⏰ when
When did mammals first give birth to live young?
Quick Answer
Live birth evolved very early in mammal history, by at least the Jurassic, over 160 million years ago.
The Full Story
Live birth is found in all modern placental mammals and marsupials, but its deeper origin goes back much farther. Fossil evidence from the Jurassic suggests mammals were already giving birth to live young by at least 160 million years ago. This reproductive strategy likely evolved gradually and may have helped protect developing embryos. It became a major success factor in mammalian evolution.
Key Facts
1.Live birth is at least 160 million years old in mammals
2.Jurassic-period evidence
3.It likely evolved to protect developing embryos
YouTube Angle
Suggested video title for this topic:
"The ancient origin of live birth in mammals"
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