3 ms·
>placental mammals were mainly or even exclusively nocturnal through most of their evolutionary story, starting with their origin 225 million years ago, and onl
by trhway 4y ago
>placental mammals were mainly or even exclusively nocturnal through most of their evolutionary story, starting with their origin 225 million years ago, and only ending with the demise of the non-avian dinosaurs 66 million years ago.
i guess we're lucky that dinosaurs didn't evolve IR vision (not that it wasn't impossible given that snakes did get IR sense).
- thriftwy 4y agoIR does not work for warm-blooded creatures. You will be jamming your own IR vision with heat coming from your body. That, or having eyes on beanstalks. And archosaurs were at least partly warm blooded.
- eru 4y agoEven 'cold blooded' creatures warm up when they move around a lot, or when they bask in the sun.