Balfour Formation

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Balfour Formation
Stratigraphic range: Lopingian - Induan
256.3–251.2  Ma
Nieu-Bethesda, Karoo, Eastern Cape, South Africa (20323012538).jpg
Outcrops of the Balfour Formation are found in the hillsides surrounding Nieu-Bethesda, Eastern Cape, South Africa
Type Geological formation
Unit ofAdelaide Subgroup, Beaufort Group
Sub-unitsOudeberg Member, Daggaboersnek Member, Ripplemead Member, Elandsberg Member, Palingkloof Member
Underlies Katberg Formation
Overlies Middleton Formation
Thicknessup to 2,150 m (7,050 ft)
Lithology
Primary Mudstone, siltstone
Other Sandstone
Location
Coordinates 32°18′S24°30′E / 32.3°S 24.5°E / -32.3; 24.5
Approximate paleocoordinates 62°42′S29°18′W / 62.7°S 29.3°W / -62.7; -29.3
Region Northern Cape, Eastern Cape and Free State
CountryFlag of South Africa.svg  South Africa
Geology of Karoo Supergroup.png

The Balfour Formation is a geological formation that is found in the Beaufort Group, a major geological group that forms part of the greater Karoo Supergroup in South Africa. The Balfour Formation is the uppermost formation of the Adelaide Subgroup which contains all the Late Permian - Early Triassic aged biozones of the Beaufort Group. Outcrops and exposures of the Balfour Formation are found from east of 24 degrees in the highest mountainous escarpments between Beaufort West and Fraserburg, but most notably in the Winterberg and Sneeuberg mountain ranges near Cradock, the Baviaanskloof river valley, Graaff-Reniet and Nieu Bethesda in the Eastern Cape, and in the southern Free State province. [1] [2]

Contents

Geology

The Balfour Formation overlies the Middleton Formation of the Adelaide Subgroup and underlies the Katberg Formation of the lower Tarkastad Subgroup, all comprising the greater Beaufort Group. The Balfour Formation is composed of five members which are listed below (from oldest to youngest):

The rocks of the Balfour Formation also incorporate the entire Daptocephalus Assemblage Zone, the lowermost portion of the Lystrosaurus Assemblage Zone, [3] and the uppermost rocks of the Cistecephalus Assemblage Zone. [4] Up until the middle section of the Ripplemead Member, the Balfour Formation correlates with the near contemporaneous Teekloof Formation west of the 24 degrees from Beaufort West westwards, and to the Normadien Formation north of the Orange River. However, the Elandsberg and Palingkloof Members do not have any lateral correlates west of 24 degrees. This is either due to past erosion of the upper, unknown members of the Teekloof Formation or there was a sudden cessation of sedimentary deposition in the western section of the Karoo Basin. [5] [6] [7] [8]

The sedimentary rocks of this formation are composed predominantly of alternating greenish-grey, bluish-grey, and grey-ish red mudstone that often contain siltstone lenses. The mudstones are very fine-grained, massive and exhibit blocky weathering. Claystone successions are also found which, along with the mudstones, frequently contain desiccation cracks, raindrop impressions, and calcareous nodules or concretions are found throughout. Rhythmites are also found. Sandstones are less common, but some notable units have been studied in the Balfour Formation. In the lowermost section of the Balfour is a sandstone-rich unit known as the Oudeberg Member. The sandstones in this unit are very fine-grained and are rich in feldspar. Another sandstone unit in the middle of the Balfour Formation is the Daggaboersnek Member which contains thin, tabular sandstones, and ripple structures are common. [9] [10]

The presence of these rocks reveal much about the past environment that they were deposited in. The dominance of fine-grained mudstone and less common, fine-grained sandstones indicates that the rock sediments were deposited in a low-energy, fluvial environment, most likely one that had meandering rivers. At the time of sedimentary deposition, the Karoo retroarc foreland system was in an overfilled phase, and purely terrestrial sediments occupied the Karoo Basin at this time. As this formation includes the rocks of both the Cistecephalus , Daptocephalus, Lystrosaurus Assemblage Zones, the Balfour Formation preserves the geological record for the end Permian extinction event. This is important as the end Permian extinction event was the largest mass extinction event in the Earth's history. This was followed by one of the worst biotic crises, which is reflected in the sudden and drastic sedimentary facies changes in the overlying Katberg Formation. [11] [12] [13] [14] [15]

