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Elliotherium kersteni, a new tritheledontid from the lower Elliot Formation (Upper Triassic) of South Africa

Published online by Cambridge University Press:  14 July 2015

C. A. Sidor  and
P. J. Hancox
C. A. Sidor
Affiliation:
Burke Museum and Department of Biology, University of Washington, Seattle 98195,
P. J. Hancox
Affiliation:
Bernard Price Institute for Palaeontological Research, University of the Witwatersrand, Johannesburg, WITS 2050, South Africa,
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Abstract

We describe a new tritheledontid, Elliotherium kersteni n. gen. and sp., on the basis of a partial skull collected from the lower Elliot Formation (Upper Triassic; Euskelosaurus Range Zone) on the farm Beatrix, Free State Province, South Africa. Although similar to Pachygenelus, the genus differs from other South African tritheledontids in its higher maxillary postcanine tooth count, lack of labial cingula on the upper postcanine teeth, shorter secondary palate, retention of a median vomerine ridge behind the secondary palate, and smaller interpterygoid vacuity. With regard to these features, Elliotherium is most similar to the South American tritheledontid Chaliminia. Elliotherium is autapomorphic in its possession of a long parasphenoid rostrum, ventrally depressed secondary palate, medially convex margins of the interpterygoid vacuity, and a thin lamina of palatine covering the interpterygoid vacuity. Although Elliotherium is the stratigraphically lowest positioned tritheledontid from southern Africa, it is still probably later occurring than the South American taxa Chaliminia or Riograndia. Based on a revision of a previous analysis of advanced cynodont relationships, we propose a sister-group relationship between Elliotherium and Chaliminia, although support for this pairing is weak.

Type
Research Article
Information
Journal of Paleontology , Volume 80 , Issue 2 , March 2006 , pp. 333 - 342
Copyright
Copyright © The Paleontological Society 

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References

Amalitzky, V. 1922. Diagnoses of the new forms of vertebrates and plants from the Upper Permian of North Dvina. Bulletin of the Academy of Science, St. Petersburg, 16:329–340.Google Scholar
Bonaparte, J. F. 1980. El primero Ictidosaurio (Reptilia–Therapsida) de America del Su, Chaliminia musterloides, del Triasico Superior de La Rioja, Republica Argentina. Actas II Congreso Argentino de Paleontología y Bioestratigrafía y I Congreso Latinamericano de Paleontología, p. 123–133.Google Scholar
Bonaparte, J. F., Ferigolo, J., and Ribeiro, A. M. 2001. A primitive Late Triassic ‘ictidosaur’ from Rio Grande do Sul, Brazil. Palaeontology, 44:623–635.CrossRefGoogle Scholar
Bonaparte, J. F., Martinelli, A. G., Schultz, C. L., and Rubert, R. 2003. The sister group of mammals: small cynodonts from the Late Triassic of southern Brazil. Revista Brasileira de Paleontologia, 5:5–27.Google Scholar
Bordy, E. M., Hancox, P. J., and Rubidge, B. S. 2004. Fluvial style variations in the Late Triassic–Early Jurassic Elliot Formation, main Karoo Basin, South Africa. Journal of African Earth Sciences, 38:383–400.CrossRefGoogle Scholar
Broom, R. 1903. On the lower jaw of a small mammal from the Karroo beds of Aliwal North, South Africa. Geological Magazine, 10:345.CrossRefGoogle Scholar
Broom, R. 1912. On a new type of cynodont from the Stormberg. Annals of the South African Museum, 7:334–336.Google Scholar
Broom, R. 1929. On some recent new light on the origin of mammals. Proceedings of the Linnean Society, New South Wales, 54:688–694.Google Scholar
