Mammalian Explosion 305(B)known from most of the Cretaceous. The Liaoning beds also yield one of the oldest known
placental mammals, Eomaia scansoria, and the fossil also preserves the hair and soft tissues
(fig. 13.11). An even earlier placental fossil is Juramaia, from the Jurassic of China. Thus the
split between marsupials and placentals (the mammals that give live birth to their young,
including most living mammals) occurred much earlier in the Cretaceous than we thought
FIGURE 13.11. (Continued )