The next time you see a mammal, remember the incredible biological engineering—the placenta—that allowed them to become the dominant group they are today.
: It also produces hormones necessary to maintain the pregnancy and support fetal development. 2. The Strategy: Quality Over Speed placental mammal
But what exactly makes us so special? It all comes down to a temporary, high-tech organ called the . 1. The Placenta: Nature’s Ultimate Life Support The next time you see a mammal, remember
While the exact "first" placental is debated, fossil evidence suggests a massive explosion in their numbers shortly after the extinction of the dinosaurs about 65 million years ago. They quickly filled the ecological niches left behind, eventually spreading to almost every habitat on Earth. Quick Comparison: Mammal Reproductive Types Marsupial Monotreme Birth Style Live birth (Mature) Live birth (Underdeveloped) Early Care Internal (Placenta) External (Pouch) Egg Incubation Examples Kangaroos , Opossums Platypus , Echidna The Strategy: Quality Over Speed But what exactly