Abrahamskraal Formation | |
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Stratigraphic range: Wordian-Capitanian ~ | |
![]() Hill with outcropping Teekloof and Abrahamskraal Formations | |
Type | Geological formation |
Unit of | Beaufort Group |
Sub-units | Tapinocephalus Assemblage Zone, Eodicynodon Assemblage Zone |
Underlies | Teekloof Formation |
Overlies | Ecca Group |
Thickness | up to 2,565 m (8,415 ft) |
Lithology | |
Primary | Mudstone, sandstone |
Other | Siltstone |
Location | |
Coordinates | 31°24′S23°06′E / 31.400°S 23.100°E |
Approximate paleocoordinates | 59°54′S38°54′W / 59.9°S 38.9°W |
Region | Northern, Western & Eastern Cape |
Country | ![]() |
Type section | |
Named for | Abrahams Kraal 29 (farm), 18 km south of Leeu-Gamka |
Named by | A.W. Keyser, P.J. Rossouw & Lieuwe Dirk Boonstra |
![]() A simplified geological map of the outcrops of Karoo Supergroup rocks in Southern Africa. The Beaufort Group is represented by the yellow key on the map. |
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. [1] [2]
The Abrahamskraal Formation comprises the majority of the Middle Permian Beaufort sequence, and are thought to range between 268 - 259 million years in age. The lowermost deposits of the Abrahamskraal Formation found in the Eastern Cape until recently were named the Koonap Formation, but these outcrops have been amalgamated into the Abrahamskraal Formation due to recent stratigraphic and biostratigraphic research. [3] The Abrahamskraal Formation incorporates the entire Tapinocephalus Assemblage Zone in its upper sections and the entire Eodicynodon Assemblage Zone its lowermost southern deposits. In the west and northerly deposits the Abrahamskraal Formation overlies the Waterford Formation and the Middleton Formation in the south, both formations containing the uppermost deposits of the Ecca Group.
The rocks of the Abrahamskraal Formation comprise mainly greenish-grey to blueish-grey mudstone coupled with rarer instances of greyish-red, reddish-brown or purple mudstones. These include subordinate greenish-grey, fine-grained sandstones which are normally observed in fining upward cycles. The sandstones vary in thickness from several metres to several tens of metres in some localities. Siltstones are also found interbedded with the mudstone beds. The presence of these rocks reveal much about the past environment that they were deposited in. They were formed by sedimentary material being deposited in the Karoo Basin - a retro-arc foreland basin - by vast, low-energy alluvial plains flowing northwards from the south. The lowermost deposits are considered to be deltaic and grade laterally into the underlying Ecca Group deposits in its southern localities. Deposits grade steadily younger in the northeast where the sedimentary facies turn fully terrestrial. The greenish-grey mudstones are usually associated with the deltaic sedimentary facies while the redder mudstones with the terrestrial. [4] [5] [6] [7] [8]
All sedimentary rocks of the Karoo Basin were transported downhill from the south in the shadow of the rising Gondwanide mountain range. The Gondwanides were the result of tectonic uplift that had previously begun to take course due to subduction of the Palaeo-pacific plate beneath the Gondwanan Plate. Orogenic pulses from the growing Gondwanides mountain chain and associated subduction created accommodation space for sedimentation in the Karoo Basin where the deposits of the Abrahamskraal Formation and all succeeding deposits of the Karoo Basin were deposited over millions of years. [9] [10] [11] [12] [13] [14] [15] [16]
The Abrahamskraal Formation is highly fossiliferous and well known for its biozone assemblages of therapsid fossils. [17] [18] [19] [20] The Eodicynodon and Tapinocephalus Assemblage Zones to which this geological formation incorporates preserve the first appearance of the earliest dicynodonts, dinocephalians, biarmosuchians, therocephalians, gorgonopsians, [21] [22] and pareiasaurian parareptiles. [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] The upper sections of this formation document the rise of and diversification of the dinocephalians. [35] [36] [37] [38] [39] The dinocephalians subsequently went extinct at the contact of the Abrahamskraal Formation with the overlying Teekloof Formation. [40] [41] [42] The basal pelycosaur synapsid species, Elliotsmithia longiceps , has also been found in the deposits of