Atlantogenata

Atlantogenata
Temporal range:
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Placentalia
Magnorder: Atlantogenata
Waddell et al, 1999
Subgroups
Synonyms
  • Atlantogenta (Phillips, 2001)
  • Notoplacentalia (Arnason, 2008)
  • Xenafrotheria (Asher, 2005)

Atlantogenata ("born around the Atlantic Ocean") is a proposed magnorder of placental mammals containing the cohorts or superorders Xenarthra and Afrotheria. These groups originated and radiated in the South American and African continents, respectively, presumably in the Cretaceous. Together with Boreoeutheria, they make up Placentalia. The monophyly of this grouping is supported by some genetic evidence.

Alternative hypotheses are that Boreoeutheria and Afrotheria combine to form Epitheria (as generally supported by anatomical and other physiological evidence) or that Boreoeutheria and Xenarthra combine to form Exafroplacentalia or Notolegia.

Updated analysis of transposable element insertions around the time of divergence strongly supports the fourth hypothesis of a near-concomitant origin (trifurcation) of the three superorders of mammals: Afrotheria, Boreoeutheria, and Xenarthra.

Placentalia

Below shows the phylogeny of the extant atlantogenate families.