Laurasiatheria

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Laurasiatheria
Temporal range: Upper Cretaceous – Recent
Clockwise from the upper left: giraffe, fruit bat, lion, hedgehog
Scientific classification
Kingdom: Animalia
Class: Mammalia
Infraclass: Eutheria
Superorder: Laurasiatheria
Waddell et al., 1999
Orders

Laurasiatheria is a large group of placental mammals. The name comes from the area where advanced mammals evolved. This was on the northern supercontinent of Laurasia, roughly corresponding to Eurasia today plus North America. When Pangaea broke up, it split first into Laurasia in the north and Gondwana in the south.

Members of the group include shrews, hedgehogs, pangolins, bats, whales, most hoofed mammals, and carnivorans, and others.

The Laurasiatheria is defined by DNA sequence analysis. The group does not share any obvious anatomical features. It includes these living orders:

  • Eulipotyphla: hedgehogs, gymnures, 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)
  • Pholidota: pangolins or scaly anteaters (Africa, South Asia)
  • Chiroptera: bats (cosmopolitan)
  • Carnivora: carnivores (cosmopolitan)
  • Perissodactyla: odd-toed ungulates

There are various ideas as to how these groups are related to each other, and no tree of descent is agreed by experts so far.[1][2]

References[change | change source]

  1. Zhou, Xuming et al 2011. Phylogenomic analysis resolves the interordinal relationships and rapid diversification of the laurasiatherian mammals. Systematic Biology 61 (1): 150–164. [1]
  2. Nery M.F. et al 2012. Resolution of the laurasiatherian phylogeny: evidence from genomic data. Molecular Phylogenetics and Evolution 64 (3): 685–689. [2]