Question

What caused the Cretaceous radiation of angiosperms (flowering plants) and how does this relate to coevolution?

Answer 1

The first flowering plant fossils occurred as rare and undiverse pollen grains in the Early Cretaceous period and angiosperms are diversified slowly during the Barremian-Aptian period but rapidly during the Albian-Cenomanian period. By the end of the Cretaceous, half of the living angiosperm orders were present, and angiosperms were greater than 70% of terrestrial plant species are present globally. The rapid diversification of the group and its dominance in modern vegetation led it to the idea that the Cretaceous radiation of angiosperms also represents their rise to
vegetational dominance. The diversification of flowering plants in the Cretaceous represents the evolution of a highly speciose clade of weeds. With the exception of high-latitude and montane conifer forests, most of the world’s major biomes, from wet tropical forest to temperate deciduous forest to steppe to tropical grassland and desert, are overwhelmingly occupied by angiosperms, both in terms of biomass and number of species and now this angiosperms radiation is a hypothesis that explains primate origins. It states that primates developed their traits in response to the availability of fruit and flowers following the spread of angiosperms.