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Dinocephalia

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Oxford.</ref> Dinocephalians are among the earliest group of [[Therapsida|therapsids]], and have been found in Brazil<ref name="Langer 2000">Langer, M.C. (2000) The first record of dinocephalians in South America, Late Permian
Oxford.</ref> Dinocephalians are among the earliest group of [[Therapsida|therapsids]], and have been found in Brazil<ref name="Langer 2000">Langer, M.C. (2000) The first record of dinocephalians in South America, Late Permian
Rio do Rosta Formation) of the Paraná Basin, Brazil. ''Neues Jahrbuch für Geologie
Rio do Rosta Formation) of the Paraná Basin, Brazil. ''Neues Jahrbuch für Geologie
-
und Palaontologie, Abhandlungen''. '''215''': 69-95.</ref>,  
+
und Palaontologie, Abhandlungen''. '''215''': 69-95.</ref>, China (Li & Cheng 1995)<ref name="Cheng & Li 1996">Cheng, Z. & Li, J. (1996) First record of a primitive anteosaurid dinocephalian from the Upper Permian of Gansu, China. ''Vertebrate PalAsiatica.'' '''34''': 123-134.</ref><ref name="Cheng & Li 1997">Cheng, Z. & Li, J. (1997) A new genus of primitive dinocephalian: the third report on Late Permian Dashankou lower tetrapod fauna. ''Vertebrate PalAsiatica.'' '''35''': 35-43.</ref><ref name="Li et al. 1996">Li, J., Rubidge, B.S. & Cheng, Z. (1996) A primitive anteosaurid dinocephalian from China – implications for the distribution of earliest therapsid faunas. ''South African
 +
Journal of Science''. '''92''': 252-253.</ref>,
-
China (Li & Cheng 1995; Cheng & Li 1996, 1997; Li et al. 1996),
 
Russia (Ivachnenko 1995, 2000) and southern Africa (Boonstra 1963; <ref name="Rubidge 1991"/> , 1994;
Russia (Ivachnenko 1995, 2000) and southern Africa (Boonstra 1963; <ref name="Rubidge 1991"/> , 1994;
Rubidge & van den Heever, 1997; Lepper et al. 2000; Munyikwa 2001; Kemp 2005). Despite
Rubidge & van den Heever, 1997; Lepper et al. 2000; Munyikwa 2001; Kemp 2005). Despite

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Dinocephalia
Fossil range: Permian
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Synapsida
Order: Therapsida


The infraorder Dinocephalia[1] were a group of medium to large, heavily built therapsid mammal-like reptiles that lived during the Mid-Permian.[2][3] Dinocephalians are among the earliest group of therapsids, and have been found in Brazil[4], China (Li & Cheng 1995)[5][6][7],

Russia (Ivachnenko 1995, 2000) and southern Africa (Boonstra 1963; [2] , 1994; Rubidge & van den Heever, 1997; Lepper et al. 2000; Munyikwa 2001; Kemp 2005). Despite an early adaptive radiation (Ruben 1986), the dinocephalians became completely extinct by the end of the Permian, leaving no descendent lineages (Kemp 1982).


Early Taxonomy

Dinocephalia was initially considered to comprise six families, namely the Estemmenosuchidae, Brithopodidae, Anteosauridae, Titanosuchidae, Tapinocephalidae and the Styracocephalidae (Boonstra 1963; Kemp 1982). In 1988 King reclassified these as subfamilies within the three families Estemmenosuchidae, Brithopodidae and Titanosuchidae. She considered Styracocephalus, the only genus within the Styracocephalidae as incertia sedis. Later Rubidge and van den Heever (1997), on the basis of the discovery of several additional specimens, confirmed the validity of the genus and considered Styracocephalus to be the sister taxon to the Titanosuchidae. Of the three families of Dinocephalia recognised by King (1988), only the Estemmenosuchidae have yet to be found in Africa[2].


The subfamily Tapinocephalinae (Lydekker 1890) is considered to be the most derived of the infraorder Dinocephalia (Boonstra 1969). The dentition of this taxon is thought to be more specialised than that of other dinocephalians as their canines are reduced in size and resemble the incisors (Boonstra 1962, 1963, 1969). Both the incisors and canines are unusual as they have a “talon” and “heel” structure, with the talons of the upper and lower incisors intermeshing to create a crushing surface between the heels (Boonstra 1962, 1963, 1969). Boonstra (1962) also thought that the postcanine teeth of the maxilla may have intermeshed, but to a lesser extent. Tapinocephalians thus had crushing surfaces in the front of their mouths, which was a novel adaptation.


