A new open-access paper discusses the “explosive boost” — massive changes generated by angiosperms (most flowering plants):
Biodiversity today has the unusual property that 85% of plants and animal species live on land rather than in the sea, and half of these in tropical rainforests. An explosive boost to terrestrial diversity occurred from ca. 100–50 million years ago, the Late Cretaceous and early Palaeogene. During this interval, the Earth-life system on land was reset, and the biosphere expanded to a new level of productivity, enhancing the capacity and species diversity of terrestrial environments. This boost in terrestrial biodiversity coincided with innovations in flowering plant biology and evolutionary ecology, including their (1) flowers and efficiencies in reproduction, (2) coevolution with animals, especially pollinators and herbivores, (3) photosynthetic capacities, (4) adaptability, and (5) ability to modify habitats. The rise of angiosperms triggered a macroecological revolution on land and drove modern biodiversity in a secular, prolonged shift to new, high levels, a series of processes we name here the Angiosperm Terrestrial Revolution.Benton, M.J., Wilf, P. and Sauquet, H. (2021), The Angiosperm Terrestrial Revolution and the origins of modern biodiversity. New Phytologist. Accepted Author Manuscript. https://doi.org/10.1111/nph.17822 (October 26, 2021)
From the concluding portion:
In sum, despite several outstanding and data-rich examples such as the PETM, the data are far Angiosperm evolution from the Early Cretaceous onward seems to have driven the diversification of life on land in four ways: (1) ongoing evolutionary radiations of hugely diverse lineages with a dizzying variety of structural, chemical, vegetative, and reproductive novelties providing niche opportunities; (2) pollinator and herbivore opportunities often through intricate plant-animal mutualistic relationships, with cascading biodiversity effects through the food web; (3) increased productivity allowing for a greater flux of energy into the fauna; and (4) increasing the geographic extent of wet tropical biomes through their hydrological effects. Therefore, many insect groups owed their biodiversity boost to eating plant parts, pollinating flowers, or preying on the insects that did so. Others, such as fungi, liverworts, ferns, frogs, and angiosperms themselves benefited from new habitats in expanding angiosperm-dominated everwet tropical forests. Angiosperm innovations continue to the present day with ongoing evolutionary radiations, as shown by the Neogene expansion of important biomes such as seasonal tropical forests, temperate forests, and grasslands.Preceding and underlying all these physiological and ecological changes, angiosperms underwent genomic revolutions that enabled them to diversify and evolve in different ways from other plants, as a consequence of new pathways through whole genome duplication and post-polyploidization diploidization. It is not just that angiosperms are species-rich, but many individual angiosperm families show more morphological variety than all other seed plants combined, a distinction that reflects the dynamics of their genomes.
An episode we never heard before from the history of life. Is this the new Cambrian Explosion?