Probably more importantly, an obvious adaptation in such an environment for prey animals would be to hide in dark places like caves where predators can't see yo

Probably more importantly, an obvious adaptation in such an environment for prey animals would be to hide in dark places like caves where predators can't see you...so predators would develop with low-light vision for hunting where other predators couldn't and in turn.... Basically evolution tends to do every weird thing it can - and we can't know which would be likely to end up as traits on the dominant intelligent species.