this formation. [43] [44] [45] The presence of this basal synapsid is indicative of this geological formations significance. For decades, paleontologists have puzzled over what has been termed Olsen’s Gap, which is used to describe the evolutionary gap in the tetrapod fossil record between the appearance of the more derived therapsids and their ancestors, the pelycosaurs. The rocks of the Abrahamskraal Formation and its geological correlates abroad hold the promise of that fossil gap being bridged through future research endeavors in the years to come. More notable fossil species include the dicynodont Diictodon feliceps which first appears in the upper sections of this formation, remaining ubiquitous until the Permian-Triassic boundary. [46] [47] [48] Finally, fossils of temnospondyl amphibians such as of Rhinesuchus , the fish Namaichthys, invertebrate fossils of molluscs, invertebrate trackways and burrows, vertebrate footprints of therapsids, and a variety of plant fossils such as Dadoxylon , Equisetum modderdriftensis , Schizoneura africana, and several different species of Glossopteris have been recovered. [49] [50]
Among the species found in the Abrahamskraal Formation is Moschops Capensis [51]
Color key
| Notes Uncertain or tentative taxa are in small text; |
Amphibians of the Abrahamskraal Formation | ||||||
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Taxa | Species | Locality | Assemblage Zone | Material | Notes | Images |
Rhinesuchus [52] | R. tenuceps | Farm Stinkfontein, Prince Albert District | Tapinocephalus A-Z. | A skull associated with a partial left mandibular ramus. | A temnospondyl amphibian. | ![]() |
R. whaitsi | Leeu-Gamka, Prince Albert District | A basicranium, seven fragments of the middle portion of the left hemi-mandible, and multiple skull fragments. |
Actinopterygians of the Abrahamskraal Formation | ||||||
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Taxa | Species | Locality | Assemblage Zone | Material | Notes | Images |
Bethesdaichthys | B. kitchingi | Blourug farm, Victoria West. | Tapinocephalus A-Z | A preserved skull. | An actinopterygian fish. | |
Blourugia [53] | B. seeleyi | Blourug farm, Victoria West. | Tapinocephalus A-Z | A partial skeleton. | An actinopterygian fish. | |
Westlepis | W. kempeni | Blourug farm, Victoria West | Tapinocephalus A-Z | An actinopterygian fish. |
Sauropsids of the Abrahamskraal Formation | ||||||
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Taxa | Species | Locality | Assemblage Zone | Material | Notes | Images |
Australothyris | A. smithi | Beukesplaas farm | Upper part of Tapinocephalus A-Z | A skull and portions of the rest of the skeleton | A parareptile. | |
Bradysaurus | B. baini | Prince Albert, Leeu Gamka, Hottentotsrivier Farm, Leeurivier, Mynhardtskraal, Groot Kruidfortein, Zwarts Siding, Sutherland, and Knoffelfortein. | Tapinocephalus A-Z | A complete skull and separate lower jaw with a complete postcranial skeleton consisting of a complete shoulder girdle and pelvis, a complete vertebral column with few missing at the end of the caudal vertebrae. The right fore and hind limbs are complete. The left humerus, radius, ulna, femur, tibia, and fibula are partially preserved. | A pareiasaur. | ![]() |
B. seeleyi | A partial skeleton consists of a complete skull, lower jaw, partial vertebral column, some ribs, osteoderms, and parts of girdles. | ![]() | ||||
Embrithosaurus | E. schwarzi | Hoogeveld farm. | Tapinocephalus A-Z | Distorted skull with the occluded lower jaw, vertebrae 1 to 27 with articulated osteoderms, two small articulated caudal vertebrae, partial left scapulocoracoid, cleithrum, left and right clavicle, and interclavicle, complete right humerus, partial left humerus, complete right radius, partial left radius, both ulnae complete, both femora complete, both tibia complete, right fibula, partial left fibula, complete pelvis, two digits of the forelimb and two digits of the hindlimb | A pareiasaur. | |
Eunotosaurus | E. africanus | De bad farm, Prince Albert, Boesmanrivier and Rietfortien | Upper Tapinocephalus A-Z and parts of Pristerognathus A-Z. | Fossilized ribbones. | An early relative of reptile. | ![]() |
Chainosaurs of the Abrahamskraal Formation | ||||||
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Taxa | Species | Locality | Assemblage Zone | Material | Notes | Images |
Galechirus | G. scholtzl | Victoria West | Tapinocephalus A-Z. | A partial skeleton | An insectivorous anomodont. | ![]() |