Broom, R. 1932. The Mammal-Like Reptiles of South Africa and the Origin of Mammals. Witherby, London, 376 p.Google Scholar
Broom, R. 1937. A further contribution to our knowledge of the fossil reptiles of the Karoo. Proceedings of Zoological Society of London B, 107:299–318.CrossRefGoogle Scholar
Chatterjee, S. 1983. An ictidosaur fossil from North America. Science, 220:1151–1153.CrossRefGoogle ScholarPubMed
Crompton, A. W. 1958. The cranial morphology of a new genus and species of ictidosaurian. Proceedings of the Zoological Society of London, 130:183–215.CrossRefGoogle Scholar
Crompton, A. W. 1963. On the lower jaw of Diarthrognathus and the origin of the mammalian lower jaw. Proceedings of the Zoological Society of London, 140:697–750.CrossRefGoogle Scholar
Crompton, A. W., and Luo, Z. 1993. Relationship of the Liassic mammals Sinoconodon, Morganucodon oehleri, and Dinnetherium , p. 30–44. In Szalay, F. S., Novacek, M. J., and McKenna, M. C. (eds.), Mammal Phylogeny: Mesozoic Differentiation, Multituberculates, Monotremes, Early Therians, and Marsupials. Springer-Verlag, New York.CrossRefGoogle Scholar
Duncan, R. A., Hooper, P. R., Rehacek, J., Marsh, J. S., and Duncan, A. R. 1997. The timing and duration of the Karoo igneous event, southern Gondwana. Journal of Geophysical Research, 102:18127–18138.CrossRefGoogle Scholar
Fourie, S. 1974. The cranial morphology of Thrinaxodon liorhinus Seeley. Annals of the South African Museum, 65:337–400.Google Scholar
Gauthier, J., Kluge, A., and Rowe, T. 1988. Amniote phylogeny and the importance of fossils. Cladistics, 4:105–209.CrossRefGoogle ScholarPubMed
Gow, C. E. 1980. The dentition of the Tritheledontidae (Therapsida: Cynodontia). Proceedings of the Royal Society of London B, 208:461–481.Google ScholarPubMed
Gow, C. E. 1981. Pachygenelus, Diarthrognathus and the double jaw articulation. Palaeontologia Africana, 24:15.Google Scholar
Gow, C. E. 1994. New find of Diarthrognathus (Therapsida: Cynodontia) after seventy years. Palaeontologia Africana, 31:51–54.Google Scholar
Gow, C. E. 2001. A partial skeleton of the tritheledontid Pachygenelus (Therapsida: Cynodontia). Palaeontologia Africana, 37:93–97.Google Scholar
Gow, C. E., and Hancox, P. J. 1993. First complete skull of the Late Triassic Scalenodontoides (Reptilia Cynodontia) from southern Africa, p. 161–168. In Lucas, S. G. and Morales, M. (eds.), The Nonmarine Triassic. New Mexico Museum of Natural History & Science Bulletin, No. 3.Google Scholar
Haughton, S. H. 1924. The fauna and stratigraphy of the Stormberg Series. Annals of the South African Museum, 12:323–497.Google Scholar
Hopson, J. A. 1964. The braincase of the advanced mammal-like reptile Bienotherium . Postilla, 87:1–30.Google Scholar
Hopson, J. A. 1975. On the generic separation of the ornithischian dinosaurs Lycorhinus and Heterodontosaurus from the Stormberg Series (Upper Triassic) of South Africa. South African Journal of Science, 71:302–305.Google Scholar
Hopson, J. A. 1984. Late Triassic traversodont cynodonts from Nova Scotia and southern Africa. Palaeontologia Africana, 25:181–201.Google Scholar
Hopson, J. A., and Barghusen, H. 1986. An analysis of therapsid relationships, p. 83–106. In Hotton, N., MacLean, P. D., Roth, J. J., and Roth, E. C. (eds.), The Ecology and Biology of the Mammal-Like Reptiles. Smithsonian Institution Press, Washington, DC.Google Scholar
Hopson, J. A., and Kitching, J. W. 1972. A revised classification of cynodonts (Reptilia; Therapsida). Palaeontologia Africana, 14:71–85.Google Scholar
