GEOLOGIC  TIME

BIOLOGICAL  FORMS

BEGINNING OF INTERVAL

EPOCHS AND SERIES

PERIODS AND SYSTEMS

ERA

EON

PHANER-

CENOZOIC

QUATERNARY

HOLOCENE

PLEISTOCENE

.01

1.6

EARLIEST  HUMANS

TERTIARY

PLIOCENE

MIOCENE

OLIGOCENE

EOCENE

PALEOCENE

5

24

37

58

65

EARLIEST HOMINIDS

EARLIEST GRASSES

EARLIEST LARGE MAMMALS

Cretaceous-Tertiary boundary ( 65 million years ago ): the extinction of the dinosaurs

MESOZOIC

CRETACEOUS

98

144

JURASSIC

TRIASSIC

EARLIEST FLOWERING PLANTS; DINOSAURS DECLINING

UPPER

LOWER

EARLIEST BIRDS & MAMMALS

AGE OF DINOSAURS BEGINS

PERMIAN

CARBONIFEROUS

208

360

245

286

MISSISSIPPIAN

320

PENNSYLVANIAN

PALEOZOIC

DEVONIAN

408

ORDOVICIAN

438

SILURIAN

CAMBRIAN

EARLIEST REPTILES

EARLIEST VASCULAR PLANTS

505

507

EARLIEST LAND PLANTS,

EARLIEST WINGED INSECTS

( as ferns & mosses )  AMPHIBIANS

ARCHEAN

PRIMITIVE BACTERIA

EARLIEST FISH

EARLIEST CORALS

INSECTS

2500

PRECAM-

LIFE APPEARS: EARLIEST &

3500

PROTER-

SOFT-BODIED INVERTEBRATES

EARLIEST COLONIAL ALGAE &

IN MILLIONS OF YEARS BEFORE THE PRESENT

OZOIC

OZOIC

BRIAN