Patranomodon | P. nyaphulii | Prince Albert | Eodicynodon A-Z | A fossilized skull | A rare genus of anomodont. | ![]() |
Dicynodonts of the Abrahamskraal Formation | ||||||
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Taxa | Species | Locality | Assemblage Zone | Material | Notes | Images |
Brachyprosopus | B. broomi | Beukesplaas | Tapinocephalus A-Z | A skull. | A dicynodont. | |
Colobodectes [54] | C. cluveri | Keerom farm, Kruidfontein farm, Bastardsfontein farm, and Altringham farm. | Eodicynodon and Tapinocephalus A-Z | A skull lacking zygomatic arches and postorbital bars | A dicynodont. | |
Diictodon | D. feliceps | Prince Albert. | Tapinocephalus A-Z | Several skeletal specimens. | A pylaecephalid dicynodont. | ![]() |
Emydops | E. arctatus | Beaufort West and Prince Albert. | Either Tapinocephalus A-Z or Pristerognathus A-Z. | A partial skull | A dicynodont. | ![]() |
Eodicynodon [55] | E. oosthuizeni | Tuinkraal and Zwartskraal farm, Prince Albert district | Tapinocephalus A-Z | Postcranial skeleton. | A dicynodont. | ![]() |
Eosimops | E. newtoni | Victoria West. | Tapinocephalus A-Z. | several skull specimens and one complete skeleton. | A pylaecephalid dicynodont. | ![]() |
Nyaphulia [55] | N. oelofseni | Botterkraal farm | Eodicynodon A-Z. | Partial skull, jaws, and teeth. | A dicynodont, formally named E. oelofseni. | ![]() |
Robertia | R. broomiana | Klein Koedoeskop, Beaufort West. | Lower part of the Tapinocephalus A-Z. | Partial skull and postcranial skeleton. | A small herbivorous dicynodont. | ![]() |
Biarmosuchians of the Abrahamskraal Formation | ||||||
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Taxa | Species | Locality | Assemblage Zone | Material | Notes | Images |
Hipposaurus | H. boonstrai | Beaufort west and Riet Fontein | Tapinocephalus A-Z | A single skull. | A hipposaurid therapsid. | ![]() |
H. brinki | A preserved skull. | |||||
Nierkoppia | N. brucei | Farm Stellenboschvlei | Tapinocephalus A-Z. | A relatively well-preserved fragment of skull roof, preserving the interorbital and inter-temporal regions and dorso-medial portion of the occiput. | A proburnetiine burnetiamorph. | |
Anteosaurs of the Abrahamskraal Formation | ||||||
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Taxa | Species | Locality | Assemblage Zone | Material | Notes | Images |
Anteosaurus | A. magnificus | Beaufort West, Prince Albert, and Laingsburg | Tapinocephalus A-Z. | Several complete skulls, dentition, and partial postcranial skeleton. | A large carnivorous dinocephalian. | ![]() |
Australosyodon | A. nyaphuli | Prince Albert and Tuinkraal | Eodicynodon A-Z. | A skull and mandible with a preserved left side. | A dinocephalian. | ![]() |
Tapinocephalians of the Abrahamskraal Formation | ||||||
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Taxa | Species | Locality | Assemblage Zone | Material | Notes | Images |
Criocephalosaurus | C. vanderbyli | Prince Albert | Lower and Middle Tapinocephalus A-Z. | A skull cap consists of the frontals, parietals, postfrontals, and one pre-frontal. | A tapinocephalian therapsid. | ![]() |
Keratocephalus | K. moloch | Prince Albert, Leeu Gamka, and Buffelsvlei. | Tapinocephalus A-Z. | Variable skulls and postcrania. | A tapinocephalian therapsid. | |
Mormosaurus | M. seeleyi | Gouph tract | Tapinocephalus A-Z. | A partial skull. | A Tapinocephalian. | ![]() |
Moschops | M. capensis | De Cypher Farm and Hottentotsrivier. | Tapinocephalus A-Z. | Several skeletal specimens consist of skulls and postcranial skeletons. | A subaquatic tapinocephalian. | ![]() |
M. koupensis | ||||||
M. romeri | ||||||
Phocosaurus | P. megischion | Boesmansrivier and Vers Fontein/Jan Willem Fontein. | Tapinocephalus A-Z. | A partial skull. | A Tapinocephalian. | ![]() |
Tapinocaninus | T. pamelae | Modderdrift farm | Eodicynodon A-Z. | Paratypes consist of several skulls with few post-cranial skeletons. | A Tapinocephalian. | ![]() |
Tapinocephalus | T. atherstonei | Boesmanshoek and Prince Albert | Lower, Middle, and Upper part of the Tapinocephalus A-Z. | A skull and postcranial elements. | A giant herbivorous Tapinocephalian. | ![]() |
Struthiocephalus | S. whaitsi | Prince Albert | Lower to Middle Tapinocephalus A-Z. | A partial skull. | A Tapinocephalian. | ![]() |
Styracocephalids of the Abrahamskraal Formation | ||||||
