: Humans, monkeys , and apes , known for large brains and grasping limbs. Carnivores : Predators like , and seals with specialized teeth. Cetaceans : Aquatic masters like whales and dolphins .
: Crucially, it keeps the mother's and baby's blood from mixing. This prevents the mother's immune system from attacking the fetus as a "foreign parasite". placental mammal
Placental mammals are mind-bogglingly diverse, categorized largely by how they move and eat. : Humans, monkeys , and apes , known