Dinosaurs had their chance and they lost, but I'm slightly terrified of the idea of a crow scaled up to the size of a chimpanzee, and I actually like corvids (though not as much as some). There are raptors roughly that size, so it's not impossible, unlike scaling an ant to the size of a crow, which would only give you a paperweight made out of chitin.

They clearly have a different 'instructions per cycle' ratio from mammal brains.