Geology from a Plant's Viewpoint
Modified from: Stewart, W.N. Paleobotany and the evolution of plants. Cambridge University Press 

Era Period Epoch Featured events Started (MBP) Length (MY)
Cenozoic Quaternary Recent Warming since last ice sheet; change in CO2 levels; spread of C4 grasslands (possibly going into decline now); humans become dominant. 0.005 0.005
Recent 
Pleistocene
Ice sheets; changes in drainage, CO2 levels change; redistribution of floras; mammoths, bisons, humans. 2.5 2.5
Tertiary Pliocene More arid areas; spread of grasslands; mastodons, camels, horses, cats 7 4.5
Miocene Continental uplifts; Alps; climatic cooling; restriction of broad-leafed forests to high latitudes; grazing mammals 26 19
Oligocene Mild temperate climates; many now relic plant taxa widespread in higher latitudes; cats, dogs, rodents 38 12
Eocene Subtropical climates; grasslands limited; many genera of angiosperms go extinct; first horses 54 16
Paleocene Move from temperate to subtropical climates; inundation of synclines; older angiosperm families present 65 11
Mesozoic Cretaceous Uniform, temperate climate; major inundations; Rocky Mountains; angiosperms become dominant, monocots & dicots present; modern insects; extinction of giant land & marine reptiles  141 76
Jurassic Uniform mild climates; very similar plant communities throughout northern hemisphere (?world) of ginkgos, conifers, ferns, cycads, cycadeoids; some seed ferns left; probable origin of angiosperms (but possibly in Triassic); dinosaurs 195 54
Triassic Arid to semi-arid savannah-like climates; diversification of conifers and ferns; first mammals; rise of dinosaurs 225 30
Paleozoic Permian Cooler drier climeates, extensive glaciation in southern hemisphere; extinction of arborescent lycopsids & sphenopsids; diversification of reptiles 280 55
Pennsylvanian

Mississippian

Uniformly warm, humid climates; further intrusion of seas forming swamps; mosses, lycopods, horsetails, ferns, seed ferns, cordaites FLOURISH; origin of reptiles, diversification of amphibians; many insects 325 45
Devonian Heavy rainfall & aridity; major inundation of continents; diversification of vascular plants; all major groups except angiosperms present, including seed ferns; also liverworts & macrofungi; diversification of fish; origin of amphibians  395 50
Silurian Mild climates, low continents; first vascular plants; scorpions & millipedes; air-breathing animals
Ordovician Warm, mild climates; warm epicontinental seas with lots of green and red algae 500 65
Cambrian Climate warm & equitable; epicontinental seas; blue-green bacteria, green & red-algae 570 70
Precambrian Blue-greens and other bacteria; possibly green algae 4,700 4,130
Note: I have not checked for recent discoveries that might lead to modification of this table. There have been many recent discoveries of interest, but the overall order of events has not, so far as I am aware, changed.                                          

Mary Barkworth (01/09/2003)