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Laurasiatheria
Introduction
Laurasiatheria is a clade of rank cohort or super-order, within the Placentalia (living) or Eutheria (Placentals and their extinct ancestors) infraclass of mammals, based on DNA sequence analyses and Retrotransposon presence/absence data. The name comes from the theory that these mammals evolved on the supercontinent of Laurasia, after it split from Gondwana when Pangaea broke up. It is a sister group to Euarchontoglires (Supraprimates) and Afrotheria. It includes the following extant orders:
- Erinaceomorpha: hedgehogs and gymnures
- Soricomorpha: moles, shrews, solenodons (cosmopolitan)
- Cetartiodactyla: cosmopolitan; includes former orders Cetacea (whales, dolphins and porpoises) and Artiodactyla (even-toed ungulates, including pigs, hippopotamus, camels, giraffe, deer, antelope, cattle, sheep, goats)
- Pegasoferae:
- Pholidota: pangolins or scaly anteaters (Africa, South Asia)
- Chiroptera: bats (cosmopolitan)
- Carnivora: carnivores (cosmopolitan)
- Perissodactyla: odd-toed ungulates
Within the Laurasiatheria, the Erinaceomorpha appears (surprisingly) to be the most divergent branch. Some studies link the Perissodactyla and Ferae in a clade Zooamata; others link Perissodactyla and Cetartiodactyla in a clade of true ungulates. Neither clade is well supported.
Laurasiatheria is also posited to include several extinct orders and superorders:
Template:Laurasiatheria Cladogram
References
- William J. Murphy, Eduardo Eizirik, Mark S. Springer et al., Resolution of the Early Placental Mammal Radiation Using Bayesian Phylogenetics,Science, Vol 294, Issue 5550, 2348-2351, 14 December 2001.
- Jan Ole Kriegs, Gennady Churakov, Martin Kiefmann, Ursula Jordan, Juergen Brosius, Juergen Schmitz. (2006) Retroposed Elements as Archives for the Evolutionary History of Placental Mammals. PLoS Biol 4(4): e91.[1] (pdf version)
- Kitazoe Y, Kishino H, Waddell PJ, Nakajima N, Okabayashi T, et al (2007) “Robust Time Estimation Reconciles Views of the Antiquity of Placental Mammals.” PLoS ONE 2(4): e384. doi:10.1371/journal.pone.0000384
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