Haughton and Brink (1954) compiled a list of the known genera of Tapinocephalia in South Africa, recognising five families. These were; Mormosauridae: including the genera Mormosaurus (Watson 1914), Struthiocephalus (Haughton 1915a), Struthiocephaloides (Boonstra 1952e), Struthionops (Boonstra 1952b) and Taurocephalus (Broom 1928); Moschopidae: including the genera Avenantia (Boonstra 1952f), 'Delphinognathus (Seeley 1892), Moschognathus (Broom 1914), Moschcoides (Byrne 1937), Moschops (Broom 1911) and Pnigalion (Watson 1914); Moschosauridae: including the genera Agnosaurus (Boonstra 1952a) and Moschosaurus (Haughton 1915b); Tapinocephalidae: including the genera Keratocephalus (von Huene 1931), Riebeeckosaurus (Boonstra 1952c), Tapinocephalus (Owen 1876) and Taurops (Broom 1912); and Styracocephalidae; including the genus Styracocephalus (Haughton 1929).


Boonstra (1963) used the same classifications as Haughton and Brink (1954), but changed their taxonomic levels to that of subfamily. Moschosaurus was viewed as being morphologically the most primitive of the tapinocephalids yet discovered, and proposed that all other sub-families diversified from the Moschosaurinae (Boonstra 1963). Boonstra later thought that the genera Moschosaurus and Struthiocephalellus were “growth stages” of Struthiocephalus (1969, p39) and thus considered them as synonyms. As a result Boonstra (1969) synonymised the Moschosaurinae with the Struthiocephalinae. The Struthiocephalinae were described by Boonstra (1969) as having a long and fairly strong snout, as well as having undergone moderate pachyostosis. Other genera of the Struthiocephalinae are Struthiocephaloides, Struthionops and Taurocephalus.


The Moschopinae consisted of the genera Avenantia, Criocephalus (Broom 1928), Delphinognathus and Moschops. Criocephalus was renamed Criocephalosaurus in 2002 by Kammerer and Sidor, as the name had been used previously to describe a species of cerambycid beetle (Mulsant 1839). The genera Agnosaurus, Moschognathus, Moschoides and Pnigalion were synonymised with the genus Moschops (Boonstra 1969). Boonstra (1969) suggested that Delphinognathus may be a skull of a young Moschops, but did not synonymise the two genera. These tapinocephalids were distinguished as having a short, gently curving snout (Boonstra 1969).


Riebeeckosaurus longirostris (Boonstra 1952c), the only species of the Riebeeckosaurinae, is known from two skulls. These specimens have a long, slender snout and very narrow intertemporal region, which forms a sigittal crest at the posterior of the skull (Boonstra 1969).


Boonstra (1969) described the Tapinocephalinae as large to massive tapinocephalids, with a short, weak snout. Members of this taxon have skulls which are usually heavily pachyostosed, and have either prominent naso-frontal boss or a greatly swollen frons (Boonstra 1969).


According to Boonstra’s (1969) classification the Tapinocephalinae consisted of the genera Keratocephalus (with synonym Pelosuchus (Broom 1905b), see Boonstra 1969), Mormosaurus, Phocosaurus (Seeley 1888) and Tapinocephalus (with synonym Taurops, see Boonstra 1969). King (1988) later reclassified Boontsra’s four subfamilies into three tribes, the Struthiocephalini (Boonstra 1963), Tapinocephalini (Gregory 1926) and the Riebeeckosaurini (Boonstra 1963). The Moschopinae, still considered as a valid taxon by Boonstra (1969), was sunk into the Tapinocephalini by King (1988). These groups were based predominantly on the length of the snout and the degree to which the skull had undergone pachyostosis. The genera contained within each tribe did not differ from Boonstra’s 1969 classification. The Struthiocephalini are characterised as having a reasonably long snout, and having a skull that has undergone moderate pachyostosis (King 1988). Tapinocephalini tend to have short, weak snouts, and great to moderate pachyostification of the skull. Some members of this tribe also have a well developed naso-frontal boss or swollen frons (King 1988).


