Phylogenetic position of Euarchontoglires (in blue) among placentals in a genus-level molecular phylogeny of 116 extant mammals inferred from the gene tree information of 14,509 coding DNA sequences.[3] The other major clades are colored: marsupials (magenta), xenarthrans (orange), afrotherians (red), and laurasiatherians (green).
The Euarchontoglires clade is based on DNA sequence analyses and retrotransposonmarkers that combine the clades Glires (Rodentia + Lagomorpha) and Euarchonta (Scandentia + Primates + Dermoptera).[1] It is usually discussed without a taxonomic rank but has been called a cohort, magnorder, or superorder. Relations among the four cohorts (Euarchontoglires, Xenarthra, Laurasiatheria, Afrotheria) and the identity of the placental root remain controversial.[4][5]
So far, few, if any, distinctive anatomical features have been recognized that support Euarchontoglires; nor does any strong evidence from anatomy support alternative hypotheses.[citation needed] Although both Euarchontoglires and diprotodontmarsupials are documented to possess a vermiform appendix, this feature evolved as a result of convergent evolution.[6]
Euarchontoglires probably split from the Boreoeutheriamagnorder about 85 to 95 million years ago, during the Cretaceous, and developed in the Laurasian island group that would later become Europe.[citation needed] This hypothesis is supported by molecular evidence; so far, the earliest known fossils date to the early Paleocene.[7] The combined clade of Euarchontoglires and Laurasiatheria is recognized as Boreoeutheria.[citation needed]
One study based on DNA analysis suggests that Scandentia and Primates are sister clades, but does not discuss the position of Dermoptera.[9] Although it is known that Scandentia is one of the most basal Euarchontoglires clades, the exact phylogenetic position is not yet considered resolved, and it may be a sister of Glires, Primatomorpha or Dermoptera or to all other Euarchontoglires.[10][5][11] Some old studies place Scandentia as sister of the Glires, invalidating Euarchonta.[12][13]
^ abMurphy, William J.; Eizirik, Eduardo; O'Brien, Stephen J.; Madsen, Ole; Scally, Mark; Douady, Christophe J.; Teeling, Emma; Ryder, Oliver A.; Stanhope, Michael J.; de Jong, Wilfried W.; Springer, Mark S. (2001). "Resolution of the early placental mammal radiation using Bayesian phylogenetics". Science. 294 (5550): 2348–2351. doi:10.1126/science.1067179. PMID11743200. S2CID34367609.
^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. doi:10.1126/science.1229237. hdl:11336/7302. PMID23393258. S2CID206544776.
^Zhou, Xuming; Sun, Fengming; Xu, Shixia; Yang, Guang; Li, Ming (2015-03-01). "The position of tree shrews in the mammalian tree: Comparing multi-gene analyses with phylogenomic results leaves monophyly of Euarchonta doubtful". Integrative Zoology. 10 (2): 186–198. doi:10.1111/1749-4877.12116. ISSN1749-4877. PMID25311886.
^Meredith, Robert W.; Janečka, Jan E.; Gatesy, John; Ryder, Oliver A.; Fisher, Colleen A.; Teeling, Emma C.; Goodbla, Alisha; Eizirik, Eduardo; Simão, Taiz L. L. (2011-10-28). "Impacts of the Cretaceous terrestrial revolution and KPg extinction on mammal diversification". Science. 334 (6055): 521–524. doi:10.1126/science.1211028. ISSN0036-8075. PMID21940861. S2CID38120449.
^Zhou, Xuming; Sun, Fengming; Xu, Shixia; Yang, Guang; Li, Ming (2015-03-01). "The position of tree shrews in the mammalian tree: Comparing multi-gene analyses with phylogenomic results leaves monophyly of Euarchonta doubtful". Integrative Zoology. 10 (2): 186–198. doi:10.1111/1749-4877.12116. ISSN1749-4877. PMID25311886.