Paleontology

Where the Balfour Formation deposits correlate with the Daptocephalus Assemblage Zone, a great diversity of vertebrate fauna are found. This richness in species diversity observed in the Balfour Formation is especially true of dicynodonts as numerous different species of this successful, herbivorous therapsid have been recovered. [16] [17] Various species of burnetiamorph biarmosuchians, rubidgeine gorgonopsians, and therocephalian species such as Moschorhinus kitchingi and the earliest cynodont, Charassognathus gracilis , also appear. [18] Parareptile species, [19] namely captorhinids, the Younginiforme Youngina capensis , [20] [21] and a variety of temnospondyl amphibians, [22] fishes, and plant fossils such as Glossopteris are likewise found. Glossopteris fossils or leaf impressions are particularly common in the Daggaboersnek Member. The uppermost unit of the Balfour Formation marks the Permian-aged side of the Permian-Triassic boundary. At this point in the biostratigraphy there is a marked drop in species diversity as the Permian-Triassic extinction event began to take its course at the time of sediment deposition.

Paleofauna

Reptiles

Diapsids
GenusSpeciesLocalityStratigraphic positionTimeMaterialNotesImages
Youngina Y. capensisDicynodon Assemblage zone.LopingianA diapsid reptile.
Parareptiles
GenusSpeciesLocalityStratigraphic positionTimeMaterialNotesImages
Anthodon A. serrariusChanghsingianA pareiasaur.
Milleropsis M. priceiDicynodon Assemblage zone.ChanghsingianA millerettid parareptile.
Milleretta M. rubidgeiDicynodon Assemblage zone.ChanghsingianA millerettid parareptile.
Milleretta BW.jpg
Millerosaurus M. nuffieldiChanghsingianA millerettid parareptile.
Millerosaurus BACKGROUND.JPG
Pareiasaurus P. serridensWuchiapingian and Changhsingian.A pareiasaur.
Owenetta O. rubidgeiCistecephalus and Lystrosaurus Assemblage ZonesWuchiapingian and ChanghsingianA procolophonian parareptile.

