There is no evidence of major changes in the angle of the Earth's axis, so polar dinosaurs and the rest of these ecosystems would have had to cope with the same extreme variation of day length through the year that occurs at similar latitudes today (up to a full day with no darkness in summer, and a full day with no sunlight in winter).
Ne postoje dokazi za promjenu ugla nagnutosti Zemlje, pa su se polarni dinosauri i ostatak ekosistema morali prilagoditi istim ekstremnim varijacijama dužine dana kroz godinu, koje se i danas dešavaju na sličnim geografskim širinama (u ljeto cijeli dan može biti bez noći, a u zimu cijeli dan bez svjetlosti).