds: Amphibians

Onchiodon (Temnospondyl)

Pantylus (Leptospondylii, Microsaurial)

Zygosaurus (Temnospondyl)

Actinodontus Dasyceps (Temnospondyl) (Temnospondyl) Permian Terrestrial Quadrupeds: Amphibians

Diagram from Reisz (2006) Permian Terrestrial Quadrupeds: Reptiles

Limnoscelis (Diadectomorphan) Limnopus (Leptospondylii, Microsaurial)

Lystrosaurus Inostrancevia (Dicynodontid) (Gorgonopsian) Dimetrodon (Sphenacodontid) Permian Terrestrial Quadrupeds: Amphibians

Diagram from Reisz (2006) Permian Terrestrial Quadrupeds: Therapsids (Mammal Ancestors)

Biarmosuchia Gorgonops (Stem Therapsid) (Gorgonopsian) Anteosaurus (Dinocephalian)

Thrinaxodon (Cynodont) Eodictyon (Dicynodont) Moschorhinus (Therocephalian) Permian Terrestrial Quadrupeds: Therapsids (Mammal Ancestors)

Biarmosuchia Anteosaurus Gorgonops Eodictyon Moschorhinus Thrinaxodon (Stem Therapsid) (Dinocephalian) (Gorgonopsian) (Dicynodont) (Therocephalian) (Cynodont) Permian Terrestrial Quadrupeds: Therapsids (Mammal Ancestors)

Diagram modified from Angielczyk (2009) Permian Biodiversity

800

600 End-Permian Extinction Event

400

Modern Fauna

200 Paleozoic Fauna NumberFamiliesof

Cambrian Fauna 0 Cambrian Ordovician Sil. Devonian Carbon. Permian Tri. Jurassic Cretaceous Tertiary 500 400 300 200 100 0 Geological Time Data from Sepkoski (1981) Permian Biodiversity

Figure from Fan et al. (2020) Permian Extinctions End-Ordovician End-Devonian End-Permian End-Triassic End-Cretaceous 80 Palaeozoic Mesozoic Cenozoic Permian 60

40 PercentExtinction 20

0 Cambrian Ord. Sil. Dev. Carb. Perm. Trias. Jurassic Cretaceous Paleoc. Neo. Paleozoic Mesozoic Cenozoic

Data from Sepkoski (1998) Permian Timescale

System/ Numerical Period Series/Epoch Stage/Age Age (Ma)

252.9 End-Permian Extinction II Changhsingian Lopingian 254.1 End-Permian Extinction I Wuchiapingian 259.1 Capitanian 265.1 Guadalupian Wordian 268.8 Roadian 273.0 Kungurian

Permian 283.5 Artinskian Cisuralian 290.1 Sakmarian 293.5 Asselian 298.9 0 20 40 60 80 % Extinction (Genera) ICS International Chronostrat. Chart 2020/03 Permian Extinctions

Victims Survivors Reefs Benthos Stroma- Foraminifera toporoids Brachiopods Corals Bryozoans Benthos Bivalves Foraminifera Gastropods Brachiopods Echinoderms Bryozoans Nekton Bivalves Ammonites Gastropods Plankton Trilobites Radiolaria Echinoderms Nekton Ammonites Plankton Radiolaria Permian Sea-Level Change System/ Numerical Period Series/Epoch Stage/Age Age (Ma) 252.9 Changhsingian Lopingian 254.1 Wuchiapingian 259.1 Capitanian 265.1 Guadalupian Wordian 268.8 Roadian 273.0 Kungurian

Permian 283.5 Artinskian Cisuralian 290.1 Sakmarian 293.5 Asselian 298.9 0 20 40 60 80 0.5 0.0 200 100 0 % Extinction (Genera) Onlap Sea Level Permian Ocean Anoxia Events System/ Numerical Period Series/Epoch Stage/Age Age (Ma)

252.9 End-Permian OAE Changhsingian Lopingian 254.1 Wuchiapingian 259.1 Capitanian 265.1 Guadalupian Wordian 268.8 Roadian 273.0 Kungurian

Permian 283.5 Artinskian Cisuralian 290.1 Sakmarian 293.5 Asselian 298.9 0 20 40 60 80 % Extinction (Genera) Permian Ocean Anoxia Events

End-Permian Anoxia Event This extended interval of marine axon is thought to have been caused primarily by the global warming that resulted from massive injection of greenhouse gases into the atmosphere from the Siberian Traps eruptions, augmented by end extreme continentality of Pangea.