Synapsids

Therapsids

Cynodonts
GenusSpeciesLocalityStratigraphic positionTimeMaterialNotesImages
Charassognathus C. gracilisA cynodont.
Charassognathus, a primitive type of cynodont. Charassognathus gracilis.jpg
Charassognathus, a primitive type of cynodont.
Cynosaurus C. suppostusCistecephalus and Daptocephalus Assemblage Zones.Wuchiapingian - Changhsingian.A cynodont.
Procynosuchus P. delaharpeaeNew Bathsheba.WuchiapingianA cynodont.
Progalesaurus P. lootbergensisNew Lootsberg Pass.Lystrosaurus Assemblage Zone.LopingianA skull, dentition, and postcranial skeleton.A cynodont.
Vetusodon V. elikhuluDaptocephalus Assemblage Zone.LopingianA cynodont.
Dicynodonts
GenusSpeciesLocalityStratigraphic positionTimeMaterialNotesImages
Daptocephalus D. leonicepsDaptocephalus Assemblage Zone.ChanghsingianA dicynodont.
Daptocephalus leoniceps.jpg
Dolomitipes D. accordiiA dicynodont.
D. icelsi
Dicynodontoides D. recurvidensNooitgedacht 68.Uppermost part in Dicynodon Assemblage Zone.A skull and postcranial element.A dicynodont.
KingoriaDB.jpg
Emydops E. arctatusA dicynodont.
Lystrosaurus L. curvatusNooitgedacht 68 and Fairydale.lower part of Palingkloof Member, Dicynodon Assemblage Zone.Induan.A skull.A dicynodont.
Lystrosaurus Lystrosaurus.jpg
Lystrosaurus
L. declivisuppermost part of Lystrosaurus Assemblage Zone.Induan.A skull and a complete skeleton.
L. maccaigiPalingkloof Member, Dicynodon Assemblage ZoneChanghsingian.
L. murrayilower part of Palingkloof Member, Lystrosaurus Assemblage Zone.Induan.A skull and skeleton.
Oudenodon O. bainiiA small dicynodont.
Oudenodon.jpg
Gorgonopsids
GenusSpeciesLocalityStratigraphic positionTimeMaterialNotesImages
Aloposaurus A. tenuisA gorgonopsid.
Alopsaurus Aloposaurus.jpg
Alopsaurus
Cyonosaurus C. kitchingiA gorgonopsid.
Cyonosaurus1DB.jpg
C. longiceps
Dinogorgon D. rubidgeiCistecephalus and Daptocephalus assemblage.A gorgonopsid.
Dinogorgo rubigei.jpg
Inostrancevia [23] I. africanalower slope of the hill Loskop, Nooitgedacht 68.Daptocephalus Assemblage ZoneA partial skeleton including a complete skull and occluded mandible, entirety of the precaudal axial column, partial scapulae, partial right pelvis, the right femur, and a disarticulated left humerus, ulna, radius, and tibia.A predatory inostranceviinae gorgonopsid.
Inostrancevia africana.jpg
Leontosaurus L. vanderhorstiDicynodon Assemblage Zone.A gorgonopsid.
Lycaenops L. ornatusA gorgonopsid.
Lycaenops ornatus (2).jpg
Paragalerhinus P. rubidgeiWellwoodDicynodon Assemblage Zone.A partial skull.A gorgonopsid.
Rubidgea R. atroxCistecephalus and Daptocephalus assemblage zone.A gorgonopsid.
Scylacops S. capensisA gorgonopsid.
Therocephalians
GenusSpeciesLocalityStratigraphic positionTimeMaterialNotesImages
Ictidochampsa I. platycepsDicynodon Assemblage Zone.A therocephalian.
Ictidosuchoides I. intermediusA therocephalian.
Ictidosuchops I. intermediusA therocephalian.
Moschorhinus M. kitchingiSpitskop, Nooitgedacht 68.Dicynodon Assemblage Zone.A weathered skull along with a complete skull, partially articulated anterior skeleton, and disarticulated pelvis and hind limb.A therocephalian.
Moschorhinus. Moschorhinus kitch1DB.jpg
Moschorhinus.
Notaelurodon N. kitchingiA therocephalian.
Olivierosuchus O. parringtoniPalingkloof MemberLystrosaurus assemblege zone.A complete skull and anterior half of skeleton in articulation, including vertebrae, ribs, pectoral girdle, partial left humerus, complete right forelimb,

including terminal phalanges.

A therocephalian.
Promoschorhynchus P. platyrhinusA therocephalian.
Theriognathus T. micropsA therocephalian.
Tetracynodon T. tenuisA therocephalian.

Correlation

The Balfour Formation is known to corresponds in age with the Cis-Uralian fauna of Russia [24] and the Sanga do Cabral Formation, Paraná Basin of Brazil. Correlations with other Late Permian - Early Triassic deposits abroad remain inconclusive.

Related Research Articles

<i>Diictodon</i> Extinct genus of dicynodonts

Diictodon is an extinct genus of pylaecephalid dicynodont that lived during the Late Permian period, approximately 255 million years ago. Fossils have been found in the Cistecephalus Assemblage Zone of the Madumabisa Mudstone of the Luangwa Basin in Zambia and the Tropidostoma Assemblage Zone of the Teekloof Formation, Tapinocephalus Assemblage Zone of the Abrahamskraal Formation, Dicynodon Assemblage Zone of the Balfour Formation, Cistecephalus Assemblage Zone of the Middleton or Balfour Formation of South Africa and the Guodikeng Formation of China. Roughly half of all Permian vertebrate specimens found in South Africa are those of Diictodon. This small herbivorous animal was one of the most successful synapsids in the Permian period.

<span class="mw-page-title-main">Beaufort Group</span> Third of the main subdivisions of the Karoo Supergroup in South Africa

The Beaufort Group is the third of the main subdivisions of the Karoo Supergroup in South Africa. It is composed of a lower Adelaide Subgroup and an upper Tarkastad Subgroup. It follows conformably after the Ecca Group and unconformably underlies the Stormberg Group. Based on stratigraphic position, lithostratigraphic and biostratigraphic correlations, palynological analyses, and other means of geological dating, the Beaufort Group rocks are considered to range between Middle Permian (Wordian) to Early Triassic (Anisian) in age.

