The structure and composition of environmentally equilibriated vegetation is controlled by, and therefore reflects, climate.Vegetation types can be recognised in modern vegetation and correlated with temperature regimes.This suggests that the ocean was warmer at the beginning of the Late Cretaceous and there was not such a variety in temperature from the equator to the poles as there is today. The tiny calcareous foram fossil, Nephrolithus frequens, which shifted towards the equator in the Maastrichtian , suggests global cooling occurred.This is supported by North Atlantic planktonic foram distributions which also trended away from the poles with time.At mid latitudes, open canopy woodlands and forests were dominated by a mixture of conifers and ferns. Low latitude (near the equator) vegetation tended to be xeromorphic and only patchily forested suggesting a hot arid environment.It has been well established that the terrestrial plant record indicates an appreciably more equable world than today, with temperate forests extending to the polar regions. Leaf size: This is related strongly to temperature, humidity/water availability, and light levels.The idea that dinosaurs coped with high latitudes (i.e.near the poles) for at least 65 million years through the Cretaceous suggests that cold and darkness may not have been the prime factors causing their extinction, as has sometimes been maintained.
The traditional approach has been confined to material visible to the naked eye, but increasing attention is paid in modern studies to spores and pollen.
It is known that the sea level at this time was substantially higher than it is today.
This allowed many marine biota to spread, such as the ammonites and belemnites into north-western Europe.
the climate at the poles was not drastically different from that at the equator.
The distribution of fossils of organisms that lived in the sea provide valuable information about the oceans and climate at the time the organisms were alive.