Squirrel Monkey ( Saimiri sciureus )
The Exafroplacentalia ("ex afro ", "place talia " = all Placentalia except the Afrotheria ) are a group within the higher mammals ( Eutheria ). They were in 2001 on the basis of genetic studies as a taxon ( subcohort ) described and in addition to the Boreoeutheria include ( Euarchontoglires and Laurasiatheria ) the Xenarthra. In systematic representations of the mammals they are often not explicitly mentioned.
The currently available data, be based on the molecular clock extrapolate that the Exafroplacentalia have emerged in the Cretaceous period, about 110-115 million years ago and 105 million years ago already segregating in the groups of Xenarthra and the Boreoeutheria. The latter split 100 million years ago in the transfer orders of Euarchontoglires and Laurasiatheria.
The following cladogram shows the systematic position of the Exafroplacentalia:
A variant positions the Xenarthra as a primitive group on the basis of the higher mammals, and thus as a sister group of all other taxa, which are summarized in the case as Epitheria. This variant is both molecular biology and morphology, on the basis of the structure of the inner ear have been proposed.
Xenarthra ( Xenarthra )
A third theory, finally, summarizes the Afrotheria and the Xenarthra together as a taxon named Atlantogenata and makes this the Boreoeutheria opposite.
Xenarthra ( Xenarthra )
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