The diversity of all organisms (microbes, algae, fungi, protists, plants and animals) is analysed by family from the Ediacaran (V) onwards. Maximum estimates are shown in lighter colours, minima in darker. Recolonisation of the seas climaxed in the Ordovician, after which the number of new families appearing was counterbalanced by the number of extinctions. Following the crisis at the end of the Permian diversity increased again sharply towards present-day levels. Recolonisation of the land lagged behind that of the seas and first climaxed in the Carboniferous, after which it leveled off and stayed roughly constant until the Jurassic. The Cretaceous (K) saw the rise of flowering plants, followed by steep increases in the diversity of insects and mammals.
The increasing steepness of the curve from the Mesozoic onwards is an artefact of the slow-down in radioisotope decay, which causes later periods to appear shorter proportionally than they actually were.
This page was last modified: 1st September 2010