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]
Phylogenetic relationships within the clade
The hypothesized relationship among the Euarchontoglires is as follows:[8]
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.