Might be a stupid question but I think the length and measurement of time is probably important when dealing with the creation of imaginary creatures and their evolution.
On this particular planet a day cycle is 25 metric hours long, 1 metric hour equals 2.4 hours totalling 60 normal hours for a single day. The length of a night is 15 metric hours or 36 normal hours and the remaining 24 are day hours.
This planet is most of the time in the darkness and all the creatures receive 24 consective hours of radiation from the sun, this is twice as much as the earth's equator which has 12 consective hours.
So how different would creatures be from earth? is the sleep cycle of an animal based on actual needed sleep or based on the movement of the planet around the sun? I only know that larger animals need less sleep, which is kind of counter intuitive and I know that some scientists suggest the actual reason sleep exist is not known or certain. Still, how would this day and night cycle compare to Earth's?
I don't really know how to narrow it down anymore since I want to see the effects on an evolutive level thus the effects on all lifeforms.
Maybe, the only way I know about narrowing it down is to imagine that all life begins from one single lucky cell and splits from that cell. This is the most accepted theory of the beginning of life on earth (some suggest life started on earth and was erased completely multiple times from multiple cells formed by chance not just once)
Now knowing that all the life on this planet has one single lucky ancestor, then they have have something in common and should react to that day and night cycle on similar ways.... right?