BIO 2 - GEOLOGIC TIME SCALE

Geologic Time Scale

is a record of how Earth and its forms have changed through time

eons,eras,periods and epochs

The GTS is divided into ________unlike divisions of time

eon

the largest unit of time is

Precambrian time

Earth’s 4.6 billion year history is divided into_______and the three eras

Paleozoic,mesozoic,cenozoic

three eras

Cenozoic

The most recent era

pre-cambrian, paleozoic,mesozoic,cenozoic

four eras

Cambrian, Ordovician,Silurian,Devonian,Carboniferous,Permian

Period Paleozoic

Triassic,Jurassic,Cretaceous

Period under Mesozoic era

Tertiary and Qarternary

Period under the cenozoic era

Eons

Longest subdivision:based on the abundance of certain fossils

Eras

Next to lonest subdivision: Marked by maor changes in the fossil record

Period

Based on type of life existing at the time

Epochs

shortest subdivision, marked by differences in life forms and can vary from continent to continent

Bacteria, Algae, Protozoa, Cloudina

Precambrian Era LIFE

544-245

Paleozoic era

544-505

Cambrian

505-440

Ordovician

440-410

Silurian

410-360

Devonian

360-290

Carboniferous

290-245

Permian

Pre cambrian

Early life, simple organism

Bacteria,Algae,Protozoa,Cloudina

life forms in Pre cambrian period

Hadean

formation of the earth

Archean

Earths crust had cooled enough to allow the formation of continents and life started to form

Archean

life started to form

Proterozoic

Bacteria,Algae,Jellyfish,Cyanobacteria producing free oxygen or photosynthesis

Phanerozoic

visible life, complex,abundant,visible in the fossil record

Paleozoic

Ancient life, periods

Cambrian

invertebrate, brachipods,trilobites

ordovician

early bony fish

Silurian

first land plants appear and land animals

Devonian

Age of the FIsh, Amphibians,evrgreens, and ferns, hardwood

Carboniferous

divided into missisippian and pennsylvanian

mississipian

many crinoids

Pennsylvanian

insects, lizards and winged insects

permian

reptiles spread, applachians rise

Mesozoic

3 periods, triassic,jurassic, cretaceous

triassic

cycads,first dinosaurs

jurassic

first birds appear

cretaceous

snakes and primates appear, t-rex develops, flowering plants and extinction of the mesozoic era

cenozoic

divided into two pars, tertiary and quaternary

tertiary

rise of mammals

Paleocene

mammals began diversifying

eocene

mammals became more diverse, horses/whales

Oligocene

dog,cats and apes

miocene

horses, mastodons,camels,tigers

pliocene

homonids develop

pleistocene

modern humans develop

holocene

humans flourish

time

In geologic time scale,___is divided into bigger blocks than years or centuries

geologic time scale

is the calendar for events in earth history

rocks, fossils

geologic time scale is based on changes or events recorded in ____and____

eon

is an extremely, long indifinite period of time

cambrian period

it is the first period after precambrian time

cenozoic

the most recent era, are further divided into epochs

544-245

PALEOZOIC ERA YEAR

544-505

CAMBRIAN TIME

505-440

ORDOVICIAN

440-410

SILURIAN TIME

410-360

DEVONIAN

360-290

CARBONIFEROUS

290-245

PERMIAN

4.6- 4.0 BILLION

HADEAN TIME

4.0-2.5 BILLION

ARCHEAN EON

2.5 BILLION-538.8 MILLION

PROTEROZOIC TIME

538.8 MILLION YEARS AGO

CAMBRIAN BEGINS

PHANEROZOIC,CENOZOIC,QUARTERNARY,HOLOCENE

WE ARE LIVING IN THE____EON,____ERA,______PERIOD, _____POCH

3.8

simple,single-celled forms of life appear___billion years ago

cambrian

explosions of lfe

cambrian

all existing phyla come into being at this time

cambrian

life forms in warm seas as oxygen levels rise enough to support life

cambrian

marine invertebrates, trilobites, and brachiopods

Ordovician

dominant animals are still trilobites,brachiopods, and corals

Silurian

coral reefs expand and land plants begin to colonize barrier land

Silurian

first millipede fossils and sea scorpions(euryptides) found in this perios

Devonian

dominant animal: fish

mississipian

first seed plants appear

misissipian

bryoza, branchi pods,blastoids

pennsylvanian

lizards and winged insects first appear

Permian

90% of earth’s species became extinct due to volcanism in siberia, this marks an end of trilobites, ammonoids, blastoids and most fish

Triassic

first mammals- small rodents appear

triassic

life and fauna re-diversifying

triassic

rocky mountains form, first turtle fossils from this period

Cretaceous

t-rex develops

Cretaceous

first snakes and primates appear

cretaceous

deciduous trees and grasses common

cretaceous

first flowering plants

tertiary

first horses appear and tropical plants dominate

Eocene

grasses spread and whales, rhinos, elephants and other large mammals develop

Oligocene

Dogs,cats and apes appear

miocene

horses,mastodons, camels and tigers roam free

Pliocene

hominids develop and grand canyon forms

Pleistocene

modern humans develop, ice sheets are predominant

Holocene

humans flourish

245-65

Mesozoic Time

245-208

Triassic time

208-145

jurassic time

145-65

cretaceous time