References

in progress


BOONSTRA, L.D. (1952a) Agnosaurus gen. nov.: ’n nuwe geslag van die dienocephaliërs. Tydskrif vir Wetenskap en Kuns. 12: 242-245.

BOONSTRA, L.D. (1952b) A new deinocephalian from the Karroo (Struthionops intermedius, gen. et sp. nov.). Annals and Magazine of Natural History, Series 12. 5: 988-989.

BOONSTRA, L.D. (1952c) ’n Nuwe tapinocephalide, Riebeeckosaurus longirostris gen. et sp. nov. Tydskrif vir Wetenskap en Kuns. 12: 246-249.

BOONSTRA, L.D. (1952d) On a new tapinocephalid deinocephalian. Annals and Magazine of Natural History, Series 12. 5: 509-511.

BOONSTRA, L.D. (1952e) Struthiocephaloides: ’n nuwe genus van mormosauride tapinocephaliërs. Tydskrif vir Wetenskap en Kuns. 12: 237-241.

BONSTRA, L.D. (1952f) ’n Uiters interessante nuwe deinocephaliër, Avenantia kruisvleiensis gen. et sp. nov. Tydskrif vir Wetenskap en Kuns. 12: 250-255.

BOONSTRA, L.D. (1955) Struthiocephalellus: a new deinocephalian. Annals of the South African Museum. 42: 180-184.

BOONSTRA, L.D. (1962) The dentition of the titanosuchian dinocephalians. Annals of the South African Museum. 46: 57-112.

BOONSTRA, L.D. (1963) Diversity within the South African Dinocephalia. South African Journal of Science. 59: 196-206.

BOONSTRA, L.D. (1969) The fauna of the Tapinocephalus Zone (Beaufort Beds of the Karoo). Annals of the South African Museum. 56: 1-73.

BOONSTRA, L.D. (1972) Discard the names Theriodontia and Anomodontia: a new classification of the Therapsida. Annals of the South African Museum. 59: 315-338.

BRINK, A. S. (1958) Struthiocephalus kitchingi sp. nov. Palaeontologia Africana. 5: 39-56.

BROOM, R. (1905a) On the use of the term Anomodontia. Records of the Albany Museum. 1: 266-269.

BROOM, R. (1905b) Notice of some new fossil reptiles from the Karroo Beds of South Africa. Records of the Albany Museum. 1: 331-337.

BROOM, R. (1911) On some new South African Permian reptiles. Proceedings of the Zoological Society of London. 1911: 1703-1082.

BROOM, R. (1912) On some fossil reptiles from the Permian and Triassic beds of South Africa. Proceedings of the Zoological Society of London. 1912: 859-876.

BROOM, R. (1914) A further comparison of the South African dinocephalians with the American pelycosaurs. Bulletin of the American Museum of Natural History. 33: 135- 141.

BROOM, R. (1928) On Tapinocephalus and two other dinocephalians. Annals of the South African Museum. 22: 427-438.

BROOM, R. (1932) The mammal-like reptiles of South Africa and the origin of mammals. H.F. & G. Witherby, London.

BYRNE, F. (1937) A preliminary report on a new mammal-like reptile from the Permian of South Africa. Transactions of the Kansas Academy of Science. 40: 221-231.

CHENG, Z. & Li, J. (1996) First record of a primitive anteosaurid dinocephalian from the Upper Permian of Gansu, China. Vertebrate PalAsiatica. 34: 123-134.

CHENG, Z. & Li, J. (1997) A new genus of primitive dinocephalian: the third report on Late Permian Dashankou lower tetrapod fauna. Vertebrate PalAsiatica. 35: 35-43.

GAUTHIER, J., KLUGE, A. & ROWE, T. (1988) Amniote phylogeny and the importance of fossils. Cladistics. 4: 105-209.

GREGORY, W.K. (1926) The Skeleton of Moschops capensis Broom, a dinocephalian reptile from the Permian of South Africa. Bulletin of the American Museum of Natural History. 56: 179-251.

HAMMER, Ø., HARPER, D.A.T. & RYAN, P.D. (2001) PAST: Palaeontological Statistics software package for education and data analysis. Palaeontologia Electronica. 4(1): 9. Ver. 1.34 available online at: http://folk.uio.no/ohammer/past

HAUGHTON, S.H. (1915a) On a new dinocephalian from the Gouph. Annals of the South African Museum. 12: 52-54.

