Euarchonta

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Euarchontans
Temporal range: Paleocene - Holocene, 65–0Ma
Euarchonts: upper left: Plesiadapis, upper right: Northern Treeshrew, lower left: Sunda Flying Lemur and lower right: Yellow Baboon
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Superorder: Euarchontoglires
Grandorder: Euarchonta
Subgroups

Scandentia
Primatomorpha

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

The term "Euarchonta" (meaning "true ancestors") first appeared in the general scientific literature in 1999, when molecular evidence suggested that the morphology-based Archonta should 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). Some interpretations of the molecular data link Primates and Dermoptera in a clade (mirorder) 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)


Primatomorpha

Dermoptera (flying lemurs)




Primates (†Plesiadapiformes, Strepsirrhini, Haplorrhini)






Note that as eu- becomes ev- before vowels in Latin, Euarchonta is not a proper Latin phonological construct—Evarchonta would be appropriate. This is applied inconsistently in English, for example in euergetism on one hand and evangelism on the other.

The current data situation be based on the molecular clock extrapolate that Euarchonta arose in the Cretaceous period about 88 million years ago and is already segregating 86.2 million years ago in the groups of tree shrews and Primatomorpha. The latter parted before 79.6 million years in the orders of primates and giant slides.1 However, the earliest actual fossil species that can be confidently referred to Euarchonta (Purgatorius coracis) dates to the early Paleocene, 65 million years ago.2 Given that euarchonta did evolve before purgatorius, this means the human ancestor that survived the Cretaceous–Paleogene extinction event belonged to euarchonta.

References

  1. ^ Jan E. Janecka, Webb Miller, Thomas H. Pringle, Frank Wiens, Annette Zitzmann, Kristofer M. Helgen, Mark S. Springer und William J. Murphy: Molecular and Genomic Data Identify the Closest Living Relative of Primates. In: Science. 318. 2007, 792-794 (PDF 384 KB)
  2. ^ O'Leary, M. A., Bloch, J. I., Flynn, J. J., Gaudin, T. J., Giallombardo, A., Giannini, N. P., ... & Cirranello, A. L. (2013). The placental mammal ancestor and the post–K-Pg radiation of placentals. Science, 339(6120): 662-667.
  • 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 doi:10.1016/j.tig.2007.02.002 (PDF version [3])

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