|Species tree by three coalescent-based approaches|
from Esselstyn et al 2017 © The Author 2017
The first problem was to resolve the root of the eutherian tree. Here they did rather well. Both the ML tree and two of the coalescent-based methods gave strong support to the Atlantogenata hypothesis, i.e. a sister relationship between Afrotheria (elephants, dugongs, tenrecs and hyraxes) and Xenarthra (sloths and armadillos) with a common ancestor basal to Boreoeutheria (all other eutherian mammals).
South American Tapir (Tapirus terrestris)
Photo by Bernard Dupont CC BY-SA 2.0
Whereas horses and cetartiodactyls (including ruminants, pigs, dolphins) all have epitheliochorial placentation, no bat does, so I am happy with their majority finding!
Pen-tailed tree shrew (Ptilocercus lowii)
From Wolf 1848 via Wikipedia Commons
Fortunately they could confirm colugos as sister to primates, which was the basis for my recent paper with Andrea Mess on the evolution from labyrinthine to villous placentation (here).