<i>Dinogorgon</i> Extinct genus of therapsids

Dinogorgon is a genus of gorgonopsid from the Late Permian of South Africa and Tanzania. The generic name Dinogorgon is derived from Greek, meaning "terrible gorgon", while its species name rubidgei is taken from the surname of renowned Karoo paleontologist, Professor Bruce Rubidge, who has contributed to much of the research conducted on therapsids of the Karoo Basin. The type species of the genus is D. rubidgei.

<i>Tapinocephalus</i> Assemblage Zone

The Tapinocephalus Assemblage Zone is a tetrapod assemblage zone or biozone which correlates to the middle Abrahamskraal Formation, Adelaide Subgroup of the Beaufort Group, a fossiliferous and geologically important geological Group of the Karoo Supergroup in South Africa. The thickest outcrops, reaching approximately 2,000 metres (6,600 ft), occur from Merweville and Leeu-Gamka in its southernmost exposures, from Sutherland through to Beaufort West where outcrops start to only be found in the south-east, north of Oudshoorn and Willowmore, reaching up to areas south of Graaff-Reinet. Its northernmost exposures occur around the towns Fraserburg and Victoria West. The Tapinocephalus Assemblage Zone is the second biozone of the Beaufort Group.

<i>Cistecephalus</i> Assemblage Zone

The Cistecephalus Assemblage Zone is a tetrapod assemblage zone or biozone found in the Adelaide Subgroup of the Beaufort Group, a majorly fossiliferous and geologically important geological group of the Karoo Supergroup in South Africa. This biozone has outcrops located in the Teekloof Formation north-west of Beaufort West in the Western Cape, in the upper Middleton and lower Balfour Formations respectively from Colesberg of the Northern Cape to east of Graaff-Reinet in the Eastern Cape. The Cistecephalus Assemblage Zone is one of eight biozones found in the Beaufort Group, and is considered to be Late Permian in age.

<i>Daptocephalus</i> Assemblage Zone

The Daptocephalus Assemblage Zone is a tetrapod assemblage zone or biozone found in the Adelaide Subgroup of the Beaufort Group, a majorly fossiliferous and geologically important geological Group of the Karoo Supergroup in South Africa. This biozone has outcrops located in the upper Teekloof Formation west of 24°E, the majority of the Balfour Formation east of 24°E, and the Normandien Formation in the north. It has numerous localities which are spread out from Colesberg in the Northern Cape, Graaff-Reniet to Mthatha in the Eastern Cape, and from Bloemfontein to Harrismith in the Free State. The Daptocephalus Assemblage Zone is one of eight biozones found in the Beaufort Group and is considered Late Permian (Lopingian) in age. Its contact with the overlying Lystrosaurus Assemblage Zone marks the Permian-Triassic boundary.

<i>Lystrosaurus</i> Assemblage Zone

The Lystrosaurus Assemblage Zone is a tetrapod assemblage zone or biozone which correlates to the upper Adelaide and lower Tarkastad Subgroups of the Beaufort Group, a fossiliferous and geologically important geological Group of the Karoo Supergroup in South Africa. This biozone has outcrops in the south central Eastern Cape and in the southern and northeastern Free State. The Lystrosaurus Assemblage Zone is one of eight biozones found in the Beaufort Group, and is considered to be Early Triassic in age.

<i>Cynognathus</i> Assemblage Zone Biozone which correlates to the Burgersdorp Formation of the Beaufort Group

The Cynognathus Assemblage Zone is a tetrapod biozone utilized in the Karoo Basin of South Africa. It is equivalent to the Burgersdorp Formation, the youngest lithostratigraphic formation in the Beaufort Group, which is part of the fossiliferous and geologically important Karoo Supergroup. The Cynognathus Assemblage Zone is the youngest of the eight biozones found in the Beaufort Group, and is considered to be late Early Triassic (Olenekian) to early Middle Triassic (Anisian) in age. The name of the biozone refers to Cynognathus crateronotus, a large and carnivorous cynodont therapsid which occurs throughout the entire biozone.

<i>Pristerognathus</i> Assemblage Zone

The Pristerognathus Assemblage Zone is a tetrapod assemblage zone or biozone which correlates to the upper Abrahamskraal Formation and lowermost Teekloof Formation, Adelaide Subgroup of the Beaufort Group, a fossiliferous and geologically important geological Group of the Karoo Supergroup in South Africa. The thickest outcrops, reaching not more than 300 metres (980 ft), occur just east of Sutherland through to Beaufort West in the south and Victoria West in the north. Exposures are also found west of Colesberg and south of Graaff-Reinet. The Pristerognathus Assemblage Zone is the third biozone of the Beaufort Group.