Hopson, J. A., and Kitching, J. W. 2001. A probainognathian cynodont from South Africa and the phylogeny of nonmammalian cynodonts. Bulletin of the Museum of Comparative Zoology, 156:3–35.Google Scholar
Hopson, J. A., and Rougier, G. W. 1993. Braincase structure in the oldest known skull of a therian mammal: Implications for mammalian systematics and cranial evolution. American Journal of Science, 293A:268–299.CrossRefGoogle Scholar
Johnson, M. R., Van Vuuren, C. J., Hegenberger, W. F., Key, R., and Shoko, U. 1996. Stratigraphy of the Karoo Supergroup in southern Africa: An overview. Journal of African Earth Sciences, 23:3–15.CrossRefGoogle Scholar
Kemp, T. S. 1979. The primitive cynodont Procynosuchus: functional anatomy of the skull and relationships. Philosophical Transactions of the Royal Society of London B, 285:73–122.Google Scholar
Kemp, T. S. 1983. The relationships of mammals. Zoological Journal of the Linnean Society, 77:353–384.CrossRefGoogle Scholar
Kitching, J. W., and Raath, M. A. 1984. Fossils from the Elliot and Clarens formations (Karoo Sequence) of the northeastern Cape, Orange Free State and Lesotho, and a suggested biozonation based on tetrapods. Palaeontologia Africana, 25:111–125.Google Scholar
Lucas, S. G., and Hancox, P. J. 2001. Tetrapod-based correlation of the nonmarine Upper Triassic of southern Africa. Albertiana, 25:5–9.Google Scholar
Luo, Z. 1994. Sister-group relationships of mammals and transformations of diagnostic mammalian characters, p. 98–128. In Fraser, N. C. and Sues, H.-D. (eds.), In the Shadow of the Dinosaurs: Early Mesozoic Tetrapods. Cambridge University Press, New York.Google Scholar
Luo, Z., and Crompton, A. W. 1994. Transformation of the quadrate (incus) through the transition from non-mammalian cynodonts to mammals. Journal of Vertebrate Paleontology, 14:341–374.CrossRefGoogle Scholar
Luo, Z., Kielan-Jaworoska, Z., and Cifelli, R. L. 2002. In quest for a phylogeny of Mesozoic mammals. Acta Palaeontologica Polonica, 47:1–78.Google Scholar
Martinelli, A. G., Bonaparte, J. F., Schultz, C. L., and Rubert, R. In press. A new tritheledontid (Therapsida, Eucynodontia) from the Late Triassic of Rio Grande do Sul (Brazil), and its phylogenetic relationships among carnivorous non-mammalian eucynodonts. Ameghiniana, 42:191–208.Google Scholar
Olsen, P. E., and Galton, P. M. 1984. A review of the reptile and amphibian assemblages from the Stormberg of southern Africa, with special reference on the footprints and the age of the Stormberg. Palaeontologia Africana, 25:87–110.Google Scholar
Owen, R. 1861. Palaeontology, or, A Systematic Summary of Extinct Animals and Their Geologic Relations. Adam and Charles Buck, Edinburgh, 463 p.CrossRefGoogle Scholar
Parrington, F. R. 1946. On a collection of Rhaetic mammalian teeth. Proceedings of the Zoological Society of London, 116:707–728.Google Scholar
Raath, M. 1972. Fossil vertebrate studies in Rhodesia: a new dinosaur (Reptilia, Saurischia) from near the Trias–Jurassic boundary. Arnoldia, 5:1–37.Google Scholar
Rowe, T. 1988. Definition, diagnosis, and the origin of Mammalia. Journal of Vertebrate Paleontology, 8:241–264.CrossRefGoogle Scholar
Rowe, T. 1993. Phylogenetic systematics and the early history of mammals, p. 129–145. In Szalay, F. S., Novacek, M. J., and McKenna, M. C. (eds.), Mammal Phylogeny: Mesozoic Differentiation, Multituberculates, Monotremes, Early Therians, and Marsupials. Springer-Verlag, New York.CrossRefGoogle Scholar
Rubidge, B. S., and Sidor, C. A. 2001. Evolutionary patterns among Permo–Triassic therapsids. Annual Review of Ecology and Systematics, 32:449–480.CrossRefGoogle Scholar
