The clean marker here is Tritylodontidae. They were cynodont therapsids close to mammals but outside Mammaliaformes, and they survived into the Early Cretaceous. Britannica specifically notes that the last known tritylodontids died out about 125 MYA.
STORY
Last Non-Mammaliaform Therapsids
By Michael Alan Prestwood
Thu 21 May 2026
Published 14 hours ago.
Updated 14 hours ago.
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Last Non-Mammaliaform Therapsids
~125 Million years ago
- < 1 minute read
— map / TST —
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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