Euarchonta

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Euarchontans Fossil range: Late Cretaceous - Recent
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Mammalia Infraclass: Eutheria Superorder: Euarchontoglires (unranked) Euarchonta
Orders
Dermoptera  Scandentia  Plesiadapiformes (extinct)  Primates

The Euarchonta are a superorder of mammals containing four orders: the Dermoptera or colugos, the Scandentia or treeshrews, the extinct Plesiadapiformes, and the Primates.

The term "Euarchonta" (means "true ancestors") first appeared in the general scientific literature in 1999, when molecular evidence suggested that the morphology-based Archonta be trimmed down to exclude Chiroptera. Major DNA sequence analyses of predominantly nuclear sequences (Murphy et al., 2001) support the Euarchonta hypothesis, while a major study investigating mitochondrial sequences supports a different tree topology (Arnason et al, 2002). A study investigating retrotransposon presence/absence data has claimed strong support for Euarchonta (Kriegs et al., 2007). However, the morphological data, together with criticism of the reliability of the molecular data, continues to call into question whether or not bats should be excluded from Archonta. In particular, some researchers believe that bats are diphyletic, and that some bats (Megachiroptera) are closely related to primates (see Flying primates theory).

Some interpretations of the molecular data link Primates and Dermoptera in a clade known as Primatomorpha, which is the sister of Scandentia. In some the Dermoptera are a member of the primates rather than a sister. Other interpretations link the Dermoptera and Scandentia together in a group called Sundatheria as the sister group of the primates. Together, the three are known as Euarchonta, the "True Founders".

Euarchonta and Glires together form the Euarchontoglires, one of the four Eutherian clades.

Euarchontoglires	Glires Rodentia (rodents) Lagomorpha (rabbits, hares, pikas) Euarchonta Scandentia (treeshrews) Dermoptera (flying lemurs) †Plesiadapiformes Primates

[edit] References

• Murphy W. J., E. Eizirik, W. E. Johnson, Y. P. Zhang, O. A. Ryder, S. J. O'Brien, 2001a. Molecular phylogenetics and the origins of placental mammals Nature 409:614-618. [1]

• Ulfur Arnason, et al. Mammalian mitogenomic relationships and the root of the eutherian tree. Proceedings of the National Academy of Science 99: 8151-8156. [2]

• Jan Ole Kriegs, Gennady Churakov, Jerzy Jurka, Jürgen Brosius, and Jürgen Schmitz (2007) Evolutionary history of 7SL RNA-derived SINEs in Supraprimates. Trends in Genetics 23 (4): 158-161 [3] (PDF version [4])