<i>Tropidostoma</i> Assemblage Zone

The Tropidostoma Assemblage Zone is a tetrapod assemblage zone or biozone which correlates to the lower Teekloof Formation, Adelaide Subgroup of the Beaufort Group, a fossiliferous and geologically important geological Group of the Karoo Supergroup in South Africa. The thickest outcrops, reaching approximately 240 metres (790 ft), occur from east of Sutherland through to Beaufort West and Victoria West, to areas south of Graaff-Reinet. Its northernmost exposures occur west/north-west of Colesberg. The Tropidostoma Assemblage Zone is the fourth biozone of the Beaufort Group.

<i>Eodicynodon</i> Assemblage Zone

The Eodicynodon Assemblage Zone is a tetrapod assemblage zone or biozone which correlates to the Abrahamskraal Formation, Adelaide Subgroup of the Beaufort Group, a fossiliferous and geologically important geological Group of the Karoo Supergroup in South Africa. The thickest outcrops, reaching approximately 620 metres (2,030 ft), occur south-east of Sutherland, north of Prince Albert, and south-east of Beaufort West. The Eodicynodon Assemblage Zone is the lowermost biozone of the Beaufort Group.

<i>Rubidgea</i> Extinct genus of therapsids

Rubidgea is a genus of gorgonopsid from the upper Permian of South Africa and Tanzania, containing the species Rubidgea atrox. The generic name Rubidgea is sometimes believed to be derived from the surname of renowned Karoo paleontologist, Professor Bruce Rubidge, who has contributed to much of the research conducted on therapsids of the Karoo Basin. However, this generic name was actually erected in honor of Rubidge's paternal grandfather, Sydney Rubidge, who was a renowned fossil hunter. Its species name atrox is derived from Latin, meaning “fierce, savage, terrible”. Rubidgea is part of the gorgonopsian subfamily Rubidgeinae, a derived group of large-bodied gorgonopsians restricted to the Late Permian (Lopingian). The subfamily Rubidgeinae first appeared in the Tropidostoma Assemblage Zone. They reached their highest diversity in the Cistecephalus and Daptocephalus assemblage zones of the Beaufort Group in South Africa.

Platycraniellus is an extinct genus of carnivorous cynodonts from the Early Triassic. It is known from the Lystrosaurus Assemblage Zone of the Normandien Formation in South Africa. P. elegans is the only species in this genus based on the holotype specimen from the Ditsong National Museum of Natural History in Pretoria, South Africa. Due to limited fossil records for study, Platycraniellus has only been briefly described a handful of times.

<i>Tropidostoma</i> Extinct genus of dicynodonts

Tropidostoma is a medium-sized herbivorous oudenodontid dicynodont therapsid that lived during the Late Permian (Lopingian) period in South Africa. The first Tropidostoma fossil was described by Harry Govier Seeley in 1889. Later two subspecies were identified. Tropidostoma fossils are an index fossil in a biozone of the Karoo Basin known as the Tropidostoma Assemblage Zone. This biozone is characterized by the presence of this species in association with another dicynodont species, Endothiodon uniseries.

<i>Langbergia</i> Extinct genus of cynodonts

Langbergia is an extinct genus of trirachodontid cynodont from the Early Triassic of South Africa. The type and only species L. modisei was named in 2006 after the farm where the holotype was found, Langberg 566. Langbergia was found in the Burgersdorp Formation in the Beaufort Group, a part of the Cynognathus Assemblage Zone. The closely related trirachodontids Trirachodon and Cricodon were found in the same area.

<span class="mw-page-title-main">Abrahamskraal Formation</span> Geological formation of the Beaufort Group in South Africa

The Abrahamskraal Formation is a geological formation and is found in numerous localities in the Northern Cape, Western Cape, and the Eastern Cape of South Africa. It is the lowermost formation of the Adelaide Subgroup of the Beaufort Group, a major geological group that forms part of the greater Karoo Supergroup. It represents the first fully terrestrial geological deposits of the Karoo Basin. Outcrops of the Abrahamskraal Formation are found from the small town Middelpos in its westernmost localities, then around Sutherland, the Moordenaarskaroo north of Laingsburg, Williston, Fraserburg, Leeu-Gamka, Loxton, and Victoria West in the Western Cape and Northern Cape. In the Eastern Cape outcrops are known from Rietbron, north of Klipplaat and Grahamstown, and also southwest of East London.

