| Boreoeutheria Temporal range: Late Cretaceous - Holocene, 65–0Ma |
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| European mole (Talpa europaea) | |
Scientific classification  |
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| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Clade: | Eutheria |
| Infraclass: | Placentalia |
| Subcohort: | Exafroplacentalia |
| Magnorder: | Boreoeutheria |
| Subgroups | |
Boreoeutheria (synonymous with Boreotheria) (Gk: βόρειο North + ευ Good + θεριό Beast) is a clade (magnorder) of placental mammals that is composed of the sister taxa Laurasiatheria (most hoofed mammals, most pawed carnivores, and several other groups) and Euarchontoglires (Supraprimates). It is now well supported by DNA sequence analyses, as well as retrotransposon presence/absence data.
The earliest known fossils belonging to this group date to about 65 million years ago, shortly after the K-Pg extinction event, though molecular data suggests they may have originated earlier, during the Cretaceous period.[1]
With the exception of rhinoceroses and cetaceans, male members of the clade share the distinction of external testicles.
Contents
Boreoeutherian ancestor[edit]
The common ancestor of Boreoeutheria lived between 100 and 80 million years ago. The boreoeutherian ancestor gave rise to species as diverse as cat, dog, mouse, rabbit, whale and humans. The concept of boreoeutherian ancestor was first proposed in 2004 in the journal Genome Research.[2][3] The genome sequence of the boreoeutherian ancestor can be computationally predicted with high accuracy. It is estimated to contain three billion base pairs.[2]
Classification[edit]
Class Mammalia
- Magnorder Boreoeutheria
- Superorder Euarchontoglires (Supraprimates)
- Clade Euarchonta
- Order Scandentia: treeshrews (Southeast Asia)
- Clade Primatomorpha
- Order Dermoptera: flying lemurs or colugos (Southeast Asia)
- Order Primates: lemurs, bushbabies, monkeys, apes (cosmopolitan)
- Clade Glires
- Order Lagomorpha: pikas, rabbits, hares (Eurasia, Africa, Americas)
- Order Rodentia: rodents (cosmopolitan)
- Clade Euarchonta
- Superorder Laurasiatheria
- Clade Eulipotyphla
- Order Erinaceomorpha: hedgehogs and gymnures (Eurasia, Africa, extinct in North America)
- Order Soricomorpha: moles, shrews, solenodons (Eurasia, Africa, North America, northern South America)
- Clade Cetartiodactyla
- Order Cetacea: whales, dolphins and porpoises (cosmopolitan in seas)
- Order Artiodactyla: even-toed ungulates, including pigs, hippopotamus, camels, giraffe, deer, antelope, cattle, sheep, goats (cosmopolitan)
- Order Chiroptera: bats (cosmopolitan)
- Clade Zooamata
- Order Perissodactyla: odd-toed ungulates, including horses, donkeys, zebras, tapirs, and rhinoceroses (cosmopolitan)
- Clade Ferae
- Clade Eulipotyphla
- Superorder Euarchontoglires (Supraprimates)
Cladogram[edit]
| Eutheria |
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Notes[edit]
While it is agreed that the cetaceans evolved within artiodactyls much of the branching order within Laurasiatheria is not yet well resolved. In particular the most difficult order to place definitively has been and still is the Perissodactyla. Their placement within the Zooamata is controversial.
One study has suggested that the carnivores, cetaceans, chiroptera and ungulates form an ancient clade.[4] This is supported by another study that suggests that Eulipotyphla are the earliest diverging clade within the Laurasiatheria.[5]
References[edit]
- ^ 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.
- ^ a b John Roach (January 25, 2005). "Scientists Recreate Genome of Ancient Human Ancestor". National Geographic. Retrieved 14 Feb 2015.
- ^ Mathieu Blanchette, Eric D. Green, Webb Miller, David Haussler (2004). "Reconstructing large regions of an ancestral mammalian genome in silico". Genome Research. doi:10.1101/gr.2800104. Retrieved 14 Feb 2015.
- ^ Tsagkogeorga G, Parker J, Stupka E, Cotton JA, Rossiter SJ (2013) Phylogenomic analyses elucidate the evolutionary relationships of bats. Curr Biol pii: S0960-9822(13)01130-5. doi: 10.1016/j.cub.2013.09.014
- ^ Morgan CC, Foster PG, Webb AE, Pisani D, McInerney JO, O'Connell MJ (2013) Heterogeneous models place the root of the placental mammal phylogeny. Mol Biol Evol 30(9):2145-256 doi: 10.1093/molbev/mst117
Additional references[edit]
- Waddell PJ, Kishino H, Ota R (2001) A phylogenetic foundation for comparative mammalian genomics. Genome Inform Ser Workshop Genome Inform 12: 141–154.
- 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.
- Kriegs, Jan Ole, 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)
- Blanchette M, Green ED, Miller W, Haussler D. (2004) Reconstructing large regions of an ancestral mammalian genome in silico. Genome Res. 2004 Dec;14(12):2412-23. ([2])
- Ma J, Zhang L, Suh BB, Raney BJ, Burhans RC, Kent WJ, Blanchette M, Haussler D, Miller W. (2006) Reconstructing contiguous regions of an ancestral genome. Genome Res. 2006 Dec;16(12):1557-65. Epub 2006 Sep 18. ([3])
External links[edit]
- Resolving the Family Tree of Placental Mammals
- Wired article: Bringing Back the Brontosaurus April 2006.