⏰ when
When did placental mammals first appear?
Quick Answer
Placental mammals likely originated around 100 to 66 million years ago, with major diversification after the dinosaur extinction.
The Full Story
Placental mammals, which nourish developing young through a placenta, likely appeared during the Late Cretaceous. Molecular studies and fossils suggest their early origins were around 100 to 66 million years ago. They diversified dramatically after the end-Cretaceous extinction 66 million years ago, when many ecological niches opened up. That expansion eventually produced most modern mammal groups.
Key Facts
1.Placental mammals likely originated in the Late Cretaceous
2.Approximate range: 100 to 66 million years ago
3.Major diversification accelerated after 66 million years ago
YouTube Angle
Suggested video title for this topic:
"Why placental mammals took over the world"
Was this answer helpful?
Tap a reaction — it helps us pick what to cover next.