This is a major collaborative effort, involving 8 countries across 3 continents 🌎🌍🌏

After the extinction of non-avian dinosaurs, mammals may have been free to diversify into the wide array of colors, from red pandas, to grey koalas, and striped tigers!
🧵(6/6) picture credits to
@michaelnicolai.bsky.social
and André Zambolli!

The fossils that we studied are extinct mammals with distinct life style, from living on ground, to swimming, and gliding through the treetops like modern day flying squirrels.
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While modern mammals had a wide variety in melanosome shapes, all of the fossils had relatively large and long shaped melanosomes that our models predicted would produce dark colors!

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We were able to determine the color thanks to the pristine fossilization of the hairs and melanosome pigments! Their shape and size was preserved in rock, and we found that, in living mammals, these shapes correlate with their color!
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Mammals evolved in the shadows of dinosaurs, where small and nocturnal habits helped them avoid larger predators! However, almost nothing was known about their coloration, which can influence their ability to camouflage!

🧵(2/6) Picture by Jonathan Goldenberg
!