Seeley, H. G. 1894. Researches on the structure, organisation, and classification of the fossil Reptilia. Pt. IX. Section 1. On the Therosuchia. Philosophical Transactions of the Royal Society of London B, 185:987–1018.Google Scholar
Seeley, H. G. 1895. Researches on the structure, organization, and classification of the fossil Reptilia. Pt. 9, Sect. 5. On the skeleton in new Cynodontia from the Karroo rocks. Philosophical Transactions of the Royal Society B, 198:59–148.Google Scholar
Shubin, N. H., Crompton, A. W., Sues, H.-D., and Olsen, P. E. 1991. New fossil evidence on the sister-group of mammals and early Mesozoic faunal distributions. Science, 251:1063–1065.CrossRefGoogle ScholarPubMed
Sidor, C. A., and Smith, R. M. H. 2004. A new galesaurid (Therapsida: Cynodontia) from the Lower Triassic of South Africa. Palaeontology, 46:535–556.CrossRefGoogle Scholar
Smith, R. M. H., and Kitching, J. W. 1997. Sedimentology and vertebrate taphonomy of the Tritylodon Acme Zone: a reworked palaeosol in the Lower Jurassic Elliot Formation, Karoo Supergroup, South Africa. Palaeogeography, Palaeoclimatology, Palaeoecology, 131:29–50.CrossRefGoogle Scholar
Sues, H.-D. 1985. The relationships of the Tritylodontidae (Synapsida). Zoological Journal of the Linnean Society, 85:205–217.CrossRefGoogle Scholar
Sues, H.-D. 1986. The skull and dentition of two tritylodontid synapsids from the Lower Jurassic of western North America. Bulletin of the Museum of Comparative Zoology, 151:217–268.Google Scholar
Swofford, D. L. 1993. PAUP: Phylogenetic Analysis Using Parsimony. Illinois Natural History Survey, Champaign.Google Scholar
Tatarinov, L. P. 1968. Morphology and systematics of the Northern Dvinia cynodonts (Reptilia, Therapsida; Upper Permian). Postilla, 126:1–15.Google Scholar
Thulborn, R. A. 1970. The systematic position of the Triassic ornithischian dinosaur Lycorhinus angustidens . Zoological Journal of the Linnean Society, 49:235–245.CrossRefGoogle Scholar
Visser, J. N. J., and Botha, B. J. V. 1980. Meander channel, point bar, crevasse splay and aeolian deposits from the Elliot Formation in Barkly Pass, north-eastern Cape. Transactions of the Geological Society of South Africa, 83:55–62.Google Scholar
von Huene, E. 1933. Zur kenntnis des Würtembergishen Rätbonebeds, etc. Jahreshefte des Vereins für vaterländische Naturkunde in Württemberg, 89:65–128.Google Scholar
Watson, D. M. S. 1913. On a new cynodont from the Stormberg. Geological Magazine, 10:145–148.CrossRefGoogle Scholar
Watson, D. M. S., and Romer, A. S. 1956. A classification of therapsid reptiles. Bulletin of the Museum of Comparative Zoology, 114:37–89.Google Scholar
Wible, J. R. 1991. Origin of Mammalia: the craniodental evidence re-examined. Journal of Vertebrate Paleontology, 11:1–28.CrossRefGoogle Scholar
Yates, A. M. 2003. A definite prosauropod dinosaur from the lower Elliot Formation (Norian: Upper Triassic) of South Africa. Palaeontologia Africana, 39:63–68.Google Scholar
Yates, A. M., and Kitching, J. W. 2003. The earliest known sauropod dinosaur and the first steps towards sauropod locomotion. Proceedings of the Royal Society of London B, 270:1753–1758.CrossRefGoogle ScholarPubMed
Yates, A. M., Hancox, P. J., and Rubidge, B. S. 2004. The first record of a sauropod dinosaur from the upper Elliot Formation (Early Jurassic) of South Africa. South African Journal of Science, 100:504–506.Google Scholar
Young, C.-C. 1947. Mammal-like reptiles from Lufeng, Yunnan, China. Proceedings of the Zoological Society of London, 117:537–597.CrossRefGoogle Scholar