By the time of early mammaliaforms like Morganucodon, the mammal-line body plan was already starting to feel familiar: small, furry, warm-blooded, long-tailed, and likely active at night. It was not a modern mammal, but it may have looked less like a “reptile” and more like a shrew-like or mouse-like creature from the deep past.
First Mammaliaforms: Morganucodon
203 Million years ago (+/- 3 million)
Differentiated teeth and true mammalian jaw
That Science Story,
was first published on TST 2 years ago.
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