<span class="mw-page-title-main">Katberg Formation</span> Geological formation in the Beaufort Group of the Karoo Supergroup in South Africa

The Katberg Formation is a geological formation that is found in the Beaufort Group, a major geological group that forms part of the greater Karoo Supergroup in South Africa. The Katberg Formation is the lowermost geological formation of the Tarkastad Subgroup which contains the Lower to Middle Triassic-aged rocks of the Beaufort Group. Outcrops and exposures of the Katberg Formation are found east of 24 degrees on wards and north of Graaff-Reniet, Nieu Bethesda, Cradock, Fort Beaufort, Queensdown, and East London in the south, and ranges as far north as Harrismith in deposits that form a ring around the Drakensberg mountain ranges.

<span class="mw-page-title-main">Middleton Formation</span> Late middle Permian geological formation in the Eastern Cape

The Middleton Formation is a geological formation that extends through the Northern Cape, Western Cape, and Eastern Cape provinces of South Africa. It overlies the lower Abrahamskraal Formation, and is the eastern correlate, East of 24ºE, of the Teekloof Formation. Outcrops and exposures of the Middleton Formation range from Graaff-Reinet in the Eastern Cape onwards. The Middleton Formation's type locality lies near the small hamlet, Middleton, approximately 25 km south of Cookhouse. Other exposures lie in hillsides along the Great Fish River in the Eastern Cape. The Middleton Formation forms part of the Adelaide Subgroup of the Beaufort Group, which itself forms part of the Karoo Supergroup.

<span class="mw-page-title-main">Teekloof Formation</span> Late Permian geological formation that forms part of the Beaufort Group of South Africa

The Teekloof Formation is a geological formation that forms part of the Beaufort Group, one of the five geological groups that comprises the Karoo Supergroup in South Africa. The Teekloof Formation is the uppermost formation of Adelaide Subgroup deposits West of 24ºE and contains Middle to Late Permian-aged deposits and four biozones of the Beaufort Group. It overlies the Abrahamskraal Formation. The Teekloof Formation does not underlie other units other than the younger Karoo dolerites and sills that relate to the emplacement of the Early Jurassic Drakensberg Group to the east. Outcrops and exposures of the Teekloof Formation range from Sutherland through the mountain escarpments between Fraserburg and Beaufort West. The northernmost localities of the Teekloof Formation are found by Loxton, Victoria West and Richmond.

<i>Thliptosaurus</i> Extinct genus of dicynodonts

Thliptosaurus is an extinct genus of small kingoriid dicynodont from the latest Permian period of the Karoo Basin in KwaZulu-Natal, South Africa. It contains the type and only known species T. imperforatus. Thliptosaurus is from the upper Daptocephalus Assemblage Zone, making it one of the youngest Permian dicynodonts known, living just prior to the Permian mass extinction. It also represents one of the few small bodied dicynodonts to exist at this time, when most other dicynodonts had large body sizes and many small dicynodonts had gone extinct. The unexpected discovery of Thliptosaurus in a region of the Karoo outside of the historically sampled localities suggests that it may have been part of an endemic local fauna not found in these historic sites. Such under-sampled localities may contain 'hidden diversities' of Permian faunas that are unknown from traditional samples. Thliptosaurus is also unusual for dicynodonts as it lacks a pineal foramen, suggesting that it played a much less important role in thermoregulation than it did for other dicynodonts.