Age: onset at 251.9 Ma Duration: c. 5 m.y. Location: global Description: Isotopic data from marine limestones suggest a 100x increase in the extent of sea-floor axoxia and a very shallow OMZ that inhibited benthic marine biotic recovery for c. 5 m.y. Permian LIP Eruptions System/ Numerical Period Series/Epoch Stage/Age Age (Ma)

252.9 Siberian (7 Mkm2, 4 Mkm3) Changhsingian Lopingian 254.1 Wuchiapingian Emeishan (250 Kkm2) 259.1 Capitanian 265.1 Guadalupian Wordian 268.8 2 Roadian Tarim (250 Kkm ) 273.0 Kungurian

Permian 283.5 Artinskian 290.1 Cisuralian 2 Sakmarian Panjal (40 Kkm ) 293.5 Asselian 298.9 0 20 40 60 80 % Extinction (Genera) Permian LIP Eruptions

Quiangtang-Panjal Igneous Province Single largest event in the Permian Himalayan Magmatic Province which is considered to be related to the formation of the Neotethys Ocean. This is a rather small LIP and no substantive extinction events are associated with its emplacement.

Age: c. 289 ± 3.0 Mya Extent: 40 Kkm2 Location: Northwestern India Permian LIP Eruptions

Tarim Igneous Province At the time of their emplacement these extrusive occupied an area within the central region of Pangea at c. 15° north latitude. Given the proximate position of this LIP to the smaller Panjal LIP it is tempting to consider them related to the same mantle plume.

Age: c. 260 - 292 Mya Diameter: 200 Kkm2 Location: Southern Tibet Permian LIP Eruptions

Emeishan Igneous Province Despite its somewhat small size this LIP has been regarded as a potential driver of the Late Capitanian - Early Wuchiapingian extinction event, which preceded the end- Permian event and, to a great extent, contributes to the latter’s perceived size.

Age: c. 380 Mya Diameter: 3 Mkm2 Location: Southern Russia, northern Ukraine Permian LIP Eruptions

Emeishan Igneous Province

Owing to the limestone cap rocks the eruption went through (at least partially) it is generally agreed that its capacity to inject CH4 into the atmosphere would have been increased substantially, leading two global climate changes via enhancement of the greenhouse effect. This, coupled with Pangean continentality would have had a detrimental effect on terrestrial and shallow marine biotas.

Diagram from Shellnutt (2013) Permian LIP Eruptions

Siberian Igneous Province One of the largest LIP emplacement events in the Phanerozoic the eruption occurred over a c. 1 million year interval spacing the Permian-Triassic boundary. Total volume of extrusive material up to 4 million km3. New age dates place this eruption precisely at the peak of the end-Permian extinction. Extent of the Triassic eruptive interval may have slowed biotic recovery. Age: c. 250.3 ± 1.1 Mya Diameter: 7 Mkm2 Location: Siberia, Russia Devonian Bolide Impacts System/ Numerical Period Series/Epoch Stage/Age Age (Ma) 252.9 Changhsingian Kursk (6 km) Lopingian 254.1 Wuchiapingian 259.1 Capitanian 265.1 Guadalupian Wordian 268.8 Roadian 273.0 Kungurian Des Plains (8 km)

Permian 283.5 Artinskian Cisuralian 290.1 Dobele (4.5 km), Sakmarian Clearwater West (36 km) 293.5 Asselian 298.9 0 20 40 60 80 % Extinction (Genera) Permian Bolide Impacts

Clearwater West Crater Impact origin confirmed by copious evidence of an impact breccia containing shatter cone structures and shocked minerals in the crater’s vicinity. This crater struck in the central region of the Pangean continent in the Early Permian at approx. 10°N latitude.

Age: c. 286.2 ± 2.6 Ma Diameter: 36 km Central Uplift: 52 m Location: Quebec, Canada Permian Bolide Impacts

Kursk Crater This is a poorly known and poorly dated small crater that is includes only insofar as its most likely age coincides with the Changhsingian extinction event. The crater has no surface expression, but has been drilled and is regarded as a confirmed crater. All of the detailed descriptions of this crater appear to be in Russian.

Age: c. 250 ± 80 Mya Central Uplift: ?? m Diameter: 6 km Location: Central Federal District, Russia Permian Extinctions

Emission of Siberian Trap Acid Rain CO2 Eruption

Emission of SO2 & Dust

Increased Short Negative �13C Global Weathering Cooling Values Darkness Rates

Productivity Glaciation & Collapse Sea-Level Fall

Increased in Sr Extinctions Isotope Rations Permian Extinctions

Coal Oxidation in S. Gondwana

Elevated Negative Atmospheric Increase in Sr 13 Weathering C Values CO2 rise isotope ratios � Rates

Siberian Trap Ocean Pyrite Burial Eruptions Global Stagnation Warming

Cosmopolitan Productivity Negative Biota Collapse �13C Values

Extinctions Eutrophic Oceans

Acritarch Black Shale Blooms Deposition Permian Extinctions

Diagram from Benton (2018) Late Paleozoic World, Life & Extinctions Norman MacLeod School of Earth Sciences & Engineering, Nanjing University