GEOLOGICAL PERIODS – # are millions of years ago
CENOZOIC ERA
(age of mammals; 65 million yrs. duration)
Quaternary Period 2-4
Holocene Epoch
modern species/subspecies
Pleistocene Epoch
modern mammal species
Tertiary Period 65
Pliocene Epoch
appearance modern mammal genera
Miocene Epoch
rise of mammalian subfamilies
Oligocene Epoch
rise of modern mammalian families
Eocene Epoch
rise of modern orders of mammals
Paleocene Epoch
dominance of archaic mammals
MESOZOIC ERA
(age of reptiles; 185 million yrs. duration)
Cretaceous Period 145
extinction large reptiles
Jurassic Period 210
reptiles dominant; first birds; arc. mammals
Triassic Period 245
first dinosaurs, turtles, mammals
PALEOZOIC ERA
(350 million yrs. duration)
Permian Period 290
primitive reptiles, decline of early amphibians
Carboniferous Period 360
amphibians dominant; first reptiles
Devonian Period 410
age of fishes; first amphibians
Silurian Period 440
archaic fishes
Ordovician Period 500
appearance of vertebrates (ostracoderms)
Cambrian Period 600
appearance of all major invertebrate phyla