References

  1. ↑ Rubidge, B. S. (ed.) 1995b. Biostratigraphy of the Beaufort Group (Karoo Supergroup). South African Committee of Stratigraphy. Biostratigraphic Series 1. Pretoria, Council for Geoscience.
  2. ↑ Catuneanu, O., Elango, H. N. (2001-04-15). "Tectonic control on fluvial styles: the Balfour Formation of the Karoo Basin, South Africa". Sedimentary Geology. 140 (3–4): 291–313. Bibcode:2001SedG..140..291C. doi:10.1016/S0037-0738(00)00190-1. ISSN   0037-0738.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  3. ↑ Botha, Jennifer; Smith, Roger M. H. (2007-06-01). "Lystrosaurus species composition across the Permo–Triassic boundary in the Karoo Basin of South Africa". Lethaia. 40 (2): 125–137. Bibcode:2007Letha..40..125B. doi:10.1111/j.1502-3931.2007.00011.x. ISSN   1502-3931.
  4. ↑ Kammerer, Christian F.; Bandyopadhyay, Saswati; Ray, Sanghamitra (2016-11-01). "A new taxon of cistecephalid dicynodont from the upper Permian Kundaram Formation of India". Papers in Palaeontology. 2 (4): 569–584. Bibcode:2016PPal....2..569K. doi:10.1002/spp2.1055. ISSN   2056-2802. S2CID   88833541.
  5. ↑ Visser, J.N.J. and Dukas, B.A., 1979. Upward-fining fluviatile megacycles in the Beaufort Group north of Graaff-Reinet, Cape Province. Trans. Geol. Soc. S. Afr, 82(149), p.e154.
  6. ↑ Johnson, M.R.; Vuuren, C.J. Van; Visser, J.N.J.; Cole, D.I.; Wickens, H. De V.; Christie, A.D.M.; Roberts, D.L. (1997-01-01). Chapter 12 The foreland karoo basin, south africa. Vol. 3. pp. 269–317. doi:10.1016/S1874-5997(97)80015-9. ISBN   9780444825711. ISSN   1874-5997.{{cite book}}: |journal= ignored (help)
  7. ↑ Rubidge, B. S.; Hancox, P. J.; Catuneanu, O. (1998-12-01). "Reciprocal flexural behaviour and contrasting stratigraphies: a new basin development model for the Karoo retroarc foreland system, South Africa". Basin Research. 10 (4): 417–439. Bibcode:1998BasR...10..417C. doi:10.1046/j.1365-2117.1998.00078.x. ISSN   1365-2117. S2CID   56420970.
  8. ↑ Katemaunzanga, David; Gunter, Cornelis Janse (2009-10-01). "Lithostratigraphy, Sedimentology, and Provenance of the Balfour Formation (Beaufort Group) in the Fort Beaufort–Alice Area, Eastern Cape Province, South Africa". Acta Geologica Sinica - English Edition. 83 (5): 902–916. Bibcode:2009AcGlS..83..902K. doi:10.1111/j.1755-6724.2009.00110.x. ISSN   1755-6724. S2CID   130345218.
  9. ↑ Viglietti, Pia; Rubidge, Bruce; Malcom Harris Smith, Roger (2017-03-01). "Revised lithostratigraphy of the upper Permian Balfour and Teekloof formations of the main Karoo Basin, South Africa". South African Journal of Geology. 120 (1): 45–60. Bibcode:2017SAJG..120...45V. doi:10.25131/gssajg.120.1.45.
  10. ↑ Hiller, N., Stavrakis, N. (1984-02-01). "Permo-Triassic fluvial systems in the southeastern Karoo Basin, South Africa". Palaeogeography, Palaeoclimatology, Palaeoecology. 45 (1): 1–21. Bibcode:1984PPP....45....1H. doi:10.1016/0031-0182(84)90106-8. ISSN   0031-0182.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  11. ↑ Ward, Peter D.; Koch, Paul L.; Smith, Roger M. H.; MacLeod, Kenneth G. (2000-03-01). "Timing of mammal-like reptile extinctions across the Permian-Triassic boundary in South Africa". Geology. 28 (3): 227–230. Bibcode:2000Geo....28..227M. doi:10.1130/0091-7613(2000)28<227:TOMREA>2.0.CO;2. ISSN   0091-7613.
  12. ↑ Ward, Peter D.; Smith, Roger M. H. (2001-12-01). "Pattern of vertebrate extinctions across an event bed at the Permian-Triassic boundary in the Karoo Basin of South Africa". Geology. 29 (12): 1147–1150. Bibcode:2001Geo....29.1147S. doi:10.1130/0091-7613(2001)029<1147:POVEAA>2.0.CO;2. ISSN   0091-7613.