HAUGHTON, S.H. (1915b) On a new type of dinocephalian (Moschosaurus longiceps). Annals of the South African Museum. 12: 78-81.

HAUGHTON, S.H. (1929) On some new therapsid genera. Annals of the South African Museum. 28: 55-78.

HAUGHTON, S.H. & BRINK, A.S. (1954) A bibliographical list of Reptilia from the Karroo beds of Africa. Palaeontologia Africana. 2: 1-187.

HOPSON, J.A. & BARGHUSEN, H. (1986) An analysis of therapsid relationships. In: HOTTON, N., MACLEAN, P.D., ROTH, J.J. & ROTH, E.C. (Eds) The ecology and biology of mammal-like reptiles. Smithsonian Institution Press, Washington. pp 83- 106.

IVACHNENKO, M.F. (1995) Primitive Late Permian dinocephalian-titanosuchids of Eastern Europe. Paleontological Journal. 29: 120-129.

IVACHNENKO, M.F. (2000) Estemmenosuchus and primitive theriodonts from the Late Permian. Paleontological Journal. 34: 189-197.

KAMMERER, C.F & SIDOR, C.A. (2002) Replacement names for the therapsid genera Criocephalus Broom 1928 and Olivieria Brink 1965. Palaeontologia Africana. 38: 71- 72.

KEMP, T. S. (1982) Mammal-like reptiles and the origin of mammals. Academic Press, London.

KEMP, T.S. (2005) The origin and evolution of mammals. Oxford University Press, Oxford.

KING, G.M. (1988) Anomodontia. In: WELLNHOFER (Ed.) Encyclopedia of Paleoherpetology, 17C. Gustav Fischer Verlag, Stuttgart. pp 1-174.

LANGER, M.C. (2000) The first record of dinocephalians in South America, Late Permian Rio do Rosta Formation) of the Paraná Basin, Brazil. Neues Jahrbuch für Geologie und Palaontologie, Abhandlungen. 215: 69-95.

LEPPER, J., RAATH, M.A. & RUBIDGE, B.S. (2000) A diverse dinocephalian fauna from Zimbabwe. South African Journal of Science. 96: 403-405. LI, J. & CHENG, Z. (1995) A new Late Permian vertebrate fauna from the Dashankou, Gansu with comments on Permian and Triassic vertebrate assemblage zones of China. In: SUN, A.I & WANG, Y.Q. (Eds) Short papers of Sixth Symposium on Mesozoic Terrestrial Ecosystems and Biota. China Ocean Press, Beijing. pp. 33-37.

LI, J., RUBIDGE, B.S. & CHENG, Z. (1996) A primitive anteosaurid dinocephalian from China – implications for the distribution of earliest therapsid faunas. South African Journal of Science. 92: 252-253.

LYDEKKER, R. (1980) Catalogue of the fossil Reptilia and Amphibia in the British Museum. Part IV. Containing the orders Anomodontia, Ecaudata, Caudata, and Labyrinthodontia; and supplement. London.

MASON, R. (2007) A bio- and litho-stratigraphic study of the Ecca-Beaufort contact in the south eastern Karoo Basin (Albany District, Eastern Cape Province). Unpublished MSc dissertation, University of the Witwatersrand.

MODESTO, S.P, RUBIDGE, B.S. & WELMAN, J. (1999) the most basal anomodont therapsid and the primacy of Gondwana in the evolution of the anomodonts. Proceedings of the Royal Society of London, Series B. 266: 331-337.

MULSANT, M.E. (1839) Longicornes. In: MULSANT, M. & REY, C. (Eds) Histoire Naturelle des Coléoptères de France. Paris, Maison; Lyon, C.S. Juene.

MUNYIKWA, D. (2001) Cranial morphology of a primitive dinocephalian from the Madumabisa Mudstone Formation, Zimbabwe. Unpublished MSc dissertation, University of the Witwatersrand.

OWEN, R. (1876) Descriptive and illustrated catalogue of the Fossil Reptilia of South Africa in the collection of the British Museum. London.

OLSON (1903) The reptilian subclasses Diapsida and Synapsida and the early history of the Diaptosauria. Memoirs from the American Museum of Natural History. 1: 265-270.

PIVETEAU, J. (1961) Tapinocephalidae. In: PIVETEAU, J. (Ed) Traité de Paléotolgie. VI(i) Mammiferes. Origine Reptilienne, Evolution. Masson et Cie, Paris. pp 274-278.