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Taxa | Species | Locality | Assemblage Zone | Material | Notes | Images |
Styracocephalus | S. platyrhynchus | Rietfontein, Prince Albert, and Boesmansrivier | Tapinocephalus A-Z. | Complete skull consists of jaws, palate, and dentition. | A dinocephalian therapsid. | ![]() |
Titanosuchids of the Abrahamskraal Formation | ||||||
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Taxa | Species | Locality | Assemblage Zone | Material | Notes | Images |
Jonkeria | J. boonstai | Farm Uitkyk, Leeu-Gamka, Groot kruidfontein, Prince Albert, and Vers Fontein. | Tapinocephalus A-Z. | A skull and humerus. | An omnivorous titanosuchid dinocephalian. | ![]() |
J. ingens | A complete skull. | |||||
J. haughtoni | A crushed skull. | |||||
J. koupensis | A complete pelvis bone. | |||||
J. parva | A femur, radius, small humerus, and tarsal. | |||||
J. rossouwi | The holotype consists of postcranial skeletons. | |||||
J. truculenta | A skull and partial skeleton. | |||||
J. vanderbyli | A complete skull. | |||||
Titanosuchus [56] | T. ferox | Beaufort West, Prince Albert, Mynhardskraal, Veldmansrivier, and Lammerskraal. | Tapinocephalus A-Z | Fragmentary jaws and post-crania that include two left humeri, femur, and two phalanges. | A carnivorous titanosuchid dinocephalian. | ![]() |
Gorgonopsians of the Abrahamskraal Formation | ||||||
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Taxa | Species | Locality | Assemblage Zone | Material | Notes | Images |
Aelurosaurus | A. felinus | Beaufort west. | Tapinocephalus A-Z. | A holotype preserved skull. | A gorgonopsian. | ![]() |
A. whaitsi | A holotype preserved skull. | |||||
Cerdodon | C. tenuidens | Beaufort west. | Tapinocephalus A-Z. | A holotype consists of a crushed skull. | A gorgonopsid. | |
Eriphostoma | E. microdon | Prince Albert, Hottentotsrivier farm, and Mynhardtskraal. | Tapinocephalus A-Z. | Partial skull remains. | A gorgonopsid formally named Galesuchus gracilis. | ![]() |
Phorcys | P. dubei | Delportsrivier | Eodicynodon and Tapinocephalus A-Z. | A partial skull from the occiput (the back face of the skull) up to the orbits, including the basicranium (the floor of the skull beneath the braincase), an eroded upper surface preserving the intact pre parietal and portions of the surrounding frontals and parietal bones, with a broken left zygomatic arch and a left palatine displaced into the left orbit, | A gorgonopsid. |
Therocephalians of the Abrahamskraal Formation | ||||||
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Taxa | Species | Locality | Assemblage Zone | Material | Notes | Images |
Alopecodon | A. priscus | Zeekoegat, Prince Albert. | Tapinocephalus A-Z | A crushed partial skull and lower jaws. | A therocephalian. | |
Alopecognathus | A. megalops | Beaufort West and Prince Albert. | Tapinocephalus A-Z. | Skull specimens. | A therocephalian. | ![]() |
Eutheriodon | E. vandenheeveri | Modderdrift, Prince Albert. | Eodicynodon A-Z. | A partial snout and lower jaws. | A scylacosaurid therocephalian. | |
Glanosuchus | G. macrops | Gioflok’s Fontein, near Van der Byl’s Iird in the Gouph | Eodicynodon A-Z. | A holotype consists of a partial skull. | A scylacosaurid therocephalian. | ![]() |
Hyaenasuchus | H. whaitsi | Rietfontein | Tapinocephalus A-Z. | A weathered skull. | A therocephalian. | ![]() |
Ictidosaurus | I. angusticeps | Beaufort West | Eodicynodon and Tapinocephalus A-Z. | A holotype preserved skull. | A scylacosaurid therocephalian. | |
Pardosuchus | P. whaitsi | Prince Albert | Tapinocephalus A-Z. | Holotypes consist of preserved skulls. | A pristerognathinae therocephalian formally named Lycedops scholtzi. | ![]() |
Pristerognathus | P. minor | Beaufort West and Prince Albert. | Pristerognathus A-Z. | Multiple skull specimens. | A therocephalian. | |
P. parvus | ||||||
P. vanderbyli | ||||||
P. vanwyki | ||||||
Scymnosaurus | S. ferox | Prince Albert and Vers Fontein/Jan Willem Fortein | Tapinocephalus A-Z. | Partial skull consists of snout tip, dentition, and palate. | A therocephalian therapsids. | |
Tamboeria | T. maraisi | Prince Albert and Tamboers Fontein. | Tapinocephalus A-Z. | A middle-sized carnivorous therocephalian | ||
Trochosuchus | T. acutus | Rietfontein and Prince Albert. | Tapinocephalus A-Z. | A fossilized skull. | A Lycosuchid therocephalian. | |
T. intermedius | ||||||
T. major |
Varanopids of the Abrahamskraal Formation | ||||||
