
Figure 1.
Different hypotheses of the placental origin. (A) The Exafroplacentalia hypothesis proposes a mammalian clade merging Boreotheria (Supraprimates plus Laurasiathera) and Xenarthra, with Afrotheria as the sister group. (B) The Epitheria hypothesis merges Boreotheria and Afrotheria, with Xenarthra as the sister group. (C) The Atlantogenata hypothesis proposes Xenarthra and Afrotheria in one clade.











