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Exafroplacentalia

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Exafroplacentalia
Temporal range: Paleocene - Holocene, 65–0 Ma
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Placentalia
Clade: Exafroplacentalia
Waddell et al, 2001[1]
Subgroups

Exafroplacentalia or Notolegia is a clade of placental mammals proposed in 2001 on the basis of molecular research.[1][2][3]

Exafroplacentalia places Xenarthra as a sister group to the Boreoeutheria (comprising Laurasiatheria and Euarchontoglires),[4] thus making Afrotheria a primitive group of placental mammals (the group name roughly means "those which are not African placentals").

Classification

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Eutheria  

Afrotheria

  Exafroplacentalia  

However, this classification makes the autapomorphy (character shared only among Exafroplacentalia) dubious: it is hard to classify a group by the absence of a feature (in this case "not coming from Africa").[5] Hence, several alternative hypotheses can be considered.

Alternative hypotheses

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One alternative hypothesis is the Epitheria hypothesis:

Another alternative hypothesis is the Atlantogenata hypothesis:

Updated analysis of transposable element insertions around the time of divergence strongly supports the fourth hypothesis of a near-concomitant origin of the three superorders of mammals:[5]

See also

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References

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  1. ^ a b Waddell, Peter J.; Kishino, Hirohisa; Ota, Rissa (2001). "A phylogenetic foundation for comparative mammalian genomics". Genome Informatics. 12: 141–154. doi:10.11234/gi1990.12.141. PMID 11791233. Archived from the original on 2019-07-10. Retrieved 2015-08-28.
  2. ^ Murphy, W.J., Pringle, T.H., Crider, T.A., Springer, M.S. & Miller, W. 2007. Using genomic data to unravel the root of the placental mammal phylogeny. Genome Research 17, pp.413-421.
  3. ^ Kriegs, J.O., Churakov, G., Kiefmann, M., Jordan, U., Brosius, J. & Schmitz, J. 2006. Retroposed elements as archives for the evolutionary history of placental mammals. Plos Biol 4, pp.e91.
  4. ^ Goloboff, Pablo A.; Catalano, Santiago A.; Mirande, J. Marcos; Szumik, Claudia A.; Arias, J. Salvador; Källersjö, Mari; Farris, James S. (2009). "Phylogenetic analysis of 73 060 taxa corroborates major eukaryotic groups". Cladistics. 25 (3): 211–230. doi:10.1111/j.1096-0031.2009.00255.x. hdl:11336/78055. PMID 34879616.
  5. ^ a b Nishihara, H., Maruyama, S. & Okada, N. 2009. Retroposon analysis and recent geological data suggest near-simultaneous divergence of the three superorders of placental mammals. PNAS 106: 5235-40.

Further reading

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