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Taxa | Species | Locality | Assemblage Zone | Material | Notes | Images |
Anningia [57] | A. megalops | Prince Albert | The Middle of the Tapinocephalus A-Z. | A partial skull. | A varanopid synapsid. | |
Elliotsmithia | E. longiceps | Prince Albert | Tapinocephalus A-Z. | A holotype consists of a skull. | A small varanopid synapsid. | |
Heleosaurus | H. scholtzi | Victoria West. | Tapinocephalus A-Z. | A preserved skeleton. | A varanopid synapsid. | |
Microvaranops | M. parentis | Beukesplaas farm | Tapinocephalus A-Z. | A skeletal aggregation containing one grown and four immature individuals. | A varanopid synapsid. |
The Abrahamskraal Formation corresponds with numerous localities abroad. Currently it is considered to correlate chronostratigraphically with the Rio do Rasto Formation from the Paraná Basin in Brazil, [58] [59] the Madumabisa Mudstone Formation of Zambia, [60] the Ocher and Isheevo faunas of Russia, [61] and to the Dashankou fauna from the Xidagou Formation of China. However, correlative dating between the Xidagou Formation and the Abrahamskraal Formation remains inconsistent and needs further study.
Robertia is an extinct genus of small herbivorous dicynodonts from the Middle to Late Permian of South Africa, between 260 and 265 million years ago. It is a monospecific genus, consisting of the type-species R. broomiana, which was classified by Lieuwe Dirk Boonstra in 1948 and named in honor of Robert Broom for his study of South African mammal-like reptiles.
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.
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.
Anteosaurus is an extinct genus of large carnivorous dinocephalian synapsid. It lived at the end of the Guadalupian during the Capitanian stage, about 265 to 260 million years ago in what is now South Africa. It is mainly known by cranial remains and few postcranial bones. Measuring 5–6 m (16–20 ft) long and weighing about 600 kg (1,300 lb), Anteosaurus was the largest known carnivorous non-mammalian synapsid and the largest terrestrial predator of the Permian period. Occupying the top of the food chain in the Middle Permian, its skull, jaws and teeth show adaptations to capture large prey like the giants titanosuchids and tapinocephalids dinocephalians and large pareiasaurs.
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.
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.
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.
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.
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.
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.
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.
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.
Eodicynodon is an extinct genus of dicynodont therapsids, a highly diverse group of herbivorous synapsids that were widespread during the middle-late Permian and early Triassic. As its name suggests, Eodicynodon is the oldest and most primitive dicynodont yet identified, ranging from the middle to late Permian and possessing a mix of ancestral Anomodont/therapsid features and derived dicynodont synapomorphies.
Tapinocaninus is an extinct genus of therapsids in the family Tapinocephalidae, of which it is the most basal member. Only one species is known, Tapinocaninus pamelae. The species is named in honor of Rubidge's mother, Pam. Fossils have been found dating from the Middle Permian.
Brachyprosopus is an extinct genus of dicynodont therapsid from the middle Permian Tapinocephalus Assemblage Zone in the Abrahamskraal Formation belonging to the Beaufort Group of the Karoo Basin, South Africa.
Pristerodon is an extinct genus of dicynodont therapsid from the Late Permian of South Africa, Zambia and India.
Criocephalosaurus is an extinct genus of tapinocephalian therapsids that lived in Southern Africa during the Guadalupian epoch of the Permian. They are the latest surviving dinocephalians, extending past the Abrahamskraal Formation into the lowermost Poortjie Member of the Teekloof Formation in South Africa. They are also regarded as the most derived of the dinocephalians, alongside Tapinocephalus, and the most abundant in the fossil record.
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.
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.
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.
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