Biology:Lumkuia

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Short description: Extinct genus of cynodonts

Lumkuia
Temporal range: Anisian, 247.2–242.0 Ma
Lumkuia.jpg
Life restoration
Scientific classification edit
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Synapsida
Clade: Therapsida
Clade: Cynodontia
Clade: Probainognathia
Family: Lumkuiidae
Hopson and Kitching, 2001
Genus: Lumkuia
Hopson and Kitching, 2001
Species:
L. fuzzi
Binomial name
Lumkuia fuzzi
Hopson and Kitching, 2001

Lumkuia is an extinct genus of cynodonts, fossils of which have been found in the Cynognathus Assemblage Zone of the Beaufort Group in the South African Karoo Basin that date back to the early Middle Triassic. It contains a single species, Lumkuia fuzzi, which was named in 2001 on the basis of the holotype specimen BP/1/2669, which can now be found at the Bernard Price Institute in Johannesburg, South Africa. The genus has been placed in its own family, Lumkuiidae. Lumkuia is not as common as other cynodonts from the same locality such as Diademodon and Trirachodon.[1]

Description

The postcanines are similar to those of the later chiniquodontids, but the secondary palate is quite short in comparison, and the genus lacks the angulation of the ventral cranial margin seen in chiniquodontids.[2] Lumkuia can be seen as more derived than other contemporary cynodonts such as Cynognathus with the crowns of its teeth high and narrow and having inwardly curving tops.

Classification

Lumkuia was first described in 2001 by the palaeontologists James A. Hopson and James W. Kitching, who considered it to be the most basal member of Probainognathia.[2] This placement has been supported by several later studies,[3][4] though others alternatively place it outside the clade formed by Cynognathia and Probainognathia.[5] Previously, early probainognathians were only known from younger strata in South America that were deposited in the late Middle and Late Triassic.[6][7][8][9][10][11][12]

References

  1. Fernando Abdala, P. John Hancox and Johann Neveling (2005). Cynodonts from the Uppermost Burgersdorp Formation, South Africa, and Their Bearing on the Biostratigraphy and Correlation of the Triassic Cynognathus Assemblage Zone. Journal of Vertebrate Paleontology 25(1):192-199.
  2. 2.0 2.1 Hopson, J. A. and Kitching, J. W. (2001). A probainognathian cynodont from South Africa and the phylogeny of non-mammalian cynodonts. Bulletin of the Museum of Comparative Zoology 156(1):5-35
  3. Martínez, R. N.; Fernandez, E.; Alcober, O. A. (2013). "A new non-mammaliaform eucynodont from the Carnian-Norian Ischigualasto Formation, Northwestern Argentina". Revista Brasileira de Paleontologia 16: 61–76. doi:10.4072/rbp.2013.1.05. 
  4. Ruta, M.; Botha-Brink, J.; Mitchell, S. A.; Benton, M. J. (2013). "The radiation of cynodonts and the ground plan of mammalian morphological diversity". Proceedings of the Royal Society B: Biological Sciences 280 (1769): 20131865. doi:10.1098/rspb.2013.1865. PMID 23986112. 
  5. Martinelli, A. G.; Soares, M. B.; Schwanke, C. (2016). "Two New Cynodonts (Therapsida) from the Middle-Early Late Triassic of Brazil and Comments on South American Probainognathians". PLOS ONE 11 (10): e0162945. doi:10.1371/journal.pone.0162945. PMID 27706191. 
  6. Romer, A. S. (1969). The Chañares (Argentina) Triassic reptile fauna V. A new chiniquodontid cynodont, Probelesodon lewisi- cynodont ancestry. Breviora 333:1–24.
  7. Romer, A. S. (1970). The Chañares (Argentina) Triassic reptile fauna VI. A chiniquodontid cynodont with an incipient squamosaldentary jaw articulation. Breviora 344:1–18
  8. Martínez, R. N. and Forster, C. A. (1996). The skull of Probelesodon sanjuanensis, Sp. Nov., from the Late Triassic Ischigualasto Formation of Argentina. Journal of Vertebrate Paleontology 16:285–91.
  9. Martínez, R. N., May, C. L. and Forster, C. A. (1996). A new carnivorous cynodont from the Ischigualasto Formation (Late Triassic, Argentina), with comments on eucynodont phylogeny. Journal of Vertebrate Paleontology 16:271–84.
  10. Romer, A. S. (1969). The Brazilian Triassic cynodont reptiles Belesodon and Chiniquodon. Breviora 332:1–16
  11. Hopson, J. A. (1995). Patterns of evolution in the manus and pes of non-mammalian therapsids. Journal of Vertebrate Paleontology 15:615–39.
  12. Rubidge, B. S. and Sidor, C. A. (2001). Evolutionary patterns among Permo-Triassic theraspids. Annual Review of Ecology and Systematics 32:449-480.

Wikidata ☰ Q3755940 entry