  13. ↑ Smith, R. M. H., Botha, J. (2005-09-01). "The recovery of terrestrial vertebrate diversity in the South African Karoo Basin after the end-Permian extinction". Comptes Rendus Palevol. 4 (6–7): 623–636. Bibcode:2005CRPal...4..623S. doi:10.1016/j.crpv.2005.07.005. ISSN   1631-0683.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  14. ↑ Smith, R. M. H., Botha, J. (2006-08-01). "Rapid vertebrate recuperation in the Karoo Basin of South Africa following the End-Permian extinction". Journal of African Earth Sciences. 45 (4–5): 502–514. Bibcode:2006JAfES..45..502B. doi:10.1016/j.jafrearsci.2006.04.006. ISSN   1464-343X.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  15. ↑ Smith, Roger; Kirschvink, Joseph L.; Garrison, Geoffrey H.; Erwin, Douglas H.; Kock, Michiel O. De; Buick, Roger; Botha, Jennifer; Ward, Peter D. (2005-02-04). "Abrupt and Gradual Extinction Among Late Permian Land Vertebrates in the Karoo Basin, South Africa". Science. 307 (5710): 709–714. Bibcode:2005Sci...307..709W. CiteSeerX   10.1.1.503.2065 . doi:10.1126/science.1107068. ISSN   1095-9203. PMID   15661973. S2CID   46198018.
  16. ↑ Fröbisch, Jörg (2008-11-17). "Global Taxonomic Diversity of Anomodonts (Tetrapoda, Therapsida) and the Terrestrial Rock Record Across the Permian-Triassic Boundary". PLOS ONE. 3 (11): e3733. Bibcode:2008PLoSO...3.3733F. doi: 10.1371/journal.pone.0003733 . ISSN   1932-6203. PMC   2581439 . PMID   19011684.
  17. ↑ Viglietti, P. A., Smith, R. M. H., Angielczyk, K. D., Kammerer, C. F., Fröbisch, J., Rubidge, B. S. (2016-01-01). "The Daptocephalus Assemblage Zone (Lopingian), South Africa: A proposed biostratigraphy based on a new compilation of stratigraphic ranges". Journal of African Earth Sciences. 113: 153–164. Bibcode:2016JAfES.113..153V. doi:10.1016/j.jafrearsci.2015.10.011. ISSN   1464-343X.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  18. ↑ Kammerer, Christian F. (2016-01-26). "Systematics of the Rubidgeinae (Therapsida: Gorgonopsia)". PeerJ. 4: e1608. doi: 10.7717/peerj.1608 . ISSN   2167-8359. PMC   4730894 . PMID   26823998.
  19. ↑ Dias-Da-Silva, Sérgio; Modesto, Sean Patrick; Schultz, Cesar Leandro (2006). "Canadian Science Publishing". Canadian Journal of Earth Sciences. 43 (11): 1685–1693. Bibcode:2006CaJES..43.1685D. doi:10.1139/e06-043. S2CID   140641975.
  20. ↑ Gow, Chris E. (1975). "The morphology and relationships of Youngina capensis Broom and Prolacerta broomi Parrington". Palaeontologia Africana. ISSN   0078-8554.
  21. ↑ Gardner, Nicholas; Holliday, Casey; O’Keefe, F. (2010-11-01). "The Braincase of Youngina Capensis (Reptilia, Diapsida): New Insights from High-Resolution CT Scanning of the Holotype". Biological Sciences Faculty Research.
  22. ↑ Damiani, R. J. (2004-01-01). "Temnospondyls from the Beaufort Group (Karoo Basin) of South Africa and Their Biostratigraphy". Gondwana Research. 7 (1): 165–173. Bibcode:2004GondR...7..165D. doi:10.1016/S1342-937X(05)70315-4. ISSN   1342-937X.
  23. ↑ Kammerer, Christian F.; Viglietti, Pia A.; Butler, Elize; Botha, Jennifer (2023). "Rapid turnover of top predators in African terrestrial faunas around the Permian-Triassic mass extinction". Current Biology. 33 (11): 2283–2290.e3. Bibcode:2023CBio...33E2283K. doi:10.1016/j.cub.2023.04.007. PMID   37220743. S2CID   258835757.
  24. ↑ Shishkin, M. A.; Ochev, V. G. (1993). "The Permo-Triassic transition and the early Triassic history of the Euramerican tetrapod fauna". New Mexico Museum of Natural History and Science Bulletin. 3: 435–437. Retrieved 2018-12-11.
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