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Mammals: First Live Births

By Michael Alan Prestwood

Sun 31 Mar 2024
Published 2 years ago.
Updated 2 months ago.
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An example of early live birth is the protomammal Kayentatherium, Jurassic period. This cynodont is related to early mammals and its clutch size suggested egg-laying, providing clues about the transition to live birth. The switch to live birth in mammals, including marsupials and placentals, likely evolved once at their common ancestor, suggesting live birth in mammals has a deep evolutionary history.

Mammals: First Live Births

185 Million BCE
Placental nutrient transfer (in placentals)

An example of early live birth is the protomammal Kayentatherium, Jurassic period. This cynodont is related to early mammals and its clutch size suggested egg-laying, providing clues about the transition to live birth. The switch to live birth in mammals, including marsupials and placentals, likely evolved once at their common ancestor, suggesting live birth in mammals has a deep evolutionary history.

 

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Michael Alan Prestwood
Author & Natural Philosopher
Prestwood writes on science-first philosophy, with particular attention to the convergence of disciplines. Drawing on his TST Framework, his work emphasizes rational inquiry grounded in empirical observation while engaging questions at the edges of established knowledge. With TouchstoneTruth positioned as a living touchstone, this work aims to contribute reliable, evolving analysis in an emerging AI era where the credibility of information is increasingly contested.
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Column Menu
June 2026
»COLUMN ARCHIVE
Column Research….
1. Timeline Story
Secular Spirituality Settles
2. Linked Quote
“Extraordinary claims require extraordinary evidence.”
3. Science FAQ »
What is the difference between a spiritual and empirical belief?
4. Philosophy FAQ »
What is secular spirituality?
5. Critical Thinking FAQ »
How does spirituality relate to public belief?
6. History FAQ!
Is secular spirituality supported in history and science?
Bonus Deep-Dive Article
The Material-Spiritual Framework: A Philosophy of Spirituality

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