RUBEN, J.A. (1986) Therapsids and their environment, a summary. In: HOTTON, N., MACLEAN, P.D., ROTH, J.J. & ROTH, E.C. (Eds) The ecology and biology of mammal-like reptiles. Smithsonian Institution Press, Washington. pp 307-312.

RUBIDGE, B.S. (1991) A new primitive dinocephalian mammal-like reptile from the Permian of southern Africa. Palaeontology. 34: 547-559.

RUBIDGE, B.S. (1994) Australosydon, the first primitive anteosaurid dinocephalian from the Upper Permian of Gondwana. Palaeontology. 37: 579-594.

RUBIDGE, B.S & KITCHING, J.W. (2003) A new burnetiamorph (Therapsida: Biarmosuchia) from the lower Beaufort Group of South Africa. Palaeontology. 46: 199-210.

RUBIDGE, B.S., SIDOR, C.A. & MODESTO, S.P. (2006) A new burnetiamorph (Therapsida: Biarmosuchia) from the Middle Permian of South Africa. Journal of Paleontology. 80(4): 740-749.

RUBIDGE, B.S. & VAN DEN HEEVER, J.A. (1997) Morphology and systematic position of the dinocephalian Styracocephalus platyrhychus. Lethaia. 30: 157-168.

RYBCZYNSKI, N. (2000) Cranial anatomy and phylogenetic position of Suminia getmanovi, a basal anomodont (Amniota: Therapsida) from the Late Permian of Eastern Europe. Zoological journal of the Linnean Society. 130: 329-373.

SEELEY, H.G. (1892) On Delphinognathus conocephalus (Seeley) from the middle Karroo beds, Cape Colony, preserved in the South African Museum, Cape Town. Quarterly Journal of the Geological Society, London. 48: 469-475.

SEELEY, H.G. (1888) Researches on the structure, organization, and classification of the fossil Reptilia. Part II. On Pareiasaurus bombidens (Owen) and the significance of its affinities to amphibians, reptiles and mammals. Philosophical Transactions of the Royal Society of London, Series B. 179: 59-109.

SEELEY, H.G. (1894) Researches on the structure, organization, and classification of the fossil Reptilia. Part IX, section 1. On the Therosuchia. Philosophical Transactions of the Royal Society, Series B. 185: 987-1018.

SIDOR, C.A. (2000) Evolutionary trends and relationships within the Synapsida. Unpublished PhD dissertation, University of Chicago.

SIDOR, C.A. & HOPSON, J.A. (1998) Ghost lineages and “mammalness”: Assessing the temporal pattern of character acquisition in the Synapsida. Paleobiology 24: 254-273.

SIDOR, C.A., HOPSON, J.A. & KEYSER, A.W. (2004) A new burnetiamorph therapsid from the Teekloof Formation, Permian, of South Africa. Journal of Vertebrate Paleontology. 24: 938-950.

SIDOR, C.A. & RUBIDGE, B.S. (2006) Herpetoskylax hopsoni, A new biarmosuchian (Therapsida: Biarmosuchia) from the Beaufort Group of South Africa. In: CARRANO, M.T, GAUDIN, T., BLOB, R. & WIBLE, J. (Eds) Amniote Paleobiology: Perspectives on the evolution of mammals, birds and reptiles. University of Chicago Press, Chicago. pp 76-113.

SIDOR, C.A. & WELMAN, J. (2003) A second specimen of Lemurosaurus pricei (Therapsida: Burnetiamorpha). Journal of Vertebrate Paleontology. 23: 631-642.

SWAFFORD, D.L. (1998) Phylogenetic Analysis Using Parsimony (and other methods). Version 4.0b10, Sinauer Associates, Sunderand, Massaschusetts.

VAN DEN HEEVER, J.A. & GRINE, F.E. (1981) Dinocephalia type material in the South African Museum (Reptilia, Therapsida). Annals of the South African Museum. 86: 73- 114.

VON HUENE, F. (1931) Bietrag zur Kenntnis der Faunder süd-afrikanischen Karrooformation. Geologisch Paläontogische, Abhandlungen. 18: 159-227.

WATSON, D.M.S. (1914) The Deinocephalia, an order of mammal-like reptiles. Proceedings Zoological Society of London. 1914: 749-786.


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